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      1 /*
      2  * Mesa 3-D graphics library
      3  * Version:  6.2
      4  *
      5  * Copyright (C) 1999-2004  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  * New (3.1) transformation code written by Keith Whitwell.
     27  */
     28 
     29 
     30 /* KW: a clever asm implementation would nestle integer versions
     31  * of the outcode calculation underneath the division.  Gcc won't
     32  * do this, strangely enough, so I only do the divide in
     33  * the case where the cliptest passes.  This isn't essential,
     34  * and an asm implementation needn't replicate that behaviour.
     35  *
     36  * \param clip_vec vector of incoming clip-space coords
     37  * \param proj_vec vector of resultant NDC-space projected coords
     38  * \param clipMask resulting array of clip flags
     39  * \param orMask bitwise-OR of clipMask values
     40  * \param andMask bitwise-AND of clipMask values
     41  * \return proj_vec pointer
     42  */
     43 static GLvector4f * _XFORMAPI TAG(cliptest_points4)( GLvector4f *clip_vec,
     44                                                      GLvector4f *proj_vec,
     45                                                      GLubyte clipMask[],
     46                                                      GLubyte *orMask,
     47                                                      GLubyte *andMask,
     48 						     GLboolean viewport_z_clip )
     49 {
     50    const GLuint stride = clip_vec->stride;
     51    const GLfloat *from = (GLfloat *)clip_vec->start;
     52    const GLuint count = clip_vec->count;
     53    GLuint c = 0;
     54    GLfloat (*vProj)[4] = (GLfloat (*)[4])proj_vec->start;
     55    GLubyte tmpAndMask = *andMask;
     56    GLubyte tmpOrMask = *orMask;
     57    GLuint i;
     58    STRIDE_LOOP {
     59       const GLfloat cx = from[0];
     60       const GLfloat cy = from[1];
     61       const GLfloat cz = from[2];
     62       const GLfloat cw = from[3];
     63 #if defined(macintosh) || defined(__powerpc__)
     64       /* on powerpc cliptest is 17% faster in this way. */
     65       GLuint mask;
     66       mask = (((cw < cx) << CLIP_RIGHT_SHIFT));
     67       mask |= (((cw < -cx) << CLIP_LEFT_SHIFT));
     68       mask |= (((cw < cy) << CLIP_TOP_SHIFT));
     69       mask |= (((cw < -cy) << CLIP_BOTTOM_SHIFT));
     70       if (viewport_z_clip) {
     71 	 mask |= (((cw < cz) << CLIP_FAR_SHIFT));
     72 	 mask |= (((cw < -cz) << CLIP_NEAR_SHIFT));
     73       }
     74 #else /* !defined(macintosh)) */
     75       GLubyte mask = 0;
     76       if (-cx + cw < 0) mask |= CLIP_RIGHT_BIT;
     77       if ( cx + cw < 0) mask |= CLIP_LEFT_BIT;
     78       if (-cy + cw < 0) mask |= CLIP_TOP_BIT;
     79       if ( cy + cw < 0) mask |= CLIP_BOTTOM_BIT;
     80       if (viewport_z_clip) {
     81 	 if (-cz + cw < 0) mask |= CLIP_FAR_BIT;
     82 	 if ( cz + cw < 0) mask |= CLIP_NEAR_BIT;
     83       }
     84 #endif /* defined(macintosh) */
     85 
     86       clipMask[i] = mask;
     87       if (mask) {
     88 	 c++;
     89 	 tmpAndMask &= mask;
     90 	 tmpOrMask |= mask;
     91 	 vProj[i][0] = 0;
     92 	 vProj[i][1] = 0;
     93 	 vProj[i][2] = 0;
     94 	 vProj[i][3] = 1;
     95       } else {
     96 	 GLfloat oow = 1.0F / cw;
     97 	 vProj[i][0] = cx * oow;
     98 	 vProj[i][1] = cy * oow;
     99 	 vProj[i][2] = cz * oow;
    100 	 vProj[i][3] = oow;
    101       }
    102    }
    103 
    104    *orMask = tmpOrMask;
    105    *andMask = (GLubyte) (c < count ? 0 : tmpAndMask);
    106 
    107    proj_vec->flags |= VEC_SIZE_4;
    108    proj_vec->size = 4;
    109    proj_vec->count = clip_vec->count;
    110    return proj_vec;
    111 }
    112 
    113 
    114 
    115 /*
    116  * \param clip_vec vector of incoming clip-space coords
    117  * \param proj_vec vector of resultant NDC-space projected coords
    118  * \param clipMask resulting array of clip flags
    119  * \param orMask bitwise-OR of clipMask values
    120  * \param andMask bitwise-AND of clipMask values
    121  * \return clip_vec pointer
    122  */
    123 static GLvector4f * _XFORMAPI TAG(cliptest_np_points4)( GLvector4f *clip_vec,
    124 							GLvector4f *proj_vec,
    125 							GLubyte clipMask[],
    126 							GLubyte *orMask,
    127 							GLubyte *andMask,
    128 							GLboolean viewport_z_clip )
    129 {
    130    const GLuint stride = clip_vec->stride;
    131    const GLuint count = clip_vec->count;
    132    const GLfloat *from = (GLfloat *)clip_vec->start;
    133    GLuint c = 0;
    134    GLubyte tmpAndMask = *andMask;
    135    GLubyte tmpOrMask = *orMask;
    136    GLuint i;
    137    (void) proj_vec;
    138    STRIDE_LOOP {
    139       const GLfloat cx = from[0];
    140       const GLfloat cy = from[1];
    141       const GLfloat cz = from[2];
    142       const GLfloat cw = from[3];
    143 #if defined(macintosh) || defined(__powerpc__)
    144       /* on powerpc cliptest is 17% faster in this way. */
    145       GLuint mask;
    146       mask = (((cw < cx) << CLIP_RIGHT_SHIFT));
    147       mask |= (((cw < -cx) << CLIP_LEFT_SHIFT));
    148       mask |= (((cw < cy) << CLIP_TOP_SHIFT));
    149       mask |= (((cw < -cy) << CLIP_BOTTOM_SHIFT));
    150       if (viewport_z_clip) {
    151 	 mask |= (((cw < cz) << CLIP_FAR_SHIFT));
    152 	 mask |= (((cw < -cz) << CLIP_NEAR_SHIFT));
    153       }
    154 #else /* !defined(macintosh)) */
    155       GLubyte mask = 0;
    156       if (-cx + cw < 0) mask |= CLIP_RIGHT_BIT;
    157       if ( cx + cw < 0) mask |= CLIP_LEFT_BIT;
    158       if (-cy + cw < 0) mask |= CLIP_TOP_BIT;
    159       if ( cy + cw < 0) mask |= CLIP_BOTTOM_BIT;
    160       if (viewport_z_clip) {
    161 	 if (-cz + cw < 0) mask |= CLIP_FAR_BIT;
    162 	 if ( cz + cw < 0) mask |= CLIP_NEAR_BIT;
    163       }
    164 #endif /* defined(macintosh) */
    165 
    166       clipMask[i] = mask;
    167       if (mask) {
    168 	 c++;
    169 	 tmpAndMask &= mask;
    170 	 tmpOrMask |= mask;
    171       }
    172    }
    173 
    174    *orMask = tmpOrMask;
    175    *andMask = (GLubyte) (c < count ? 0 : tmpAndMask);
    176    return clip_vec;
    177 }
    178 
    179 
    180 static GLvector4f * _XFORMAPI TAG(cliptest_points3)( GLvector4f *clip_vec,
    181                                                      GLvector4f *proj_vec,
    182                                                      GLubyte clipMask[],
    183                                                      GLubyte *orMask,
    184                                                      GLubyte *andMask,
    185 						     GLboolean viewport_z_clip )
    186 {
    187    const GLuint stride = clip_vec->stride;
    188    const GLuint count = clip_vec->count;
    189    const GLfloat *from = (GLfloat *)clip_vec->start;
    190    GLubyte tmpOrMask = *orMask;
    191    GLubyte tmpAndMask = *andMask;
    192    GLuint i;
    193    (void) proj_vec;
    194    STRIDE_LOOP {
    195       const GLfloat cx = from[0], cy = from[1], cz = from[2];
    196       GLubyte mask = 0;
    197       if (cx >  1.0)       mask |= CLIP_RIGHT_BIT;
    198       else if (cx < -1.0)  mask |= CLIP_LEFT_BIT;
    199       if (cy >  1.0)       mask |= CLIP_TOP_BIT;
    200       else if (cy < -1.0)  mask |= CLIP_BOTTOM_BIT;
    201       if (viewport_z_clip) {
    202 	 if (cz >  1.0)       mask |= CLIP_FAR_BIT;
    203 	 else if (cz < -1.0)  mask |= CLIP_NEAR_BIT;
    204       }
    205       clipMask[i] = mask;
    206       tmpOrMask |= mask;
    207       tmpAndMask &= mask;
    208    }
    209 
    210    *orMask = tmpOrMask;
    211    *andMask = tmpAndMask;
    212    return clip_vec;
    213 }
    214 
    215 
    216 static GLvector4f * _XFORMAPI TAG(cliptest_points2)( GLvector4f *clip_vec,
    217                                                      GLvector4f *proj_vec,
    218                                                      GLubyte clipMask[],
    219                                                      GLubyte *orMask,
    220                                                      GLubyte *andMask,
    221 						     GLboolean viewport_z_clip )
    222 {
    223    const GLuint stride = clip_vec->stride;
    224    const GLuint count = clip_vec->count;
    225    const GLfloat *from = (GLfloat *)clip_vec->start;
    226    GLubyte tmpOrMask = *orMask;
    227    GLubyte tmpAndMask = *andMask;
    228    GLuint i;
    229    (void) proj_vec;
    230    STRIDE_LOOP {
    231       const GLfloat cx = from[0], cy = from[1];
    232       GLubyte mask = 0;
    233       if (cx >  1.0)       mask |= CLIP_RIGHT_BIT;
    234       else if (cx < -1.0)  mask |= CLIP_LEFT_BIT;
    235       if (cy >  1.0)       mask |= CLIP_TOP_BIT;
    236       else if (cy < -1.0)  mask |= CLIP_BOTTOM_BIT;
    237       clipMask[i] = mask;
    238       tmpOrMask |= mask;
    239       tmpAndMask &= mask;
    240    }
    241 
    242    *orMask = tmpOrMask;
    243    *andMask = tmpAndMask;
    244    return clip_vec;
    245 }
    246 
    247 
    248 void TAG(init_c_cliptest)( void )
    249 {
    250    _mesa_clip_tab[4] = TAG(cliptest_points4);
    251    _mesa_clip_tab[3] = TAG(cliptest_points3);
    252    _mesa_clip_tab[2] = TAG(cliptest_points2);
    253 
    254    _mesa_clip_np_tab[4] = TAG(cliptest_np_points4);
    255    _mesa_clip_np_tab[3] = TAG(cliptest_points3);
    256    _mesa_clip_np_tab[2] = TAG(cliptest_points2);
    257 }
    258