3 * A collection of useful macros.
7 * Mesa 3-D graphics library
9 * Copyright (C) 1999-2006 Brian Paul All Rights Reserved.
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:
18 * The above copyright notice and this permission notice shall be included
19 * in all copies or substantial portions of the Software.
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.
38 * \name Integer / float conversion for colors, normals, etc.
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)]
46 /** Convert GLfloat in [0.0,1.0] to GLubyte in [0,255] */
47 #define FLOAT_TO_UBYTE(X) ((GLubyte) (GLint) ((X) * 255.0F))
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))
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 )
57 /** Convert GLbyte to GLfloat while preserving zero */
58 #define BYTE_TO_FLOATZ(B) ((B) == 0 ? 0.0F : BYTE_TO_FLOAT(B))
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))
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 )
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))
70 /** Convert GLfloat in [0.0,1.0] to GLushort in [0, 65535] */
71 #define FLOAT_TO_USHORT(X) ((GLuint) ((X) * 65535.0F))
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))
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 )
80 /** Convert GLshort to GLfloat while preserving zero */
81 #define SHORT_TO_FLOATZ(S) ((S) == 0 ? 0.0F : SHORT_TO_FLOAT(S))
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))
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)) )
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)))
94 /** Convert GLfloat in [0.0,1.0] to GLuint in [0,4294967295] */
95 #define FLOAT_TO_UINT(X) ((GLuint) ((X) * 4294967295.0))
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)))
101 /** Convert GLfloat in [-1.0,1.0] to GLint in [-2147483648,2147483647] */
103 #define FLOAT_TO_INT(X) ( (((GLint) (4294967294.0 * (X))) - 1) / 2 )
105 /* a close approximation: */
106 #define FLOAT_TO_INT(X) ( (GLint) (2147483647.0 * (X)) )
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)) )
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))
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)) )
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))
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) )
136 #define UNCLAMPED_FLOAT_TO_SHORT(s, f) \
137 s = ( (GLshort) F_TO_I( CLAMP((f), -1.0F, 1.0F) * 32767.0F) )
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]
144 /* This function/macro is sensitive to precision. Test very carefully
147 #define UNCLAMPED_FLOAT_TO_UBYTE(UB, F) \
153 else if (__tmp.i >= IEEE_ONE) \
154 UB = (GLubyte) 255; \
156 __tmp.f = __tmp.f * (255.0F/256.0F) + 32768.0F; \
157 UB = (GLubyte) __tmp.i; \
160 #define CLAMPED_FLOAT_TO_UBYTE(UB, F) \
163 __tmp.f = (F) * (255.0F/256.0F) + 32768.0F; \
164 UB = (GLubyte) __tmp.i; \
167 #define UNCLAMPED_FLOAT_TO_UBYTE(ub, f) \
168 ub = ((GLubyte) F_TO_I(CLAMP((f), 0.0F, 1.0F) * 255.0F))
169 #define CLAMPED_FLOAT_TO_UBYTE(ub, f) \
170 ub = ((GLubyte) F_TO_I((f) * 255.0F))
173 static inline GLfloat
INT_AS_FLT(GLint i
)
180 static inline GLfloat
UINT_AS_FLT(GLuint u
)
187 static inline unsigned FLT_AS_UINT(float f
)
195 * Convert a floating point value to an unsigned fixed point value.
197 * \param frac_bits The number of bits used to store the fractional part.
199 static inline uint32_t
200 U_FIXED(float value
, uint32_t frac_bits
)
202 value
*= (1 << frac_bits
);
203 return value
< 0.0f
? 0 : (uint32_t) value
;
207 * Convert a floating point value to an signed fixed point value.
209 * \param frac_bits The number of bits used to store the fractional part.
211 static inline int32_t
212 S_FIXED(float value
, uint32_t frac_bits
)
214 return (int32_t) (value
* (1 << frac_bits
));
219 /** Stepping a GLfloat pointer by a byte stride */
220 #define STRIDE_F(p, i) (p = (GLfloat *)((GLubyte *)p + i))
221 /** Stepping a GLuint pointer by a byte stride */
222 #define STRIDE_UI(p, i) (p = (GLuint *)((GLubyte *)p + i))
223 /** Stepping a GLubyte[4] pointer by a byte stride */
224 #define STRIDE_4UB(p, i) (p = (GLubyte (*)[4])((GLubyte *)p + i))
225 /** Stepping a GLfloat[4] pointer by a byte stride */
226 #define STRIDE_4F(p, i) (p = (GLfloat (*)[4])((GLubyte *)p + i))
227 /** Stepping a \p t pointer by a byte stride */
228 #define STRIDE_T(p, t, i) (p = (t)((GLubyte *)p + i))
231 /**********************************************************************/
232 /** \name 4-element vector operations */
236 #define ZERO_4V( DST ) (DST)[0] = (DST)[1] = (DST)[2] = (DST)[3] = 0
238 /** Test for equality */
239 #define TEST_EQ_4V(a,b) ((a)[0] == (b)[0] && \
240 (a)[1] == (b)[1] && \
241 (a)[2] == (b)[2] && \
244 /** Test for equality (unsigned bytes) */
245 static inline GLboolean
246 TEST_EQ_4UBV(const GLubyte a
[4], const GLubyte b
[4])
248 #if defined(__i386__)
249 return *((const GLuint
*) a
) == *((const GLuint
*) b
);
251 return TEST_EQ_4V(a
, b
);
256 /** Copy a 4-element vector */
257 #define COPY_4V( DST, SRC ) \
259 (DST)[0] = (SRC)[0]; \
260 (DST)[1] = (SRC)[1]; \
261 (DST)[2] = (SRC)[2]; \
262 (DST)[3] = (SRC)[3]; \
265 /** Copy a 4-element unsigned byte vector */
267 COPY_4UBV(GLubyte dst
[4], const GLubyte src
[4])
269 #if defined(__i386__)
270 *((GLuint
*) dst
) = *((GLuint
*) src
);
272 /* The GLuint cast might fail if DST or SRC are not dword-aligned (RISC) */
277 /** Copy a 4-element float vector */
279 COPY_4FV(GLfloat dst
[4], const GLfloat src
[4])
281 /* memcpy seems to be most efficient */
282 memcpy(dst
, src
, sizeof(GLfloat
) * 4);
285 /** Copy \p SZ elements into a 4-element vector */
286 #define COPY_SZ_4V(DST, SZ, SRC) \
289 case 4: (DST)[3] = (SRC)[3]; \
290 case 3: (DST)[2] = (SRC)[2]; \
291 case 2: (DST)[1] = (SRC)[1]; \
292 case 1: (DST)[0] = (SRC)[0]; \
296 /** Copy \p SZ elements into a homegeneous (4-element) vector, giving
297 * default values to the remaining */
298 #define COPY_CLEAN_4V(DST, SZ, SRC) \
300 ASSIGN_4V( DST, 0, 0, 0, 1 ); \
301 COPY_SZ_4V( DST, SZ, SRC ); \
305 #define SUB_4V( DST, SRCA, SRCB ) \
307 (DST)[0] = (SRCA)[0] - (SRCB)[0]; \
308 (DST)[1] = (SRCA)[1] - (SRCB)[1]; \
309 (DST)[2] = (SRCA)[2] - (SRCB)[2]; \
310 (DST)[3] = (SRCA)[3] - (SRCB)[3]; \
314 #define ADD_4V( DST, SRCA, SRCB ) \
316 (DST)[0] = (SRCA)[0] + (SRCB)[0]; \
317 (DST)[1] = (SRCA)[1] + (SRCB)[1]; \
318 (DST)[2] = (SRCA)[2] + (SRCB)[2]; \
319 (DST)[3] = (SRCA)[3] + (SRCB)[3]; \
322 /** Element-wise multiplication */
323 #define SCALE_4V( DST, SRCA, SRCB ) \
325 (DST)[0] = (SRCA)[0] * (SRCB)[0]; \
326 (DST)[1] = (SRCA)[1] * (SRCB)[1]; \
327 (DST)[2] = (SRCA)[2] * (SRCB)[2]; \
328 (DST)[3] = (SRCA)[3] * (SRCB)[3]; \
331 /** In-place addition */
332 #define ACC_4V( DST, SRC ) \
334 (DST)[0] += (SRC)[0]; \
335 (DST)[1] += (SRC)[1]; \
336 (DST)[2] += (SRC)[2]; \
337 (DST)[3] += (SRC)[3]; \
340 /** Element-wise multiplication and addition */
341 #define ACC_SCALE_4V( DST, SRCA, SRCB ) \
343 (DST)[0] += (SRCA)[0] * (SRCB)[0]; \
344 (DST)[1] += (SRCA)[1] * (SRCB)[1]; \
345 (DST)[2] += (SRCA)[2] * (SRCB)[2]; \
346 (DST)[3] += (SRCA)[3] * (SRCB)[3]; \
349 /** In-place scalar multiplication and addition */
350 #define ACC_SCALE_SCALAR_4V( DST, S, SRCB ) \
352 (DST)[0] += S * (SRCB)[0]; \
353 (DST)[1] += S * (SRCB)[1]; \
354 (DST)[2] += S * (SRCB)[2]; \
355 (DST)[3] += S * (SRCB)[3]; \
358 /** Scalar multiplication */
359 #define SCALE_SCALAR_4V( DST, S, SRCB ) \
361 (DST)[0] = S * (SRCB)[0]; \
362 (DST)[1] = S * (SRCB)[1]; \
363 (DST)[2] = S * (SRCB)[2]; \
364 (DST)[3] = S * (SRCB)[3]; \
367 /** In-place scalar multiplication */
368 #define SELF_SCALE_SCALAR_4V( DST, S ) \
377 #define ASSIGN_4V( V, V0, V1, V2, V3 ) \
388 /**********************************************************************/
389 /** \name 3-element vector operations*/
393 #define ZERO_3V( DST ) (DST)[0] = (DST)[1] = (DST)[2] = 0
395 /** Test for equality */
396 #define TEST_EQ_3V(a,b) \
397 ((a)[0] == (b)[0] && \
398 (a)[1] == (b)[1] && \
401 /** Copy a 3-element vector */
402 #define COPY_3V( DST, SRC ) \
404 (DST)[0] = (SRC)[0]; \
405 (DST)[1] = (SRC)[1]; \
406 (DST)[2] = (SRC)[2]; \
409 /** Copy a 3-element vector with cast */
410 #define COPY_3V_CAST( DST, SRC, CAST ) \
412 (DST)[0] = (CAST)(SRC)[0]; \
413 (DST)[1] = (CAST)(SRC)[1]; \
414 (DST)[2] = (CAST)(SRC)[2]; \
417 /** Copy a 3-element float vector */
418 #define COPY_3FV( DST, SRC ) \
420 const GLfloat *_tmp = (SRC); \
421 (DST)[0] = _tmp[0]; \
422 (DST)[1] = _tmp[1]; \
423 (DST)[2] = _tmp[2]; \
427 #define SUB_3V( DST, SRCA, SRCB ) \
429 (DST)[0] = (SRCA)[0] - (SRCB)[0]; \
430 (DST)[1] = (SRCA)[1] - (SRCB)[1]; \
431 (DST)[2] = (SRCA)[2] - (SRCB)[2]; \
435 #define ADD_3V( DST, SRCA, SRCB ) \
437 (DST)[0] = (SRCA)[0] + (SRCB)[0]; \
438 (DST)[1] = (SRCA)[1] + (SRCB)[1]; \
439 (DST)[2] = (SRCA)[2] + (SRCB)[2]; \
442 /** In-place scalar multiplication */
443 #define SCALE_3V( DST, SRCA, SRCB ) \
445 (DST)[0] = (SRCA)[0] * (SRCB)[0]; \
446 (DST)[1] = (SRCA)[1] * (SRCB)[1]; \
447 (DST)[2] = (SRCA)[2] * (SRCB)[2]; \
450 /** In-place element-wise multiplication */
451 #define SELF_SCALE_3V( DST, SRC ) \
453 (DST)[0] *= (SRC)[0]; \
454 (DST)[1] *= (SRC)[1]; \
455 (DST)[2] *= (SRC)[2]; \
458 /** In-place addition */
459 #define ACC_3V( DST, SRC ) \
461 (DST)[0] += (SRC)[0]; \
462 (DST)[1] += (SRC)[1]; \
463 (DST)[2] += (SRC)[2]; \
466 /** Element-wise multiplication and addition */
467 #define ACC_SCALE_3V( DST, SRCA, SRCB ) \
469 (DST)[0] += (SRCA)[0] * (SRCB)[0]; \
470 (DST)[1] += (SRCA)[1] * (SRCB)[1]; \
471 (DST)[2] += (SRCA)[2] * (SRCB)[2]; \
474 /** Scalar multiplication */
475 #define SCALE_SCALAR_3V( DST, S, SRCB ) \
477 (DST)[0] = S * (SRCB)[0]; \
478 (DST)[1] = S * (SRCB)[1]; \
479 (DST)[2] = S * (SRCB)[2]; \
482 /** In-place scalar multiplication and addition */
483 #define ACC_SCALE_SCALAR_3V( DST, S, SRCB ) \
485 (DST)[0] += S * (SRCB)[0]; \
486 (DST)[1] += S * (SRCB)[1]; \
487 (DST)[2] += S * (SRCB)[2]; \
490 /** In-place scalar multiplication */
491 #define SELF_SCALE_SCALAR_3V( DST, S ) \
498 /** In-place scalar addition */
499 #define ACC_SCALAR_3V( DST, S ) \
507 #define ASSIGN_3V( V, V0, V1, V2 ) \
517 /**********************************************************************/
518 /** \name 2-element vector operations*/
522 #define ZERO_2V( DST ) (DST)[0] = (DST)[1] = 0
524 /** Copy a 2-element vector */
525 #define COPY_2V( DST, SRC ) \
527 (DST)[0] = (SRC)[0]; \
528 (DST)[1] = (SRC)[1]; \
531 /** Copy a 2-element vector with cast */
532 #define COPY_2V_CAST( DST, SRC, CAST ) \
534 (DST)[0] = (CAST)(SRC)[0]; \
535 (DST)[1] = (CAST)(SRC)[1]; \
538 /** Copy a 2-element float vector */
539 #define COPY_2FV( DST, SRC ) \
541 const GLfloat *_tmp = (SRC); \
542 (DST)[0] = _tmp[0]; \
543 (DST)[1] = _tmp[1]; \
547 #define SUB_2V( DST, SRCA, SRCB ) \
549 (DST)[0] = (SRCA)[0] - (SRCB)[0]; \
550 (DST)[1] = (SRCA)[1] - (SRCB)[1]; \
554 #define ADD_2V( DST, SRCA, SRCB ) \
556 (DST)[0] = (SRCA)[0] + (SRCB)[0]; \
557 (DST)[1] = (SRCA)[1] + (SRCB)[1]; \
560 /** In-place scalar multiplication */
561 #define SCALE_2V( DST, SRCA, SRCB ) \
563 (DST)[0] = (SRCA)[0] * (SRCB)[0]; \
564 (DST)[1] = (SRCA)[1] * (SRCB)[1]; \
567 /** In-place addition */
568 #define ACC_2V( DST, SRC ) \
570 (DST)[0] += (SRC)[0]; \
571 (DST)[1] += (SRC)[1]; \
574 /** Element-wise multiplication and addition */
575 #define ACC_SCALE_2V( DST, SRCA, SRCB ) \
577 (DST)[0] += (SRCA)[0] * (SRCB)[0]; \
578 (DST)[1] += (SRCA)[1] * (SRCB)[1]; \
581 /** Scalar multiplication */
582 #define SCALE_SCALAR_2V( DST, S, SRCB ) \
584 (DST)[0] = S * (SRCB)[0]; \
585 (DST)[1] = S * (SRCB)[1]; \
588 /** In-place scalar multiplication and addition */
589 #define ACC_SCALE_SCALAR_2V( DST, S, SRCB ) \
591 (DST)[0] += S * (SRCB)[0]; \
592 (DST)[1] += S * (SRCB)[1]; \
595 /** In-place scalar multiplication */
596 #define SELF_SCALE_SCALAR_2V( DST, S ) \
602 /** In-place scalar addition */
603 #define ACC_SCALAR_2V( DST, S ) \
609 /** Assign scalers to short vectors */
610 #define ASSIGN_2V( V, V0, V1 ) \
618 /** Copy \p sz elements into a homegeneous (4-element) vector, giving
619 * default values to the remaining components.
620 * The default values are chosen based on \p type.
623 COPY_CLEAN_4V_TYPE_AS_FLOAT(GLfloat dst
[4], int sz
, const GLfloat src
[4],
628 ASSIGN_4V(dst
, 0, 0, 0, 1);
631 ASSIGN_4V(dst
, INT_AS_FLT(0), INT_AS_FLT(0),
632 INT_AS_FLT(0), INT_AS_FLT(1));
634 case GL_UNSIGNED_INT
:
635 ASSIGN_4V(dst
, UINT_AS_FLT(0), UINT_AS_FLT(0),
636 UINT_AS_FLT(0), UINT_AS_FLT(1));
639 ASSIGN_4V(dst
, 0.0f
, 0.0f
, 0.0f
, 1.0f
); /* silence warnings */
640 ASSERT(!"Unexpected type in COPY_CLEAN_4V_TYPE_AS_FLOAT macro");
642 COPY_SZ_4V(dst
, sz
, src
);
645 /** \name Linear interpolation functions */
648 static inline GLfloat
649 LINTERP(GLfloat t
, GLfloat out
, GLfloat in
)
651 return out
+ t
* (in
- out
);
655 INTERP_3F(GLfloat t
, GLfloat dst
[3], const GLfloat out
[3], const GLfloat in
[3])
657 dst
[0] = LINTERP( t
, out
[0], in
[0] );
658 dst
[1] = LINTERP( t
, out
[1], in
[1] );
659 dst
[2] = LINTERP( t
, out
[2], in
[2] );
663 INTERP_4F(GLfloat t
, GLfloat dst
[4], const GLfloat out
[4], const GLfloat in
[4])
665 dst
[0] = LINTERP( t
, out
[0], in
[0] );
666 dst
[1] = LINTERP( t
, out
[1], in
[1] );
667 dst
[2] = LINTERP( t
, out
[2], in
[2] );
668 dst
[3] = LINTERP( t
, out
[3], in
[3] );
675 /** Clamp X to [MIN,MAX] */
676 #define CLAMP( X, MIN, MAX ) ( (X)<(MIN) ? (MIN) : ((X)>(MAX) ? (MAX) : (X)) )
678 /** Minimum of two values: */
679 #define MIN2( A, B ) ( (A)<(B) ? (A) : (B) )
681 /** Maximum of two values: */
682 #define MAX2( A, B ) ( (A)>(B) ? (A) : (B) )
684 /** Minimum and maximum of three values: */
685 #define MIN3( A, B, C ) ((A) < (B) ? MIN2(A, C) : MIN2(B, C))
686 #define MAX3( A, B, C ) ((A) > (B) ? MAX2(A, C) : MAX2(B, C))
688 static inline unsigned
689 minify(unsigned value
, unsigned levels
)
691 return MAX2(1, value
>> levels
);
695 * Return true if the given value is a power of two.
697 * Note that this considers 0 a power of two.
700 is_power_of_two(unsigned value
)
702 return (value
& (value
- 1)) == 0;
706 * Align a value up to an alignment value
708 * If \c value is not already aligned to the requested alignment value, it
709 * will be rounded up.
711 * \param value Value to be rounded
712 * \param alignment Alignment value to be used. This must be a power of two.
714 * \sa ROUND_DOWN_TO()
716 #define ALIGN(value, alignment) (((value) + (alignment) - 1) & ~((alignment) - 1))
719 * Align a value down to an alignment value
721 * If \c value is not already aligned to the requested alignment value, it
722 * will be rounded down.
724 * \param value Value to be rounded
725 * \param alignment Alignment value to be used. This must be a power of two.
729 #define ROUND_DOWN_TO(value, alignment) ((value) & ~(alignment - 1))
732 /** Cross product of two 3-element vectors */
734 CROSS3(GLfloat n
[3], const GLfloat u
[3], const GLfloat v
[3])
736 n
[0] = u
[1] * v
[2] - u
[2] * v
[1];
737 n
[1] = u
[2] * v
[0] - u
[0] * v
[2];
738 n
[2] = u
[0] * v
[1] - u
[1] * v
[0];
742 /** Dot product of two 2-element vectors */
743 static inline GLfloat
744 DOT2(const GLfloat a
[2], const GLfloat b
[2])
746 return a
[0] * b
[0] + a
[1] * b
[1];
749 static inline GLfloat
750 DOT3(const GLfloat a
[3], const GLfloat b
[3])
752 return a
[0] * b
[0] + a
[1] * b
[1] + a
[2] * b
[2];
755 static inline GLfloat
756 DOT4(const GLfloat a
[4], const GLfloat b
[4])
758 return a
[0] * b
[0] + a
[1] * b
[1] + a
[2] * b
[2] + a
[3] * b
[3];
762 static inline GLfloat
763 LEN_SQUARED_3FV(const GLfloat v
[3])
768 static inline GLfloat
769 LEN_SQUARED_2FV(const GLfloat v
[2])
775 static inline GLfloat
776 LEN_3FV(const GLfloat v
[3])
778 return sqrtf(LEN_SQUARED_3FV(v
));
781 static inline GLfloat
782 LEN_2FV(const GLfloat v
[2])
784 return sqrtf(LEN_SQUARED_2FV(v
));
788 /* Normalize a 3-element vector to unit length. */
790 NORMALIZE_3FV(GLfloat v
[3])
792 GLfloat len
= (GLfloat
) LEN_SQUARED_3FV(v
);
794 len
= INV_SQRTF(len
);
802 /** Is float value negative? */
803 static inline GLboolean
806 return signbit(x
) != 0;
809 /** Test two floats have opposite signs */
810 static inline GLboolean
811 DIFFERENT_SIGNS(GLfloat x
, GLfloat y
)
813 return signbit(x
) != signbit(y
);
817 /** Compute ceiling of integer quotient of A divided by B. */
818 #define CEILING( A, B ) ( (A) % (B) == 0 ? (A)/(B) : (A)/(B)+1 )
821 /** casts to silence warnings with some compilers */
822 #define ENUM_TO_INT(E) ((GLint)(E))
823 #define ENUM_TO_FLOAT(E) ((GLfloat)(GLint)(E))
824 #define ENUM_TO_DOUBLE(E) ((GLdouble)(GLint)(E))
825 #define ENUM_TO_BOOLEAN(E) ((E) ? GL_TRUE : GL_FALSE)
827 /* Compute the size of an array */
829 # define ARRAY_SIZE(x) (sizeof(x) / sizeof(x[0]))
833 #define STRINGIFY(x) #x