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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  *
9  * Copyright (C) 1999-2006  Brian Paul   All Rights Reserved.
10  *
11  * Permission is hereby granted, free of charge, to any person obtaining a
12  * copy of this software and associated documentation files (the "Software"),
13  * to deal in the Software without restriction, including without limitation
14  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
15  * and/or sell copies of the Software, and to permit persons to whom the
16  * Software is furnished to do so, subject to the following conditions:
17  *
18  * The above copyright notice and this permission notice shall be included
19  * in all copies or substantial portions of the Software.
20  *
21  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
22  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
23  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
24  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
25  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
26  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
27  * OTHER DEALINGS IN THE SOFTWARE.
28  */
29 
30 
31 #ifndef MACROS_H
32 #define MACROS_H
33 
34 #include "util/macros.h"
35 #include "util/u_math.h"
36 #include "util/rounding.h"
37 #include "util/compiler.h"
38 #include "main/glheader.h"
39 #include "mesa_private.h"
40 
41 
42 /**
43  * \name Integer / float conversion for colors, normals, etc.
44  */
45 /*@{*/
46 
47 /** Convert GLubyte in [0,255] to GLfloat in [0.0,1.0] */
48 extern GLfloat _mesa_ubyte_to_float_color_tab[256];
49 #define UBYTE_TO_FLOAT(u) _mesa_ubyte_to_float_color_tab[(unsigned int)(u)]
50 
51 /** Convert GLfloat in [0.0,1.0] to GLubyte in [0,255] */
52 #define FLOAT_TO_UBYTE(X)   ((GLubyte) (GLint) ((X) * 255.0F))
53 
54 
55 /** Convert GLbyte in [-128,127] to GLfloat in [-1.0,1.0] */
56 #define BYTE_TO_FLOAT(B)    ((2.0F * (B) + 1.0F) * (1.0F/255.0F))
57 
58 /** Convert GLfloat in [-1.0,1.0] to GLbyte in [-128,127] */
59 #define FLOAT_TO_BYTE(X)    ( (((GLint) (255.0F * (X))) - 1) / 2 )
60 
61 
62 /** Convert GLbyte to GLfloat while preserving zero */
63 #define BYTE_TO_FLOATZ(B)   ((B) == 0 ? 0.0F : BYTE_TO_FLOAT(B))
64 
65 
66 /** Convert GLbyte in [-128,127] to GLfloat in [-1.0,1.0], texture/fb data */
67 #define BYTE_TO_FLOAT_TEX(B)    ((B) == -128 ? -1.0F : (B) * (1.0F/127.0F))
68 
69 /** Convert GLfloat in [-1.0,1.0] to GLbyte in [-128,127], texture/fb data */
70 #define FLOAT_TO_BYTE_TEX(X)    CLAMP( (GLint) (127.0F * (X)), -128, 127 )
71 
72 /** Convert GLushort in [0,65535] to GLfloat in [0.0,1.0] */
73 #define USHORT_TO_FLOAT(S)  ((GLfloat) (S) * (1.0F / 65535.0F))
74 
75 /** Convert GLfloat in [0.0,1.0] to GLushort in [0, 65535] */
76 #define FLOAT_TO_USHORT(X)   ((GLuint) ((X) * 65535.0F))
77 
78 
79 /** Convert GLshort in [-32768,32767] to GLfloat in [-1.0,1.0] */
80 #define SHORT_TO_FLOAT(S)   ((2.0F * (S) + 1.0F) * (1.0F/65535.0F))
81 
82 /** Convert GLfloat in [-1.0,1.0] to GLshort in [-32768,32767] */
83 #define FLOAT_TO_SHORT(X)   ( (((GLint) (65535.0F * (X))) - 1) / 2 )
84 
85 /** Convert GLshort to GLfloat while preserving zero */
86 #define SHORT_TO_FLOATZ(S)   ((S) == 0 ? 0.0F : SHORT_TO_FLOAT(S))
87 
88 
89 /** Convert GLshort in [-32768,32767] to GLfloat in [-1.0,1.0], texture/fb data */
90 #define SHORT_TO_FLOAT_TEX(S)    ((S) == -32768 ? -1.0F : (S) * (1.0F/32767.0F))
91 
92 /** Convert GLfloat in [-1.0,1.0] to GLshort in [-32768,32767], texture/fb data */
93 #define FLOAT_TO_SHORT_TEX(X)    ( (GLint) (32767.0F * (X)) )
94 
95 
96 /** Convert GLuint in [0,4294967295] to GLfloat in [0.0,1.0] */
97 #define UINT_TO_FLOAT(U)    ((GLfloat) ((U) * (1.0F / 4294967295.0)))
98 
99 /** Convert GLfloat in [0.0,1.0] to GLuint in [0,4294967295] */
100 #define FLOAT_TO_UINT(X)    ((GLuint) ((X) * 4294967295.0))
101 
102 
103 /** Convert GLint in [-2147483648,2147483647] to GLfloat in [-1.0,1.0] */
104 #define INT_TO_FLOAT(I)     ((GLfloat) ((2.0F * (I) + 1.0F) * (1.0F/4294967294.0)))
105 
106 /** Convert GLfloat in [-1.0,1.0] to GLint in [-2147483648,2147483647] */
107 /* causes overflow:
108 #define FLOAT_TO_INT(X)     ( (((GLint) (4294967294.0 * (X))) - 1) / 2 )
109 */
110 /* a close approximation: */
111 #define FLOAT_TO_INT(X)     ( (GLint) (2147483647.0 * (X)) )
112 
113 /** Convert GLfloat in [-1.0,1.0] to GLint64 in [-(1<<63),(1 << 63) -1] */
114 #define FLOAT_TO_INT64(X)     ( (GLint64) (9223372036854775807.0 * (double)(X)) )
115 
116 
117 /** Convert GLint in [-2147483648,2147483647] to GLfloat in [-1.0,1.0], texture/fb data */
118 #define INT_TO_FLOAT_TEX(I)    ((I) == -2147483648 ? -1.0F : (I) * (1.0F/2147483647.0))
119 
120 /** Convert GLfloat in [-1.0,1.0] to GLint in [-2147483648,2147483647], texture/fb data */
121 #define FLOAT_TO_INT_TEX(X)    ( (GLint) (2147483647.0 * (X)) )
122 
123 
124 #define BYTE_TO_UBYTE(b)   ((GLubyte) ((b) < 0 ? 0 : (GLubyte) (b)))
125 #define SHORT_TO_UBYTE(s)  ((GLubyte) ((s) < 0 ? 0 : (GLubyte) ((s) >> 7)))
126 #define USHORT_TO_UBYTE(s) ((GLubyte) ((s) >> 8))
127 #define INT_TO_UBYTE(i)    ((GLubyte) ((i) < 0 ? 0 : (GLubyte) ((i) >> 23)))
128 #define UINT_TO_UBYTE(i)   ((GLubyte) ((i) >> 24))
129 
130 
131 #define BYTE_TO_USHORT(b)  ((b) < 0 ? 0 : ((GLushort) (((b) * 65535) / 255)))
132 #define UBYTE_TO_USHORT(b) (((GLushort) (b) << 8) | (GLushort) (b))
133 #define SHORT_TO_USHORT(s) ((s) < 0 ? 0 : ((GLushort) (((s) * 65535 / 32767))))
134 #define INT_TO_USHORT(i)   ((i) < 0 ? 0 : ((GLushort) ((i) >> 15)))
135 #define UINT_TO_USHORT(i)  ((i) < 0 ? 0 : ((GLushort) ((i) >> 16)))
136 #define UNCLAMPED_FLOAT_TO_USHORT(us, f)  \
137         us = ( (GLushort) _mesa_lroundevenf( CLAMP((f), 0.0F, 1.0F) * 65535.0F) )
138 #define CLAMPED_FLOAT_TO_USHORT(us, f)  \
139         us = ( (GLushort) _mesa_lroundevenf( (f) * 65535.0F) )
140 
141 #define UNCLAMPED_FLOAT_TO_SHORT(s, f)  \
142         s = ( (GLshort) _mesa_lroundevenf( CLAMP((f), -1.0F, 1.0F) * 32767.0F) )
143 
144 /***
145  *** UNCLAMPED_FLOAT_TO_UBYTE: clamp float to [0,1] and map to ubyte in [0,255]
146  *** CLAMPED_FLOAT_TO_UBYTE: map float known to be in [0,1] to ubyte in [0,255]
147  ***/
148 #ifndef DEBUG
149 /* This function/macro is sensitive to precision.  Test very carefully
150  * if you change it!
151  */
152 #define UNCLAMPED_FLOAT_TO_UBYTE(UB, FLT)				\
153         do {								\
154            fi_type __tmp;						\
155            __tmp.f = (FLT);						\
156            if (__tmp.i < 0)						\
157               UB = (GLubyte) 0;						\
158            else if (__tmp.i >= IEEE_ONE)				\
159               UB = (GLubyte) 255;					\
160            else {							\
161               __tmp.f = __tmp.f * (255.0F/256.0F) + 32768.0F;		\
162               UB = (GLubyte) __tmp.i;					\
163            }								\
164         } while (0)
165 #define CLAMPED_FLOAT_TO_UBYTE(UB, FLT)					\
166         do {								\
167            fi_type __tmp;						\
168            __tmp.f = (FLT) * (255.0F/256.0F) + 32768.0F;		\
169            UB = (GLubyte) __tmp.i;					\
170         } while (0)
171 #else
172 #define UNCLAMPED_FLOAT_TO_UBYTE(ub, f) \
173 	ub = ((GLubyte) _mesa_lroundevenf(CLAMP((f), 0.0F, 1.0F) * 255.0F))
174 #define CLAMPED_FLOAT_TO_UBYTE(ub, f) \
175 	ub = ((GLubyte) _mesa_lroundevenf((f) * 255.0F))
176 #endif
177 
UINT_AS_UNION(GLuint u)178 static fi_type UINT_AS_UNION(GLuint u)
179 {
180    fi_type tmp;
181    tmp.u = u;
182    return tmp;
183 }
184 
INT_AS_UNION(GLint i)185 static inline fi_type INT_AS_UNION(GLint i)
186 {
187    fi_type tmp;
188    tmp.i = i;
189    return tmp;
190 }
191 
FLOAT_AS_UNION(GLfloat f)192 static inline fi_type FLOAT_AS_UNION(GLfloat f)
193 {
194    fi_type tmp;
195    tmp.f = f;
196    return tmp;
197 }
198 
DOUBLE_AS_UINT64(double d)199 static inline uint64_t DOUBLE_AS_UINT64(double d)
200 {
201    union {
202       double d;
203       uint64_t u64;
204    } tmp;
205    tmp.d = d;
206    return tmp.u64;
207 }
208 
UINT64_AS_DOUBLE(uint64_t u)209 static inline double UINT64_AS_DOUBLE(uint64_t u)
210 {
211    union {
212       double d;
213       uint64_t u64;
214    } tmp;
215    tmp.u64 = u;
216    return tmp.d;
217 }
218 
219 /* First sign-extend x, then return uint32_t. */
220 #define INT_AS_UINT(x) ((uint32_t)((int32_t)(x)))
221 #define FLOAT_AS_UINT(x) (FLOAT_AS_UNION(x).u)
222 
223 /**
224  * Convert a floating point value to an unsigned fixed point value.
225  *
226  * \param frac_bits   The number of bits used to store the fractional part.
227  */
228 static inline uint32_t
U_FIXED(float value,uint32_t frac_bits)229 U_FIXED(float value, uint32_t frac_bits)
230 {
231    value *= (1 << frac_bits);
232    return value < 0.0f ? 0 : (uint32_t) value;
233 }
234 
235 /**
236  * Convert a floating point value to an signed fixed point value.
237  *
238  * \param frac_bits   The number of bits used to store the fractional part.
239  */
240 static inline int32_t
S_FIXED(float value,uint32_t frac_bits)241 S_FIXED(float value, uint32_t frac_bits)
242 {
243    return (int32_t) (value * (1 << frac_bits));
244 }
245 /*@}*/
246 
247 
248 /** Stepping a GLfloat pointer by a byte stride */
249 #define STRIDE_F(p, i)  (p = (GLfloat *)((GLubyte *)p + i))
250 /** Stepping a GLuint pointer by a byte stride */
251 #define STRIDE_UI(p, i)  (p = (GLuint *)((GLubyte *)p + i))
252 /** Stepping a GLubyte[4] pointer by a byte stride */
253 #define STRIDE_4UB(p, i)  (p = (GLubyte (*)[4])((GLubyte *)p + i))
254 /** Stepping a GLfloat[4] pointer by a byte stride */
255 #define STRIDE_4F(p, i)  (p = (GLfloat (*)[4])((GLubyte *)p + i))
256 /** Stepping a \p t pointer by a byte stride */
257 #define STRIDE_T(p, t, i)  (p = (t)((GLubyte *)p + i))
258 
259 
260 /**********************************************************************/
261 /** \name 4-element vector operations */
262 /*@{*/
263 
264 /** Zero */
265 #define ZERO_4V( DST )  (DST)[0] = (DST)[1] = (DST)[2] = (DST)[3] = 0
266 
267 /** Test for equality */
268 #define TEST_EQ_4V(a,b)  ((a)[0] == (b)[0] &&   \
269               (a)[1] == (b)[1] &&   \
270               (a)[2] == (b)[2] &&   \
271               (a)[3] == (b)[3])
272 
273 /** Test for equality (unsigned bytes) */
274 static inline GLboolean
TEST_EQ_4UBV(const GLubyte a[4],const GLubyte b[4])275 TEST_EQ_4UBV(const GLubyte a[4], const GLubyte b[4])
276 {
277 #if defined(__i386__)
278    return *((const GLuint *) a) == *((const GLuint *) b);
279 #else
280    return TEST_EQ_4V(a, b);
281 #endif
282 }
283 
284 
285 /** Copy a 4-element vector */
286 #define COPY_4V( DST, SRC )         \
287 do {                                \
288    (DST)[0] = (SRC)[0];             \
289    (DST)[1] = (SRC)[1];             \
290    (DST)[2] = (SRC)[2];             \
291    (DST)[3] = (SRC)[3];             \
292 } while (0)
293 
294 /** Copy a 4-element unsigned byte vector */
295 static inline void
COPY_4UBV(GLubyte dst[4],const GLubyte src[4])296 COPY_4UBV(GLubyte dst[4], const GLubyte src[4])
297 {
298 #if defined(__i386__)
299    *((GLuint *) dst) = *((GLuint *) src);
300 #else
301    /* The GLuint cast might fail if DST or SRC are not dword-aligned (RISC) */
302    COPY_4V(dst, src);
303 #endif
304 }
305 
306 /** Copy \p SZ elements into a 4-element vector */
307 #define COPY_SZ_4V(DST, SZ, SRC)                  \
308 do {                                              \
309    switch (SZ) {                                  \
310    case 4: (DST)[3] = (SRC)[3];                   \
311            FALLTHROUGH;                           \
312    case 3: (DST)[2] = (SRC)[2];                   \
313            FALLTHROUGH;                           \
314    case 2: (DST)[1] = (SRC)[1];                   \
315            FALLTHROUGH;                           \
316    case 1: (DST)[0] = (SRC)[0];                   \
317    }                                              \
318 } while(0)
319 
320 /** Copy \p SZ elements into a homegeneous (4-element) vector, giving
321  * default values to the remaining */
322 #define COPY_CLEAN_4V(DST, SZ, SRC)  \
323 do {                                 \
324       ASSIGN_4V( DST, 0, 0, 0, 1 );  \
325       COPY_SZ_4V( DST, SZ, SRC );    \
326 } while (0)
327 
328 /** Subtraction */
329 #define SUB_4V( DST, SRCA, SRCB )           \
330 do {                                        \
331       (DST)[0] = (SRCA)[0] - (SRCB)[0];     \
332       (DST)[1] = (SRCA)[1] - (SRCB)[1];     \
333       (DST)[2] = (SRCA)[2] - (SRCB)[2];     \
334       (DST)[3] = (SRCA)[3] - (SRCB)[3];     \
335 } while (0)
336 
337 /** Addition */
338 #define ADD_4V( DST, SRCA, SRCB )           \
339 do {                                        \
340       (DST)[0] = (SRCA)[0] + (SRCB)[0];     \
341       (DST)[1] = (SRCA)[1] + (SRCB)[1];     \
342       (DST)[2] = (SRCA)[2] + (SRCB)[2];     \
343       (DST)[3] = (SRCA)[3] + (SRCB)[3];     \
344 } while (0)
345 
346 /** Element-wise multiplication */
347 #define SCALE_4V( DST, SRCA, SRCB )         \
348 do {                                        \
349       (DST)[0] = (SRCA)[0] * (SRCB)[0];     \
350       (DST)[1] = (SRCA)[1] * (SRCB)[1];     \
351       (DST)[2] = (SRCA)[2] * (SRCB)[2];     \
352       (DST)[3] = (SRCA)[3] * (SRCB)[3];     \
353 } while (0)
354 
355 /** In-place addition */
356 #define ACC_4V( DST, SRC )          \
357 do {                                \
358       (DST)[0] += (SRC)[0];         \
359       (DST)[1] += (SRC)[1];         \
360       (DST)[2] += (SRC)[2];         \
361       (DST)[3] += (SRC)[3];         \
362 } while (0)
363 
364 /** Element-wise multiplication and addition */
365 #define ACC_SCALE_4V( DST, SRCA, SRCB )     \
366 do {                                        \
367       (DST)[0] += (SRCA)[0] * (SRCB)[0];    \
368       (DST)[1] += (SRCA)[1] * (SRCB)[1];    \
369       (DST)[2] += (SRCA)[2] * (SRCB)[2];    \
370       (DST)[3] += (SRCA)[3] * (SRCB)[3];    \
371 } while (0)
372 
373 /** In-place scalar multiplication and addition */
374 #define ACC_SCALE_SCALAR_4V( DST, S, SRCB ) \
375 do {                                        \
376       (DST)[0] += S * (SRCB)[0];            \
377       (DST)[1] += S * (SRCB)[1];            \
378       (DST)[2] += S * (SRCB)[2];            \
379       (DST)[3] += S * (SRCB)[3];            \
380 } while (0)
381 
382 /** Scalar multiplication */
383 #define SCALE_SCALAR_4V( DST, S, SRCB ) \
384 do {                                    \
385       (DST)[0] = S * (SRCB)[0];         \
386       (DST)[1] = S * (SRCB)[1];         \
387       (DST)[2] = S * (SRCB)[2];         \
388       (DST)[3] = S * (SRCB)[3];         \
389 } while (0)
390 
391 /** In-place scalar multiplication */
392 #define SELF_SCALE_SCALAR_4V( DST, S ) \
393 do {                                   \
394       (DST)[0] *= S;                   \
395       (DST)[1] *= S;                   \
396       (DST)[2] *= S;                   \
397       (DST)[3] *= S;                   \
398 } while (0)
399 
400 /*@}*/
401 
402 
403 /**********************************************************************/
404 /** \name 3-element vector operations*/
405 /*@{*/
406 
407 /** Zero */
408 #define ZERO_3V( DST )  (DST)[0] = (DST)[1] = (DST)[2] = 0
409 
410 /** Test for equality */
411 #define TEST_EQ_3V(a,b)  \
412    ((a)[0] == (b)[0] &&  \
413     (a)[1] == (b)[1] &&  \
414     (a)[2] == (b)[2])
415 
416 /** Copy a 3-element vector */
417 #define COPY_3V( DST, SRC )         \
418 do {                                \
419    (DST)[0] = (SRC)[0];             \
420    (DST)[1] = (SRC)[1];             \
421    (DST)[2] = (SRC)[2];             \
422 } while (0)
423 
424 /** Copy a 3-element vector with cast */
425 #define COPY_3V_CAST( DST, SRC, CAST )  \
426 do {                                    \
427    (DST)[0] = (CAST)(SRC)[0];           \
428    (DST)[1] = (CAST)(SRC)[1];           \
429    (DST)[2] = (CAST)(SRC)[2];           \
430 } while (0)
431 
432 /** Copy a 3-element float vector */
433 #define COPY_3FV( DST, SRC )        \
434 do {                                \
435    const GLfloat *_tmp = (SRC);     \
436    (DST)[0] = _tmp[0];              \
437    (DST)[1] = _tmp[1];              \
438    (DST)[2] = _tmp[2];              \
439 } while (0)
440 
441 /** Subtraction */
442 #define SUB_3V( DST, SRCA, SRCB )        \
443 do {                                     \
444       (DST)[0] = (SRCA)[0] - (SRCB)[0];  \
445       (DST)[1] = (SRCA)[1] - (SRCB)[1];  \
446       (DST)[2] = (SRCA)[2] - (SRCB)[2];  \
447 } while (0)
448 
449 /** Addition */
450 #define ADD_3V( DST, SRCA, SRCB )       \
451 do {                                    \
452       (DST)[0] = (SRCA)[0] + (SRCB)[0]; \
453       (DST)[1] = (SRCA)[1] + (SRCB)[1]; \
454       (DST)[2] = (SRCA)[2] + (SRCB)[2]; \
455 } while (0)
456 
457 /** In-place scalar multiplication */
458 #define SCALE_3V( DST, SRCA, SRCB )     \
459 do {                                    \
460       (DST)[0] = (SRCA)[0] * (SRCB)[0]; \
461       (DST)[1] = (SRCA)[1] * (SRCB)[1]; \
462       (DST)[2] = (SRCA)[2] * (SRCB)[2]; \
463 } while (0)
464 
465 /** In-place element-wise multiplication */
466 #define SELF_SCALE_3V( DST, SRC )   \
467 do {                                \
468       (DST)[0] *= (SRC)[0];         \
469       (DST)[1] *= (SRC)[1];         \
470       (DST)[2] *= (SRC)[2];         \
471 } while (0)
472 
473 /** In-place addition */
474 #define ACC_3V( DST, SRC )          \
475 do {                                \
476       (DST)[0] += (SRC)[0];         \
477       (DST)[1] += (SRC)[1];         \
478       (DST)[2] += (SRC)[2];         \
479 } while (0)
480 
481 /** Element-wise multiplication and addition */
482 #define ACC_SCALE_3V( DST, SRCA, SRCB )     \
483 do {                                        \
484       (DST)[0] += (SRCA)[0] * (SRCB)[0];    \
485       (DST)[1] += (SRCA)[1] * (SRCB)[1];    \
486       (DST)[2] += (SRCA)[2] * (SRCB)[2];    \
487 } while (0)
488 
489 /** Scalar multiplication */
490 #define SCALE_SCALAR_3V( DST, S, SRCB ) \
491 do {                                    \
492       (DST)[0] = S * (SRCB)[0];         \
493       (DST)[1] = S * (SRCB)[1];         \
494       (DST)[2] = S * (SRCB)[2];         \
495 } while (0)
496 
497 /** In-place scalar multiplication and addition */
498 #define ACC_SCALE_SCALAR_3V( DST, S, SRCB ) \
499 do {                                        \
500       (DST)[0] += S * (SRCB)[0];            \
501       (DST)[1] += S * (SRCB)[1];            \
502       (DST)[2] += S * (SRCB)[2];            \
503 } while (0)
504 
505 /** In-place scalar multiplication */
506 #define SELF_SCALE_SCALAR_3V( DST, S ) \
507 do {                                   \
508       (DST)[0] *= S;                   \
509       (DST)[1] *= S;                   \
510       (DST)[2] *= S;                   \
511 } while (0)
512 
513 /** In-place scalar addition */
514 #define ACC_SCALAR_3V( DST, S )     \
515 do {                                \
516       (DST)[0] += S;                \
517       (DST)[1] += S;                \
518       (DST)[2] += S;                \
519 } while (0)
520 
521 /** Assignment */
522 #define ASSIGN_3V( V, V0, V1, V2 )  \
523 do {                                \
524     V[0] = V0;                      \
525     V[1] = V1;                      \
526     V[2] = V2;                      \
527 } while(0)
528 
529 /*@}*/
530 
531 
532 /**********************************************************************/
533 /** \name 2-element vector operations*/
534 /*@{*/
535 
536 /** Zero */
537 #define ZERO_2V( DST )  (DST)[0] = (DST)[1] = 0
538 
539 /** Copy a 2-element vector */
540 #define COPY_2V( DST, SRC )         \
541 do {                        \
542    (DST)[0] = (SRC)[0];             \
543    (DST)[1] = (SRC)[1];             \
544 } while (0)
545 
546 /** Copy a 2-element vector with cast */
547 #define COPY_2V_CAST( DST, SRC, CAST )      \
548 do {                        \
549    (DST)[0] = (CAST)(SRC)[0];           \
550    (DST)[1] = (CAST)(SRC)[1];           \
551 } while (0)
552 
553 /** Copy a 2-element float vector */
554 #define COPY_2FV( DST, SRC )            \
555 do {                        \
556    const GLfloat *_tmp = (SRC);         \
557    (DST)[0] = _tmp[0];              \
558    (DST)[1] = _tmp[1];              \
559 } while (0)
560 
561 /** Subtraction */
562 #define SUB_2V( DST, SRCA, SRCB )       \
563 do {                        \
564       (DST)[0] = (SRCA)[0] - (SRCB)[0];     \
565       (DST)[1] = (SRCA)[1] - (SRCB)[1];     \
566 } while (0)
567 
568 /** Addition */
569 #define ADD_2V( DST, SRCA, SRCB )       \
570 do {                        \
571       (DST)[0] = (SRCA)[0] + (SRCB)[0];     \
572       (DST)[1] = (SRCA)[1] + (SRCB)[1];     \
573 } while (0)
574 
575 /** In-place scalar multiplication */
576 #define SCALE_2V( DST, SRCA, SRCB )     \
577 do {                        \
578       (DST)[0] = (SRCA)[0] * (SRCB)[0];     \
579       (DST)[1] = (SRCA)[1] * (SRCB)[1];     \
580 } while (0)
581 
582 /** In-place addition */
583 #define ACC_2V( DST, SRC )          \
584 do {                        \
585       (DST)[0] += (SRC)[0];         \
586       (DST)[1] += (SRC)[1];         \
587 } while (0)
588 
589 /** Element-wise multiplication and addition */
590 #define ACC_SCALE_2V( DST, SRCA, SRCB )     \
591 do {                        \
592       (DST)[0] += (SRCA)[0] * (SRCB)[0];    \
593       (DST)[1] += (SRCA)[1] * (SRCB)[1];    \
594 } while (0)
595 
596 /** Scalar multiplication */
597 #define SCALE_SCALAR_2V( DST, S, SRCB )     \
598 do {                        \
599       (DST)[0] = S * (SRCB)[0];         \
600       (DST)[1] = S * (SRCB)[1];         \
601 } while (0)
602 
603 /** In-place scalar multiplication and addition */
604 #define ACC_SCALE_SCALAR_2V( DST, S, SRCB ) \
605 do {                        \
606       (DST)[0] += S * (SRCB)[0];        \
607       (DST)[1] += S * (SRCB)[1];        \
608 } while (0)
609 
610 /** In-place scalar multiplication */
611 #define SELF_SCALE_SCALAR_2V( DST, S )      \
612 do {                        \
613       (DST)[0] *= S;                \
614       (DST)[1] *= S;                \
615 } while (0)
616 
617 /** In-place scalar addition */
618 #define ACC_SCALAR_2V( DST, S )         \
619 do {                        \
620       (DST)[0] += S;                \
621       (DST)[1] += S;                \
622 } while (0)
623 
624 /** Assign scalers to short vectors */
625 #define ASSIGN_2V( V, V0, V1 )	\
626 do {				\
627     V[0] = V0;			\
628     V[1] = V1;			\
629 } while(0)
630 
631 /*@}*/
632 
633 /** Copy \p sz elements into a homegeneous (4-element) vector, giving
634  * default values to the remaining components.
635  * The default values are chosen based on \p type.
636  */
637 static inline void
COPY_CLEAN_4V_TYPE_AS_UNION(fi_type dst[4],int sz,const fi_type src[4],GLenum type)638 COPY_CLEAN_4V_TYPE_AS_UNION(fi_type dst[4], int sz, const fi_type src[4],
639                             GLenum type)
640 {
641    switch (type) {
642    case GL_FLOAT:
643       ASSIGN_4V(dst, FLOAT_AS_UNION(0), FLOAT_AS_UNION(0),
644                 FLOAT_AS_UNION(0), FLOAT_AS_UNION(1));
645       break;
646    case GL_INT:
647       ASSIGN_4V(dst, INT_AS_UNION(0), INT_AS_UNION(0),
648                 INT_AS_UNION(0), INT_AS_UNION(1));
649       break;
650    case GL_UNSIGNED_INT:
651       ASSIGN_4V(dst, UINT_AS_UNION(0), UINT_AS_UNION(0),
652                 UINT_AS_UNION(0), UINT_AS_UNION(1));
653       break;
654    default:
655       ASSIGN_4V(dst, FLOAT_AS_UNION(0), FLOAT_AS_UNION(0),
656                 FLOAT_AS_UNION(0), FLOAT_AS_UNION(1)); /* silence warnings */
657       assert(!"Unexpected type in COPY_CLEAN_4V_TYPE_AS_UNION macro");
658    }
659    COPY_SZ_4V(dst, sz, src);
660 }
661 
662 /** \name Linear interpolation functions */
663 /*@{*/
664 
665 static inline GLfloat
LINTERP(GLfloat t,GLfloat out,GLfloat in)666 LINTERP(GLfloat t, GLfloat out, GLfloat in)
667 {
668    return out + t * (in - out);
669 }
670 
671 static inline void
INTERP_3F(GLfloat t,GLfloat dst[3],const GLfloat out[3],const GLfloat in[3])672 INTERP_3F(GLfloat t, GLfloat dst[3], const GLfloat out[3], const GLfloat in[3])
673 {
674    dst[0] = LINTERP( t, out[0], in[0] );
675    dst[1] = LINTERP( t, out[1], in[1] );
676    dst[2] = LINTERP( t, out[2], in[2] );
677 }
678 
679 static inline void
INTERP_4F(GLfloat t,GLfloat dst[4],const GLfloat out[4],const GLfloat in[4])680 INTERP_4F(GLfloat t, GLfloat dst[4], const GLfloat out[4], const GLfloat in[4])
681 {
682    dst[0] = LINTERP( t, out[0], in[0] );
683    dst[1] = LINTERP( t, out[1], in[1] );
684    dst[2] = LINTERP( t, out[2], in[2] );
685    dst[3] = LINTERP( t, out[3], in[3] );
686 }
687 
688 /*@}*/
689 
690 
691 
692 static inline unsigned
minify(unsigned value,unsigned levels)693 minify(unsigned value, unsigned levels)
694 {
695     return MAX2(1, value >> levels);
696 }
697 
698 
699 /** Cross product of two 3-element vectors */
700 static inline void
CROSS3(GLfloat n[3],const GLfloat u[3],const GLfloat v[3])701 CROSS3(GLfloat n[3], const GLfloat u[3], const GLfloat v[3])
702 {
703    n[0] = u[1] * v[2] - u[2] * v[1];
704    n[1] = u[2] * v[0] - u[0] * v[2];
705    n[2] = u[0] * v[1] - u[1] * v[0];
706 }
707 
708 
709 /** Dot product of two 2-element vectors */
710 static inline GLfloat
DOT2(const GLfloat a[2],const GLfloat b[2])711 DOT2(const GLfloat a[2], const GLfloat b[2])
712 {
713    return a[0] * b[0] + a[1] * b[1];
714 }
715 
716 static inline GLfloat
DOT3(const GLfloat a[3],const GLfloat b[3])717 DOT3(const GLfloat a[3], const GLfloat b[3])
718 {
719    return a[0] * b[0] + a[1] * b[1] + a[2] * b[2];
720 }
721 
722 static inline GLfloat
DOT4(const GLfloat a[4],const GLfloat b[4])723 DOT4(const GLfloat a[4], const GLfloat b[4])
724 {
725    return a[0] * b[0] + a[1] * b[1] + a[2] * b[2] + a[3] * b[3];
726 }
727 
728 
729 static inline GLfloat
LEN_SQUARED_3FV(const GLfloat v[3])730 LEN_SQUARED_3FV(const GLfloat v[3])
731 {
732    return DOT3(v, v);
733 }
734 
735 static inline GLfloat
LEN_SQUARED_2FV(const GLfloat v[2])736 LEN_SQUARED_2FV(const GLfloat v[2])
737 {
738    return DOT2(v, v);
739 }
740 
741 
742 static inline GLfloat
LEN_3FV(const GLfloat v[3])743 LEN_3FV(const GLfloat v[3])
744 {
745    return sqrtf(LEN_SQUARED_3FV(v));
746 }
747 
748 static inline GLfloat
LEN_2FV(const GLfloat v[2])749 LEN_2FV(const GLfloat v[2])
750 {
751    return sqrtf(LEN_SQUARED_2FV(v));
752 }
753 
754 
755 /* Normalize a 3-element vector to unit length. */
756 static inline void
NORMALIZE_3FV(GLfloat v[3])757 NORMALIZE_3FV(GLfloat v[3])
758 {
759    GLfloat len = (GLfloat) LEN_SQUARED_3FV(v);
760    if (len) {
761       len = 1.0f / sqrtf(len);
762       v[0] *= len;
763       v[1] *= len;
764       v[2] *= len;
765    }
766 }
767 
768 
769 /** Test two floats have opposite signs */
770 static inline GLboolean
DIFFERENT_SIGNS(GLfloat x,GLfloat y)771 DIFFERENT_SIGNS(GLfloat x, GLfloat y)
772 {
773 #ifdef _MSC_VER
774 #pragma warning( push )
775 #pragma warning( disable : 6334 ) /* sizeof operator applied to an expression with an operator may yield unexpected results */
776 #endif
777    return signbit(x) != signbit(y);
778 #ifdef _MSC_VER
779 #pragma warning( pop )
780 #endif
781 }
782 
783 
784 /** casts to silence warnings with some compilers */
785 #define ENUM_TO_INT(E)     ((GLint)(E))
786 #define ENUM_TO_FLOAT(E)   ((GLfloat)(GLint)(E))
787 #define ENUM_TO_DOUBLE(E)  ((GLdouble)(GLint)(E))
788 #define ENUM_TO_BOOLEAN(E) ((E) ? GL_TRUE : GL_FALSE)
789 
790 
791 /* Stringify */
792 #define STRINGIFY(x) #x
793 
794 /*
795  * For GL_ARB_vertex_buffer_object we need to treat vertex array pointers
796  * as offsets into buffer stores.  Since the vertex array pointer and
797  * buffer store pointer are both pointers and we need to add them, we use
798  * this macro.
799  * Both pointers/offsets are expressed in bytes.
800  */
801 #define ADD_POINTERS(A, B)  ( (GLubyte *) (A) + (uintptr_t) (B) )
802 
803 #endif
804