3 * A collection of useful macros.
7 * Mesa 3-D graphics library
10 * Copyright (C) 1999-2006 Brian Paul All Rights Reserved.
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:
19 * The above copyright notice and this permission notice shall be included
20 * in all copies or substantial portions of the Software.
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.
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]
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
148 #define UNCLAMPED_FLOAT_TO_UBYTE(UB, F) \
154 else if (__tmp.i >= IEEE_0996) \
155 UB = (GLubyte) 255; \
157 __tmp.f = __tmp.f * (255.0F/256.0F) + 32768.0F; \
158 UB = (GLubyte) __tmp.i; \
161 #define CLAMPED_FLOAT_TO_UBYTE(UB, F) \
164 __tmp.f = (F) * (255.0F/256.0F) + 32768.0F; \
165 UB = (GLubyte) __tmp.i; \
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))
174 static inline GLfloat
INT_AS_FLT(GLint i
)
181 static inline GLfloat
UINT_AS_FLT(GLuint u
)
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))
203 /**********************************************************************/
204 /** \name 4-element vector operations */
208 #define ZERO_4V( DST ) (DST)[0] = (DST)[1] = (DST)[2] = (DST)[3] = 0
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] && \
216 /** Test for equality (unsigned bytes) */
217 static inline GLboolean
218 TEST_EQ_4UBV(const GLubyte a
[4], const GLubyte b
[4])
220 #if defined(__i386__)
221 return *((const GLuint
*) a
) == *((const GLuint
*) b
);
223 return TEST_EQ_4V(a
, b
);
228 /** Copy a 4-element vector */
229 #define COPY_4V( DST, SRC ) \
231 (DST)[0] = (SRC)[0]; \
232 (DST)[1] = (SRC)[1]; \
233 (DST)[2] = (SRC)[2]; \
234 (DST)[3] = (SRC)[3]; \
237 /** Copy a 4-element unsigned byte vector */
239 COPY_4UBV(GLubyte dst
[4], const GLubyte src
[4])
241 #if defined(__i386__)
242 *((GLuint
*) dst
) = *((GLuint
*) src
);
244 /* The GLuint cast might fail if DST or SRC are not dword-aligned (RISC) */
249 /** Copy a 4-element float vector */
251 COPY_4FV(GLfloat dst
[4], const GLfloat src
[4])
253 /* memcpy seems to be most efficient */
254 memcpy(dst
, src
, sizeof(GLfloat
) * 4);
257 /** Copy \p SZ elements into a 4-element vector */
258 #define COPY_SZ_4V(DST, SZ, SRC) \
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]; \
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) \
272 ASSIGN_4V( DST, 0, 0, 0, 1 ); \
273 COPY_SZ_4V( DST, SZ, SRC ); \
277 #define SUB_4V( DST, SRCA, SRCB ) \
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]; \
286 #define ADD_4V( DST, SRCA, SRCB ) \
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]; \
294 /** Element-wise multiplication */
295 #define SCALE_4V( DST, SRCA, SRCB ) \
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]; \
303 /** In-place addition */
304 #define ACC_4V( DST, SRC ) \
306 (DST)[0] += (SRC)[0]; \
307 (DST)[1] += (SRC)[1]; \
308 (DST)[2] += (SRC)[2]; \
309 (DST)[3] += (SRC)[3]; \
312 /** Element-wise multiplication and addition */
313 #define ACC_SCALE_4V( DST, SRCA, SRCB ) \
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]; \
321 /** In-place scalar multiplication and addition */
322 #define ACC_SCALE_SCALAR_4V( DST, S, SRCB ) \
324 (DST)[0] += S * (SRCB)[0]; \
325 (DST)[1] += S * (SRCB)[1]; \
326 (DST)[2] += S * (SRCB)[2]; \
327 (DST)[3] += S * (SRCB)[3]; \
330 /** Scalar multiplication */
331 #define SCALE_SCALAR_4V( DST, S, SRCB ) \
333 (DST)[0] = S * (SRCB)[0]; \
334 (DST)[1] = S * (SRCB)[1]; \
335 (DST)[2] = S * (SRCB)[2]; \
336 (DST)[3] = S * (SRCB)[3]; \
339 /** In-place scalar multiplication */
340 #define SELF_SCALE_SCALAR_4V( DST, S ) \
349 #define ASSIGN_4V( V, V0, V1, V2, V3 ) \
360 /**********************************************************************/
361 /** \name 3-element vector operations*/
365 #define ZERO_3V( DST ) (DST)[0] = (DST)[1] = (DST)[2] = 0
367 /** Test for equality */
368 #define TEST_EQ_3V(a,b) \
369 ((a)[0] == (b)[0] && \
370 (a)[1] == (b)[1] && \
373 /** Copy a 3-element vector */
374 #define COPY_3V( DST, SRC ) \
376 (DST)[0] = (SRC)[0]; \
377 (DST)[1] = (SRC)[1]; \
378 (DST)[2] = (SRC)[2]; \
381 /** Copy a 3-element vector with cast */
382 #define COPY_3V_CAST( DST, SRC, CAST ) \
384 (DST)[0] = (CAST)(SRC)[0]; \
385 (DST)[1] = (CAST)(SRC)[1]; \
386 (DST)[2] = (CAST)(SRC)[2]; \
389 /** Copy a 3-element float vector */
390 #define COPY_3FV( DST, SRC ) \
392 const GLfloat *_tmp = (SRC); \
393 (DST)[0] = _tmp[0]; \
394 (DST)[1] = _tmp[1]; \
395 (DST)[2] = _tmp[2]; \
399 #define SUB_3V( DST, SRCA, SRCB ) \
401 (DST)[0] = (SRCA)[0] - (SRCB)[0]; \
402 (DST)[1] = (SRCA)[1] - (SRCB)[1]; \
403 (DST)[2] = (SRCA)[2] - (SRCB)[2]; \
407 #define ADD_3V( DST, SRCA, SRCB ) \
409 (DST)[0] = (SRCA)[0] + (SRCB)[0]; \
410 (DST)[1] = (SRCA)[1] + (SRCB)[1]; \
411 (DST)[2] = (SRCA)[2] + (SRCB)[2]; \
414 /** In-place scalar multiplication */
415 #define SCALE_3V( DST, SRCA, SRCB ) \
417 (DST)[0] = (SRCA)[0] * (SRCB)[0]; \
418 (DST)[1] = (SRCA)[1] * (SRCB)[1]; \
419 (DST)[2] = (SRCA)[2] * (SRCB)[2]; \
422 /** In-place element-wise multiplication */
423 #define SELF_SCALE_3V( DST, SRC ) \
425 (DST)[0] *= (SRC)[0]; \
426 (DST)[1] *= (SRC)[1]; \
427 (DST)[2] *= (SRC)[2]; \
430 /** In-place addition */
431 #define ACC_3V( DST, SRC ) \
433 (DST)[0] += (SRC)[0]; \
434 (DST)[1] += (SRC)[1]; \
435 (DST)[2] += (SRC)[2]; \
438 /** Element-wise multiplication and addition */
439 #define ACC_SCALE_3V( DST, SRCA, SRCB ) \
441 (DST)[0] += (SRCA)[0] * (SRCB)[0]; \
442 (DST)[1] += (SRCA)[1] * (SRCB)[1]; \
443 (DST)[2] += (SRCA)[2] * (SRCB)[2]; \
446 /** Scalar multiplication */
447 #define SCALE_SCALAR_3V( DST, S, SRCB ) \
449 (DST)[0] = S * (SRCB)[0]; \
450 (DST)[1] = S * (SRCB)[1]; \
451 (DST)[2] = S * (SRCB)[2]; \
454 /** In-place scalar multiplication and addition */
455 #define ACC_SCALE_SCALAR_3V( DST, S, SRCB ) \
457 (DST)[0] += S * (SRCB)[0]; \
458 (DST)[1] += S * (SRCB)[1]; \
459 (DST)[2] += S * (SRCB)[2]; \
462 /** In-place scalar multiplication */
463 #define SELF_SCALE_SCALAR_3V( DST, S ) \
470 /** In-place scalar addition */
471 #define ACC_SCALAR_3V( DST, S ) \
479 #define ASSIGN_3V( V, V0, V1, V2 ) \
489 /**********************************************************************/
490 /** \name 2-element vector operations*/
494 #define ZERO_2V( DST ) (DST)[0] = (DST)[1] = 0
496 /** Copy a 2-element vector */
497 #define COPY_2V( DST, SRC ) \
499 (DST)[0] = (SRC)[0]; \
500 (DST)[1] = (SRC)[1]; \
503 /** Copy a 2-element vector with cast */
504 #define COPY_2V_CAST( DST, SRC, CAST ) \
506 (DST)[0] = (CAST)(SRC)[0]; \
507 (DST)[1] = (CAST)(SRC)[1]; \
510 /** Copy a 2-element float vector */
511 #define COPY_2FV( DST, SRC ) \
513 const GLfloat *_tmp = (SRC); \
514 (DST)[0] = _tmp[0]; \
515 (DST)[1] = _tmp[1]; \
519 #define SUB_2V( DST, SRCA, SRCB ) \
521 (DST)[0] = (SRCA)[0] - (SRCB)[0]; \
522 (DST)[1] = (SRCA)[1] - (SRCB)[1]; \
526 #define ADD_2V( DST, SRCA, SRCB ) \
528 (DST)[0] = (SRCA)[0] + (SRCB)[0]; \
529 (DST)[1] = (SRCA)[1] + (SRCB)[1]; \
532 /** In-place scalar multiplication */
533 #define SCALE_2V( DST, SRCA, SRCB ) \
535 (DST)[0] = (SRCA)[0] * (SRCB)[0]; \
536 (DST)[1] = (SRCA)[1] * (SRCB)[1]; \
539 /** In-place addition */
540 #define ACC_2V( DST, SRC ) \
542 (DST)[0] += (SRC)[0]; \
543 (DST)[1] += (SRC)[1]; \
546 /** Element-wise multiplication and addition */
547 #define ACC_SCALE_2V( DST, SRCA, SRCB ) \
549 (DST)[0] += (SRCA)[0] * (SRCB)[0]; \
550 (DST)[1] += (SRCA)[1] * (SRCB)[1]; \
553 /** Scalar multiplication */
554 #define SCALE_SCALAR_2V( DST, S, SRCB ) \
556 (DST)[0] = S * (SRCB)[0]; \
557 (DST)[1] = S * (SRCB)[1]; \
560 /** In-place scalar multiplication and addition */
561 #define ACC_SCALE_SCALAR_2V( DST, S, SRCB ) \
563 (DST)[0] += S * (SRCB)[0]; \
564 (DST)[1] += S * (SRCB)[1]; \
567 /** In-place scalar multiplication */
568 #define SELF_SCALE_SCALAR_2V( DST, S ) \
574 /** In-place scalar addition */
575 #define ACC_SCALAR_2V( DST, S ) \
581 /** Assign scalers to short vectors */
582 #define ASSIGN_2V( V, V0, V1 ) \
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.
595 COPY_CLEAN_4V_TYPE_AS_FLOAT(GLfloat dst
[4], int sz
, const GLfloat src
[4],
600 ASSIGN_4V(dst
, 0, 0, 0, 1);
603 ASSIGN_4V(dst
, INT_AS_FLT(0), INT_AS_FLT(0),
604 INT_AS_FLT(0), INT_AS_FLT(1));
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));
613 COPY_SZ_4V(dst
, sz
, src
);
616 /** \name Linear interpolation functions */
619 static inline GLfloat
620 LINTERP(GLfloat t
, GLfloat out
, GLfloat in
)
622 return out
+ t
* (in
- out
);
626 INTERP_3F(GLfloat t
, GLfloat dst
[3], const GLfloat out
[3], const GLfloat in
[3])
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] );
634 INTERP_4F(GLfloat t
, GLfloat dst
[4], const GLfloat out
[4], const GLfloat in
[4])
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] );
646 /** Clamp X to [MIN,MAX] */
647 #define CLAMP( X, MIN, MAX ) ( (X)<(MIN) ? (MIN) : ((X)>(MAX) ? (MAX) : (X)) )
649 /** Minimum of two values: */
650 #define MIN2( A, B ) ( (A)<(B) ? (A) : (B) )
652 /** Maximum of two values: */
653 #define MAX2( A, B ) ( (A)>(B) ? (A) : (B) )
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))
660 * Align a value up to an alignment value
662 * If \c value is not already aligned to the requested alignment value, it
663 * will be rounded up.
665 * \param value Value to be rounded
666 * \param alignment Alignment value to be used. This must be a power of two.
668 * \sa ROUND_DOWN_TO()
670 #define ALIGN(value, alignment) (((value) + alignment - 1) & ~(alignment - 1))
674 /** Cross product of two 3-element vectors */
676 CROSS3(GLfloat n
[3], const GLfloat u
[3], const GLfloat v
[3])
678 n
[0] = u
[1] * v
[2] - u
[2] * v
[1];
679 n
[1] = u
[2] * v
[0] - u
[0] * v
[2];
680 n
[2] = u
[0] * v
[1] - u
[1] * v
[0];
684 /** Dot product of two 2-element vectors */
685 static inline GLfloat
686 DOT2(const GLfloat a
[2], const GLfloat b
[2])
688 return a
[0] * b
[0] + a
[1] * b
[1];
691 static inline GLfloat
692 DOT3(const GLfloat a
[3], const GLfloat b
[3])
694 return a
[0] * b
[0] + a
[1] * b
[1] + a
[2] * b
[2];
697 static inline GLfloat
698 DOT4(const GLfloat a
[4], const GLfloat b
[4])
700 return a
[0] * b
[0] + a
[1] * b
[1] + a
[2] * b
[2] + a
[3] * b
[3];
704 static inline GLfloat
705 LEN_SQUARED_3FV(const GLfloat v
[3])
710 static inline GLfloat
711 LEN_SQUARED_2FV(const GLfloat v
[2])
717 static inline GLfloat
718 LEN_3FV(const GLfloat v
[3])
720 return sqrtf(LEN_SQUARED_3FV(v
));
723 static inline GLfloat
724 LEN_2FV(const GLfloat v
[2])
726 return sqrtf(LEN_SQUARED_2FV(v
));
730 /* Normalize a 3-element vector to unit length. */
732 NORMALIZE_3FV(GLfloat v
[3])
734 GLfloat len
= (GLfloat
) LEN_SQUARED_3FV(v
);
736 len
= INV_SQRTF(len
);
744 /** Is float value negative? */
745 static inline GLboolean
748 return signbit(x
) != 0;
751 /** Test two floats have opposite signs */
752 static inline GLboolean
753 DIFFERENT_SIGNS(GLfloat x
, GLfloat y
)
755 return signbit(x
) != signbit(y
);
759 /** Compute ceiling of integer quotient of A divided by B. */
760 #define CEILING( A, B ) ( (A) % (B) == 0 ? (A)/(B) : (A)/(B)+1 )
763 /** casts to silence warnings with some compilers */
764 #define ENUM_TO_INT(E) ((GLint)(E))
765 #define ENUM_TO_FLOAT(E) ((GLfloat)(GLint)(E))
766 #define ENUM_TO_DOUBLE(E) ((GLdouble)(GLint)(E))
767 #define ENUM_TO_BOOLEAN(E) ((E) ? GL_TRUE : GL_FALSE)
769 /* Compute the size of an array */
770 #define ARRAY_SIZE(x) (sizeof(x) / sizeof(x[0]))