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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 
INT_AS_FLT(GLint i)174 static inline GLfloat INT_AS_FLT(GLint i)
175 {
176    fi_type tmp;
177    tmp.i = i;
178    return tmp.f;
179 }
180 
UINT_AS_FLT(GLuint u)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
TEST_EQ_4UBV(const GLubyte a[4],const GLubyte b[4])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
COPY_4UBV(GLubyte dst[4],const GLubyte src[4])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
COPY_4FV(GLfloat dst[4],const GLfloat src[4])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
COPY_CLEAN_4V_TYPE_AS_FLOAT(GLfloat dst[4],int sz,const GLfloat src[4],GLenum type)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
LINTERP(GLfloat t,GLfloat out,GLfloat in)620 LINTERP(GLfloat t, GLfloat out, GLfloat in)
621 {
622    return out + t * (in - out);
623 }
624 
625 static inline void
INTERP_3F(GLfloat t,GLfloat dst[3],const GLfloat out[3],const GLfloat in[3])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
INTERP_4F(GLfloat t,GLfloat dst[4],const GLfloat out[4],const GLfloat in[4])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
CROSS3(GLfloat n[3],const GLfloat u[3],const GLfloat v[3])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
DOT2(const GLfloat a[2],const GLfloat b[2])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
DOT3(const GLfloat a[3],const GLfloat b[3])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
DOT4(const GLfloat a[4],const GLfloat b[4])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
LEN_SQUARED_3FV(const GLfloat v[3])692 LEN_SQUARED_3FV(const GLfloat v[3])
693 {
694    return DOT3(v, v);
695 }
696 
697 static inline GLfloat
LEN_SQUARED_2FV(const GLfloat v[2])698 LEN_SQUARED_2FV(const GLfloat v[2])
699 {
700    return DOT2(v, v);
701 }
702 
703 
704 static inline GLfloat
LEN_3FV(const GLfloat v[3])705 LEN_3FV(const GLfloat v[3])
706 {
707    return SQRTF(LEN_SQUARED_3FV(v));
708 }
709 
710 static inline GLfloat
LEN_2FV(const GLfloat v[2])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
NORMALIZE_3FV(GLfloat v[3])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