Home | History | Annotate | Download | only in main
      1 /**
      2  * \file macros.h
      3  * A collection of useful macros.
      4  */
      5 
      6 /*
      7  * Mesa 3-D graphics library
      8  * Version:  6.5.2
      9  *
     10  * Copyright (C) 1999-2006  Brian Paul   All Rights Reserved.
     11  *
     12  * Permission is hereby granted, free of charge, to any person obtaining a
     13  * copy of this software and associated documentation files (the "Software"),
     14  * to deal in the Software without restriction, including without limitation
     15  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
     16  * and/or sell copies of the Software, and to permit persons to whom the
     17  * Software is furnished to do so, subject to the following conditions:
     18  *
     19  * The above copyright notice and this permission notice shall be included
     20  * in all copies or substantial portions of the Software.
     21  *
     22  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
     23  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
     24  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
     25  * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
     26  * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
     27  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
     28  */
     29 
     30 
     31 #ifndef MACROS_H
     32 #define MACROS_H
     33 
     34 #include "imports.h"
     35 
     36 
     37 /**
     38  * \name Integer / float conversion for colors, normals, etc.
     39  */
     40 /*@{*/
     41 
     42 /** Convert GLubyte in [0,255] to GLfloat in [0.0,1.0] */
     43 extern GLfloat _mesa_ubyte_to_float_color_tab[256];
     44 #define UBYTE_TO_FLOAT(u) _mesa_ubyte_to_float_color_tab[(unsigned int)(u)]
     45 
     46 /** Convert GLfloat in [0.0,1.0] to GLubyte in [0,255] */
     47 #define FLOAT_TO_UBYTE(X)   ((GLubyte) (GLint) ((X) * 255.0F))
     48 
     49 
     50 /** Convert GLbyte in [-128,127] to GLfloat in [-1.0,1.0] */
     51 #define BYTE_TO_FLOAT(B)    ((2.0F * (B) + 1.0F) * (1.0F/255.0F))
     52 
     53 /** Convert GLfloat in [-1.0,1.0] to GLbyte in [-128,127] */
     54 #define FLOAT_TO_BYTE(X)    ( (((GLint) (255.0F * (X))) - 1) / 2 )
     55 
     56 
     57 /** Convert GLbyte to GLfloat while preserving zero */
     58 #define BYTE_TO_FLOATZ(B)   ((B) == 0 ? 0.0F : BYTE_TO_FLOAT(B))
     59 
     60 
     61 /** Convert GLbyte in [-128,127] to GLfloat in [-1.0,1.0], texture/fb data */
     62 #define BYTE_TO_FLOAT_TEX(B)    ((B) == -128 ? -1.0F : (B) * (1.0F/127.0F))
     63 
     64 /** Convert GLfloat in [-1.0,1.0] to GLbyte in [-128,127], texture/fb data */
     65 #define FLOAT_TO_BYTE_TEX(X)    CLAMP( (GLint) (127.0F * (X)), -128, 127 )
     66 
     67 /** Convert GLushort in [0,65535] to GLfloat in [0.0,1.0] */
     68 #define USHORT_TO_FLOAT(S)  ((GLfloat) (S) * (1.0F / 65535.0F))
     69 
     70 /** Convert GLfloat in [0.0,1.0] to GLushort in [0, 65535] */
     71 #define FLOAT_TO_USHORT(X)   ((GLuint) ((X) * 65535.0F))
     72 
     73 
     74 /** Convert GLshort in [-32768,32767] to GLfloat in [-1.0,1.0] */
     75 #define SHORT_TO_FLOAT(S)   ((2.0F * (S) + 1.0F) * (1.0F/65535.0F))
     76 
     77 /** Convert GLfloat in [-1.0,1.0] to GLshort in [-32768,32767] */
     78 #define FLOAT_TO_SHORT(X)   ( (((GLint) (65535.0F * (X))) - 1) / 2 )
     79 
     80 /** Convert GLshort to GLfloat while preserving zero */
     81 #define SHORT_TO_FLOATZ(S)   ((S) == 0 ? 0.0F : SHORT_TO_FLOAT(S))
     82 
     83 
     84 /** Convert GLshort in [-32768,32767] to GLfloat in [-1.0,1.0], texture/fb data */
     85 #define SHORT_TO_FLOAT_TEX(S)    ((S) == -32768 ? -1.0F : (S) * (1.0F/32767.0F))
     86 
     87 /** Convert GLfloat in [-1.0,1.0] to GLshort in [-32768,32767], texture/fb data */
     88 #define FLOAT_TO_SHORT_TEX(X)    ( (GLint) (32767.0F * (X)) )
     89 
     90 
     91 /** Convert GLuint in [0,4294967295] to GLfloat in [0.0,1.0] */
     92 #define UINT_TO_FLOAT(U)    ((GLfloat) ((U) * (1.0F / 4294967295.0)))
     93 
     94 /** Convert GLfloat in [0.0,1.0] to GLuint in [0,4294967295] */
     95 #define FLOAT_TO_UINT(X)    ((GLuint) ((X) * 4294967295.0))
     96 
     97 
     98 /** Convert GLint in [-2147483648,2147483647] to GLfloat in [-1.0,1.0] */
     99 #define INT_TO_FLOAT(I)     ((GLfloat) ((2.0F * (I) + 1.0F) * (1.0F/4294967294.0)))
    100 
    101 /** Convert GLfloat in [-1.0,1.0] to GLint in [-2147483648,2147483647] */
    102 /* causes overflow:
    103 #define FLOAT_TO_INT(X)     ( (((GLint) (4294967294.0 * (X))) - 1) / 2 )
    104 */
    105 /* a close approximation: */
    106 #define FLOAT_TO_INT(X)     ( (GLint) (2147483647.0 * (X)) )
    107 
    108 /** Convert GLfloat in [-1.0,1.0] to GLint64 in [-(1<<63),(1 << 63) -1] */
    109 #define FLOAT_TO_INT64(X)     ( (GLint64) (9223372036854775807.0 * (double)(X)) )
    110 
    111 
    112 /** Convert GLint in [-2147483648,2147483647] to GLfloat in [-1.0,1.0], texture/fb data */
    113 #define INT_TO_FLOAT_TEX(I)    ((I) == -2147483648 ? -1.0F : (I) * (1.0F/2147483647.0))
    114 
    115 /** Convert GLfloat in [-1.0,1.0] to GLint in [-2147483648,2147483647], texture/fb data */
    116 #define FLOAT_TO_INT_TEX(X)    ( (GLint) (2147483647.0 * (X)) )
    117 
    118 
    119 #define BYTE_TO_UBYTE(b)   ((GLubyte) ((b) < 0 ? 0 : (GLubyte) (b)))
    120 #define SHORT_TO_UBYTE(s)  ((GLubyte) ((s) < 0 ? 0 : (GLubyte) ((s) >> 7)))
    121 #define USHORT_TO_UBYTE(s) ((GLubyte) ((s) >> 8))
    122 #define INT_TO_UBYTE(i)    ((GLubyte) ((i) < 0 ? 0 : (GLubyte) ((i) >> 23)))
    123 #define UINT_TO_UBYTE(i)   ((GLubyte) ((i) >> 24))
    124 
    125 
    126 #define BYTE_TO_USHORT(b)  ((b) < 0 ? 0 : ((GLushort) (((b) * 65535) / 255)))
    127 #define UBYTE_TO_USHORT(b) (((GLushort) (b) << 8) | (GLushort) (b))
    128 #define SHORT_TO_USHORT(s) ((s) < 0 ? 0 : ((GLushort) (((s) * 65535 / 32767))))
    129 #define INT_TO_USHORT(i)   ((i) < 0 ? 0 : ((GLushort) ((i) >> 15)))
    130 #define UINT_TO_USHORT(i)  ((i) < 0 ? 0 : ((GLushort) ((i) >> 16)))
    131 #define UNCLAMPED_FLOAT_TO_USHORT(us, f)  \
    132         us = ( (GLushort) F_TO_I( CLAMP((f), 0.0F, 1.0F) * 65535.0F) )
    133 #define CLAMPED_FLOAT_TO_USHORT(us, f)  \
    134         us = ( (GLushort) F_TO_I( (f) * 65535.0F) )
    135 
    136 #define UNCLAMPED_FLOAT_TO_SHORT(s, f)  \
    137         s = ( (GLshort) F_TO_I( CLAMP((f), -1.0F, 1.0F) * 32767.0F) )
    138 
    139 /***
    140  *** UNCLAMPED_FLOAT_TO_UBYTE: clamp float to [0,1] and map to ubyte in [0,255]
    141  *** CLAMPED_FLOAT_TO_UBYTE: map float known to be in [0,1] to ubyte in [0,255]
    142  ***/
    143 #if defined(USE_IEEE) && !defined(DEBUG)
    144 #define IEEE_0996 0x3f7f0000	/* 0.996 or so */
    145 /* This function/macro is sensitive to precision.  Test very carefully
    146  * if you change it!
    147  */
    148 #define UNCLAMPED_FLOAT_TO_UBYTE(UB, F)					\
    149         do {								\
    150            fi_type __tmp;						\
    151            __tmp.f = (F);						\
    152            if (__tmp.i < 0)						\
    153               UB = (GLubyte) 0;						\
    154            else if (__tmp.i >= IEEE_0996)				\
    155               UB = (GLubyte) 255;					\
    156            else {							\
    157               __tmp.f = __tmp.f * (255.0F/256.0F) + 32768.0F;		\
    158               UB = (GLubyte) __tmp.i;					\
    159            }								\
    160         } while (0)
    161 #define CLAMPED_FLOAT_TO_UBYTE(UB, F)					\
    162         do {								\
    163            fi_type __tmp;						\
    164            __tmp.f = (F) * (255.0F/256.0F) + 32768.0F;			\
    165            UB = (GLubyte) __tmp.i;					\
    166         } while (0)
    167 #else
    168 #define UNCLAMPED_FLOAT_TO_UBYTE(ub, f) \
    169 	ub = ((GLubyte) F_TO_I(CLAMP((f), 0.0F, 1.0F) * 255.0F))
    170 #define CLAMPED_FLOAT_TO_UBYTE(ub, f) \
    171 	ub = ((GLubyte) F_TO_I((f) * 255.0F))
    172 #endif
    173 
    174 static inline GLfloat INT_AS_FLT(GLint i)
    175 {
    176    fi_type tmp;
    177    tmp.i = i;
    178    return tmp.f;
    179 }
    180 
    181 static inline GLfloat UINT_AS_FLT(GLuint u)
    182 {
    183    fi_type tmp;
    184    tmp.u = u;
    185    return tmp.f;
    186 }
    187 
    188 /*@}*/
    189 
    190 
    191 /** Stepping a GLfloat pointer by a byte stride */
    192 #define STRIDE_F(p, i)  (p = (GLfloat *)((GLubyte *)p + i))
    193 /** Stepping a GLuint pointer by a byte stride */
    194 #define STRIDE_UI(p, i)  (p = (GLuint *)((GLubyte *)p + i))
    195 /** Stepping a GLubyte[4] pointer by a byte stride */
    196 #define STRIDE_4UB(p, i)  (p = (GLubyte (*)[4])((GLubyte *)p + i))
    197 /** Stepping a GLfloat[4] pointer by a byte stride */
    198 #define STRIDE_4F(p, i)  (p = (GLfloat (*)[4])((GLubyte *)p + i))
    199 /** Stepping a \p t pointer by a byte stride */
    200 #define STRIDE_T(p, t, i)  (p = (t)((GLubyte *)p + i))
    201 
    202 
    203 /**********************************************************************/
    204 /** \name 4-element vector operations */
    205 /*@{*/
    206 
    207 /** Zero */
    208 #define ZERO_4V( DST )  (DST)[0] = (DST)[1] = (DST)[2] = (DST)[3] = 0
    209 
    210 /** Test for equality */
    211 #define TEST_EQ_4V(a,b)  ((a)[0] == (b)[0] &&   \
    212               (a)[1] == (b)[1] &&   \
    213               (a)[2] == (b)[2] &&   \
    214               (a)[3] == (b)[3])
    215 
    216 /** Test for equality (unsigned bytes) */
    217 static inline GLboolean
    218 TEST_EQ_4UBV(const GLubyte a[4], const GLubyte b[4])
    219 {
    220 #if defined(__i386__)
    221    return *((const GLuint *) a) == *((const GLuint *) b);
    222 #else
    223    return TEST_EQ_4V(a, b);
    224 #endif
    225 }
    226 
    227 
    228 /** Copy a 4-element vector */
    229 #define COPY_4V( DST, SRC )         \
    230 do {                                \
    231    (DST)[0] = (SRC)[0];             \
    232    (DST)[1] = (SRC)[1];             \
    233    (DST)[2] = (SRC)[2];             \
    234    (DST)[3] = (SRC)[3];             \
    235 } while (0)
    236 
    237 /** Copy a 4-element unsigned byte vector */
    238 static inline void
    239 COPY_4UBV(GLubyte dst[4], const GLubyte src[4])
    240 {
    241 #if defined(__i386__)
    242    *((GLuint *) dst) = *((GLuint *) src);
    243 #else
    244    /* The GLuint cast might fail if DST or SRC are not dword-aligned (RISC) */
    245    COPY_4V(dst, src);
    246 #endif
    247 }
    248 
    249 /** Copy a 4-element float vector */
    250 static inline void
    251 COPY_4FV(GLfloat dst[4], const GLfloat src[4])
    252 {
    253    /* memcpy seems to be most efficient */
    254    memcpy(dst, src, sizeof(GLfloat) * 4);
    255 }
    256 
    257 /** Copy \p SZ elements into a 4-element vector */
    258 #define COPY_SZ_4V(DST, SZ, SRC)  \
    259 do {                              \
    260    switch (SZ) {                  \
    261    case 4: (DST)[3] = (SRC)[3];   \
    262    case 3: (DST)[2] = (SRC)[2];   \
    263    case 2: (DST)[1] = (SRC)[1];   \
    264    case 1: (DST)[0] = (SRC)[0];   \
    265    }                              \
    266 } while(0)
    267 
    268 /** Copy \p SZ elements into a homegeneous (4-element) vector, giving
    269  * default values to the remaining */
    270 #define COPY_CLEAN_4V(DST, SZ, SRC)  \
    271 do {                                 \
    272       ASSIGN_4V( DST, 0, 0, 0, 1 );  \
    273       COPY_SZ_4V( DST, SZ, SRC );    \
    274 } while (0)
    275 
    276 /** Subtraction */
    277 #define SUB_4V( DST, SRCA, SRCB )           \
    278 do {                                        \
    279       (DST)[0] = (SRCA)[0] - (SRCB)[0];     \
    280       (DST)[1] = (SRCA)[1] - (SRCB)[1];     \
    281       (DST)[2] = (SRCA)[2] - (SRCB)[2];     \
    282       (DST)[3] = (SRCA)[3] - (SRCB)[3];     \
    283 } while (0)
    284 
    285 /** Addition */
    286 #define ADD_4V( DST, SRCA, SRCB )           \
    287 do {                                        \
    288       (DST)[0] = (SRCA)[0] + (SRCB)[0];     \
    289       (DST)[1] = (SRCA)[1] + (SRCB)[1];     \
    290       (DST)[2] = (SRCA)[2] + (SRCB)[2];     \
    291       (DST)[3] = (SRCA)[3] + (SRCB)[3];     \
    292 } while (0)
    293 
    294 /** Element-wise multiplication */
    295 #define SCALE_4V( DST, SRCA, SRCB )         \
    296 do {                                        \
    297       (DST)[0] = (SRCA)[0] * (SRCB)[0];     \
    298       (DST)[1] = (SRCA)[1] * (SRCB)[1];     \
    299       (DST)[2] = (SRCA)[2] * (SRCB)[2];     \
    300       (DST)[3] = (SRCA)[3] * (SRCB)[3];     \
    301 } while (0)
    302 
    303 /** In-place addition */
    304 #define ACC_4V( DST, SRC )          \
    305 do {                                \
    306       (DST)[0] += (SRC)[0];         \
    307       (DST)[1] += (SRC)[1];         \
    308       (DST)[2] += (SRC)[2];         \
    309       (DST)[3] += (SRC)[3];         \
    310 } while (0)
    311 
    312 /** Element-wise multiplication and addition */
    313 #define ACC_SCALE_4V( DST, SRCA, SRCB )     \
    314 do {                                        \
    315       (DST)[0] += (SRCA)[0] * (SRCB)[0];    \
    316       (DST)[1] += (SRCA)[1] * (SRCB)[1];    \
    317       (DST)[2] += (SRCA)[2] * (SRCB)[2];    \
    318       (DST)[3] += (SRCA)[3] * (SRCB)[3];    \
    319 } while (0)
    320 
    321 /** In-place scalar multiplication and addition */
    322 #define ACC_SCALE_SCALAR_4V( DST, S, SRCB ) \
    323 do {                                        \
    324       (DST)[0] += S * (SRCB)[0];            \
    325       (DST)[1] += S * (SRCB)[1];            \
    326       (DST)[2] += S * (SRCB)[2];            \
    327       (DST)[3] += S * (SRCB)[3];            \
    328 } while (0)
    329 
    330 /** Scalar multiplication */
    331 #define SCALE_SCALAR_4V( DST, S, SRCB ) \
    332 do {                                    \
    333       (DST)[0] = S * (SRCB)[0];         \
    334       (DST)[1] = S * (SRCB)[1];         \
    335       (DST)[2] = S * (SRCB)[2];         \
    336       (DST)[3] = S * (SRCB)[3];         \
    337 } while (0)
    338 
    339 /** In-place scalar multiplication */
    340 #define SELF_SCALE_SCALAR_4V( DST, S ) \
    341 do {                                   \
    342       (DST)[0] *= S;                   \
    343       (DST)[1] *= S;                   \
    344       (DST)[2] *= S;                   \
    345       (DST)[3] *= S;                   \
    346 } while (0)
    347 
    348 /** Assignment */
    349 #define ASSIGN_4V( V, V0, V1, V2, V3 )  \
    350 do {                                    \
    351     V[0] = V0;                          \
    352     V[1] = V1;                          \
    353     V[2] = V2;                          \
    354     V[3] = V3;                          \
    355 } while(0)
    356 
    357 /*@}*/
    358 
    359 
    360 /**********************************************************************/
    361 /** \name 3-element vector operations*/
    362 /*@{*/
    363 
    364 /** Zero */
    365 #define ZERO_3V( DST )  (DST)[0] = (DST)[1] = (DST)[2] = 0
    366 
    367 /** Test for equality */
    368 #define TEST_EQ_3V(a,b)  \
    369    ((a)[0] == (b)[0] &&  \
    370     (a)[1] == (b)[1] &&  \
    371     (a)[2] == (b)[2])
    372 
    373 /** Copy a 3-element vector */
    374 #define COPY_3V( DST, SRC )         \
    375 do {                                \
    376    (DST)[0] = (SRC)[0];             \
    377    (DST)[1] = (SRC)[1];             \
    378    (DST)[2] = (SRC)[2];             \
    379 } while (0)
    380 
    381 /** Copy a 3-element vector with cast */
    382 #define COPY_3V_CAST( DST, SRC, CAST )  \
    383 do {                                    \
    384    (DST)[0] = (CAST)(SRC)[0];           \
    385    (DST)[1] = (CAST)(SRC)[1];           \
    386    (DST)[2] = (CAST)(SRC)[2];           \
    387 } while (0)
    388 
    389 /** Copy a 3-element float vector */
    390 #define COPY_3FV( DST, SRC )        \
    391 do {                                \
    392    const GLfloat *_tmp = (SRC);     \
    393    (DST)[0] = _tmp[0];              \
    394    (DST)[1] = _tmp[1];              \
    395    (DST)[2] = _tmp[2];              \
    396 } while (0)
    397 
    398 /** Subtraction */
    399 #define SUB_3V( DST, SRCA, SRCB )        \
    400 do {                                     \
    401       (DST)[0] = (SRCA)[0] - (SRCB)[0];  \
    402       (DST)[1] = (SRCA)[1] - (SRCB)[1];  \
    403       (DST)[2] = (SRCA)[2] - (SRCB)[2];  \
    404 } while (0)
    405 
    406 /** Addition */
    407 #define ADD_3V( DST, SRCA, SRCB )       \
    408 do {                                    \
    409       (DST)[0] = (SRCA)[0] + (SRCB)[0]; \
    410       (DST)[1] = (SRCA)[1] + (SRCB)[1]; \
    411       (DST)[2] = (SRCA)[2] + (SRCB)[2]; \
    412 } while (0)
    413 
    414 /** In-place scalar multiplication */
    415 #define SCALE_3V( DST, SRCA, SRCB )     \
    416 do {                                    \
    417       (DST)[0] = (SRCA)[0] * (SRCB)[0]; \
    418       (DST)[1] = (SRCA)[1] * (SRCB)[1]; \
    419       (DST)[2] = (SRCA)[2] * (SRCB)[2]; \
    420 } while (0)
    421 
    422 /** In-place element-wise multiplication */
    423 #define SELF_SCALE_3V( DST, SRC )   \
    424 do {                                \
    425       (DST)[0] *= (SRC)[0];         \
    426       (DST)[1] *= (SRC)[1];         \
    427       (DST)[2] *= (SRC)[2];         \
    428 } while (0)
    429 
    430 /** In-place addition */
    431 #define ACC_3V( DST, SRC )          \
    432 do {                                \
    433       (DST)[0] += (SRC)[0];         \
    434       (DST)[1] += (SRC)[1];         \
    435       (DST)[2] += (SRC)[2];         \
    436 } while (0)
    437 
    438 /** Element-wise multiplication and addition */
    439 #define ACC_SCALE_3V( DST, SRCA, SRCB )     \
    440 do {                                        \
    441       (DST)[0] += (SRCA)[0] * (SRCB)[0];    \
    442       (DST)[1] += (SRCA)[1] * (SRCB)[1];    \
    443       (DST)[2] += (SRCA)[2] * (SRCB)[2];    \
    444 } while (0)
    445 
    446 /** Scalar multiplication */
    447 #define SCALE_SCALAR_3V( DST, S, SRCB ) \
    448 do {                                    \
    449       (DST)[0] = S * (SRCB)[0];         \
    450       (DST)[1] = S * (SRCB)[1];         \
    451       (DST)[2] = S * (SRCB)[2];         \
    452 } while (0)
    453 
    454 /** In-place scalar multiplication and addition */
    455 #define ACC_SCALE_SCALAR_3V( DST, S, SRCB ) \
    456 do {                                        \
    457       (DST)[0] += S * (SRCB)[0];            \
    458       (DST)[1] += S * (SRCB)[1];            \
    459       (DST)[2] += S * (SRCB)[2];            \
    460 } while (0)
    461 
    462 /** In-place scalar multiplication */
    463 #define SELF_SCALE_SCALAR_3V( DST, S ) \
    464 do {                                   \
    465       (DST)[0] *= S;                   \
    466       (DST)[1] *= S;                   \
    467       (DST)[2] *= S;                   \
    468 } while (0)
    469 
    470 /** In-place scalar addition */
    471 #define ACC_SCALAR_3V( DST, S )     \
    472 do {                                \
    473       (DST)[0] += S;                \
    474       (DST)[1] += S;                \
    475       (DST)[2] += S;                \
    476 } while (0)
    477 
    478 /** Assignment */
    479 #define ASSIGN_3V( V, V0, V1, V2 )  \
    480 do {                                \
    481     V[0] = V0;                      \
    482     V[1] = V1;                      \
    483     V[2] = V2;                      \
    484 } while(0)
    485 
    486 /*@}*/
    487 
    488 
    489 /**********************************************************************/
    490 /** \name 2-element vector operations*/
    491 /*@{*/
    492 
    493 /** Zero */
    494 #define ZERO_2V( DST )  (DST)[0] = (DST)[1] = 0
    495 
    496 /** Copy a 2-element vector */
    497 #define COPY_2V( DST, SRC )         \
    498 do {                        \
    499    (DST)[0] = (SRC)[0];             \
    500    (DST)[1] = (SRC)[1];             \
    501 } while (0)
    502 
    503 /** Copy a 2-element vector with cast */
    504 #define COPY_2V_CAST( DST, SRC, CAST )      \
    505 do {                        \
    506    (DST)[0] = (CAST)(SRC)[0];           \
    507    (DST)[1] = (CAST)(SRC)[1];           \
    508 } while (0)
    509 
    510 /** Copy a 2-element float vector */
    511 #define COPY_2FV( DST, SRC )            \
    512 do {                        \
    513    const GLfloat *_tmp = (SRC);         \
    514    (DST)[0] = _tmp[0];              \
    515    (DST)[1] = _tmp[1];              \
    516 } while (0)
    517 
    518 /** Subtraction */
    519 #define SUB_2V( DST, SRCA, SRCB )       \
    520 do {                        \
    521       (DST)[0] = (SRCA)[0] - (SRCB)[0];     \
    522       (DST)[1] = (SRCA)[1] - (SRCB)[1];     \
    523 } while (0)
    524 
    525 /** Addition */
    526 #define ADD_2V( DST, SRCA, SRCB )       \
    527 do {                        \
    528       (DST)[0] = (SRCA)[0] + (SRCB)[0];     \
    529       (DST)[1] = (SRCA)[1] + (SRCB)[1];     \
    530 } while (0)
    531 
    532 /** In-place scalar multiplication */
    533 #define SCALE_2V( DST, SRCA, SRCB )     \
    534 do {                        \
    535       (DST)[0] = (SRCA)[0] * (SRCB)[0];     \
    536       (DST)[1] = (SRCA)[1] * (SRCB)[1];     \
    537 } while (0)
    538 
    539 /** In-place addition */
    540 #define ACC_2V( DST, SRC )          \
    541 do {                        \
    542       (DST)[0] += (SRC)[0];         \
    543       (DST)[1] += (SRC)[1];         \
    544 } while (0)
    545 
    546 /** Element-wise multiplication and addition */
    547 #define ACC_SCALE_2V( DST, SRCA, SRCB )     \
    548 do {                        \
    549       (DST)[0] += (SRCA)[0] * (SRCB)[0];    \
    550       (DST)[1] += (SRCA)[1] * (SRCB)[1];    \
    551 } while (0)
    552 
    553 /** Scalar multiplication */
    554 #define SCALE_SCALAR_2V( DST, S, SRCB )     \
    555 do {                        \
    556       (DST)[0] = S * (SRCB)[0];         \
    557       (DST)[1] = S * (SRCB)[1];         \
    558 } while (0)
    559 
    560 /** In-place scalar multiplication and addition */
    561 #define ACC_SCALE_SCALAR_2V( DST, S, SRCB ) \
    562 do {                        \
    563       (DST)[0] += S * (SRCB)[0];        \
    564       (DST)[1] += S * (SRCB)[1];        \
    565 } while (0)
    566 
    567 /** In-place scalar multiplication */
    568 #define SELF_SCALE_SCALAR_2V( DST, S )      \
    569 do {                        \
    570       (DST)[0] *= S;                \
    571       (DST)[1] *= S;                \
    572 } while (0)
    573 
    574 /** In-place scalar addition */
    575 #define ACC_SCALAR_2V( DST, S )         \
    576 do {                        \
    577       (DST)[0] += S;                \
    578       (DST)[1] += S;                \
    579 } while (0)
    580 
    581 /** Assign scalers to short vectors */
    582 #define ASSIGN_2V( V, V0, V1 )	\
    583 do {				\
    584     V[0] = V0;			\
    585     V[1] = V1;			\
    586 } while(0)
    587 
    588 /*@}*/
    589 
    590 /** Copy \p sz elements into a homegeneous (4-element) vector, giving
    591  * default values to the remaining components.
    592  * The default values are chosen based on \p type.
    593  */
    594 static inline void
    595 COPY_CLEAN_4V_TYPE_AS_FLOAT(GLfloat dst[4], int sz, const GLfloat src[4],
    596                             GLenum type)
    597 {
    598    switch (type) {
    599    case GL_FLOAT:
    600       ASSIGN_4V(dst, 0, 0, 0, 1);
    601       break;
    602    case GL_INT:
    603       ASSIGN_4V(dst, INT_AS_FLT(0), INT_AS_FLT(0),
    604                      INT_AS_FLT(0), INT_AS_FLT(1));
    605       break;
    606    case GL_UNSIGNED_INT:
    607       ASSIGN_4V(dst, UINT_AS_FLT(0), UINT_AS_FLT(0),
    608                      UINT_AS_FLT(0), UINT_AS_FLT(1));
    609       break;
    610    default:
    611       ASSERT(0);
    612    }
    613    COPY_SZ_4V(dst, sz, src);
    614 }
    615 
    616 /** \name Linear interpolation functions */
    617 /*@{*/
    618 
    619 static inline GLfloat
    620 LINTERP(GLfloat t, GLfloat out, GLfloat in)
    621 {
    622    return out + t * (in - out);
    623 }
    624 
    625 static inline void
    626 INTERP_3F(GLfloat t, GLfloat dst[3], const GLfloat out[3], const GLfloat in[3])
    627 {
    628    dst[0] = LINTERP( t, out[0], in[0] );
    629    dst[1] = LINTERP( t, out[1], in[1] );
    630    dst[2] = LINTERP( t, out[2], in[2] );
    631 }
    632 
    633 static inline void
    634 INTERP_4F(GLfloat t, GLfloat dst[4], const GLfloat out[4], const GLfloat in[4])
    635 {
    636    dst[0] = LINTERP( t, out[0], in[0] );
    637    dst[1] = LINTERP( t, out[1], in[1] );
    638    dst[2] = LINTERP( t, out[2], in[2] );
    639    dst[3] = LINTERP( t, out[3], in[3] );
    640 }
    641 
    642 /*@}*/
    643 
    644 
    645 
    646 /** Clamp X to [MIN,MAX] */
    647 #define CLAMP( X, MIN, MAX )  ( (X)<(MIN) ? (MIN) : ((X)>(MAX) ? (MAX) : (X)) )
    648 
    649 /** Minimum of two values: */
    650 #define MIN2( A, B )   ( (A)<(B) ? (A) : (B) )
    651 
    652 /** Maximum of two values: */
    653 #define MAX2( A, B )   ( (A)>(B) ? (A) : (B) )
    654 
    655 /** Minimum and maximum of three values: */
    656 #define MIN3( A, B, C ) ((A) < (B) ? MIN2(A, C) : MIN2(B, C))
    657 #define MAX3( A, B, C ) ((A) > (B) ? MAX2(A, C) : MAX2(B, C))
    658 
    659 
    660 
    661 /** Cross product of two 3-element vectors */
    662 static inline void
    663 CROSS3(GLfloat n[3], const GLfloat u[3], const GLfloat v[3])
    664 {
    665    n[0] = u[1] * v[2] - u[2] * v[1];
    666    n[1] = u[2] * v[0] - u[0] * v[2];
    667    n[2] = u[0] * v[1] - u[1] * v[0];
    668 }
    669 
    670 
    671 /** Dot product of two 2-element vectors */
    672 static inline GLfloat
    673 DOT2(const GLfloat a[2], const GLfloat b[2])
    674 {
    675    return a[0] * b[0] + a[1] * b[1];
    676 }
    677 
    678 static inline GLfloat
    679 DOT3(const GLfloat a[3], const GLfloat b[3])
    680 {
    681    return a[0] * b[0] + a[1] * b[1] + a[2] * b[2];
    682 }
    683 
    684 static inline GLfloat
    685 DOT4(const GLfloat a[4], const GLfloat b[4])
    686 {
    687    return a[0] * b[0] + a[1] * b[1] + a[2] * b[2] + a[3] * b[3];
    688 }
    689 
    690 
    691 static inline GLfloat
    692 LEN_SQUARED_3FV(const GLfloat v[3])
    693 {
    694    return DOT3(v, v);
    695 }
    696 
    697 static inline GLfloat
    698 LEN_SQUARED_2FV(const GLfloat v[2])
    699 {
    700    return DOT2(v, v);
    701 }
    702 
    703 
    704 static inline GLfloat
    705 LEN_3FV(const GLfloat v[3])
    706 {
    707    return SQRTF(LEN_SQUARED_3FV(v));
    708 }
    709 
    710 static inline GLfloat
    711 LEN_2FV(const GLfloat v[2])
    712 {
    713    return SQRTF(LEN_SQUARED_2FV(v));
    714 }
    715 
    716 
    717 /* Normalize a 3-element vector to unit length. */
    718 static inline void
    719 NORMALIZE_3FV(GLfloat v[3])
    720 {
    721    GLfloat len = (GLfloat) LEN_SQUARED_3FV(v);
    722    if (len) {
    723       len = INV_SQRTF(len);
    724       v[0] *= len;
    725       v[1] *= len;
    726       v[2] *= len;
    727    }
    728 }
    729 
    730 
    731 /** Compute ceiling of integer quotient of A divided by B. */
    732 #define CEILING( A, B )  ( (A) % (B) == 0 ? (A)/(B) : (A)/(B)+1 )
    733 
    734 
    735 /** casts to silence warnings with some compilers */
    736 #define ENUM_TO_INT(E)     ((GLint)(E))
    737 #define ENUM_TO_FLOAT(E)   ((GLfloat)(GLint)(E))
    738 #define ENUM_TO_DOUBLE(E)  ((GLdouble)(GLint)(E))
    739 #define ENUM_TO_BOOLEAN(E) ((E) ? GL_TRUE : GL_FALSE)
    740 
    741 
    742 #endif
    743