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      1 /*
      2  * Mesa 3-D graphics library
      3  * Version:  7.1
      4  *
      5  * Copyright (C) 1999-2007  Brian Paul   All Rights Reserved.
      6  *
      7  * Permission is hereby granted, free of charge, to any person obtaining a
      8  * copy of this software and associated documentation files (the "Software"),
      9  * to deal in the Software without restriction, including without limitation
     10  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
     11  * and/or sell copies of the Software, and to permit persons to whom the
     12  * Software is furnished to do so, subject to the following conditions:
     13  *
     14  * The above copyright notice and this permission notice shall be included
     15  * in all copies or substantial portions of the Software.
     16  *
     17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
     18  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
     19  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
     20  * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
     21  * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
     22  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
     23  */
     24 
     25 
     26 /**
     27  * \file mipmap.c  mipmap generation and teximage resizing functions.
     28  */
     29 
     30 #include "imports.h"
     31 #include "formats.h"
     32 #include "glformats.h"
     33 #include "mipmap.h"
     34 #include "mtypes.h"
     35 #include "teximage.h"
     36 #include "texobj.h"
     37 #include "texstore.h"
     38 #include "image.h"
     39 #include "macros.h"
     40 #include "../../gallium/auxiliary/util/u_format_rgb9e5.h"
     41 #include "../../gallium/auxiliary/util/u_format_r11g11b10f.h"
     42 
     43 
     44 
     45 static GLint
     46 bytes_per_pixel(GLenum datatype, GLuint comps)
     47 {
     48    GLint b;
     49 
     50    if (datatype == GL_UNSIGNED_INT_8_24_REV_MESA ||
     51        datatype == GL_UNSIGNED_INT_24_8_MESA)
     52       return 4;
     53 
     54    b = _mesa_sizeof_packed_type(datatype);
     55    assert(b >= 0);
     56 
     57    if (_mesa_type_is_packed(datatype))
     58       return b;
     59    else
     60       return b * comps;
     61 }
     62 
     63 
     64 /**
     65  * \name Support macros for do_row and do_row_3d
     66  *
     67  * The macro madness is here for two reasons.  First, it compacts the code
     68  * slightly.  Second, it makes it much easier to adjust the specifics of the
     69  * filter to tune the rounding characteristics.
     70  */
     71 /*@{*/
     72 #define DECLARE_ROW_POINTERS(t, e) \
     73       const t(*rowA)[e] = (const t(*)[e]) srcRowA; \
     74       const t(*rowB)[e] = (const t(*)[e]) srcRowB; \
     75       const t(*rowC)[e] = (const t(*)[e]) srcRowC; \
     76       const t(*rowD)[e] = (const t(*)[e]) srcRowD; \
     77       t(*dst)[e] = (t(*)[e]) dstRow
     78 
     79 #define DECLARE_ROW_POINTERS0(t) \
     80       const t *rowA = (const t *) srcRowA; \
     81       const t *rowB = (const t *) srcRowB; \
     82       const t *rowC = (const t *) srcRowC; \
     83       const t *rowD = (const t *) srcRowD; \
     84       t *dst = (t *) dstRow
     85 
     86 #define FILTER_SUM_3D(Aj, Ak, Bj, Bk, Cj, Ck, Dj, Dk) \
     87    ((unsigned) Aj + (unsigned) Ak \
     88     + (unsigned) Bj + (unsigned) Bk \
     89     + (unsigned) Cj + (unsigned) Ck \
     90     + (unsigned) Dj + (unsigned) Dk \
     91     + 4) >> 3
     92 
     93 #define FILTER_3D(e) \
     94    do { \
     95       dst[i][e] = FILTER_SUM_3D(rowA[j][e], rowA[k][e], \
     96                                 rowB[j][e], rowB[k][e], \
     97                                 rowC[j][e], rowC[k][e], \
     98                                 rowD[j][e], rowD[k][e]); \
     99    } while(0)
    100 
    101 #define FILTER_SUM_3D_SIGNED(Aj, Ak, Bj, Bk, Cj, Ck, Dj, Dk) \
    102    (Aj + Ak \
    103     + Bj + Bk \
    104     + Cj + Ck \
    105     + Dj + Dk \
    106     + 4) / 8
    107 
    108 #define FILTER_3D_SIGNED(e) \
    109    do { \
    110       dst[i][e] = FILTER_SUM_3D_SIGNED(rowA[j][e], rowA[k][e], \
    111                                        rowB[j][e], rowB[k][e], \
    112                                        rowC[j][e], rowC[k][e], \
    113                                        rowD[j][e], rowD[k][e]); \
    114    } while(0)
    115 
    116 #define FILTER_F_3D(e) \
    117    do { \
    118       dst[i][e] = (rowA[j][e] + rowA[k][e] \
    119                    + rowB[j][e] + rowB[k][e] \
    120                    + rowC[j][e] + rowC[k][e] \
    121                    + rowD[j][e] + rowD[k][e]) * 0.125F; \
    122    } while(0)
    123 
    124 #define FILTER_HF_3D(e) \
    125    do { \
    126       const GLfloat aj = _mesa_half_to_float(rowA[j][e]); \
    127       const GLfloat ak = _mesa_half_to_float(rowA[k][e]); \
    128       const GLfloat bj = _mesa_half_to_float(rowB[j][e]); \
    129       const GLfloat bk = _mesa_half_to_float(rowB[k][e]); \
    130       const GLfloat cj = _mesa_half_to_float(rowC[j][e]); \
    131       const GLfloat ck = _mesa_half_to_float(rowC[k][e]); \
    132       const GLfloat dj = _mesa_half_to_float(rowD[j][e]); \
    133       const GLfloat dk = _mesa_half_to_float(rowD[k][e]); \
    134       dst[i][e] = _mesa_float_to_half((aj + ak + bj + bk + cj + ck + dj + dk) \
    135                                       * 0.125F); \
    136    } while(0)
    137 /*@}*/
    138 
    139 
    140 /**
    141  * Average together two rows of a source image to produce a single new
    142  * row in the dest image.  It's legal for the two source rows to point
    143  * to the same data.  The source width must be equal to either the
    144  * dest width or two times the dest width.
    145  * \param datatype  GL_UNSIGNED_BYTE, GL_UNSIGNED_SHORT, GL_FLOAT, etc.
    146  * \param comps  number of components per pixel (1..4)
    147  */
    148 static void
    149 do_row(GLenum datatype, GLuint comps, GLint srcWidth,
    150        const GLvoid *srcRowA, const GLvoid *srcRowB,
    151        GLint dstWidth, GLvoid *dstRow)
    152 {
    153    const GLuint k0 = (srcWidth == dstWidth) ? 0 : 1;
    154    const GLuint colStride = (srcWidth == dstWidth) ? 1 : 2;
    155 
    156    ASSERT(comps >= 1);
    157    ASSERT(comps <= 4);
    158 
    159    /* This assertion is no longer valid with non-power-of-2 textures
    160    assert(srcWidth == dstWidth || srcWidth == 2 * dstWidth);
    161    */
    162 
    163    if (datatype == GL_UNSIGNED_BYTE && comps == 4) {
    164       GLuint i, j, k;
    165       const GLubyte(*rowA)[4] = (const GLubyte(*)[4]) srcRowA;
    166       const GLubyte(*rowB)[4] = (const GLubyte(*)[4]) srcRowB;
    167       GLubyte(*dst)[4] = (GLubyte(*)[4]) dstRow;
    168       for (i = j = 0, k = k0; i < (GLuint) dstWidth;
    169            i++, j += colStride, k += colStride) {
    170          dst[i][0] = (rowA[j][0] + rowA[k][0] + rowB[j][0] + rowB[k][0]) / 4;
    171          dst[i][1] = (rowA[j][1] + rowA[k][1] + rowB[j][1] + rowB[k][1]) / 4;
    172          dst[i][2] = (rowA[j][2] + rowA[k][2] + rowB[j][2] + rowB[k][2]) / 4;
    173          dst[i][3] = (rowA[j][3] + rowA[k][3] + rowB[j][3] + rowB[k][3]) / 4;
    174       }
    175    }
    176    else if (datatype == GL_UNSIGNED_BYTE && comps == 3) {
    177       GLuint i, j, k;
    178       const GLubyte(*rowA)[3] = (const GLubyte(*)[3]) srcRowA;
    179       const GLubyte(*rowB)[3] = (const GLubyte(*)[3]) srcRowB;
    180       GLubyte(*dst)[3] = (GLubyte(*)[3]) dstRow;
    181       for (i = j = 0, k = k0; i < (GLuint) dstWidth;
    182            i++, j += colStride, k += colStride) {
    183          dst[i][0] = (rowA[j][0] + rowA[k][0] + rowB[j][0] + rowB[k][0]) / 4;
    184          dst[i][1] = (rowA[j][1] + rowA[k][1] + rowB[j][1] + rowB[k][1]) / 4;
    185          dst[i][2] = (rowA[j][2] + rowA[k][2] + rowB[j][2] + rowB[k][2]) / 4;
    186       }
    187    }
    188    else if (datatype == GL_UNSIGNED_BYTE && comps == 2) {
    189       GLuint i, j, k;
    190       const GLubyte(*rowA)[2] = (const GLubyte(*)[2]) srcRowA;
    191       const GLubyte(*rowB)[2] = (const GLubyte(*)[2]) srcRowB;
    192       GLubyte(*dst)[2] = (GLubyte(*)[2]) dstRow;
    193       for (i = j = 0, k = k0; i < (GLuint) dstWidth;
    194            i++, j += colStride, k += colStride) {
    195          dst[i][0] = (rowA[j][0] + rowA[k][0] + rowB[j][0] + rowB[k][0]) >> 2;
    196          dst[i][1] = (rowA[j][1] + rowA[k][1] + rowB[j][1] + rowB[k][1]) >> 2;
    197       }
    198    }
    199    else if (datatype == GL_UNSIGNED_BYTE && comps == 1) {
    200       GLuint i, j, k;
    201       const GLubyte *rowA = (const GLubyte *) srcRowA;
    202       const GLubyte *rowB = (const GLubyte *) srcRowB;
    203       GLubyte *dst = (GLubyte *) dstRow;
    204       for (i = j = 0, k = k0; i < (GLuint) dstWidth;
    205            i++, j += colStride, k += colStride) {
    206          dst[i] = (rowA[j] + rowA[k] + rowB[j] + rowB[k]) >> 2;
    207       }
    208    }
    209 
    210    else if (datatype == GL_BYTE && comps == 4) {
    211       GLuint i, j, k;
    212       const GLbyte(*rowA)[4] = (const GLbyte(*)[4]) srcRowA;
    213       const GLbyte(*rowB)[4] = (const GLbyte(*)[4]) srcRowB;
    214       GLbyte(*dst)[4] = (GLbyte(*)[4]) dstRow;
    215       for (i = j = 0, k = k0; i < (GLuint) dstWidth;
    216            i++, j += colStride, k += colStride) {
    217          dst[i][0] = (rowA[j][0] + rowA[k][0] + rowB[j][0] + rowB[k][0]) / 4;
    218          dst[i][1] = (rowA[j][1] + rowA[k][1] + rowB[j][1] + rowB[k][1]) / 4;
    219          dst[i][2] = (rowA[j][2] + rowA[k][2] + rowB[j][2] + rowB[k][2]) / 4;
    220          dst[i][3] = (rowA[j][3] + rowA[k][3] + rowB[j][3] + rowB[k][3]) / 4;
    221       }
    222    }
    223    else if (datatype == GL_BYTE && comps == 3) {
    224       GLuint i, j, k;
    225       const GLbyte(*rowA)[3] = (const GLbyte(*)[3]) srcRowA;
    226       const GLbyte(*rowB)[3] = (const GLbyte(*)[3]) srcRowB;
    227       GLbyte(*dst)[3] = (GLbyte(*)[3]) dstRow;
    228       for (i = j = 0, k = k0; i < (GLuint) dstWidth;
    229            i++, j += colStride, k += colStride) {
    230          dst[i][0] = (rowA[j][0] + rowA[k][0] + rowB[j][0] + rowB[k][0]) / 4;
    231          dst[i][1] = (rowA[j][1] + rowA[k][1] + rowB[j][1] + rowB[k][1]) / 4;
    232          dst[i][2] = (rowA[j][2] + rowA[k][2] + rowB[j][2] + rowB[k][2]) / 4;
    233       }
    234    }
    235    else if (datatype == GL_BYTE && comps == 2) {
    236       GLuint i, j, k;
    237       const GLbyte(*rowA)[2] = (const GLbyte(*)[2]) srcRowA;
    238       const GLbyte(*rowB)[2] = (const GLbyte(*)[2]) srcRowB;
    239       GLbyte(*dst)[2] = (GLbyte(*)[2]) dstRow;
    240       for (i = j = 0, k = k0; i < (GLuint) dstWidth;
    241            i++, j += colStride, k += colStride) {
    242          dst[i][0] = (rowA[j][0] + rowA[k][0] + rowB[j][0] + rowB[k][0]) / 4;
    243          dst[i][1] = (rowA[j][1] + rowA[k][1] + rowB[j][1] + rowB[k][1]) / 4;
    244       }
    245    }
    246    else if (datatype == GL_BYTE && comps == 1) {
    247       GLuint i, j, k;
    248       const GLbyte *rowA = (const GLbyte *) srcRowA;
    249       const GLbyte *rowB = (const GLbyte *) srcRowB;
    250       GLbyte *dst = (GLbyte *) dstRow;
    251       for (i = j = 0, k = k0; i < (GLuint) dstWidth;
    252            i++, j += colStride, k += colStride) {
    253          dst[i] = (rowA[j] + rowA[k] + rowB[j] + rowB[k]) / 4;
    254       }
    255    }
    256 
    257    else if (datatype == GL_UNSIGNED_SHORT && comps == 4) {
    258       GLuint i, j, k;
    259       const GLushort(*rowA)[4] = (const GLushort(*)[4]) srcRowA;
    260       const GLushort(*rowB)[4] = (const GLushort(*)[4]) srcRowB;
    261       GLushort(*dst)[4] = (GLushort(*)[4]) dstRow;
    262       for (i = j = 0, k = k0; i < (GLuint) dstWidth;
    263            i++, j += colStride, k += colStride) {
    264          dst[i][0] = (rowA[j][0] + rowA[k][0] + rowB[j][0] + rowB[k][0]) / 4;
    265          dst[i][1] = (rowA[j][1] + rowA[k][1] + rowB[j][1] + rowB[k][1]) / 4;
    266          dst[i][2] = (rowA[j][2] + rowA[k][2] + rowB[j][2] + rowB[k][2]) / 4;
    267          dst[i][3] = (rowA[j][3] + rowA[k][3] + rowB[j][3] + rowB[k][3]) / 4;
    268       }
    269    }
    270    else if (datatype == GL_UNSIGNED_SHORT && comps == 3) {
    271       GLuint i, j, k;
    272       const GLushort(*rowA)[3] = (const GLushort(*)[3]) srcRowA;
    273       const GLushort(*rowB)[3] = (const GLushort(*)[3]) srcRowB;
    274       GLushort(*dst)[3] = (GLushort(*)[3]) dstRow;
    275       for (i = j = 0, k = k0; i < (GLuint) dstWidth;
    276            i++, j += colStride, k += colStride) {
    277          dst[i][0] = (rowA[j][0] + rowA[k][0] + rowB[j][0] + rowB[k][0]) / 4;
    278          dst[i][1] = (rowA[j][1] + rowA[k][1] + rowB[j][1] + rowB[k][1]) / 4;
    279          dst[i][2] = (rowA[j][2] + rowA[k][2] + rowB[j][2] + rowB[k][2]) / 4;
    280       }
    281    }
    282    else if (datatype == GL_UNSIGNED_SHORT && comps == 2) {
    283       GLuint i, j, k;
    284       const GLushort(*rowA)[2] = (const GLushort(*)[2]) srcRowA;
    285       const GLushort(*rowB)[2] = (const GLushort(*)[2]) srcRowB;
    286       GLushort(*dst)[2] = (GLushort(*)[2]) dstRow;
    287       for (i = j = 0, k = k0; i < (GLuint) dstWidth;
    288            i++, j += colStride, k += colStride) {
    289          dst[i][0] = (rowA[j][0] + rowA[k][0] + rowB[j][0] + rowB[k][0]) / 4;
    290          dst[i][1] = (rowA[j][1] + rowA[k][1] + rowB[j][1] + rowB[k][1]) / 4;
    291       }
    292    }
    293    else if (datatype == GL_UNSIGNED_SHORT && comps == 1) {
    294       GLuint i, j, k;
    295       const GLushort *rowA = (const GLushort *) srcRowA;
    296       const GLushort *rowB = (const GLushort *) srcRowB;
    297       GLushort *dst = (GLushort *) dstRow;
    298       for (i = j = 0, k = k0; i < (GLuint) dstWidth;
    299            i++, j += colStride, k += colStride) {
    300          dst[i] = (rowA[j] + rowA[k] + rowB[j] + rowB[k]) / 4;
    301       }
    302    }
    303 
    304    else if (datatype == GL_SHORT && comps == 4) {
    305       GLuint i, j, k;
    306       const GLshort(*rowA)[4] = (const GLshort(*)[4]) srcRowA;
    307       const GLshort(*rowB)[4] = (const GLshort(*)[4]) srcRowB;
    308       GLshort(*dst)[4] = (GLshort(*)[4]) dstRow;
    309       for (i = j = 0, k = k0; i < (GLuint) dstWidth;
    310            i++, j += colStride, k += colStride) {
    311          dst[i][0] = (rowA[j][0] + rowA[k][0] + rowB[j][0] + rowB[k][0]) / 4;
    312          dst[i][1] = (rowA[j][1] + rowA[k][1] + rowB[j][1] + rowB[k][1]) / 4;
    313          dst[i][2] = (rowA[j][2] + rowA[k][2] + rowB[j][2] + rowB[k][2]) / 4;
    314          dst[i][3] = (rowA[j][3] + rowA[k][3] + rowB[j][3] + rowB[k][3]) / 4;
    315       }
    316    }
    317    else if (datatype == GL_SHORT && comps == 3) {
    318       GLuint i, j, k;
    319       const GLshort(*rowA)[3] = (const GLshort(*)[3]) srcRowA;
    320       const GLshort(*rowB)[3] = (const GLshort(*)[3]) srcRowB;
    321       GLshort(*dst)[3] = (GLshort(*)[3]) dstRow;
    322       for (i = j = 0, k = k0; i < (GLuint) dstWidth;
    323            i++, j += colStride, k += colStride) {
    324          dst[i][0] = (rowA[j][0] + rowA[k][0] + rowB[j][0] + rowB[k][0]) / 4;
    325          dst[i][1] = (rowA[j][1] + rowA[k][1] + rowB[j][1] + rowB[k][1]) / 4;
    326          dst[i][2] = (rowA[j][2] + rowA[k][2] + rowB[j][2] + rowB[k][2]) / 4;
    327       }
    328    }
    329    else if (datatype == GL_SHORT && comps == 2) {
    330       GLuint i, j, k;
    331       const GLshort(*rowA)[2] = (const GLshort(*)[2]) srcRowA;
    332       const GLshort(*rowB)[2] = (const GLshort(*)[2]) srcRowB;
    333       GLshort(*dst)[2] = (GLshort(*)[2]) dstRow;
    334       for (i = j = 0, k = k0; i < (GLuint) dstWidth;
    335            i++, j += colStride, k += colStride) {
    336          dst[i][0] = (rowA[j][0] + rowA[k][0] + rowB[j][0] + rowB[k][0]) / 4;
    337          dst[i][1] = (rowA[j][1] + rowA[k][1] + rowB[j][1] + rowB[k][1]) / 4;
    338       }
    339    }
    340    else if (datatype == GL_SHORT && comps == 1) {
    341       GLuint i, j, k;
    342       const GLshort *rowA = (const GLshort *) srcRowA;
    343       const GLshort *rowB = (const GLshort *) srcRowB;
    344       GLshort *dst = (GLshort *) dstRow;
    345       for (i = j = 0, k = k0; i < (GLuint) dstWidth;
    346            i++, j += colStride, k += colStride) {
    347          dst[i] = (rowA[j] + rowA[k] + rowB[j] + rowB[k]) / 4;
    348       }
    349    }
    350 
    351    else if (datatype == GL_FLOAT && comps == 4) {
    352       GLuint i, j, k;
    353       const GLfloat(*rowA)[4] = (const GLfloat(*)[4]) srcRowA;
    354       const GLfloat(*rowB)[4] = (const GLfloat(*)[4]) srcRowB;
    355       GLfloat(*dst)[4] = (GLfloat(*)[4]) dstRow;
    356       for (i = j = 0, k = k0; i < (GLuint) dstWidth;
    357            i++, j += colStride, k += colStride) {
    358          dst[i][0] = (rowA[j][0] + rowA[k][0] +
    359                       rowB[j][0] + rowB[k][0]) * 0.25F;
    360          dst[i][1] = (rowA[j][1] + rowA[k][1] +
    361                       rowB[j][1] + rowB[k][1]) * 0.25F;
    362          dst[i][2] = (rowA[j][2] + rowA[k][2] +
    363                       rowB[j][2] + rowB[k][2]) * 0.25F;
    364          dst[i][3] = (rowA[j][3] + rowA[k][3] +
    365                       rowB[j][3] + rowB[k][3]) * 0.25F;
    366       }
    367    }
    368    else if (datatype == GL_FLOAT && comps == 3) {
    369       GLuint i, j, k;
    370       const GLfloat(*rowA)[3] = (const GLfloat(*)[3]) srcRowA;
    371       const GLfloat(*rowB)[3] = (const GLfloat(*)[3]) srcRowB;
    372       GLfloat(*dst)[3] = (GLfloat(*)[3]) dstRow;
    373       for (i = j = 0, k = k0; i < (GLuint) dstWidth;
    374            i++, j += colStride, k += colStride) {
    375          dst[i][0] = (rowA[j][0] + rowA[k][0] +
    376                       rowB[j][0] + rowB[k][0]) * 0.25F;
    377          dst[i][1] = (rowA[j][1] + rowA[k][1] +
    378                       rowB[j][1] + rowB[k][1]) * 0.25F;
    379          dst[i][2] = (rowA[j][2] + rowA[k][2] +
    380                       rowB[j][2] + rowB[k][2]) * 0.25F;
    381       }
    382    }
    383    else if (datatype == GL_FLOAT && comps == 2) {
    384       GLuint i, j, k;
    385       const GLfloat(*rowA)[2] = (const GLfloat(*)[2]) srcRowA;
    386       const GLfloat(*rowB)[2] = (const GLfloat(*)[2]) srcRowB;
    387       GLfloat(*dst)[2] = (GLfloat(*)[2]) dstRow;
    388       for (i = j = 0, k = k0; i < (GLuint) dstWidth;
    389            i++, j += colStride, k += colStride) {
    390          dst[i][0] = (rowA[j][0] + rowA[k][0] +
    391                       rowB[j][0] + rowB[k][0]) * 0.25F;
    392          dst[i][1] = (rowA[j][1] + rowA[k][1] +
    393                       rowB[j][1] + rowB[k][1]) * 0.25F;
    394       }
    395    }
    396    else if (datatype == GL_FLOAT && comps == 1) {
    397       GLuint i, j, k;
    398       const GLfloat *rowA = (const GLfloat *) srcRowA;
    399       const GLfloat *rowB = (const GLfloat *) srcRowB;
    400       GLfloat *dst = (GLfloat *) dstRow;
    401       for (i = j = 0, k = k0; i < (GLuint) dstWidth;
    402            i++, j += colStride, k += colStride) {
    403          dst[i] = (rowA[j] + rowA[k] + rowB[j] + rowB[k]) * 0.25F;
    404       }
    405    }
    406 
    407    else if (datatype == GL_HALF_FLOAT_ARB && comps == 4) {
    408       GLuint i, j, k, comp;
    409       const GLhalfARB(*rowA)[4] = (const GLhalfARB(*)[4]) srcRowA;
    410       const GLhalfARB(*rowB)[4] = (const GLhalfARB(*)[4]) srcRowB;
    411       GLhalfARB(*dst)[4] = (GLhalfARB(*)[4]) dstRow;
    412       for (i = j = 0, k = k0; i < (GLuint) dstWidth;
    413            i++, j += colStride, k += colStride) {
    414          for (comp = 0; comp < 4; comp++) {
    415             GLfloat aj, ak, bj, bk;
    416             aj = _mesa_half_to_float(rowA[j][comp]);
    417             ak = _mesa_half_to_float(rowA[k][comp]);
    418             bj = _mesa_half_to_float(rowB[j][comp]);
    419             bk = _mesa_half_to_float(rowB[k][comp]);
    420             dst[i][comp] = _mesa_float_to_half((aj + ak + bj + bk) * 0.25F);
    421          }
    422       }
    423    }
    424    else if (datatype == GL_HALF_FLOAT_ARB && comps == 3) {
    425       GLuint i, j, k, comp;
    426       const GLhalfARB(*rowA)[3] = (const GLhalfARB(*)[3]) srcRowA;
    427       const GLhalfARB(*rowB)[3] = (const GLhalfARB(*)[3]) srcRowB;
    428       GLhalfARB(*dst)[3] = (GLhalfARB(*)[3]) dstRow;
    429       for (i = j = 0, k = k0; i < (GLuint) dstWidth;
    430            i++, j += colStride, k += colStride) {
    431          for (comp = 0; comp < 3; comp++) {
    432             GLfloat aj, ak, bj, bk;
    433             aj = _mesa_half_to_float(rowA[j][comp]);
    434             ak = _mesa_half_to_float(rowA[k][comp]);
    435             bj = _mesa_half_to_float(rowB[j][comp]);
    436             bk = _mesa_half_to_float(rowB[k][comp]);
    437             dst[i][comp] = _mesa_float_to_half((aj + ak + bj + bk) * 0.25F);
    438          }
    439       }
    440    }
    441    else if (datatype == GL_HALF_FLOAT_ARB && comps == 2) {
    442       GLuint i, j, k, comp;
    443       const GLhalfARB(*rowA)[2] = (const GLhalfARB(*)[2]) srcRowA;
    444       const GLhalfARB(*rowB)[2] = (const GLhalfARB(*)[2]) srcRowB;
    445       GLhalfARB(*dst)[2] = (GLhalfARB(*)[2]) dstRow;
    446       for (i = j = 0, k = k0; i < (GLuint) dstWidth;
    447            i++, j += colStride, k += colStride) {
    448          for (comp = 0; comp < 2; comp++) {
    449             GLfloat aj, ak, bj, bk;
    450             aj = _mesa_half_to_float(rowA[j][comp]);
    451             ak = _mesa_half_to_float(rowA[k][comp]);
    452             bj = _mesa_half_to_float(rowB[j][comp]);
    453             bk = _mesa_half_to_float(rowB[k][comp]);
    454             dst[i][comp] = _mesa_float_to_half((aj + ak + bj + bk) * 0.25F);
    455          }
    456       }
    457    }
    458    else if (datatype == GL_HALF_FLOAT_ARB && comps == 1) {
    459       GLuint i, j, k;
    460       const GLhalfARB *rowA = (const GLhalfARB *) srcRowA;
    461       const GLhalfARB *rowB = (const GLhalfARB *) srcRowB;
    462       GLhalfARB *dst = (GLhalfARB *) dstRow;
    463       for (i = j = 0, k = k0; i < (GLuint) dstWidth;
    464            i++, j += colStride, k += colStride) {
    465          GLfloat aj, ak, bj, bk;
    466          aj = _mesa_half_to_float(rowA[j]);
    467          ak = _mesa_half_to_float(rowA[k]);
    468          bj = _mesa_half_to_float(rowB[j]);
    469          bk = _mesa_half_to_float(rowB[k]);
    470          dst[i] = _mesa_float_to_half((aj + ak + bj + bk) * 0.25F);
    471       }
    472    }
    473 
    474    else if (datatype == GL_UNSIGNED_INT && comps == 1) {
    475       GLuint i, j, k;
    476       const GLuint *rowA = (const GLuint *) srcRowA;
    477       const GLuint *rowB = (const GLuint *) srcRowB;
    478       GLuint *dst = (GLuint *) dstRow;
    479       for (i = j = 0, k = k0; i < (GLuint) dstWidth;
    480            i++, j += colStride, k += colStride) {
    481          dst[i] = rowA[j] / 4 + rowA[k] / 4 + rowB[j] / 4 + rowB[k] / 4;
    482       }
    483    }
    484 
    485    else if (datatype == GL_UNSIGNED_SHORT_5_6_5 && comps == 3) {
    486       GLuint i, j, k;
    487       const GLushort *rowA = (const GLushort *) srcRowA;
    488       const GLushort *rowB = (const GLushort *) srcRowB;
    489       GLushort *dst = (GLushort *) dstRow;
    490       for (i = j = 0, k = k0; i < (GLuint) dstWidth;
    491            i++, j += colStride, k += colStride) {
    492          const GLint rowAr0 = rowA[j] & 0x1f;
    493          const GLint rowAr1 = rowA[k] & 0x1f;
    494          const GLint rowBr0 = rowB[j] & 0x1f;
    495          const GLint rowBr1 = rowB[k] & 0x1f;
    496          const GLint rowAg0 = (rowA[j] >> 5) & 0x3f;
    497          const GLint rowAg1 = (rowA[k] >> 5) & 0x3f;
    498          const GLint rowBg0 = (rowB[j] >> 5) & 0x3f;
    499          const GLint rowBg1 = (rowB[k] >> 5) & 0x3f;
    500          const GLint rowAb0 = (rowA[j] >> 11) & 0x1f;
    501          const GLint rowAb1 = (rowA[k] >> 11) & 0x1f;
    502          const GLint rowBb0 = (rowB[j] >> 11) & 0x1f;
    503          const GLint rowBb1 = (rowB[k] >> 11) & 0x1f;
    504          const GLint red = (rowAr0 + rowAr1 + rowBr0 + rowBr1) >> 2;
    505          const GLint green = (rowAg0 + rowAg1 + rowBg0 + rowBg1) >> 2;
    506          const GLint blue = (rowAb0 + rowAb1 + rowBb0 + rowBb1) >> 2;
    507          dst[i] = (blue << 11) | (green << 5) | red;
    508       }
    509    }
    510    else if (datatype == GL_UNSIGNED_SHORT_4_4_4_4 && comps == 4) {
    511       GLuint i, j, k;
    512       const GLushort *rowA = (const GLushort *) srcRowA;
    513       const GLushort *rowB = (const GLushort *) srcRowB;
    514       GLushort *dst = (GLushort *) dstRow;
    515       for (i = j = 0, k = k0; i < (GLuint) dstWidth;
    516            i++, j += colStride, k += colStride) {
    517          const GLint rowAr0 = rowA[j] & 0xf;
    518          const GLint rowAr1 = rowA[k] & 0xf;
    519          const GLint rowBr0 = rowB[j] & 0xf;
    520          const GLint rowBr1 = rowB[k] & 0xf;
    521          const GLint rowAg0 = (rowA[j] >> 4) & 0xf;
    522          const GLint rowAg1 = (rowA[k] >> 4) & 0xf;
    523          const GLint rowBg0 = (rowB[j] >> 4) & 0xf;
    524          const GLint rowBg1 = (rowB[k] >> 4) & 0xf;
    525          const GLint rowAb0 = (rowA[j] >> 8) & 0xf;
    526          const GLint rowAb1 = (rowA[k] >> 8) & 0xf;
    527          const GLint rowBb0 = (rowB[j] >> 8) & 0xf;
    528          const GLint rowBb1 = (rowB[k] >> 8) & 0xf;
    529          const GLint rowAa0 = (rowA[j] >> 12) & 0xf;
    530          const GLint rowAa1 = (rowA[k] >> 12) & 0xf;
    531          const GLint rowBa0 = (rowB[j] >> 12) & 0xf;
    532          const GLint rowBa1 = (rowB[k] >> 12) & 0xf;
    533          const GLint red = (rowAr0 + rowAr1 + rowBr0 + rowBr1) >> 2;
    534          const GLint green = (rowAg0 + rowAg1 + rowBg0 + rowBg1) >> 2;
    535          const GLint blue = (rowAb0 + rowAb1 + rowBb0 + rowBb1) >> 2;
    536          const GLint alpha = (rowAa0 + rowAa1 + rowBa0 + rowBa1) >> 2;
    537          dst[i] = (alpha << 12) | (blue << 8) | (green << 4) | red;
    538       }
    539    }
    540    else if (datatype == GL_UNSIGNED_SHORT_1_5_5_5_REV && comps == 4) {
    541       GLuint i, j, k;
    542       const GLushort *rowA = (const GLushort *) srcRowA;
    543       const GLushort *rowB = (const GLushort *) srcRowB;
    544       GLushort *dst = (GLushort *) dstRow;
    545       for (i = j = 0, k = k0; i < (GLuint) dstWidth;
    546            i++, j += colStride, k += colStride) {
    547          const GLint rowAr0 = rowA[j] & 0x1f;
    548          const GLint rowAr1 = rowA[k] & 0x1f;
    549          const GLint rowBr0 = rowB[j] & 0x1f;
    550          const GLint rowBr1 = rowB[k] & 0x1f;
    551          const GLint rowAg0 = (rowA[j] >> 5) & 0x1f;
    552          const GLint rowAg1 = (rowA[k] >> 5) & 0x1f;
    553          const GLint rowBg0 = (rowB[j] >> 5) & 0x1f;
    554          const GLint rowBg1 = (rowB[k] >> 5) & 0x1f;
    555          const GLint rowAb0 = (rowA[j] >> 10) & 0x1f;
    556          const GLint rowAb1 = (rowA[k] >> 10) & 0x1f;
    557          const GLint rowBb0 = (rowB[j] >> 10) & 0x1f;
    558          const GLint rowBb1 = (rowB[k] >> 10) & 0x1f;
    559          const GLint rowAa0 = (rowA[j] >> 15) & 0x1;
    560          const GLint rowAa1 = (rowA[k] >> 15) & 0x1;
    561          const GLint rowBa0 = (rowB[j] >> 15) & 0x1;
    562          const GLint rowBa1 = (rowB[k] >> 15) & 0x1;
    563          const GLint red = (rowAr0 + rowAr1 + rowBr0 + rowBr1) >> 2;
    564          const GLint green = (rowAg0 + rowAg1 + rowBg0 + rowBg1) >> 2;
    565          const GLint blue = (rowAb0 + rowAb1 + rowBb0 + rowBb1) >> 2;
    566          const GLint alpha = (rowAa0 + rowAa1 + rowBa0 + rowBa1) >> 2;
    567          dst[i] = (alpha << 15) | (blue << 10) | (green << 5) | red;
    568       }
    569    }
    570    else if (datatype == GL_UNSIGNED_SHORT_5_5_5_1 && comps == 4) {
    571       GLuint i, j, k;
    572       const GLushort *rowA = (const GLushort *) srcRowA;
    573       const GLushort *rowB = (const GLushort *) srcRowB;
    574       GLushort *dst = (GLushort *) dstRow;
    575       for (i = j = 0, k = k0; i < (GLuint) dstWidth;
    576            i++, j += colStride, k += colStride) {
    577          const GLint rowAr0 = (rowA[j] >> 11) & 0x1f;
    578          const GLint rowAr1 = (rowA[k] >> 11) & 0x1f;
    579          const GLint rowBr0 = (rowB[j] >> 11) & 0x1f;
    580          const GLint rowBr1 = (rowB[k] >> 11) & 0x1f;
    581          const GLint rowAg0 = (rowA[j] >> 6) & 0x1f;
    582          const GLint rowAg1 = (rowA[k] >> 6) & 0x1f;
    583          const GLint rowBg0 = (rowB[j] >> 6) & 0x1f;
    584          const GLint rowBg1 = (rowB[k] >> 6) & 0x1f;
    585          const GLint rowAb0 = (rowA[j] >> 1) & 0x1f;
    586          const GLint rowAb1 = (rowA[k] >> 1) & 0x1f;
    587          const GLint rowBb0 = (rowB[j] >> 1) & 0x1f;
    588          const GLint rowBb1 = (rowB[k] >> 1) & 0x1f;
    589          const GLint rowAa0 = (rowA[j] & 0x1);
    590          const GLint rowAa1 = (rowA[k] & 0x1);
    591          const GLint rowBa0 = (rowB[j] & 0x1);
    592          const GLint rowBa1 = (rowB[k] & 0x1);
    593          const GLint red = (rowAr0 + rowAr1 + rowBr0 + rowBr1) >> 2;
    594          const GLint green = (rowAg0 + rowAg1 + rowBg0 + rowBg1) >> 2;
    595          const GLint blue = (rowAb0 + rowAb1 + rowBb0 + rowBb1) >> 2;
    596          const GLint alpha = (rowAa0 + rowAa1 + rowBa0 + rowBa1) >> 2;
    597          dst[i] = (red << 11) | (green << 6) | (blue << 1) | alpha;
    598       }
    599    }
    600 
    601    else if (datatype == GL_UNSIGNED_BYTE_3_3_2 && comps == 3) {
    602       GLuint i, j, k;
    603       const GLubyte *rowA = (const GLubyte *) srcRowA;
    604       const GLubyte *rowB = (const GLubyte *) srcRowB;
    605       GLubyte *dst = (GLubyte *) dstRow;
    606       for (i = j = 0, k = k0; i < (GLuint) dstWidth;
    607            i++, j += colStride, k += colStride) {
    608          const GLint rowAr0 = rowA[j] & 0x3;
    609          const GLint rowAr1 = rowA[k] & 0x3;
    610          const GLint rowBr0 = rowB[j] & 0x3;
    611          const GLint rowBr1 = rowB[k] & 0x3;
    612          const GLint rowAg0 = (rowA[j] >> 2) & 0x7;
    613          const GLint rowAg1 = (rowA[k] >> 2) & 0x7;
    614          const GLint rowBg0 = (rowB[j] >> 2) & 0x7;
    615          const GLint rowBg1 = (rowB[k] >> 2) & 0x7;
    616          const GLint rowAb0 = (rowA[j] >> 5) & 0x7;
    617          const GLint rowAb1 = (rowA[k] >> 5) & 0x7;
    618          const GLint rowBb0 = (rowB[j] >> 5) & 0x7;
    619          const GLint rowBb1 = (rowB[k] >> 5) & 0x7;
    620          const GLint red = (rowAr0 + rowAr1 + rowBr0 + rowBr1) >> 2;
    621          const GLint green = (rowAg0 + rowAg1 + rowBg0 + rowBg1) >> 2;
    622          const GLint blue = (rowAb0 + rowAb1 + rowBb0 + rowBb1) >> 2;
    623          dst[i] = (blue << 5) | (green << 2) | red;
    624       }
    625    }
    626 
    627    else if (datatype == MESA_UNSIGNED_BYTE_4_4 && comps == 2) {
    628       GLuint i, j, k;
    629       const GLubyte *rowA = (const GLubyte *) srcRowA;
    630       const GLubyte *rowB = (const GLubyte *) srcRowB;
    631       GLubyte *dst = (GLubyte *) dstRow;
    632       for (i = j = 0, k = k0; i < (GLuint) dstWidth;
    633            i++, j += colStride, k += colStride) {
    634          const GLint rowAr0 = rowA[j] & 0xf;
    635          const GLint rowAr1 = rowA[k] & 0xf;
    636          const GLint rowBr0 = rowB[j] & 0xf;
    637          const GLint rowBr1 = rowB[k] & 0xf;
    638          const GLint rowAg0 = (rowA[j] >> 4) & 0xf;
    639          const GLint rowAg1 = (rowA[k] >> 4) & 0xf;
    640          const GLint rowBg0 = (rowB[j] >> 4) & 0xf;
    641          const GLint rowBg1 = (rowB[k] >> 4) & 0xf;
    642          const GLint r = (rowAr0 + rowAr1 + rowBr0 + rowBr1) >> 2;
    643          const GLint g = (rowAg0 + rowAg1 + rowBg0 + rowBg1) >> 2;
    644          dst[i] = (g << 4) | r;
    645       }
    646    }
    647 
    648    else if (datatype == GL_UNSIGNED_INT_2_10_10_10_REV && comps == 4) {
    649       GLuint i, j, k;
    650       const GLuint *rowA = (const GLuint *) srcRowA;
    651       const GLuint *rowB = (const GLuint *) srcRowB;
    652       GLuint *dst = (GLuint *) dstRow;
    653       for (i = j = 0, k = k0; i < (GLuint) dstWidth;
    654            i++, j += colStride, k += colStride) {
    655          const GLint rowAr0 = rowA[j] & 0x3ff;
    656          const GLint rowAr1 = rowA[k] & 0x3ff;
    657          const GLint rowBr0 = rowB[j] & 0x3ff;
    658          const GLint rowBr1 = rowB[k] & 0x3ff;
    659          const GLint rowAg0 = (rowA[j] >> 10) & 0x3ff;
    660          const GLint rowAg1 = (rowA[k] >> 10) & 0x3ff;
    661          const GLint rowBg0 = (rowB[j] >> 10) & 0x3ff;
    662          const GLint rowBg1 = (rowB[k] >> 10) & 0x3ff;
    663          const GLint rowAb0 = (rowA[j] >> 20) & 0x3ff;
    664          const GLint rowAb1 = (rowA[k] >> 20) & 0x3ff;
    665          const GLint rowBb0 = (rowB[j] >> 20) & 0x3ff;
    666          const GLint rowBb1 = (rowB[k] >> 20) & 0x3ff;
    667          const GLint rowAa0 = (rowA[j] >> 30) & 0x3;
    668          const GLint rowAa1 = (rowA[k] >> 30) & 0x3;
    669          const GLint rowBa0 = (rowB[j] >> 30) & 0x3;
    670          const GLint rowBa1 = (rowB[k] >> 30) & 0x3;
    671          const GLint red = (rowAr0 + rowAr1 + rowBr0 + rowBr1) >> 2;
    672          const GLint green = (rowAg0 + rowAg1 + rowBg0 + rowBg1) >> 2;
    673          const GLint blue = (rowAb0 + rowAb1 + rowBb0 + rowBb1) >> 2;
    674          const GLint alpha = (rowAa0 + rowAa1 + rowBa0 + rowBa1) >> 2;
    675          dst[i] = (alpha << 30) | (blue << 20) | (green << 10) | red;
    676       }
    677    }
    678 
    679    else if (datatype == GL_UNSIGNED_INT_5_9_9_9_REV && comps == 3) {
    680       GLuint i, j, k;
    681       const GLuint *rowA = (const GLuint*) srcRowA;
    682       const GLuint *rowB = (const GLuint*) srcRowB;
    683       GLuint *dst = (GLuint*)dstRow;
    684       GLfloat res[3], rowAj[3], rowBj[3], rowAk[3], rowBk[3];
    685       for (i = j = 0, k = k0; i < (GLuint) dstWidth;
    686            i++, j += colStride, k += colStride) {
    687          rgb9e5_to_float3(rowA[j], rowAj);
    688          rgb9e5_to_float3(rowB[j], rowBj);
    689          rgb9e5_to_float3(rowA[k], rowAk);
    690          rgb9e5_to_float3(rowB[k], rowBk);
    691          res[0] = (rowAj[0] + rowAk[0] + rowBj[0] + rowBk[0]) * 0.25F;
    692          res[1] = (rowAj[1] + rowAk[1] + rowBj[1] + rowBk[1]) * 0.25F;
    693          res[2] = (rowAj[2] + rowAk[2] + rowBj[2] + rowBk[2]) * 0.25F;
    694          dst[i] = float3_to_rgb9e5(res);
    695       }
    696    }
    697 
    698    else if (datatype == GL_UNSIGNED_INT_10F_11F_11F_REV && comps == 3) {
    699       GLuint i, j, k;
    700       const GLuint *rowA = (const GLuint*) srcRowA;
    701       const GLuint *rowB = (const GLuint*) srcRowB;
    702       GLuint *dst = (GLuint*)dstRow;
    703       GLfloat res[3], rowAj[3], rowBj[3], rowAk[3], rowBk[3];
    704       for (i = j = 0, k = k0; i < (GLuint) dstWidth;
    705            i++, j += colStride, k += colStride) {
    706          r11g11b10f_to_float3(rowA[j], rowAj);
    707          r11g11b10f_to_float3(rowB[j], rowBj);
    708          r11g11b10f_to_float3(rowA[k], rowAk);
    709          r11g11b10f_to_float3(rowB[k], rowBk);
    710          res[0] = (rowAj[0] + rowAk[0] + rowBj[0] + rowBk[0]) * 0.25F;
    711          res[1] = (rowAj[1] + rowAk[1] + rowBj[1] + rowBk[1]) * 0.25F;
    712          res[2] = (rowAj[2] + rowAk[2] + rowBj[2] + rowBk[2]) * 0.25F;
    713          dst[i] = float3_to_r11g11b10f(res);
    714       }
    715    }
    716 
    717    else if (datatype == GL_FLOAT_32_UNSIGNED_INT_24_8_REV && comps == 1) {
    718       GLuint i, j, k;
    719       const GLfloat *rowA = (const GLfloat *) srcRowA;
    720       const GLfloat *rowB = (const GLfloat *) srcRowB;
    721       GLfloat *dst = (GLfloat *) dstRow;
    722       for (i = j = 0, k = k0; i < (GLuint) dstWidth;
    723            i++, j += colStride, k += colStride) {
    724          dst[i*2] = (rowA[j*2] + rowA[k*2] + rowB[j*2] + rowB[k*2]) * 0.25F;
    725       }
    726    }
    727 
    728    else if (datatype == GL_UNSIGNED_INT_24_8_MESA && comps == 2) {
    729       GLuint i, j, k;
    730       const GLuint *rowA = (const GLuint *) srcRowA;
    731       const GLuint *rowB = (const GLuint *) srcRowB;
    732       GLuint *dst = (GLuint *) dstRow;
    733       /* note: averaging stencil values seems weird, but what else? */
    734       for (i = j = 0, k = k0; i < (GLuint) dstWidth;
    735            i++, j += colStride, k += colStride) {
    736          GLuint z = (((rowA[j] >> 8) + (rowA[k] >> 8) +
    737                       (rowB[j] >> 8) + (rowB[k] >> 8)) / 4) << 8;
    738          GLuint s = ((rowA[j] & 0xff) + (rowA[k] & 0xff) +
    739                      (rowB[j] & 0xff) + (rowB[k] & 0xff)) / 4;
    740          dst[i] = z | s;
    741       }
    742    }
    743    else if (datatype == GL_UNSIGNED_INT_8_24_REV_MESA && comps == 2) {
    744       GLuint i, j, k;
    745       const GLuint *rowA = (const GLuint *) srcRowA;
    746       const GLuint *rowB = (const GLuint *) srcRowB;
    747       GLuint *dst = (GLuint *) dstRow;
    748       for (i = j = 0, k = k0; i < (GLuint) dstWidth;
    749            i++, j += colStride, k += colStride) {
    750          GLuint z = ((rowA[j] & 0xffffff) + (rowA[k] & 0xffffff) +
    751                      (rowB[j] & 0xffffff) + (rowB[k] & 0xffffff)) / 4;
    752          GLuint s = (((rowA[j] >> 24) + (rowA[k] >> 24) +
    753                       (rowB[j] >> 24) + (rowB[k] >> 24)) / 4) << 24;
    754          dst[i] = z | s;
    755       }
    756    }
    757 
    758    else {
    759       _mesa_problem(NULL, "bad format in do_row()");
    760    }
    761 }
    762 
    763 
    764 /**
    765  * Average together four rows of a source image to produce a single new
    766  * row in the dest image.  It's legal for the two source rows to point
    767  * to the same data.  The source width must be equal to either the
    768  * dest width or two times the dest width.
    769  *
    770  * \param datatype  GL pixel type \c GL_UNSIGNED_BYTE, \c GL_UNSIGNED_SHORT,
    771  *                  \c GL_FLOAT, etc.
    772  * \param comps     number of components per pixel (1..4)
    773  * \param srcWidth  Width of a row in the source data
    774  * \param srcRowA   Pointer to one of the rows of source data
    775  * \param srcRowB   Pointer to one of the rows of source data
    776  * \param srcRowC   Pointer to one of the rows of source data
    777  * \param srcRowD   Pointer to one of the rows of source data
    778  * \param dstWidth  Width of a row in the destination data
    779  * \param srcRowA   Pointer to the row of destination data
    780  */
    781 static void
    782 do_row_3D(GLenum datatype, GLuint comps, GLint srcWidth,
    783           const GLvoid *srcRowA, const GLvoid *srcRowB,
    784           const GLvoid *srcRowC, const GLvoid *srcRowD,
    785           GLint dstWidth, GLvoid *dstRow)
    786 {
    787    const GLuint k0 = (srcWidth == dstWidth) ? 0 : 1;
    788    const GLuint colStride = (srcWidth == dstWidth) ? 1 : 2;
    789    GLuint i, j, k;
    790 
    791    ASSERT(comps >= 1);
    792    ASSERT(comps <= 4);
    793 
    794    if ((datatype == GL_UNSIGNED_BYTE) && (comps == 4)) {
    795       DECLARE_ROW_POINTERS(GLubyte, 4);
    796 
    797       for (i = j = 0, k = k0; i < (GLuint) dstWidth;
    798            i++, j += colStride, k += colStride) {
    799          FILTER_3D(0);
    800          FILTER_3D(1);
    801          FILTER_3D(2);
    802          FILTER_3D(3);
    803       }
    804    }
    805    else if ((datatype == GL_UNSIGNED_BYTE) && (comps == 3)) {
    806       DECLARE_ROW_POINTERS(GLubyte, 3);
    807 
    808       for (i = j = 0, k = k0; i < (GLuint) dstWidth;
    809            i++, j += colStride, k += colStride) {
    810          FILTER_3D(0);
    811          FILTER_3D(1);
    812          FILTER_3D(2);
    813       }
    814    }
    815    else if ((datatype == GL_UNSIGNED_BYTE) && (comps == 2)) {
    816       DECLARE_ROW_POINTERS(GLubyte, 2);
    817 
    818       for (i = j = 0, k = k0; i < (GLuint) dstWidth;
    819            i++, j += colStride, k += colStride) {
    820          FILTER_3D(0);
    821          FILTER_3D(1);
    822       }
    823    }
    824    else if ((datatype == GL_UNSIGNED_BYTE) && (comps == 1)) {
    825       DECLARE_ROW_POINTERS(GLubyte, 1);
    826 
    827       for (i = j = 0, k = k0; i < (GLuint) dstWidth;
    828            i++, j += colStride, k += colStride) {
    829          FILTER_3D(0);
    830       }
    831    }
    832    else if ((datatype == GL_BYTE) && (comps == 4)) {
    833       DECLARE_ROW_POINTERS(GLbyte, 4);
    834 
    835       for (i = j = 0, k = k0; i < (GLuint) dstWidth;
    836            i++, j += colStride, k += colStride) {
    837          FILTER_3D_SIGNED(0);
    838          FILTER_3D_SIGNED(1);
    839          FILTER_3D_SIGNED(2);
    840          FILTER_3D_SIGNED(3);
    841       }
    842    }
    843    else if ((datatype == GL_BYTE) && (comps == 3)) {
    844       DECLARE_ROW_POINTERS(GLbyte, 3);
    845 
    846       for (i = j = 0, k = k0; i < (GLuint) dstWidth;
    847            i++, j += colStride, k += colStride) {
    848          FILTER_3D_SIGNED(0);
    849          FILTER_3D_SIGNED(1);
    850          FILTER_3D_SIGNED(2);
    851       }
    852    }
    853    else if ((datatype == GL_BYTE) && (comps == 2)) {
    854       DECLARE_ROW_POINTERS(GLbyte, 2);
    855 
    856       for (i = j = 0, k = k0; i < (GLuint) dstWidth;
    857            i++, j += colStride, k += colStride) {
    858          FILTER_3D_SIGNED(0);
    859          FILTER_3D_SIGNED(1);
    860        }
    861    }
    862    else if ((datatype == GL_BYTE) && (comps == 1)) {
    863       DECLARE_ROW_POINTERS(GLbyte, 1);
    864 
    865       for (i = j = 0, k = k0; i < (GLuint) dstWidth;
    866            i++, j += colStride, k += colStride) {
    867          FILTER_3D_SIGNED(0);
    868       }
    869    }
    870    else if ((datatype == GL_UNSIGNED_SHORT) && (comps == 4)) {
    871       DECLARE_ROW_POINTERS(GLushort, 4);
    872 
    873       for (i = j = 0, k = k0; i < (GLuint) dstWidth;
    874            i++, j += colStride, k += colStride) {
    875          FILTER_3D(0);
    876          FILTER_3D(1);
    877          FILTER_3D(2);
    878          FILTER_3D(3);
    879       }
    880    }
    881    else if ((datatype == GL_UNSIGNED_SHORT) && (comps == 3)) {
    882       DECLARE_ROW_POINTERS(GLushort, 3);
    883 
    884       for (i = j = 0, k = k0; i < (GLuint) dstWidth;
    885            i++, j += colStride, k += colStride) {
    886          FILTER_3D(0);
    887          FILTER_3D(1);
    888          FILTER_3D(2);
    889       }
    890    }
    891    else if ((datatype == GL_UNSIGNED_SHORT) && (comps == 2)) {
    892       DECLARE_ROW_POINTERS(GLushort, 2);
    893 
    894       for (i = j = 0, k = k0; i < (GLuint) dstWidth;
    895            i++, j += colStride, k += colStride) {
    896          FILTER_3D(0);
    897          FILTER_3D(1);
    898       }
    899    }
    900    else if ((datatype == GL_UNSIGNED_SHORT) && (comps == 1)) {
    901       DECLARE_ROW_POINTERS(GLushort, 1);
    902 
    903       for (i = j = 0, k = k0; i < (GLuint) dstWidth;
    904            i++, j += colStride, k += colStride) {
    905          FILTER_3D(0);
    906       }
    907    }
    908    else if ((datatype == GL_SHORT) && (comps == 4)) {
    909       DECLARE_ROW_POINTERS(GLshort, 4);
    910 
    911       for (i = j = 0, k = k0; i < (GLuint) dstWidth;
    912            i++, j += colStride, k += colStride) {
    913          FILTER_3D(0);
    914          FILTER_3D(1);
    915          FILTER_3D(2);
    916          FILTER_3D(3);
    917       }
    918    }
    919    else if ((datatype == GL_SHORT) && (comps == 3)) {
    920       DECLARE_ROW_POINTERS(GLshort, 3);
    921 
    922       for (i = j = 0, k = k0; i < (GLuint) dstWidth;
    923            i++, j += colStride, k += colStride) {
    924          FILTER_3D(0);
    925          FILTER_3D(1);
    926          FILTER_3D(2);
    927       }
    928    }
    929    else if ((datatype == GL_SHORT) && (comps == 2)) {
    930       DECLARE_ROW_POINTERS(GLshort, 2);
    931 
    932       for (i = j = 0, k = k0; i < (GLuint) dstWidth;
    933            i++, j += colStride, k += colStride) {
    934          FILTER_3D(0);
    935          FILTER_3D(1);
    936       }
    937    }
    938    else if ((datatype == GL_SHORT) && (comps == 1)) {
    939       DECLARE_ROW_POINTERS(GLshort, 1);
    940 
    941       for (i = j = 0, k = k0; i < (GLuint) dstWidth;
    942            i++, j += colStride, k += colStride) {
    943          FILTER_3D(0);
    944       }
    945    }
    946    else if ((datatype == GL_FLOAT) && (comps == 4)) {
    947       DECLARE_ROW_POINTERS(GLfloat, 4);
    948 
    949       for (i = j = 0, k = k0; i < (GLuint) dstWidth;
    950            i++, j += colStride, k += colStride) {
    951          FILTER_F_3D(0);
    952          FILTER_F_3D(1);
    953          FILTER_F_3D(2);
    954          FILTER_F_3D(3);
    955       }
    956    }
    957    else if ((datatype == GL_FLOAT) && (comps == 3)) {
    958       DECLARE_ROW_POINTERS(GLfloat, 3);
    959 
    960       for (i = j = 0, k = k0; i < (GLuint) dstWidth;
    961            i++, j += colStride, k += colStride) {
    962          FILTER_F_3D(0);
    963          FILTER_F_3D(1);
    964          FILTER_F_3D(2);
    965       }
    966    }
    967    else if ((datatype == GL_FLOAT) && (comps == 2)) {
    968       DECLARE_ROW_POINTERS(GLfloat, 2);
    969 
    970       for (i = j = 0, k = k0; i < (GLuint) dstWidth;
    971            i++, j += colStride, k += colStride) {
    972          FILTER_F_3D(0);
    973          FILTER_F_3D(1);
    974       }
    975    }
    976    else if ((datatype == GL_FLOAT) && (comps == 1)) {
    977       DECLARE_ROW_POINTERS(GLfloat, 1);
    978 
    979       for (i = j = 0, k = k0; i < (GLuint) dstWidth;
    980            i++, j += colStride, k += colStride) {
    981          FILTER_F_3D(0);
    982       }
    983    }
    984    else if ((datatype == GL_HALF_FLOAT_ARB) && (comps == 4)) {
    985       DECLARE_ROW_POINTERS(GLhalfARB, 4);
    986 
    987       for (i = j = 0, k = k0; i < (GLuint) dstWidth;
    988            i++, j += colStride, k += colStride) {
    989          FILTER_HF_3D(0);
    990          FILTER_HF_3D(1);
    991          FILTER_HF_3D(2);
    992          FILTER_HF_3D(3);
    993       }
    994    }
    995    else if ((datatype == GL_HALF_FLOAT_ARB) && (comps == 3)) {
    996       DECLARE_ROW_POINTERS(GLhalfARB, 3);
    997 
    998       for (i = j = 0, k = k0; i < (GLuint) dstWidth;
    999            i++, j += colStride, k += colStride) {
   1000          FILTER_HF_3D(0);
   1001          FILTER_HF_3D(1);
   1002          FILTER_HF_3D(2);
   1003       }
   1004    }
   1005    else if ((datatype == GL_HALF_FLOAT_ARB) && (comps == 2)) {
   1006       DECLARE_ROW_POINTERS(GLhalfARB, 2);
   1007 
   1008       for (i = j = 0, k = k0; i < (GLuint) dstWidth;
   1009            i++, j += colStride, k += colStride) {
   1010          FILTER_HF_3D(0);
   1011          FILTER_HF_3D(1);
   1012       }
   1013    }
   1014    else if ((datatype == GL_HALF_FLOAT_ARB) && (comps == 1)) {
   1015       DECLARE_ROW_POINTERS(GLhalfARB, 1);
   1016 
   1017       for (i = j = 0, k = k0; i < (GLuint) dstWidth;
   1018            i++, j += colStride, k += colStride) {
   1019          FILTER_HF_3D(0);
   1020       }
   1021    }
   1022    else if ((datatype == GL_UNSIGNED_INT) && (comps == 1)) {
   1023       const GLuint *rowA = (const GLuint *) srcRowA;
   1024       const GLuint *rowB = (const GLuint *) srcRowB;
   1025       const GLuint *rowC = (const GLuint *) srcRowC;
   1026       const GLuint *rowD = (const GLuint *) srcRowD;
   1027       GLfloat *dst = (GLfloat *) dstRow;
   1028 
   1029       for (i = j = 0, k = k0; i < (GLuint) dstWidth;
   1030            i++, j += colStride, k += colStride) {
   1031          const uint64_t tmp = (((uint64_t) rowA[j] + (uint64_t) rowA[k])
   1032                                + ((uint64_t) rowB[j] + (uint64_t) rowB[k])
   1033                                + ((uint64_t) rowC[j] + (uint64_t) rowC[k])
   1034                                + ((uint64_t) rowD[j] + (uint64_t) rowD[k]));
   1035          dst[i] = (GLfloat)((double) tmp * 0.125);
   1036       }
   1037    }
   1038    else if ((datatype == GL_UNSIGNED_SHORT_5_6_5) && (comps == 3)) {
   1039       DECLARE_ROW_POINTERS0(GLushort);
   1040 
   1041       for (i = j = 0, k = k0; i < (GLuint) dstWidth;
   1042            i++, j += colStride, k += colStride) {
   1043          const GLint rowAr0 = rowA[j] & 0x1f;
   1044          const GLint rowAr1 = rowA[k] & 0x1f;
   1045          const GLint rowBr0 = rowB[j] & 0x1f;
   1046          const GLint rowBr1 = rowB[k] & 0x1f;
   1047          const GLint rowCr0 = rowC[j] & 0x1f;
   1048          const GLint rowCr1 = rowC[k] & 0x1f;
   1049          const GLint rowDr0 = rowD[j] & 0x1f;
   1050          const GLint rowDr1 = rowD[k] & 0x1f;
   1051          const GLint rowAg0 = (rowA[j] >> 5) & 0x3f;
   1052          const GLint rowAg1 = (rowA[k] >> 5) & 0x3f;
   1053          const GLint rowBg0 = (rowB[j] >> 5) & 0x3f;
   1054          const GLint rowBg1 = (rowB[k] >> 5) & 0x3f;
   1055          const GLint rowCg0 = (rowC[j] >> 5) & 0x3f;
   1056          const GLint rowCg1 = (rowC[k] >> 5) & 0x3f;
   1057          const GLint rowDg0 = (rowD[j] >> 5) & 0x3f;
   1058          const GLint rowDg1 = (rowD[k] >> 5) & 0x3f;
   1059          const GLint rowAb0 = (rowA[j] >> 11) & 0x1f;
   1060          const GLint rowAb1 = (rowA[k] >> 11) & 0x1f;
   1061          const GLint rowBb0 = (rowB[j] >> 11) & 0x1f;
   1062          const GLint rowBb1 = (rowB[k] >> 11) & 0x1f;
   1063          const GLint rowCb0 = (rowC[j] >> 11) & 0x1f;
   1064          const GLint rowCb1 = (rowC[k] >> 11) & 0x1f;
   1065          const GLint rowDb0 = (rowD[j] >> 11) & 0x1f;
   1066          const GLint rowDb1 = (rowD[k] >> 11) & 0x1f;
   1067          const GLint r = FILTER_SUM_3D(rowAr0, rowAr1, rowBr0, rowBr1,
   1068                                        rowCr0, rowCr1, rowDr0, rowDr1);
   1069          const GLint g = FILTER_SUM_3D(rowAg0, rowAg1, rowBg0, rowBg1,
   1070                                        rowCg0, rowCg1, rowDg0, rowDg1);
   1071          const GLint b = FILTER_SUM_3D(rowAb0, rowAb1, rowBb0, rowBb1,
   1072                                        rowCb0, rowCb1, rowDb0, rowDb1);
   1073          dst[i] = (b << 11) | (g << 5) | r;
   1074       }
   1075    }
   1076    else if ((datatype == GL_UNSIGNED_SHORT_4_4_4_4) && (comps == 4)) {
   1077       DECLARE_ROW_POINTERS0(GLushort);
   1078 
   1079       for (i = j = 0, k = k0; i < (GLuint) dstWidth;
   1080            i++, j += colStride, k += colStride) {
   1081          const GLint rowAr0 = rowA[j] & 0xf;
   1082          const GLint rowAr1 = rowA[k] & 0xf;
   1083          const GLint rowBr0 = rowB[j] & 0xf;
   1084          const GLint rowBr1 = rowB[k] & 0xf;
   1085          const GLint rowCr0 = rowC[j] & 0xf;
   1086          const GLint rowCr1 = rowC[k] & 0xf;
   1087          const GLint rowDr0 = rowD[j] & 0xf;
   1088          const GLint rowDr1 = rowD[k] & 0xf;
   1089          const GLint rowAg0 = (rowA[j] >> 4) & 0xf;
   1090          const GLint rowAg1 = (rowA[k] >> 4) & 0xf;
   1091          const GLint rowBg0 = (rowB[j] >> 4) & 0xf;
   1092          const GLint rowBg1 = (rowB[k] >> 4) & 0xf;
   1093          const GLint rowCg0 = (rowC[j] >> 4) & 0xf;
   1094          const GLint rowCg1 = (rowC[k] >> 4) & 0xf;
   1095          const GLint rowDg0 = (rowD[j] >> 4) & 0xf;
   1096          const GLint rowDg1 = (rowD[k] >> 4) & 0xf;
   1097          const GLint rowAb0 = (rowA[j] >> 8) & 0xf;
   1098          const GLint rowAb1 = (rowA[k] >> 8) & 0xf;
   1099          const GLint rowBb0 = (rowB[j] >> 8) & 0xf;
   1100          const GLint rowBb1 = (rowB[k] >> 8) & 0xf;
   1101          const GLint rowCb0 = (rowC[j] >> 8) & 0xf;
   1102          const GLint rowCb1 = (rowC[k] >> 8) & 0xf;
   1103          const GLint rowDb0 = (rowD[j] >> 8) & 0xf;
   1104          const GLint rowDb1 = (rowD[k] >> 8) & 0xf;
   1105          const GLint rowAa0 = (rowA[j] >> 12) & 0xf;
   1106          const GLint rowAa1 = (rowA[k] >> 12) & 0xf;
   1107          const GLint rowBa0 = (rowB[j] >> 12) & 0xf;
   1108          const GLint rowBa1 = (rowB[k] >> 12) & 0xf;
   1109          const GLint rowCa0 = (rowC[j] >> 12) & 0xf;
   1110          const GLint rowCa1 = (rowC[k] >> 12) & 0xf;
   1111          const GLint rowDa0 = (rowD[j] >> 12) & 0xf;
   1112          const GLint rowDa1 = (rowD[k] >> 12) & 0xf;
   1113          const GLint r = FILTER_SUM_3D(rowAr0, rowAr1, rowBr0, rowBr1,
   1114                                        rowCr0, rowCr1, rowDr0, rowDr1);
   1115          const GLint g = FILTER_SUM_3D(rowAg0, rowAg1, rowBg0, rowBg1,
   1116                                        rowCg0, rowCg1, rowDg0, rowDg1);
   1117          const GLint b = FILTER_SUM_3D(rowAb0, rowAb1, rowBb0, rowBb1,
   1118                                        rowCb0, rowCb1, rowDb0, rowDb1);
   1119          const GLint a = FILTER_SUM_3D(rowAa0, rowAa1, rowBa0, rowBa1,
   1120                                        rowCa0, rowCa1, rowDa0, rowDa1);
   1121 
   1122          dst[i] = (a << 12) | (b << 8) | (g << 4) | r;
   1123       }
   1124    }
   1125    else if ((datatype == GL_UNSIGNED_SHORT_1_5_5_5_REV) && (comps == 4)) {
   1126       DECLARE_ROW_POINTERS0(GLushort);
   1127 
   1128       for (i = j = 0, k = k0; i < (GLuint) dstWidth;
   1129            i++, j += colStride, k += colStride) {
   1130          const GLint rowAr0 = rowA[j] & 0x1f;
   1131          const GLint rowAr1 = rowA[k] & 0x1f;
   1132          const GLint rowBr0 = rowB[j] & 0x1f;
   1133          const GLint rowBr1 = rowB[k] & 0x1f;
   1134          const GLint rowCr0 = rowC[j] & 0x1f;
   1135          const GLint rowCr1 = rowC[k] & 0x1f;
   1136          const GLint rowDr0 = rowD[j] & 0x1f;
   1137          const GLint rowDr1 = rowD[k] & 0x1f;
   1138          const GLint rowAg0 = (rowA[j] >> 5) & 0x1f;
   1139          const GLint rowAg1 = (rowA[k] >> 5) & 0x1f;
   1140          const GLint rowBg0 = (rowB[j] >> 5) & 0x1f;
   1141          const GLint rowBg1 = (rowB[k] >> 5) & 0x1f;
   1142          const GLint rowCg0 = (rowC[j] >> 5) & 0x1f;
   1143          const GLint rowCg1 = (rowC[k] >> 5) & 0x1f;
   1144          const GLint rowDg0 = (rowD[j] >> 5) & 0x1f;
   1145          const GLint rowDg1 = (rowD[k] >> 5) & 0x1f;
   1146          const GLint rowAb0 = (rowA[j] >> 10) & 0x1f;
   1147          const GLint rowAb1 = (rowA[k] >> 10) & 0x1f;
   1148          const GLint rowBb0 = (rowB[j] >> 10) & 0x1f;
   1149          const GLint rowBb1 = (rowB[k] >> 10) & 0x1f;
   1150          const GLint rowCb0 = (rowC[j] >> 10) & 0x1f;
   1151          const GLint rowCb1 = (rowC[k] >> 10) & 0x1f;
   1152          const GLint rowDb0 = (rowD[j] >> 10) & 0x1f;
   1153          const GLint rowDb1 = (rowD[k] >> 10) & 0x1f;
   1154          const GLint rowAa0 = (rowA[j] >> 15) & 0x1;
   1155          const GLint rowAa1 = (rowA[k] >> 15) & 0x1;
   1156          const GLint rowBa0 = (rowB[j] >> 15) & 0x1;
   1157          const GLint rowBa1 = (rowB[k] >> 15) & 0x1;
   1158          const GLint rowCa0 = (rowC[j] >> 15) & 0x1;
   1159          const GLint rowCa1 = (rowC[k] >> 15) & 0x1;
   1160          const GLint rowDa0 = (rowD[j] >> 15) & 0x1;
   1161          const GLint rowDa1 = (rowD[k] >> 15) & 0x1;
   1162          const GLint r = FILTER_SUM_3D(rowAr0, rowAr1, rowBr0, rowBr1,
   1163                                        rowCr0, rowCr1, rowDr0, rowDr1);
   1164          const GLint g = FILTER_SUM_3D(rowAg0, rowAg1, rowBg0, rowBg1,
   1165                                        rowCg0, rowCg1, rowDg0, rowDg1);
   1166          const GLint b = FILTER_SUM_3D(rowAb0, rowAb1, rowBb0, rowBb1,
   1167                                        rowCb0, rowCb1, rowDb0, rowDb1);
   1168          const GLint a = FILTER_SUM_3D(rowAa0, rowAa1, rowBa0, rowBa1,
   1169                                        rowCa0, rowCa1, rowDa0, rowDa1);
   1170 
   1171          dst[i] = (a << 15) | (b << 10) | (g << 5) | r;
   1172       }
   1173    }
   1174    else if ((datatype == GL_UNSIGNED_SHORT_5_5_5_1) && (comps == 4)) {
   1175       DECLARE_ROW_POINTERS0(GLushort);
   1176 
   1177       for (i = j = 0, k = k0; i < (GLuint) dstWidth;
   1178            i++, j += colStride, k += colStride) {
   1179          const GLint rowAr0 = (rowA[j] >> 11) & 0x1f;
   1180          const GLint rowAr1 = (rowA[k] >> 11) & 0x1f;
   1181          const GLint rowBr0 = (rowB[j] >> 11) & 0x1f;
   1182          const GLint rowBr1 = (rowB[k] >> 11) & 0x1f;
   1183          const GLint rowCr0 = (rowC[j] >> 11) & 0x1f;
   1184          const GLint rowCr1 = (rowC[k] >> 11) & 0x1f;
   1185          const GLint rowDr0 = (rowD[j] >> 11) & 0x1f;
   1186          const GLint rowDr1 = (rowD[k] >> 11) & 0x1f;
   1187          const GLint rowAg0 = (rowA[j] >> 6) & 0x1f;
   1188          const GLint rowAg1 = (rowA[k] >> 6) & 0x1f;
   1189          const GLint rowBg0 = (rowB[j] >> 6) & 0x1f;
   1190          const GLint rowBg1 = (rowB[k] >> 6) & 0x1f;
   1191          const GLint rowCg0 = (rowC[j] >> 6) & 0x1f;
   1192          const GLint rowCg1 = (rowC[k] >> 6) & 0x1f;
   1193          const GLint rowDg0 = (rowD[j] >> 6) & 0x1f;
   1194          const GLint rowDg1 = (rowD[k] >> 6) & 0x1f;
   1195          const GLint rowAb0 = (rowA[j] >> 1) & 0x1f;
   1196          const GLint rowAb1 = (rowA[k] >> 1) & 0x1f;
   1197          const GLint rowBb0 = (rowB[j] >> 1) & 0x1f;
   1198          const GLint rowBb1 = (rowB[k] >> 1) & 0x1f;
   1199          const GLint rowCb0 = (rowC[j] >> 1) & 0x1f;
   1200          const GLint rowCb1 = (rowC[k] >> 1) & 0x1f;
   1201          const GLint rowDb0 = (rowD[j] >> 1) & 0x1f;
   1202          const GLint rowDb1 = (rowD[k] >> 1) & 0x1f;
   1203          const GLint rowAa0 = (rowA[j] & 0x1);
   1204          const GLint rowAa1 = (rowA[k] & 0x1);
   1205          const GLint rowBa0 = (rowB[j] & 0x1);
   1206          const GLint rowBa1 = (rowB[k] & 0x1);
   1207          const GLint rowCa0 = (rowC[j] & 0x1);
   1208          const GLint rowCa1 = (rowC[k] & 0x1);
   1209          const GLint rowDa0 = (rowD[j] & 0x1);
   1210          const GLint rowDa1 = (rowD[k] & 0x1);
   1211          const GLint r = FILTER_SUM_3D(rowAr0, rowAr1, rowBr0, rowBr1,
   1212                                        rowCr0, rowCr1, rowDr0, rowDr1);
   1213          const GLint g = FILTER_SUM_3D(rowAg0, rowAg1, rowBg0, rowBg1,
   1214                                        rowCg0, rowCg1, rowDg0, rowDg1);
   1215          const GLint b = FILTER_SUM_3D(rowAb0, rowAb1, rowBb0, rowBb1,
   1216                                        rowCb0, rowCb1, rowDb0, rowDb1);
   1217          const GLint a = FILTER_SUM_3D(rowAa0, rowAa1, rowBa0, rowBa1,
   1218                                        rowCa0, rowCa1, rowDa0, rowDa1);
   1219 
   1220          dst[i] = (r << 11) | (g << 6) | (b << 1) | a;
   1221       }
   1222    }
   1223    else if ((datatype == GL_UNSIGNED_BYTE_3_3_2) && (comps == 3)) {
   1224       DECLARE_ROW_POINTERS0(GLubyte);
   1225 
   1226       for (i = j = 0, k = k0; i < (GLuint) dstWidth;
   1227            i++, j += colStride, k += colStride) {
   1228          const GLint rowAr0 = rowA[j] & 0x3;
   1229          const GLint rowAr1 = rowA[k] & 0x3;
   1230          const GLint rowBr0 = rowB[j] & 0x3;
   1231          const GLint rowBr1 = rowB[k] & 0x3;
   1232          const GLint rowCr0 = rowC[j] & 0x3;
   1233          const GLint rowCr1 = rowC[k] & 0x3;
   1234          const GLint rowDr0 = rowD[j] & 0x3;
   1235          const GLint rowDr1 = rowD[k] & 0x3;
   1236          const GLint rowAg0 = (rowA[j] >> 2) & 0x7;
   1237          const GLint rowAg1 = (rowA[k] >> 2) & 0x7;
   1238          const GLint rowBg0 = (rowB[j] >> 2) & 0x7;
   1239          const GLint rowBg1 = (rowB[k] >> 2) & 0x7;
   1240          const GLint rowCg0 = (rowC[j] >> 2) & 0x7;
   1241          const GLint rowCg1 = (rowC[k] >> 2) & 0x7;
   1242          const GLint rowDg0 = (rowD[j] >> 2) & 0x7;
   1243          const GLint rowDg1 = (rowD[k] >> 2) & 0x7;
   1244          const GLint rowAb0 = (rowA[j] >> 5) & 0x7;
   1245          const GLint rowAb1 = (rowA[k] >> 5) & 0x7;
   1246          const GLint rowBb0 = (rowB[j] >> 5) & 0x7;
   1247          const GLint rowBb1 = (rowB[k] >> 5) & 0x7;
   1248          const GLint rowCb0 = (rowC[j] >> 5) & 0x7;
   1249          const GLint rowCb1 = (rowC[k] >> 5) & 0x7;
   1250          const GLint rowDb0 = (rowD[j] >> 5) & 0x7;
   1251          const GLint rowDb1 = (rowD[k] >> 5) & 0x7;
   1252          const GLint r = FILTER_SUM_3D(rowAr0, rowAr1, rowBr0, rowBr1,
   1253                                        rowCr0, rowCr1, rowDr0, rowDr1);
   1254          const GLint g = FILTER_SUM_3D(rowAg0, rowAg1, rowBg0, rowBg1,
   1255                                        rowCg0, rowCg1, rowDg0, rowDg1);
   1256          const GLint b = FILTER_SUM_3D(rowAb0, rowAb1, rowBb0, rowBb1,
   1257                                        rowCb0, rowCb1, rowDb0, rowDb1);
   1258          dst[i] = (b << 5) | (g << 2) | r;
   1259       }
   1260    }
   1261    else if (datatype == MESA_UNSIGNED_BYTE_4_4 && comps == 2) {
   1262       DECLARE_ROW_POINTERS0(GLubyte);
   1263 
   1264       for (i = j = 0, k = k0; i < (GLuint) dstWidth;
   1265            i++, j += colStride, k += colStride) {
   1266          const GLint rowAr0 = rowA[j] & 0xf;
   1267          const GLint rowAr1 = rowA[k] & 0xf;
   1268          const GLint rowBr0 = rowB[j] & 0xf;
   1269          const GLint rowBr1 = rowB[k] & 0xf;
   1270          const GLint rowCr0 = rowC[j] & 0xf;
   1271          const GLint rowCr1 = rowC[k] & 0xf;
   1272          const GLint rowDr0 = rowD[j] & 0xf;
   1273          const GLint rowDr1 = rowD[k] & 0xf;
   1274          const GLint rowAg0 = (rowA[j] >> 4) & 0xf;
   1275          const GLint rowAg1 = (rowA[k] >> 4) & 0xf;
   1276          const GLint rowBg0 = (rowB[j] >> 4) & 0xf;
   1277          const GLint rowBg1 = (rowB[k] >> 4) & 0xf;
   1278          const GLint rowCg0 = (rowC[j] >> 4) & 0xf;
   1279          const GLint rowCg1 = (rowC[k] >> 4) & 0xf;
   1280          const GLint rowDg0 = (rowD[j] >> 4) & 0xf;
   1281          const GLint rowDg1 = (rowD[k] >> 4) & 0xf;
   1282          const GLint r = FILTER_SUM_3D(rowAr0, rowAr1, rowBr0, rowBr1,
   1283                                        rowCr0, rowCr1, rowDr0, rowDr1);
   1284          const GLint g = FILTER_SUM_3D(rowAg0, rowAg1, rowBg0, rowBg1,
   1285                                        rowCg0, rowCg1, rowDg0, rowDg1);
   1286          dst[i] = (g << 4) | r;
   1287       }
   1288    }
   1289    else if ((datatype == GL_UNSIGNED_INT_2_10_10_10_REV) && (comps == 4)) {
   1290       DECLARE_ROW_POINTERS0(GLuint);
   1291 
   1292       for (i = j = 0, k = k0; i < (GLuint) dstWidth;
   1293            i++, j += colStride, k += colStride) {
   1294          const GLint rowAr0 = rowA[j] & 0x3ff;
   1295          const GLint rowAr1 = rowA[k] & 0x3ff;
   1296          const GLint rowBr0 = rowB[j] & 0x3ff;
   1297          const GLint rowBr1 = rowB[k] & 0x3ff;
   1298          const GLint rowCr0 = rowC[j] & 0x3ff;
   1299          const GLint rowCr1 = rowC[k] & 0x3ff;
   1300          const GLint rowDr0 = rowD[j] & 0x3ff;
   1301          const GLint rowDr1 = rowD[k] & 0x3ff;
   1302          const GLint rowAg0 = (rowA[j] >> 10) & 0x3ff;
   1303          const GLint rowAg1 = (rowA[k] >> 10) & 0x3ff;
   1304          const GLint rowBg0 = (rowB[j] >> 10) & 0x3ff;
   1305          const GLint rowBg1 = (rowB[k] >> 10) & 0x3ff;
   1306          const GLint rowCg0 = (rowC[j] >> 10) & 0x3ff;
   1307          const GLint rowCg1 = (rowC[k] >> 10) & 0x3ff;
   1308          const GLint rowDg0 = (rowD[j] >> 10) & 0x3ff;
   1309          const GLint rowDg1 = (rowD[k] >> 10) & 0x3ff;
   1310          const GLint rowAb0 = (rowA[j] >> 20) & 0x3ff;
   1311          const GLint rowAb1 = (rowA[k] >> 20) & 0x3ff;
   1312          const GLint rowBb0 = (rowB[j] >> 20) & 0x3ff;
   1313          const GLint rowBb1 = (rowB[k] >> 20) & 0x3ff;
   1314          const GLint rowCb0 = (rowC[j] >> 20) & 0x3ff;
   1315          const GLint rowCb1 = (rowC[k] >> 20) & 0x3ff;
   1316          const GLint rowDb0 = (rowD[j] >> 20) & 0x3ff;
   1317          const GLint rowDb1 = (rowD[k] >> 20) & 0x3ff;
   1318          const GLint rowAa0 = (rowA[j] >> 30) & 0x3;
   1319          const GLint rowAa1 = (rowA[k] >> 30) & 0x3;
   1320          const GLint rowBa0 = (rowB[j] >> 30) & 0x3;
   1321          const GLint rowBa1 = (rowB[k] >> 30) & 0x3;
   1322          const GLint rowCa0 = (rowC[j] >> 30) & 0x3;
   1323          const GLint rowCa1 = (rowC[k] >> 30) & 0x3;
   1324          const GLint rowDa0 = (rowD[j] >> 30) & 0x3;
   1325          const GLint rowDa1 = (rowD[k] >> 30) & 0x3;
   1326          const GLint r = FILTER_SUM_3D(rowAr0, rowAr1, rowBr0, rowBr1,
   1327                                        rowCr0, rowCr1, rowDr0, rowDr1);
   1328          const GLint g = FILTER_SUM_3D(rowAg0, rowAg1, rowBg0, rowBg1,
   1329                                        rowCg0, rowCg1, rowDg0, rowDg1);
   1330          const GLint b = FILTER_SUM_3D(rowAb0, rowAb1, rowBb0, rowBb1,
   1331                                        rowCb0, rowCb1, rowDb0, rowDb1);
   1332          const GLint a = FILTER_SUM_3D(rowAa0, rowAa1, rowBa0, rowBa1,
   1333                                        rowCa0, rowCa1, rowDa0, rowDa1);
   1334 
   1335          dst[i] = (a << 30) | (b << 20) | (g << 10) | r;
   1336       }
   1337    }
   1338 
   1339    else if (datatype == GL_UNSIGNED_INT_5_9_9_9_REV && comps == 3) {
   1340       DECLARE_ROW_POINTERS0(GLuint);
   1341 
   1342       GLfloat res[3];
   1343       GLfloat rowAj[3], rowBj[3], rowCj[3], rowDj[3];
   1344       GLfloat rowAk[3], rowBk[3], rowCk[3], rowDk[3];
   1345 
   1346       for (i = j = 0, k = k0; i < (GLuint) dstWidth;
   1347            i++, j += colStride, k += colStride) {
   1348          rgb9e5_to_float3(rowA[j], rowAj);
   1349          rgb9e5_to_float3(rowB[j], rowBj);
   1350          rgb9e5_to_float3(rowC[j], rowCj);
   1351          rgb9e5_to_float3(rowD[j], rowDj);
   1352          rgb9e5_to_float3(rowA[k], rowAk);
   1353          rgb9e5_to_float3(rowB[k], rowBk);
   1354          rgb9e5_to_float3(rowC[k], rowCk);
   1355          rgb9e5_to_float3(rowD[k], rowDk);
   1356          res[0] = (rowAj[0] + rowAk[0] + rowBj[0] + rowBk[0] +
   1357                    rowCj[0] + rowCk[0] + rowDj[0] + rowDk[0]) * 0.125F;
   1358          res[1] = (rowAj[1] + rowAk[1] + rowBj[1] + rowBk[1] +
   1359                    rowCj[1] + rowCk[1] + rowDj[1] + rowDk[1]) * 0.125F;
   1360          res[2] = (rowAj[2] + rowAk[2] + rowBj[2] + rowBk[2] +
   1361                    rowCj[2] + rowCk[2] + rowDj[2] + rowDk[2]) * 0.125F;
   1362          dst[i] = float3_to_rgb9e5(res);
   1363       }
   1364    }
   1365 
   1366    else if (datatype == GL_UNSIGNED_INT_10F_11F_11F_REV && comps == 3) {
   1367       DECLARE_ROW_POINTERS0(GLuint);
   1368 
   1369       GLfloat res[3];
   1370       GLfloat rowAj[3], rowBj[3], rowCj[3], rowDj[3];
   1371       GLfloat rowAk[3], rowBk[3], rowCk[3], rowDk[3];
   1372 
   1373       for (i = j = 0, k = k0; i < (GLuint) dstWidth;
   1374            i++, j += colStride, k += colStride) {
   1375          r11g11b10f_to_float3(rowA[j], rowAj);
   1376          r11g11b10f_to_float3(rowB[j], rowBj);
   1377          r11g11b10f_to_float3(rowC[j], rowCj);
   1378          r11g11b10f_to_float3(rowD[j], rowDj);
   1379          r11g11b10f_to_float3(rowA[k], rowAk);
   1380          r11g11b10f_to_float3(rowB[k], rowBk);
   1381          r11g11b10f_to_float3(rowC[k], rowCk);
   1382          r11g11b10f_to_float3(rowD[k], rowDk);
   1383          res[0] = (rowAj[0] + rowAk[0] + rowBj[0] + rowBk[0] +
   1384                    rowCj[0] + rowCk[0] + rowDj[0] + rowDk[0]) * 0.125F;
   1385          res[1] = (rowAj[1] + rowAk[1] + rowBj[1] + rowBk[1] +
   1386                    rowCj[1] + rowCk[1] + rowDj[1] + rowDk[1]) * 0.125F;
   1387          res[2] = (rowAj[2] + rowAk[2] + rowBj[2] + rowBk[2] +
   1388                    rowCj[2] + rowCk[2] + rowDj[2] + rowDk[2]) * 0.125F;
   1389          dst[i] = float3_to_r11g11b10f(res);
   1390       }
   1391    }
   1392 
   1393    else if (datatype == GL_FLOAT_32_UNSIGNED_INT_24_8_REV && comps == 1) {
   1394       DECLARE_ROW_POINTERS(GLfloat, 2);
   1395 
   1396       for (i = j = 0, k = k0; i < (GLuint) dstWidth;
   1397            i++, j += colStride, k += colStride) {
   1398          FILTER_F_3D(0);
   1399       }
   1400    }
   1401 
   1402    else {
   1403       _mesa_problem(NULL, "bad format in do_row()");
   1404    }
   1405 }
   1406 
   1407 
   1408 /*
   1409  * These functions generate a 1/2-size mipmap image from a source image.
   1410  * Texture borders are handled by copying or averaging the source image's
   1411  * border texels, depending on the scale-down factor.
   1412  */
   1413 
   1414 static void
   1415 make_1d_mipmap(GLenum datatype, GLuint comps, GLint border,
   1416                GLint srcWidth, const GLubyte *srcPtr,
   1417                GLint dstWidth, GLubyte *dstPtr)
   1418 {
   1419    const GLint bpt = bytes_per_pixel(datatype, comps);
   1420    const GLubyte *src;
   1421    GLubyte *dst;
   1422 
   1423    /* skip the border pixel, if any */
   1424    src = srcPtr + border * bpt;
   1425    dst = dstPtr + border * bpt;
   1426 
   1427    /* we just duplicate the input row, kind of hack, saves code */
   1428    do_row(datatype, comps, srcWidth - 2 * border, src, src,
   1429           dstWidth - 2 * border, dst);
   1430 
   1431    if (border) {
   1432       /* copy left-most pixel from source */
   1433       assert(dstPtr);
   1434       assert(srcPtr);
   1435       memcpy(dstPtr, srcPtr, bpt);
   1436       /* copy right-most pixel from source */
   1437       memcpy(dstPtr + (dstWidth - 1) * bpt,
   1438              srcPtr + (srcWidth - 1) * bpt,
   1439              bpt);
   1440    }
   1441 }
   1442 
   1443 
   1444 static void
   1445 make_2d_mipmap(GLenum datatype, GLuint comps, GLint border,
   1446                GLint srcWidth, GLint srcHeight,
   1447 	       const GLubyte *srcPtr, GLint srcRowStride,
   1448                GLint dstWidth, GLint dstHeight,
   1449 	       GLubyte *dstPtr, GLint dstRowStride)
   1450 {
   1451    const GLint bpt = bytes_per_pixel(datatype, comps);
   1452    const GLint srcWidthNB = srcWidth - 2 * border;  /* sizes w/out border */
   1453    const GLint dstWidthNB = dstWidth - 2 * border;
   1454    const GLint dstHeightNB = dstHeight - 2 * border;
   1455    const GLubyte *srcA, *srcB;
   1456    GLubyte *dst;
   1457    GLint row, srcRowStep;
   1458 
   1459    /* Compute src and dst pointers, skipping any border */
   1460    srcA = srcPtr + border * ((srcWidth + 1) * bpt);
   1461    if (srcHeight > 1 && srcHeight > dstHeight) {
   1462       /* sample from two source rows */
   1463       srcB = srcA + srcRowStride;
   1464       srcRowStep = 2;
   1465    }
   1466    else {
   1467       /* sample from one source row */
   1468       srcB = srcA;
   1469       srcRowStep = 1;
   1470    }
   1471 
   1472    dst = dstPtr + border * ((dstWidth + 1) * bpt);
   1473 
   1474    for (row = 0; row < dstHeightNB; row++) {
   1475       do_row(datatype, comps, srcWidthNB, srcA, srcB,
   1476              dstWidthNB, dst);
   1477       srcA += srcRowStep * srcRowStride;
   1478       srcB += srcRowStep * srcRowStride;
   1479       dst += dstRowStride;
   1480    }
   1481 
   1482    /* This is ugly but probably won't be used much */
   1483    if (border > 0) {
   1484       /* fill in dest border */
   1485       /* lower-left border pixel */
   1486       assert(dstPtr);
   1487       assert(srcPtr);
   1488       memcpy(dstPtr, srcPtr, bpt);
   1489       /* lower-right border pixel */
   1490       memcpy(dstPtr + (dstWidth - 1) * bpt,
   1491              srcPtr + (srcWidth - 1) * bpt, bpt);
   1492       /* upper-left border pixel */
   1493       memcpy(dstPtr + dstWidth * (dstHeight - 1) * bpt,
   1494              srcPtr + srcWidth * (srcHeight - 1) * bpt, bpt);
   1495       /* upper-right border pixel */
   1496       memcpy(dstPtr + (dstWidth * dstHeight - 1) * bpt,
   1497              srcPtr + (srcWidth * srcHeight - 1) * bpt, bpt);
   1498       /* lower border */
   1499       do_row(datatype, comps, srcWidthNB,
   1500              srcPtr + bpt,
   1501              srcPtr + bpt,
   1502              dstWidthNB, dstPtr + bpt);
   1503       /* upper border */
   1504       do_row(datatype, comps, srcWidthNB,
   1505              srcPtr + (srcWidth * (srcHeight - 1) + 1) * bpt,
   1506              srcPtr + (srcWidth * (srcHeight - 1) + 1) * bpt,
   1507              dstWidthNB,
   1508              dstPtr + (dstWidth * (dstHeight - 1) + 1) * bpt);
   1509       /* left and right borders */
   1510       if (srcHeight == dstHeight) {
   1511          /* copy border pixel from src to dst */
   1512          for (row = 1; row < srcHeight; row++) {
   1513             memcpy(dstPtr + dstWidth * row * bpt,
   1514                    srcPtr + srcWidth * row * bpt, bpt);
   1515             memcpy(dstPtr + (dstWidth * row + dstWidth - 1) * bpt,
   1516                    srcPtr + (srcWidth * row + srcWidth - 1) * bpt, bpt);
   1517          }
   1518       }
   1519       else {
   1520          /* average two src pixels each dest pixel */
   1521          for (row = 0; row < dstHeightNB; row += 2) {
   1522             do_row(datatype, comps, 1,
   1523                    srcPtr + (srcWidth * (row * 2 + 1)) * bpt,
   1524                    srcPtr + (srcWidth * (row * 2 + 2)) * bpt,
   1525                    1, dstPtr + (dstWidth * row + 1) * bpt);
   1526             do_row(datatype, comps, 1,
   1527                    srcPtr + (srcWidth * (row * 2 + 1) + srcWidth - 1) * bpt,
   1528                    srcPtr + (srcWidth * (row * 2 + 2) + srcWidth - 1) * bpt,
   1529                    1, dstPtr + (dstWidth * row + 1 + dstWidth - 1) * bpt);
   1530          }
   1531       }
   1532    }
   1533 }
   1534 
   1535 
   1536 static void
   1537 make_3d_mipmap(GLenum datatype, GLuint comps, GLint border,
   1538                GLint srcWidth, GLint srcHeight, GLint srcDepth,
   1539                const GLubyte **srcPtr, GLint srcRowStride,
   1540                GLint dstWidth, GLint dstHeight, GLint dstDepth,
   1541                GLubyte **dstPtr, GLint dstRowStride)
   1542 {
   1543    const GLint bpt = bytes_per_pixel(datatype, comps);
   1544    const GLint srcWidthNB = srcWidth - 2 * border;  /* sizes w/out border */
   1545    const GLint srcDepthNB = srcDepth - 2 * border;
   1546    const GLint dstWidthNB = dstWidth - 2 * border;
   1547    const GLint dstHeightNB = dstHeight - 2 * border;
   1548    const GLint dstDepthNB = dstDepth - 2 * border;
   1549    GLint img, row;
   1550    GLint bytesPerSrcImage, bytesPerDstImage;
   1551    GLint bytesPerSrcRow, bytesPerDstRow;
   1552    GLint srcImageOffset, srcRowOffset;
   1553 
   1554    (void) srcDepthNB; /* silence warnings */
   1555 
   1556 
   1557    bytesPerSrcImage = srcWidth * srcHeight * bpt;
   1558    bytesPerDstImage = dstWidth * dstHeight * bpt;
   1559 
   1560    bytesPerSrcRow = srcWidth * bpt;
   1561    bytesPerDstRow = dstWidth * bpt;
   1562 
   1563    /* Offset between adjacent src images to be averaged together */
   1564    srcImageOffset = (srcDepth == dstDepth) ? 0 : 1;
   1565 
   1566    /* Offset between adjacent src rows to be averaged together */
   1567    srcRowOffset = (srcHeight == dstHeight) ? 0 : srcWidth * bpt;
   1568 
   1569    /*
   1570     * Need to average together up to 8 src pixels for each dest pixel.
   1571     * Break that down into 3 operations:
   1572     *   1. take two rows from source image and average them together.
   1573     *   2. take two rows from next source image and average them together.
   1574     *   3. take the two averaged rows and average them for the final dst row.
   1575     */
   1576 
   1577    /*
   1578    printf("mip3d %d x %d x %d  ->  %d x %d x %d\n",
   1579           srcWidth, srcHeight, srcDepth, dstWidth, dstHeight, dstDepth);
   1580    */
   1581 
   1582    for (img = 0; img < dstDepthNB; img++) {
   1583       /* first source image pointer, skipping border */
   1584       const GLubyte *imgSrcA = srcPtr[img * 2 + border]
   1585          + bytesPerSrcRow * border + bpt * border;
   1586       /* second source image pointer, skipping border */
   1587       const GLubyte *imgSrcB = srcPtr[img * 2 + srcImageOffset + border]
   1588          + bytesPerSrcRow * border + bpt * border;
   1589 
   1590       /* address of the dest image, skipping border */
   1591       GLubyte *imgDst = dstPtr[img + border]
   1592          + bytesPerDstRow * border + bpt * border;
   1593 
   1594       /* setup the four source row pointers and the dest row pointer */
   1595       const GLubyte *srcImgARowA = imgSrcA;
   1596       const GLubyte *srcImgARowB = imgSrcA + srcRowOffset;
   1597       const GLubyte *srcImgBRowA = imgSrcB;
   1598       const GLubyte *srcImgBRowB = imgSrcB + srcRowOffset;
   1599       GLubyte *dstImgRow = imgDst;
   1600 
   1601       for (row = 0; row < dstHeightNB; row++) {
   1602          do_row_3D(datatype, comps, srcWidthNB,
   1603                    srcImgARowA, srcImgARowB,
   1604                    srcImgBRowA, srcImgBRowB,
   1605                    dstWidthNB, dstImgRow);
   1606 
   1607          /* advance to next rows */
   1608          srcImgARowA += bytesPerSrcRow + srcRowOffset;
   1609          srcImgARowB += bytesPerSrcRow + srcRowOffset;
   1610          srcImgBRowA += bytesPerSrcRow + srcRowOffset;
   1611          srcImgBRowB += bytesPerSrcRow + srcRowOffset;
   1612          dstImgRow += bytesPerDstRow;
   1613       }
   1614    }
   1615 
   1616 
   1617    /* Luckily we can leverage the make_2d_mipmap() function here! */
   1618    if (border > 0) {
   1619       /* do front border image */
   1620       make_2d_mipmap(datatype, comps, 1,
   1621                      srcWidth, srcHeight, srcPtr[0], srcRowStride,
   1622                      dstWidth, dstHeight, dstPtr[0], dstRowStride);
   1623       /* do back border image */
   1624       make_2d_mipmap(datatype, comps, 1,
   1625                      srcWidth, srcHeight, srcPtr[srcDepth - 1], srcRowStride,
   1626                      dstWidth, dstHeight, dstPtr[dstDepth - 1], dstRowStride);
   1627 
   1628       /* do four remaining border edges that span the image slices */
   1629       if (srcDepth == dstDepth) {
   1630          /* just copy border pixels from src to dst */
   1631          for (img = 0; img < dstDepthNB; img++) {
   1632             const GLubyte *src;
   1633             GLubyte *dst;
   1634 
   1635             /* do border along [img][row=0][col=0] */
   1636             src = srcPtr[img * 2];
   1637             dst = dstPtr[img];
   1638             memcpy(dst, src, bpt);
   1639 
   1640             /* do border along [img][row=dstHeight-1][col=0] */
   1641             src = srcPtr[img * 2] + (srcHeight - 1) * bytesPerSrcRow;
   1642             dst = dstPtr[img] + (dstHeight - 1) * bytesPerDstRow;
   1643             memcpy(dst, src, bpt);
   1644 
   1645             /* do border along [img][row=0][col=dstWidth-1] */
   1646             src = srcPtr[img * 2] + (srcWidth - 1) * bpt;
   1647             dst = dstPtr[img] + (dstWidth - 1) * bpt;
   1648             memcpy(dst, src, bpt);
   1649 
   1650             /* do border along [img][row=dstHeight-1][col=dstWidth-1] */
   1651             src = srcPtr[img * 2] + (bytesPerSrcImage - bpt);
   1652             dst = dstPtr[img] + (bytesPerDstImage - bpt);
   1653             memcpy(dst, src, bpt);
   1654          }
   1655       }
   1656       else {
   1657          /* average border pixels from adjacent src image pairs */
   1658          ASSERT(srcDepthNB == 2 * dstDepthNB);
   1659          for (img = 0; img < dstDepthNB; img++) {
   1660             const GLubyte *srcA, *srcB;
   1661             GLubyte *dst;
   1662 
   1663             /* do border along [img][row=0][col=0] */
   1664             srcA = srcPtr[img * 2 + 0];
   1665             srcB = srcPtr[img * 2 + srcImageOffset];
   1666             dst = dstPtr[img];
   1667             do_row(datatype, comps, 1, srcA, srcB, 1, dst);
   1668 
   1669             /* do border along [img][row=dstHeight-1][col=0] */
   1670             srcA = srcPtr[img * 2 + 0]
   1671                + (srcHeight - 1) * bytesPerSrcRow;
   1672             srcB = srcPtr[img * 2 + srcImageOffset]
   1673                + (srcHeight - 1) * bytesPerSrcRow;
   1674             dst = dstPtr[img] + (dstHeight - 1) * bytesPerDstRow;
   1675             do_row(datatype, comps, 1, srcA, srcB, 1, dst);
   1676 
   1677             /* do border along [img][row=0][col=dstWidth-1] */
   1678             srcA = srcPtr[img * 2 + 0] + (srcWidth - 1) * bpt;
   1679             srcB = srcPtr[img * 2 + srcImageOffset] + (srcWidth - 1) * bpt;
   1680             dst = dstPtr[img] + (dstWidth - 1) * bpt;
   1681             do_row(datatype, comps, 1, srcA, srcB, 1, dst);
   1682 
   1683             /* do border along [img][row=dstHeight-1][col=dstWidth-1] */
   1684             srcA = srcPtr[img * 2 + 0] + (bytesPerSrcImage - bpt);
   1685             srcB = srcPtr[img * 2 + srcImageOffset] + (bytesPerSrcImage - bpt);
   1686             dst = dstPtr[img] + (bytesPerDstImage - bpt);
   1687             do_row(datatype, comps, 1, srcA, srcB, 1, dst);
   1688          }
   1689       }
   1690    }
   1691 }
   1692 
   1693 
   1694 /**
   1695  * Down-sample a texture image to produce the next lower mipmap level.
   1696  * \param comps  components per texel (1, 2, 3 or 4)
   1697  * \param srcData  array[slice] of pointers to source image slices
   1698  * \param dstData  array[slice] of pointers to dest image slices
   1699  * \param srcRowStride  stride between source rows, in bytes
   1700  * \param dstRowStride  stride between destination rows, in bytes
   1701  */
   1702 void
   1703 _mesa_generate_mipmap_level(GLenum target,
   1704                             GLenum datatype, GLuint comps,
   1705                             GLint border,
   1706                             GLint srcWidth, GLint srcHeight, GLint srcDepth,
   1707                             const GLubyte **srcData,
   1708                             GLint srcRowStride,
   1709                             GLint dstWidth, GLint dstHeight, GLint dstDepth,
   1710                             GLubyte **dstData,
   1711                             GLint dstRowStride)
   1712 {
   1713    int i;
   1714 
   1715    switch (target) {
   1716    case GL_TEXTURE_1D:
   1717       make_1d_mipmap(datatype, comps, border,
   1718                      srcWidth, srcData[0],
   1719                      dstWidth, dstData[0]);
   1720       break;
   1721    case GL_TEXTURE_2D:
   1722    case GL_TEXTURE_CUBE_MAP_POSITIVE_X_ARB:
   1723    case GL_TEXTURE_CUBE_MAP_NEGATIVE_X_ARB:
   1724    case GL_TEXTURE_CUBE_MAP_POSITIVE_Y_ARB:
   1725    case GL_TEXTURE_CUBE_MAP_NEGATIVE_Y_ARB:
   1726    case GL_TEXTURE_CUBE_MAP_POSITIVE_Z_ARB:
   1727    case GL_TEXTURE_CUBE_MAP_NEGATIVE_Z_ARB:
   1728       make_2d_mipmap(datatype, comps, border,
   1729                      srcWidth, srcHeight, srcData[0], srcRowStride,
   1730                      dstWidth, dstHeight, dstData[0], dstRowStride);
   1731       break;
   1732    case GL_TEXTURE_3D:
   1733       make_3d_mipmap(datatype, comps, border,
   1734                      srcWidth, srcHeight, srcDepth,
   1735                      srcData, srcRowStride,
   1736                      dstWidth, dstHeight, dstDepth,
   1737                      dstData, dstRowStride);
   1738       break;
   1739    case GL_TEXTURE_1D_ARRAY_EXT:
   1740       assert(srcHeight == 1);
   1741       assert(dstHeight == 1);
   1742       for (i = 0; i < dstDepth; i++) {
   1743 	 make_1d_mipmap(datatype, comps, border,
   1744 			srcWidth, srcData[i],
   1745 			dstWidth, dstData[i]);
   1746       }
   1747       break;
   1748    case GL_TEXTURE_2D_ARRAY_EXT:
   1749       for (i = 0; i < dstDepth; i++) {
   1750 	 make_2d_mipmap(datatype, comps, border,
   1751 			srcWidth, srcHeight, srcData[i], srcRowStride,
   1752 			dstWidth, dstHeight, dstData[i], dstRowStride);
   1753       }
   1754       break;
   1755    case GL_TEXTURE_RECTANGLE_NV:
   1756    case GL_TEXTURE_EXTERNAL_OES:
   1757       /* no mipmaps, do nothing */
   1758       break;
   1759    default:
   1760       _mesa_problem(NULL, "bad tex target in _mesa_generate_mipmaps");
   1761       return;
   1762    }
   1763 }
   1764 
   1765 
   1766 /**
   1767  * compute next (level+1) image size
   1768  * \return GL_FALSE if no smaller size can be generated (eg. src is 1x1x1 size)
   1769  */
   1770 static GLboolean
   1771 next_mipmap_level_size(GLenum target, GLint border,
   1772                        GLint srcWidth, GLint srcHeight, GLint srcDepth,
   1773                        GLint *dstWidth, GLint *dstHeight, GLint *dstDepth)
   1774 {
   1775    if (srcWidth - 2 * border > 1) {
   1776       *dstWidth = (srcWidth - 2 * border) / 2 + 2 * border;
   1777    }
   1778    else {
   1779       *dstWidth = srcWidth; /* can't go smaller */
   1780    }
   1781 
   1782    if ((srcHeight - 2 * border > 1) &&
   1783        (target != GL_TEXTURE_1D_ARRAY_EXT)) {
   1784       *dstHeight = (srcHeight - 2 * border) / 2 + 2 * border;
   1785    }
   1786    else {
   1787       *dstHeight = srcHeight; /* can't go smaller */
   1788    }
   1789 
   1790    if ((srcDepth - 2 * border > 1) &&
   1791        (target != GL_TEXTURE_2D_ARRAY_EXT)) {
   1792       *dstDepth = (srcDepth - 2 * border) / 2 + 2 * border;
   1793    }
   1794    else {
   1795       *dstDepth = srcDepth; /* can't go smaller */
   1796    }
   1797 
   1798    if (*dstWidth == srcWidth &&
   1799        *dstHeight == srcHeight &&
   1800        *dstDepth == srcDepth) {
   1801       return GL_FALSE;
   1802    }
   1803    else {
   1804       return GL_TRUE;
   1805    }
   1806 }
   1807 
   1808 
   1809 /**
   1810  * Helper function for mipmap generation.
   1811  * Make sure the specified destination mipmap level is the right size/format
   1812  * for mipmap generation.  If not, (re) allocate it.
   1813  * \return GL_TRUE if successful, GL_FALSE if mipmap generation should stop
   1814  */
   1815 GLboolean
   1816 _mesa_prepare_mipmap_level(struct gl_context *ctx,
   1817                            struct gl_texture_object *texObj, GLuint level,
   1818                            GLsizei width, GLsizei height, GLsizei depth,
   1819                            GLsizei border, GLenum intFormat, gl_format format)
   1820 {
   1821    const GLuint numFaces = _mesa_num_tex_faces(texObj->Target);
   1822    GLuint face;
   1823 
   1824    if (texObj->Immutable) {
   1825       /* The texture was created with glTexStorage() so the number/size of
   1826        * mipmap levels is fixed and the storage for all images is already
   1827        * allocated.
   1828        */
   1829       if (!texObj->Image[0][level]) {
   1830          /* No more levels to create - we're done */
   1831          return GL_FALSE;
   1832       }
   1833       else {
   1834          /* Nothing to do - the texture memory must have already been
   1835           * allocated to the right size so we're all set.
   1836           */
   1837          return GL_TRUE;
   1838       }
   1839    }
   1840 
   1841    for (face = 0; face < numFaces; face++) {
   1842       struct gl_texture_image *dstImage;
   1843       GLenum target;
   1844 
   1845       if (numFaces == 1)
   1846          target = texObj->Target;
   1847       else
   1848          target = GL_TEXTURE_CUBE_MAP_POSITIVE_X + face;
   1849 
   1850       dstImage = _mesa_get_tex_image(ctx, texObj, target, level);
   1851       if (!dstImage) {
   1852          /* out of memory */
   1853          return GL_FALSE;
   1854       }
   1855 
   1856       if (dstImage->Width != width ||
   1857           dstImage->Height != height ||
   1858           dstImage->Depth != depth ||
   1859           dstImage->Border != border ||
   1860           dstImage->InternalFormat != intFormat ||
   1861           dstImage->TexFormat != format) {
   1862          /* need to (re)allocate image */
   1863          ctx->Driver.FreeTextureImageBuffer(ctx, dstImage);
   1864 
   1865          _mesa_init_teximage_fields(ctx, dstImage,
   1866                                     width, height, depth,
   1867                                     border, intFormat, format);
   1868 
   1869          ctx->Driver.AllocTextureImageBuffer(ctx, dstImage);
   1870 
   1871          /* in case the mipmap level is part of an FBO: */
   1872          _mesa_update_fbo_texture(ctx, texObj, face, level);
   1873 
   1874          ctx->NewState |= _NEW_TEXTURE;
   1875       }
   1876    }
   1877 
   1878    return GL_TRUE;
   1879 }
   1880 
   1881 
   1882 static void
   1883 generate_mipmap_uncompressed(struct gl_context *ctx, GLenum target,
   1884 			     struct gl_texture_object *texObj,
   1885 			     const struct gl_texture_image *srcImage,
   1886 			     GLuint maxLevel)
   1887 {
   1888    GLint level;
   1889    GLenum datatype;
   1890    GLuint comps;
   1891 
   1892    _mesa_format_to_type_and_comps(srcImage->TexFormat, &datatype, &comps);
   1893 
   1894    for (level = texObj->BaseLevel; level < maxLevel; level++) {
   1895       /* generate image[level+1] from image[level] */
   1896       struct gl_texture_image *srcImage, *dstImage;
   1897       GLint srcRowStride, dstRowStride;
   1898       GLint srcWidth, srcHeight, srcDepth;
   1899       GLint dstWidth, dstHeight, dstDepth;
   1900       GLint border;
   1901       GLint slice;
   1902       GLboolean nextLevel;
   1903       GLubyte **srcMaps, **dstMaps;
   1904       GLboolean success = GL_TRUE;
   1905 
   1906       /* get src image parameters */
   1907       srcImage = _mesa_select_tex_image(ctx, texObj, target, level);
   1908       ASSERT(srcImage);
   1909       srcWidth = srcImage->Width;
   1910       srcHeight = srcImage->Height;
   1911       srcDepth = srcImage->Depth;
   1912       border = srcImage->Border;
   1913 
   1914       nextLevel = next_mipmap_level_size(target, border,
   1915                                          srcWidth, srcHeight, srcDepth,
   1916                                          &dstWidth, &dstHeight, &dstDepth);
   1917       if (!nextLevel)
   1918          return;
   1919 
   1920       if (!_mesa_prepare_mipmap_level(ctx, texObj, level + 1,
   1921                                       dstWidth, dstHeight, dstDepth,
   1922                                       border, srcImage->InternalFormat,
   1923                                       srcImage->TexFormat)) {
   1924          return;
   1925       }
   1926 
   1927       /* get dest gl_texture_image */
   1928       dstImage = _mesa_get_tex_image(ctx, texObj, target, level + 1);
   1929       if (!dstImage) {
   1930          _mesa_error(ctx, GL_OUT_OF_MEMORY, "generating mipmaps");
   1931          return;
   1932       }
   1933 
   1934       if (target == GL_TEXTURE_1D_ARRAY) {
   1935 	 srcDepth = srcHeight;
   1936 	 dstDepth = dstHeight;
   1937 	 srcHeight = 1;
   1938 	 dstHeight = 1;
   1939       }
   1940 
   1941       /* Map src texture image slices */
   1942       srcMaps = (GLubyte **) calloc(srcDepth, sizeof(GLubyte *));
   1943       if (srcMaps) {
   1944          for (slice = 0; slice < srcDepth; slice++) {
   1945             ctx->Driver.MapTextureImage(ctx, srcImage, slice,
   1946                                         0, 0, srcWidth, srcHeight,
   1947                                         GL_MAP_READ_BIT,
   1948                                         &srcMaps[slice], &srcRowStride);
   1949             if (!srcMaps[slice]) {
   1950                success = GL_FALSE;
   1951                break;
   1952             }
   1953          }
   1954       }
   1955       else {
   1956          success = GL_FALSE;
   1957       }
   1958 
   1959       /* Map dst texture image slices */
   1960       dstMaps = (GLubyte **) calloc(dstDepth, sizeof(GLubyte *));
   1961       if (dstMaps) {
   1962          for (slice = 0; slice < dstDepth; slice++) {
   1963             ctx->Driver.MapTextureImage(ctx, dstImage, slice,
   1964                                         0, 0, dstWidth, dstHeight,
   1965                                         GL_MAP_WRITE_BIT,
   1966                                         &dstMaps[slice], &dstRowStride);
   1967             if (!dstMaps[slice]) {
   1968                success = GL_FALSE;
   1969                break;
   1970             }
   1971          }
   1972       }
   1973       else {
   1974          success = GL_FALSE;
   1975       }
   1976 
   1977       if (success) {
   1978          /* generate one mipmap level (for 1D/2D/3D/array/etc texture) */
   1979          _mesa_generate_mipmap_level(target, datatype, comps, border,
   1980                                      srcWidth, srcHeight, srcDepth,
   1981                                      (const GLubyte **) srcMaps, srcRowStride,
   1982                                      dstWidth, dstHeight, dstDepth,
   1983                                      dstMaps, dstRowStride);
   1984       }
   1985 
   1986       /* Unmap src image slices */
   1987       if (srcMaps) {
   1988          for (slice = 0; slice < srcDepth; slice++) {
   1989             if (srcMaps[slice]) {
   1990                ctx->Driver.UnmapTextureImage(ctx, srcImage, slice);
   1991             }
   1992          }
   1993          free(srcMaps);
   1994       }
   1995 
   1996       /* Unmap dst image slices */
   1997       if (dstMaps) {
   1998          for (slice = 0; slice < dstDepth; slice++) {
   1999             if (dstMaps[slice]) {
   2000                ctx->Driver.UnmapTextureImage(ctx, dstImage, slice);
   2001             }
   2002          }
   2003          free(dstMaps);
   2004       }
   2005 
   2006       if (!success) {
   2007          _mesa_error(ctx, GL_OUT_OF_MEMORY, "mipmap generation");
   2008          break;
   2009       }
   2010    } /* loop over mipmap levels */
   2011 }
   2012 
   2013 
   2014 static void
   2015 generate_mipmap_compressed(struct gl_context *ctx, GLenum target,
   2016 			   struct gl_texture_object *texObj,
   2017 			   struct gl_texture_image *srcImage,
   2018 			   GLuint maxLevel)
   2019 {
   2020    GLint level;
   2021    gl_format temp_format;
   2022    GLint components;
   2023    GLuint temp_src_stride; /* in bytes */
   2024    GLubyte *temp_src = NULL, *temp_dst = NULL;
   2025    GLenum temp_datatype;
   2026    GLenum temp_base_format;
   2027 
   2028    /* only two types of compressed textures at this time */
   2029    assert(texObj->Target == GL_TEXTURE_2D ||
   2030 	  texObj->Target == GL_TEXTURE_CUBE_MAP_ARB);
   2031 
   2032    /*
   2033     * Choose a format for the temporary, uncompressed base image.
   2034     * Then, get number of components, choose temporary image datatype,
   2035     * and get base format.
   2036     */
   2037    temp_format = _mesa_get_uncompressed_format(srcImage->TexFormat);
   2038 
   2039    components = _mesa_format_num_components(temp_format);
   2040 
   2041    /* Revisit this if we get compressed formats with >8 bits per component */
   2042    if (_mesa_get_format_datatype(srcImage->TexFormat)
   2043        == GL_SIGNED_NORMALIZED) {
   2044       temp_datatype = GL_BYTE;
   2045    }
   2046    else {
   2047       temp_datatype = GL_UNSIGNED_BYTE;
   2048    }
   2049 
   2050    temp_base_format = _mesa_get_format_base_format(temp_format);
   2051 
   2052 
   2053    /* allocate storage for the temporary, uncompressed image */
   2054    /* 20 extra bytes, just be safe when calling last FetchTexel */
   2055    temp_src_stride = _mesa_format_row_stride(temp_format, srcImage->Width);
   2056    temp_src = (GLubyte *) malloc(temp_src_stride * srcImage->Height + 20);
   2057    if (!temp_src) {
   2058       _mesa_error(ctx, GL_OUT_OF_MEMORY, "generate mipmaps");
   2059       return;
   2060    }
   2061 
   2062    /* decompress base image to the temporary */
   2063    {
   2064       /* save pixel packing mode */
   2065       struct gl_pixelstore_attrib save = ctx->Pack;
   2066       /* use default/tight packing parameters */
   2067       ctx->Pack = ctx->DefaultPacking;
   2068 
   2069       /* Get the uncompressed image */
   2070       assert(srcImage->Level == texObj->BaseLevel);
   2071       ctx->Driver.GetTexImage(ctx,
   2072                               temp_base_format, temp_datatype,
   2073                               temp_src, srcImage);
   2074       /* restore packing mode */
   2075       ctx->Pack = save;
   2076    }
   2077 
   2078 
   2079    for (level = texObj->BaseLevel; level < maxLevel; level++) {
   2080       /* generate image[level+1] from image[level] */
   2081       const struct gl_texture_image *srcImage;
   2082       struct gl_texture_image *dstImage;
   2083       GLint srcWidth, srcHeight, srcDepth;
   2084       GLint dstWidth, dstHeight, dstDepth;
   2085       GLint border;
   2086       GLboolean nextLevel;
   2087       GLuint temp_dst_stride; /* in bytes */
   2088 
   2089       /* get src image parameters */
   2090       srcImage = _mesa_select_tex_image(ctx, texObj, target, level);
   2091       ASSERT(srcImage);
   2092       srcWidth = srcImage->Width;
   2093       srcHeight = srcImage->Height;
   2094       srcDepth = srcImage->Depth;
   2095       border = srcImage->Border;
   2096 
   2097       nextLevel = next_mipmap_level_size(target, border,
   2098                                          srcWidth, srcHeight, srcDepth,
   2099                                          &dstWidth, &dstHeight, &dstDepth);
   2100       if (!nextLevel)
   2101 	 break;
   2102 
   2103       temp_dst_stride = _mesa_format_row_stride(temp_format, dstWidth);
   2104       if (!temp_dst) {
   2105 	 temp_dst = (GLubyte *) malloc(temp_dst_stride * dstHeight);
   2106 	 if (!temp_dst) {
   2107 	    _mesa_error(ctx, GL_OUT_OF_MEMORY, "generate mipmaps");
   2108 	    break;
   2109 	 }
   2110       }
   2111 
   2112       /* get dest gl_texture_image */
   2113       dstImage = _mesa_get_tex_image(ctx, texObj, target, level + 1);
   2114       if (!dstImage) {
   2115          _mesa_error(ctx, GL_OUT_OF_MEMORY, "generating mipmaps");
   2116          free(temp_dst);
   2117          return;
   2118       }
   2119 
   2120       /* rescale src image to dest image */
   2121       _mesa_generate_mipmap_level(target, temp_datatype, components, border,
   2122                                   srcWidth, srcHeight, srcDepth,
   2123                                   (const GLubyte **) &temp_src,
   2124                                   temp_src_stride,
   2125                                   dstWidth, dstHeight, dstDepth,
   2126                                   &temp_dst, temp_dst_stride);
   2127 
   2128       if (!_mesa_prepare_mipmap_level(ctx, texObj, level + 1,
   2129                                       dstWidth, dstHeight, dstDepth,
   2130                                       border, srcImage->InternalFormat,
   2131                                       srcImage->TexFormat)) {
   2132          free(temp_dst);
   2133          return;
   2134       }
   2135 
   2136       /* The image space was allocated above so use glTexSubImage now */
   2137       ctx->Driver.TexSubImage(ctx, 2, dstImage,
   2138                               0, 0, 0, dstWidth, dstHeight, 1,
   2139                               temp_base_format, temp_datatype,
   2140                               temp_dst, &ctx->DefaultPacking);
   2141 
   2142       /* swap src and dest pointers */
   2143       {
   2144 	 GLubyte *temp = temp_src;
   2145 	 temp_src = temp_dst;
   2146 	 temp_dst = temp;
   2147 	 temp_src_stride = temp_dst_stride;
   2148       }
   2149    } /* loop over mipmap levels */
   2150 
   2151    free(temp_src);
   2152    free(temp_dst);
   2153 }
   2154 
   2155 /**
   2156  * Automatic mipmap generation.
   2157  * This is the fallback/default function for ctx->Driver.GenerateMipmap().
   2158  * Generate a complete set of mipmaps from texObj's BaseLevel image.
   2159  * Stop at texObj's MaxLevel or when we get to the 1x1 texture.
   2160  * For cube maps, target will be one of
   2161  * GL_TEXTURE_CUBE_MAP_POSITIVE/NEGATIVE_X/Y/Z; never GL_TEXTURE_CUBE_MAP.
   2162  */
   2163 void
   2164 _mesa_generate_mipmap(struct gl_context *ctx, GLenum target,
   2165                       struct gl_texture_object *texObj)
   2166 {
   2167    struct gl_texture_image *srcImage;
   2168    GLint maxLevel;
   2169 
   2170    ASSERT(texObj);
   2171    srcImage = _mesa_select_tex_image(ctx, texObj, target, texObj->BaseLevel);
   2172    ASSERT(srcImage);
   2173 
   2174    maxLevel = _mesa_max_texture_levels(ctx, texObj->Target) - 1;
   2175    ASSERT(maxLevel >= 0);  /* bad target */
   2176 
   2177    maxLevel = MIN2(maxLevel, texObj->MaxLevel);
   2178 
   2179    if (_mesa_is_format_compressed(srcImage->TexFormat)) {
   2180       generate_mipmap_compressed(ctx, target, texObj, srcImage, maxLevel);
   2181    } else {
   2182       generate_mipmap_uncompressed(ctx, target, texObj, srcImage, maxLevel);
   2183    }
   2184 }
   2185