2 * Mesa 3-D graphics library
5 * Copyright (C) 1999-2005 Brian Paul All Rights Reserved.
7 * Permission is hereby granted, free of charge, to any person obtaining a
8 * copy of this software and associated documentation files (the "Software"),
9 * to deal in the Software without restriction, including without limitation
10 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
11 * and/or sell copies of the Software, and to permit persons to whom the
12 * Software is furnished to do so, subject to the following conditions:
14 * The above copyright notice and this permission notice shall be included
15 * in all copies or substantial portions of the Software.
17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
18 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
20 * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
21 * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
22 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
31 * -# 4x4 transformation matrices are stored in memory in column major order.
32 * -# Points/vertices are to be thought of as column vectors.
33 * -# Transformation of a point p by a matrix M is: p' = M * p
37 #include "main/glheader.h"
38 #include "main/imports.h"
39 #include "main/macros.h"
45 * \defgroup MatFlags MAT_FLAG_XXX-flags
47 * Bitmasks to indicate different kinds of 4x4 matrices in GLmatrix::flags
50 #define MAT_FLAG_IDENTITY 0 /**< is an identity matrix flag.
51 * (Not actually used - the identity
52 * matrix is identified by the absense
53 * of all other flags.)
55 #define MAT_FLAG_GENERAL 0x1 /**< is a general matrix flag */
56 #define MAT_FLAG_ROTATION 0x2 /**< is a rotation matrix flag */
57 #define MAT_FLAG_TRANSLATION 0x4 /**< is a translation matrix flag */
58 #define MAT_FLAG_UNIFORM_SCALE 0x8 /**< is an uniform scaling matrix flag */
59 #define MAT_FLAG_GENERAL_SCALE 0x10 /**< is a general scaling matrix flag */
60 #define MAT_FLAG_GENERAL_3D 0x20 /**< general 3D matrix flag */
61 #define MAT_FLAG_PERSPECTIVE 0x40 /**< is a perspective proj matrix flag */
62 #define MAT_FLAG_SINGULAR 0x80 /**< is a singular matrix flag */
63 #define MAT_DIRTY_TYPE 0x100 /**< matrix type is dirty */
64 #define MAT_DIRTY_FLAGS 0x200 /**< matrix flags are dirty */
65 #define MAT_DIRTY_INVERSE 0x400 /**< matrix inverse is dirty */
67 /** angle preserving matrix flags mask */
68 #define MAT_FLAGS_ANGLE_PRESERVING (MAT_FLAG_ROTATION | \
69 MAT_FLAG_TRANSLATION | \
70 MAT_FLAG_UNIFORM_SCALE)
72 /** geometry related matrix flags mask */
73 #define MAT_FLAGS_GEOMETRY (MAT_FLAG_GENERAL | \
75 MAT_FLAG_TRANSLATION | \
76 MAT_FLAG_UNIFORM_SCALE | \
77 MAT_FLAG_GENERAL_SCALE | \
78 MAT_FLAG_GENERAL_3D | \
79 MAT_FLAG_PERSPECTIVE | \
82 /** length preserving matrix flags mask */
83 #define MAT_FLAGS_LENGTH_PRESERVING (MAT_FLAG_ROTATION | \
87 /** 3D (non-perspective) matrix flags mask */
88 #define MAT_FLAGS_3D (MAT_FLAG_ROTATION | \
89 MAT_FLAG_TRANSLATION | \
90 MAT_FLAG_UNIFORM_SCALE | \
91 MAT_FLAG_GENERAL_SCALE | \
94 /** dirty matrix flags mask */
95 #define MAT_DIRTY (MAT_DIRTY_TYPE | \
103 * Test geometry related matrix flags.
105 * \param mat a pointer to a GLmatrix structure.
106 * \param a flags mask.
108 * \returns non-zero if all geometry related matrix flags are contained within
109 * the mask, or zero otherwise.
111 #define TEST_MAT_FLAGS(mat, a) \
112 ((MAT_FLAGS_GEOMETRY & (~(a)) & ((mat)->flags) ) == 0)
117 * Names of the corresponding GLmatrixtype values.
119 static const char *types[] = {
123 "MATRIX_PERSPECTIVE",
133 static GLfloat Identity[16] = {
142 /**********************************************************************/
143 /** \name Matrix multiplication */
146 #define A(row,col) a[(col<<2)+row]
147 #define B(row,col) b[(col<<2)+row]
148 #define P(row,col) product[(col<<2)+row]
151 * Perform a full 4x4 matrix multiplication.
155 * \param product will receive the product of \p a and \p b.
157 * \warning Is assumed that \p product != \p b. \p product == \p a is allowed.
159 * \note KW: 4*16 = 64 multiplications
161 * \author This \c matmul was contributed by Thomas Malik
163 static void matmul4( GLfloat *product, const GLfloat *a, const GLfloat *b )
166 for (i = 0; i < 4; i++) {
167 const GLfloat ai0=A(i,0), ai1=A(i,1), ai2=A(i,2), ai3=A(i,3);
168 P(i,0) = ai0 * B(0,0) + ai1 * B(1,0) + ai2 * B(2,0) + ai3 * B(3,0);
169 P(i,1) = ai0 * B(0,1) + ai1 * B(1,1) + ai2 * B(2,1) + ai3 * B(3,1);
170 P(i,2) = ai0 * B(0,2) + ai1 * B(1,2) + ai2 * B(2,2) + ai3 * B(3,2);
171 P(i,3) = ai0 * B(0,3) + ai1 * B(1,3) + ai2 * B(2,3) + ai3 * B(3,3);
176 * Multiply two matrices known to occupy only the top three rows, such
177 * as typical model matrices, and orthogonal matrices.
181 * \param product will receive the product of \p a and \p b.
183 static void matmul34( GLfloat *product, const GLfloat *a, const GLfloat *b )
186 for (i = 0; i < 3; i++) {
187 const GLfloat ai0=A(i,0), ai1=A(i,1), ai2=A(i,2), ai3=A(i,3);
188 P(i,0) = ai0 * B(0,0) + ai1 * B(1,0) + ai2 * B(2,0);
189 P(i,1) = ai0 * B(0,1) + ai1 * B(1,1) + ai2 * B(2,1);
190 P(i,2) = ai0 * B(0,2) + ai1 * B(1,2) + ai2 * B(2,2);
191 P(i,3) = ai0 * B(0,3) + ai1 * B(1,3) + ai2 * B(2,3) + ai3;
204 * Multiply a matrix by an array of floats with known properties.
206 * \param mat pointer to a GLmatrix structure containing the left multiplication
207 * matrix, and that will receive the product result.
208 * \param m right multiplication matrix array.
209 * \param flags flags of the matrix \p m.
211 * Joins both flags and marks the type and inverse as dirty. Calls matmul34()
212 * if both matrices are 3D, or matmul4() otherwise.
214 static void matrix_multf( GLmatrix *mat, const GLfloat *m, GLuint flags )
216 mat->flags |= (flags | MAT_DIRTY_TYPE | MAT_DIRTY_INVERSE);
218 if (TEST_MAT_FLAGS(mat, MAT_FLAGS_3D))
219 matmul34( mat->m, mat->m, m );
221 matmul4( mat->m, mat->m, m );
225 * Matrix multiplication.
227 * \param dest destination matrix.
228 * \param a left matrix.
229 * \param b right matrix.
231 * Joins both flags and marks the type and inverse as dirty. Calls matmul34()
232 * if both matrices are 3D, or matmul4() otherwise.
235 _math_matrix_mul_matrix( GLmatrix *dest, const GLmatrix *a, const GLmatrix *b )
237 dest->flags = (a->flags |
242 if (TEST_MAT_FLAGS(dest, MAT_FLAGS_3D))
243 matmul34( dest->m, a->m, b->m );
245 matmul4( dest->m, a->m, b->m );
249 * Matrix multiplication.
251 * \param dest left and destination matrix.
252 * \param m right matrix array.
254 * Marks the matrix flags with general flag, and type and inverse dirty flags.
255 * Calls matmul4() for the multiplication.
258 _math_matrix_mul_floats( GLmatrix *dest, const GLfloat *m )
260 dest->flags |= (MAT_FLAG_GENERAL |
265 matmul4( dest->m, dest->m, m );
271 /**********************************************************************/
272 /** \name Matrix output */
276 * Print a matrix array.
278 * \param m matrix array.
280 * Called by _math_matrix_print() to print a matrix or its inverse.
282 static void print_matrix_floats( const GLfloat m[16] )
286 _mesa_debug(NULL,"\t%f %f %f %f\n", m[i], m[4+i], m[8+i], m[12+i] );
291 * Dumps the contents of a GLmatrix structure.
293 * \param m pointer to the GLmatrix structure.
296 _math_matrix_print( const GLmatrix *m )
300 _mesa_debug(NULL, "Matrix type: %s, flags: %x\n", types[m->type], m->flags);
301 print_matrix_floats(m->m);
302 _mesa_debug(NULL, "Inverse: \n");
303 print_matrix_floats(m->inv);
304 matmul4(prod, m->m, m->inv);
305 _mesa_debug(NULL, "Mat * Inverse:\n");
306 print_matrix_floats(prod);
313 * References an element of 4x4 matrix.
315 * \param m matrix array.
316 * \param c column of the desired element.
317 * \param r row of the desired element.
319 * \return value of the desired element.
321 * Calculate the linear storage index of the element and references it.
323 #define MAT(m,r,c) (m)[(c)*4+(r)]
326 /**********************************************************************/
327 /** \name Matrix inversion */
331 * Swaps the values of two floating point variables.
333 * Used by invert_matrix_general() to swap the row pointers.
335 #define SWAP_ROWS(a, b) { GLfloat *_tmp = a; (a)=(b); (b)=_tmp; }
338 * Compute inverse of 4x4 transformation matrix.
340 * \param mat pointer to a GLmatrix structure. The matrix inverse will be
341 * stored in the GLmatrix::inv attribute.
343 * \return GL_TRUE for success, GL_FALSE for failure (\p singular matrix).
346 * Code contributed by Jacques Leroy jle@star.be
348 * Calculates the inverse matrix by performing the gaussian matrix reduction
349 * with partial pivoting followed by back/substitution with the loops manually
352 static GLboolean invert_matrix_general( GLmatrix *mat )
354 const GLfloat *m = mat->m;
355 GLfloat *out = mat->inv;
357 GLfloat m0, m1, m2, m3, s;
358 GLfloat *r0, *r1, *r2, *r3;
360 r0 = wtmp[0], r1 = wtmp[1], r2 = wtmp[2], r3 = wtmp[3];
362 r0[0] = MAT(m,0,0), r0[1] = MAT(m,0,1),
363 r0[2] = MAT(m,0,2), r0[3] = MAT(m,0,3),
364 r0[4] = 1.0, r0[5] = r0[6] = r0[7] = 0.0,
366 r1[0] = MAT(m,1,0), r1[1] = MAT(m,1,1),
367 r1[2] = MAT(m,1,2), r1[3] = MAT(m,1,3),
368 r1[5] = 1.0, r1[4] = r1[6] = r1[7] = 0.0,
370 r2[0] = MAT(m,2,0), r2[1] = MAT(m,2,1),
371 r2[2] = MAT(m,2,2), r2[3] = MAT(m,2,3),
372 r2[6] = 1.0, r2[4] = r2[5] = r2[7] = 0.0,
374 r3[0] = MAT(m,3,0), r3[1] = MAT(m,3,1),
375 r3[2] = MAT(m,3,2), r3[3] = MAT(m,3,3),
376 r3[7] = 1.0, r3[4] = r3[5] = r3[6] = 0.0;
378 /* choose pivot - or die */
379 if (FABSF(r3[0])>FABSF(r2[0])) SWAP_ROWS(r3, r2);
380 if (FABSF(r2[0])>FABSF(r1[0])) SWAP_ROWS(r2, r1);
381 if (FABSF(r1[0])>FABSF(r0[0])) SWAP_ROWS(r1, r0);
382 if (0.0 == r0[0]) return GL_FALSE;
384 /* eliminate first variable */
385 m1 = r1[0]/r0[0]; m2 = r2[0]/r0[0]; m3 = r3[0]/r0[0];
386 s = r0[1]; r1[1] -= m1 * s; r2[1] -= m2 * s; r3[1] -= m3 * s;
387 s = r0[2]; r1[2] -= m1 * s; r2[2] -= m2 * s; r3[2] -= m3 * s;
388 s = r0[3]; r1[3] -= m1 * s; r2[3] -= m2 * s; r3[3] -= m3 * s;
390 if (s != 0.0) { r1[4] -= m1 * s; r2[4] -= m2 * s; r3[4] -= m3 * s; }
392 if (s != 0.0) { r1[5] -= m1 * s; r2[5] -= m2 * s; r3[5] -= m3 * s; }
394 if (s != 0.0) { r1[6] -= m1 * s; r2[6] -= m2 * s; r3[6] -= m3 * s; }
396 if (s != 0.0) { r1[7] -= m1 * s; r2[7] -= m2 * s; r3[7] -= m3 * s; }
398 /* choose pivot - or die */
399 if (FABSF(r3[1])>FABSF(r2[1])) SWAP_ROWS(r3, r2);
400 if (FABSF(r2[1])>FABSF(r1[1])) SWAP_ROWS(r2, r1);
401 if (0.0 == r1[1]) return GL_FALSE;
403 /* eliminate second variable */
404 m2 = r2[1]/r1[1]; m3 = r3[1]/r1[1];
405 r2[2] -= m2 * r1[2]; r3[2] -= m3 * r1[2];
406 r2[3] -= m2 * r1[3]; r3[3] -= m3 * r1[3];
407 s = r1[4]; if (0.0 != s) { r2[4] -= m2 * s; r3[4] -= m3 * s; }
408 s = r1[5]; if (0.0 != s) { r2[5] -= m2 * s; r3[5] -= m3 * s; }
409 s = r1[6]; if (0.0 != s) { r2[6] -= m2 * s; r3[6] -= m3 * s; }
410 s = r1[7]; if (0.0 != s) { r2[7] -= m2 * s; r3[7] -= m3 * s; }
412 /* choose pivot - or die */
413 if (FABSF(r3[2])>FABSF(r2[2])) SWAP_ROWS(r3, r2);
414 if (0.0 == r2[2]) return GL_FALSE;
416 /* eliminate third variable */
418 r3[3] -= m3 * r2[3], r3[4] -= m3 * r2[4],
419 r3[5] -= m3 * r2[5], r3[6] -= m3 * r2[6],
423 if (0.0 == r3[3]) return GL_FALSE;
425 s = 1.0F/r3[3]; /* now back substitute row 3 */
426 r3[4] *= s; r3[5] *= s; r3[6] *= s; r3[7] *= s;
428 m2 = r2[3]; /* now back substitute row 2 */
430 r2[4] = s * (r2[4] - r3[4] * m2), r2[5] = s * (r2[5] - r3[5] * m2),
431 r2[6] = s * (r2[6] - r3[6] * m2), r2[7] = s * (r2[7] - r3[7] * m2);
433 r1[4] -= r3[4] * m1, r1[5] -= r3[5] * m1,
434 r1[6] -= r3[6] * m1, r1[7] -= r3[7] * m1;
436 r0[4] -= r3[4] * m0, r0[5] -= r3[5] * m0,
437 r0[6] -= r3[6] * m0, r0[7] -= r3[7] * m0;
439 m1 = r1[2]; /* now back substitute row 1 */
441 r1[4] = s * (r1[4] - r2[4] * m1), r1[5] = s * (r1[5] - r2[5] * m1),
442 r1[6] = s * (r1[6] - r2[6] * m1), r1[7] = s * (r1[7] - r2[7] * m1);
444 r0[4] -= r2[4] * m0, r0[5] -= r2[5] * m0,
445 r0[6] -= r2[6] * m0, r0[7] -= r2[7] * m0;
447 m0 = r0[1]; /* now back substitute row 0 */
449 r0[4] = s * (r0[4] - r1[4] * m0), r0[5] = s * (r0[5] - r1[5] * m0),
450 r0[6] = s * (r0[6] - r1[6] * m0), r0[7] = s * (r0[7] - r1[7] * m0);
452 MAT(out,0,0) = r0[4]; MAT(out,0,1) = r0[5],
453 MAT(out,0,2) = r0[6]; MAT(out,0,3) = r0[7],
454 MAT(out,1,0) = r1[4]; MAT(out,1,1) = r1[5],
455 MAT(out,1,2) = r1[6]; MAT(out,1,3) = r1[7],
456 MAT(out,2,0) = r2[4]; MAT(out,2,1) = r2[5],
457 MAT(out,2,2) = r2[6]; MAT(out,2,3) = r2[7],
458 MAT(out,3,0) = r3[4]; MAT(out,3,1) = r3[5],
459 MAT(out,3,2) = r3[6]; MAT(out,3,3) = r3[7];
466 * Compute inverse of a general 3d transformation matrix.
468 * \param mat pointer to a GLmatrix structure. The matrix inverse will be
469 * stored in the GLmatrix::inv attribute.
471 * \return GL_TRUE for success, GL_FALSE for failure (\p singular matrix).
473 * \author Adapted from graphics gems II.
475 * Calculates the inverse of the upper left by first calculating its
476 * determinant and multiplying it to the symmetric adjust matrix of each
477 * element. Finally deals with the translation part by transforming the
478 * original translation vector using by the calculated submatrix inverse.
480 static GLboolean invert_matrix_3d_general( GLmatrix *mat )
482 const GLfloat *in = mat->m;
483 GLfloat *out = mat->inv;
487 /* Calculate the determinant of upper left 3x3 submatrix and
488 * determine if the matrix is singular.
491 t = MAT(in,0,0) * MAT(in,1,1) * MAT(in,2,2);
492 if (t >= 0.0) pos += t; else neg += t;
494 t = MAT(in,1,0) * MAT(in,2,1) * MAT(in,0,2);
495 if (t >= 0.0) pos += t; else neg += t;
497 t = MAT(in,2,0) * MAT(in,0,1) * MAT(in,1,2);
498 if (t >= 0.0) pos += t; else neg += t;
500 t = -MAT(in,2,0) * MAT(in,1,1) * MAT(in,0,2);
501 if (t >= 0.0) pos += t; else neg += t;
503 t = -MAT(in,1,0) * MAT(in,0,1) * MAT(in,2,2);
504 if (t >= 0.0) pos += t; else neg += t;
506 t = -MAT(in,0,0) * MAT(in,2,1) * MAT(in,1,2);
507 if (t >= 0.0) pos += t; else neg += t;
511 if (FABSF(det) < 1e-25)
515 MAT(out,0,0) = ( (MAT(in,1,1)*MAT(in,2,2) - MAT(in,2,1)*MAT(in,1,2) )*det);
516 MAT(out,0,1) = (- (MAT(in,0,1)*MAT(in,2,2) - MAT(in,2,1)*MAT(in,0,2) )*det);
517 MAT(out,0,2) = ( (MAT(in,0,1)*MAT(in,1,2) - MAT(in,1,1)*MAT(in,0,2) )*det);
518 MAT(out,1,0) = (- (MAT(in,1,0)*MAT(in,2,2) - MAT(in,2,0)*MAT(in,1,2) )*det);
519 MAT(out,1,1) = ( (MAT(in,0,0)*MAT(in,2,2) - MAT(in,2,0)*MAT(in,0,2) )*det);
520 MAT(out,1,2) = (- (MAT(in,0,0)*MAT(in,1,2) - MAT(in,1,0)*MAT(in,0,2) )*det);
521 MAT(out,2,0) = ( (MAT(in,1,0)*MAT(in,2,1) - MAT(in,2,0)*MAT(in,1,1) )*det);
522 MAT(out,2,1) = (- (MAT(in,0,0)*MAT(in,2,1) - MAT(in,2,0)*MAT(in,0,1) )*det);
523 MAT(out,2,2) = ( (MAT(in,0,0)*MAT(in,1,1) - MAT(in,1,0)*MAT(in,0,1) )*det);
525 /* Do the translation part */
526 MAT(out,0,3) = - (MAT(in,0,3) * MAT(out,0,0) +
527 MAT(in,1,3) * MAT(out,0,1) +
528 MAT(in,2,3) * MAT(out,0,2) );
529 MAT(out,1,3) = - (MAT(in,0,3) * MAT(out,1,0) +
530 MAT(in,1,3) * MAT(out,1,1) +
531 MAT(in,2,3) * MAT(out,1,2) );
532 MAT(out,2,3) = - (MAT(in,0,3) * MAT(out,2,0) +
533 MAT(in,1,3) * MAT(out,2,1) +
534 MAT(in,2,3) * MAT(out,2,2) );
540 * Compute inverse of a 3d transformation matrix.
542 * \param mat pointer to a GLmatrix structure. The matrix inverse will be
543 * stored in the GLmatrix::inv attribute.
545 * \return GL_TRUE for success, GL_FALSE for failure (\p singular matrix).
547 * If the matrix is not an angle preserving matrix then calls
548 * invert_matrix_3d_general for the actual calculation. Otherwise calculates
549 * the inverse matrix analyzing and inverting each of the scaling, rotation and
552 static GLboolean invert_matrix_3d( GLmatrix *mat )
554 const GLfloat *in = mat->m;
555 GLfloat *out = mat->inv;
557 if (!TEST_MAT_FLAGS(mat, MAT_FLAGS_ANGLE_PRESERVING)) {
558 return invert_matrix_3d_general( mat );
561 if (mat->flags & MAT_FLAG_UNIFORM_SCALE) {
562 GLfloat scale = (MAT(in,0,0) * MAT(in,0,0) +
563 MAT(in,0,1) * MAT(in,0,1) +
564 MAT(in,0,2) * MAT(in,0,2));
569 scale = 1.0F / scale;
571 /* Transpose and scale the 3 by 3 upper-left submatrix. */
572 MAT(out,0,0) = scale * MAT(in,0,0);
573 MAT(out,1,0) = scale * MAT(in,0,1);
574 MAT(out,2,0) = scale * MAT(in,0,2);
575 MAT(out,0,1) = scale * MAT(in,1,0);
576 MAT(out,1,1) = scale * MAT(in,1,1);
577 MAT(out,2,1) = scale * MAT(in,1,2);
578 MAT(out,0,2) = scale * MAT(in,2,0);
579 MAT(out,1,2) = scale * MAT(in,2,1);
580 MAT(out,2,2) = scale * MAT(in,2,2);
582 else if (mat->flags & MAT_FLAG_ROTATION) {
583 /* Transpose the 3 by 3 upper-left submatrix. */
584 MAT(out,0,0) = MAT(in,0,0);
585 MAT(out,1,0) = MAT(in,0,1);
586 MAT(out,2,0) = MAT(in,0,2);
587 MAT(out,0,1) = MAT(in,1,0);
588 MAT(out,1,1) = MAT(in,1,1);
589 MAT(out,2,1) = MAT(in,1,2);
590 MAT(out,0,2) = MAT(in,2,0);
591 MAT(out,1,2) = MAT(in,2,1);
592 MAT(out,2,2) = MAT(in,2,2);
595 /* pure translation */
596 memcpy( out, Identity, sizeof(Identity) );
597 MAT(out,0,3) = - MAT(in,0,3);
598 MAT(out,1,3) = - MAT(in,1,3);
599 MAT(out,2,3) = - MAT(in,2,3);
603 if (mat->flags & MAT_FLAG_TRANSLATION) {
604 /* Do the translation part */
605 MAT(out,0,3) = - (MAT(in,0,3) * MAT(out,0,0) +
606 MAT(in,1,3) * MAT(out,0,1) +
607 MAT(in,2,3) * MAT(out,0,2) );
608 MAT(out,1,3) = - (MAT(in,0,3) * MAT(out,1,0) +
609 MAT(in,1,3) * MAT(out,1,1) +
610 MAT(in,2,3) * MAT(out,1,2) );
611 MAT(out,2,3) = - (MAT(in,0,3) * MAT(out,2,0) +
612 MAT(in,1,3) * MAT(out,2,1) +
613 MAT(in,2,3) * MAT(out,2,2) );
616 MAT(out,0,3) = MAT(out,1,3) = MAT(out,2,3) = 0.0;
623 * Compute inverse of an identity transformation matrix.
625 * \param mat pointer to a GLmatrix structure. The matrix inverse will be
626 * stored in the GLmatrix::inv attribute.
628 * \return always GL_TRUE.
630 * Simply copies Identity into GLmatrix::inv.
632 static GLboolean invert_matrix_identity( GLmatrix *mat )
634 memcpy( mat->inv, Identity, sizeof(Identity) );
639 * Compute inverse of a no-rotation 3d transformation matrix.
641 * \param mat pointer to a GLmatrix structure. The matrix inverse will be
642 * stored in the GLmatrix::inv attribute.
644 * \return GL_TRUE for success, GL_FALSE for failure (\p singular matrix).
648 static GLboolean invert_matrix_3d_no_rot( GLmatrix *mat )
650 const GLfloat *in = mat->m;
651 GLfloat *out = mat->inv;
653 if (MAT(in,0,0) == 0 || MAT(in,1,1) == 0 || MAT(in,2,2) == 0 )
656 memcpy( out, Identity, 16 * sizeof(GLfloat) );
657 MAT(out,0,0) = 1.0F / MAT(in,0,0);
658 MAT(out,1,1) = 1.0F / MAT(in,1,1);
659 MAT(out,2,2) = 1.0F / MAT(in,2,2);
661 if (mat->flags & MAT_FLAG_TRANSLATION) {
662 MAT(out,0,3) = - (MAT(in,0,3) * MAT(out,0,0));
663 MAT(out,1,3) = - (MAT(in,1,3) * MAT(out,1,1));
664 MAT(out,2,3) = - (MAT(in,2,3) * MAT(out,2,2));
671 * Compute inverse of a no-rotation 2d transformation matrix.
673 * \param mat pointer to a GLmatrix structure. The matrix inverse will be
674 * stored in the GLmatrix::inv attribute.
676 * \return GL_TRUE for success, GL_FALSE for failure (\p singular matrix).
678 * Calculates the inverse matrix by applying the inverse scaling and
679 * translation to the identity matrix.
681 static GLboolean invert_matrix_2d_no_rot( GLmatrix *mat )
683 const GLfloat *in = mat->m;
684 GLfloat *out = mat->inv;
686 if (MAT(in,0,0) == 0 || MAT(in,1,1) == 0)
689 memcpy( out, Identity, 16 * sizeof(GLfloat) );
690 MAT(out,0,0) = 1.0F / MAT(in,0,0);
691 MAT(out,1,1) = 1.0F / MAT(in,1,1);
693 if (mat->flags & MAT_FLAG_TRANSLATION) {
694 MAT(out,0,3) = - (MAT(in,0,3) * MAT(out,0,0));
695 MAT(out,1,3) = - (MAT(in,1,3) * MAT(out,1,1));
703 static GLboolean invert_matrix_perspective( GLmatrix *mat )
705 const GLfloat *in = mat->m;
706 GLfloat *out = mat->inv;
708 if (MAT(in,2,3) == 0)
711 memcpy( out, Identity, 16 * sizeof(GLfloat) );
713 MAT(out,0,0) = 1.0F / MAT(in,0,0);
714 MAT(out,1,1) = 1.0F / MAT(in,1,1);
716 MAT(out,0,3) = MAT(in,0,2);
717 MAT(out,1,3) = MAT(in,1,2);
722 MAT(out,3,2) = 1.0F / MAT(in,2,3);
723 MAT(out,3,3) = MAT(in,2,2) * MAT(out,3,2);
730 * Matrix inversion function pointer type.
732 typedef GLboolean (*inv_mat_func)( GLmatrix *mat );
735 * Table of the matrix inversion functions according to the matrix type.
737 static inv_mat_func inv_mat_tab[7] = {
738 invert_matrix_general,
739 invert_matrix_identity,
740 invert_matrix_3d_no_rot,
742 /* Don't use this function for now - it fails when the projection matrix
743 * is premultiplied by a translation (ala Chromium's tilesort SPU).
745 invert_matrix_perspective,
747 invert_matrix_general,
749 invert_matrix_3d, /* lazy! */
750 invert_matrix_2d_no_rot,
755 * Compute inverse of a transformation matrix.
757 * \param mat pointer to a GLmatrix structure. The matrix inverse will be
758 * stored in the GLmatrix::inv attribute.
760 * \return GL_TRUE for success, GL_FALSE for failure (\p singular matrix).
762 * Calls the matrix inversion function in inv_mat_tab corresponding to the
763 * given matrix type. In case of failure, updates the MAT_FLAG_SINGULAR flag,
764 * and copies the identity matrix into GLmatrix::inv.
766 static GLboolean matrix_invert( GLmatrix *mat )
768 if (inv_mat_tab[mat->type](mat)) {
769 mat->flags &= ~MAT_FLAG_SINGULAR;
772 mat->flags |= MAT_FLAG_SINGULAR;
773 memcpy( mat->inv, Identity, sizeof(Identity) );
781 /**********************************************************************/
782 /** \name Matrix generation */
786 * Generate a 4x4 transformation matrix from glRotate parameters, and
787 * post-multiply the input matrix by it.
790 * This function was contributed by Erich Boleyn (erich@uruk.org).
791 * Optimizations contributed by Rudolf Opalla (rudi@khm.de).
794 _math_matrix_rotate( GLmatrix *mat,
795 GLfloat angle, GLfloat x, GLfloat y, GLfloat z )
797 GLfloat xx, yy, zz, xy, yz, zx, xs, ys, zs, one_c, s, c;
801 s = (GLfloat) sin( angle * DEG2RAD );
802 c = (GLfloat) cos( angle * DEG2RAD );
804 memcpy(m, Identity, sizeof(GLfloat)*16);
805 optimized = GL_FALSE;
807 #define M(row,col) m[col*4+row]
813 /* rotate only around z-axis */
826 else if (z == 0.0F) {
828 /* rotate only around y-axis */
841 else if (y == 0.0F) {
844 /* rotate only around x-axis */
859 const GLfloat mag = SQRTF(x * x + y * y + z * z);
862 /* no rotation, leave mat as-is */
872 * Arbitrary axis rotation matrix.
874 * This is composed of 5 matrices, Rz, Ry, T, Ry', Rz', multiplied
875 * like so: Rz * Ry * T * Ry' * Rz'. T is the final rotation
876 * (which is about the X-axis), and the two composite transforms
877 * Ry' * Rz' and Rz * Ry are (respectively) the rotations necessary
878 * from the arbitrary axis to the X-axis then back. They are
879 * all elementary rotations.
881 * Rz' is a rotation about the Z-axis, to bring the axis vector
882 * into the x-z plane. Then Ry' is applied, rotating about the
883 * Y-axis to bring the axis vector parallel with the X-axis. The
884 * rotation about the X-axis is then performed. Ry and Rz are
885 * simply the respective inverse transforms to bring the arbitrary
886 * axis back to its original orientation. The first transforms
887 * Rz' and Ry' are considered inverses, since the data from the
888 * arbitrary axis gives you info on how to get to it, not how
889 * to get away from it, and an inverse must be applied.
891 * The basic calculation used is to recognize that the arbitrary
892 * axis vector (x, y, z), since it is of unit length, actually
893 * represents the sines and cosines of the angles to rotate the
894 * X-axis to the same orientation, with theta being the angle about
895 * Z and phi the angle about Y (in the order described above)
898 * cos ( theta ) = x / sqrt ( 1 - z^2 )
899 * sin ( theta ) = y / sqrt ( 1 - z^2 )
901 * cos ( phi ) = sqrt ( 1 - z^2 )
904 * Note that cos ( phi ) can further be inserted to the above
907 * cos ( theta ) = x / cos ( phi )
908 * sin ( theta ) = y / sin ( phi )
910 * ...etc. Because of those relations and the standard trigonometric
911 * relations, it is pssible to reduce the transforms down to what
912 * is used below. It may be that any primary axis chosen will give the
913 * same results (modulo a sign convention) using thie method.
915 * Particularly nice is to notice that all divisions that might
916 * have caused trouble when parallel to certain planes or
917 * axis go away with care paid to reducing the expressions.
918 * After checking, it does perform correctly under all cases, since
919 * in all the cases of division where the denominator would have
920 * been zero, the numerator would have been zero as well, giving
921 * the expected result.
935 /* We already hold the identity-matrix so we can skip some statements */
936 M(0,0) = (one_c * xx) + c;
937 M(0,1) = (one_c * xy) - zs;
938 M(0,2) = (one_c * zx) + ys;
941 M(1,0) = (one_c * xy) + zs;
942 M(1,1) = (one_c * yy) + c;
943 M(1,2) = (one_c * yz) - xs;
946 M(2,0) = (one_c * zx) - ys;
947 M(2,1) = (one_c * yz) + xs;
948 M(2,2) = (one_c * zz) + c;
960 matrix_multf( mat, m, MAT_FLAG_ROTATION );
964 * Apply a perspective projection matrix.
966 * \param mat matrix to apply the projection.
967 * \param left left clipping plane coordinate.
968 * \param right right clipping plane coordinate.
969 * \param bottom bottom clipping plane coordinate.
970 * \param top top clipping plane coordinate.
971 * \param nearval distance to the near clipping plane.
972 * \param farval distance to the far clipping plane.
974 * Creates the projection matrix and multiplies it with \p mat, marking the
975 * MAT_FLAG_PERSPECTIVE flag.
978 _math_matrix_frustum( GLmatrix *mat,
979 GLfloat left, GLfloat right,
980 GLfloat bottom, GLfloat top,
981 GLfloat nearval, GLfloat farval )
983 GLfloat x, y, a, b, c, d;
986 x = (2.0F*nearval) / (right-left);
987 y = (2.0F*nearval) / (top-bottom);
988 a = (right+left) / (right-left);
989 b = (top+bottom) / (top-bottom);
990 c = -(farval+nearval) / ( farval-nearval);
991 d = -(2.0F*farval*nearval) / (farval-nearval); /* error? */
993 #define M(row,col) m[col*4+row]
994 M(0,0) = x; M(0,1) = 0.0F; M(0,2) = a; M(0,3) = 0.0F;
995 M(1,0) = 0.0F; M(1,1) = y; M(1,2) = b; M(1,3) = 0.0F;
996 M(2,0) = 0.0F; M(2,1) = 0.0F; M(2,2) = c; M(2,3) = d;
997 M(3,0) = 0.0F; M(3,1) = 0.0F; M(3,2) = -1.0F; M(3,3) = 0.0F;
1000 matrix_multf( mat, m, MAT_FLAG_PERSPECTIVE );
1004 * Apply an orthographic projection matrix.
1006 * \param mat matrix to apply the projection.
1007 * \param left left clipping plane coordinate.
1008 * \param right right clipping plane coordinate.
1009 * \param bottom bottom clipping plane coordinate.
1010 * \param top top clipping plane coordinate.
1011 * \param nearval distance to the near clipping plane.
1012 * \param farval distance to the far clipping plane.
1014 * Creates the projection matrix and multiplies it with \p mat, marking the
1015 * MAT_FLAG_GENERAL_SCALE and MAT_FLAG_TRANSLATION flags.
1018 _math_matrix_ortho( GLmatrix *mat,
1019 GLfloat left, GLfloat right,
1020 GLfloat bottom, GLfloat top,
1021 GLfloat nearval, GLfloat farval )
1025 #define M(row,col) m[col*4+row]
1026 M(0,0) = 2.0F / (right-left);
1029 M(0,3) = -(right+left) / (right-left);
1032 M(1,1) = 2.0F / (top-bottom);
1034 M(1,3) = -(top+bottom) / (top-bottom);
1038 M(2,2) = -2.0F / (farval-nearval);
1039 M(2,3) = -(farval+nearval) / (farval-nearval);
1047 matrix_multf( mat, m, (MAT_FLAG_GENERAL_SCALE|MAT_FLAG_TRANSLATION));
1051 * Multiply a matrix with a general scaling matrix.
1053 * \param mat matrix.
1054 * \param x x axis scale factor.
1055 * \param y y axis scale factor.
1056 * \param z z axis scale factor.
1058 * Multiplies in-place the elements of \p mat by the scale factors. Checks if
1059 * the scales factors are roughly the same, marking the MAT_FLAG_UNIFORM_SCALE
1060 * flag, or MAT_FLAG_GENERAL_SCALE. Marks the MAT_DIRTY_TYPE and
1061 * MAT_DIRTY_INVERSE dirty flags.
1064 _math_matrix_scale( GLmatrix *mat, GLfloat x, GLfloat y, GLfloat z )
1066 GLfloat *m = mat->m;
1067 m[0] *= x; m[4] *= y; m[8] *= z;
1068 m[1] *= x; m[5] *= y; m[9] *= z;
1069 m[2] *= x; m[6] *= y; m[10] *= z;
1070 m[3] *= x; m[7] *= y; m[11] *= z;
1072 if (FABSF(x - y) < 1e-8 && FABSF(x - z) < 1e-8)
1073 mat->flags |= MAT_FLAG_UNIFORM_SCALE;
1075 mat->flags |= MAT_FLAG_GENERAL_SCALE;
1077 mat->flags |= (MAT_DIRTY_TYPE |
1082 * Multiply a matrix with a translation matrix.
1084 * \param mat matrix.
1085 * \param x translation vector x coordinate.
1086 * \param y translation vector y coordinate.
1087 * \param z translation vector z coordinate.
1089 * Adds the translation coordinates to the elements of \p mat in-place. Marks
1090 * the MAT_FLAG_TRANSLATION flag, and the MAT_DIRTY_TYPE and MAT_DIRTY_INVERSE
1094 _math_matrix_translate( GLmatrix *mat, GLfloat x, GLfloat y, GLfloat z )
1096 GLfloat *m = mat->m;
1097 m[12] = m[0] * x + m[4] * y + m[8] * z + m[12];
1098 m[13] = m[1] * x + m[5] * y + m[9] * z + m[13];
1099 m[14] = m[2] * x + m[6] * y + m[10] * z + m[14];
1100 m[15] = m[3] * x + m[7] * y + m[11] * z + m[15];
1102 mat->flags |= (MAT_FLAG_TRANSLATION |
1109 * Set matrix to do viewport and depthrange mapping.
1110 * Transforms Normalized Device Coords to window/Z values.
1113 _math_matrix_viewport(GLmatrix *m, GLint x, GLint y, GLint width, GLint height,
1114 GLfloat zNear, GLfloat zFar, GLfloat depthMax)
1116 m->m[MAT_SX] = (GLfloat) width / 2.0F;
1117 m->m[MAT_TX] = m->m[MAT_SX] + x;
1118 m->m[MAT_SY] = (GLfloat) height / 2.0F;
1119 m->m[MAT_TY] = m->m[MAT_SY] + y;
1120 m->m[MAT_SZ] = depthMax * ((zFar - zNear) / 2.0F);
1121 m->m[MAT_TZ] = depthMax * ((zFar - zNear) / 2.0F + zNear);
1122 m->flags = MAT_FLAG_GENERAL_SCALE | MAT_FLAG_TRANSLATION;
1123 m->type = MATRIX_3D_NO_ROT;
1128 * Set a matrix to the identity matrix.
1130 * \param mat matrix.
1132 * Copies ::Identity into \p GLmatrix::m, and into GLmatrix::inv if not NULL.
1133 * Sets the matrix type to identity, and clear the dirty flags.
1136 _math_matrix_set_identity( GLmatrix *mat )
1138 memcpy( mat->m, Identity, 16*sizeof(GLfloat) );
1139 memcpy( mat->inv, Identity, 16*sizeof(GLfloat) );
1141 mat->type = MATRIX_IDENTITY;
1142 mat->flags &= ~(MAT_DIRTY_FLAGS|
1150 /**********************************************************************/
1151 /** \name Matrix analysis */
1154 #define ZERO(x) (1<<x)
1155 #define ONE(x) (1<<(x+16))
1157 #define MASK_NO_TRX (ZERO(12) | ZERO(13) | ZERO(14))
1158 #define MASK_NO_2D_SCALE ( ONE(0) | ONE(5))
1160 #define MASK_IDENTITY ( ONE(0) | ZERO(4) | ZERO(8) | ZERO(12) |\
1161 ZERO(1) | ONE(5) | ZERO(9) | ZERO(13) |\
1162 ZERO(2) | ZERO(6) | ONE(10) | ZERO(14) |\
1163 ZERO(3) | ZERO(7) | ZERO(11) | ONE(15) )
1165 #define MASK_2D_NO_ROT ( ZERO(4) | ZERO(8) | \
1166 ZERO(1) | ZERO(9) | \
1167 ZERO(2) | ZERO(6) | ONE(10) | ZERO(14) |\
1168 ZERO(3) | ZERO(7) | ZERO(11) | ONE(15) )
1170 #define MASK_2D ( ZERO(8) | \
1172 ZERO(2) | ZERO(6) | ONE(10) | ZERO(14) |\
1173 ZERO(3) | ZERO(7) | ZERO(11) | ONE(15) )
1176 #define MASK_3D_NO_ROT ( ZERO(4) | ZERO(8) | \
1177 ZERO(1) | ZERO(9) | \
1178 ZERO(2) | ZERO(6) | \
1179 ZERO(3) | ZERO(7) | ZERO(11) | ONE(15) )
1184 ZERO(3) | ZERO(7) | ZERO(11) | ONE(15) )
1187 #define MASK_PERSPECTIVE ( ZERO(4) | ZERO(12) |\
1188 ZERO(1) | ZERO(13) |\
1189 ZERO(2) | ZERO(6) | \
1190 ZERO(3) | ZERO(7) | ZERO(15) )
1192 #define SQ(x) ((x)*(x))
1195 * Determine type and flags from scratch.
1197 * \param mat matrix.
1199 * This is expensive enough to only want to do it once.
1201 static void analyse_from_scratch( GLmatrix *mat )
1203 const GLfloat *m = mat->m;
1207 for (i = 0 ; i < 16 ; i++) {
1208 if (m[i] == 0.0) mask |= (1<<i);
1211 if (m[0] == 1.0F) mask |= (1<<16);
1212 if (m[5] == 1.0F) mask |= (1<<21);
1213 if (m[10] == 1.0F) mask |= (1<<26);
1214 if (m[15] == 1.0F) mask |= (1<<31);
1216 mat->flags &= ~MAT_FLAGS_GEOMETRY;
1218 /* Check for translation - no-one really cares
1220 if ((mask & MASK_NO_TRX) != MASK_NO_TRX)
1221 mat->flags |= MAT_FLAG_TRANSLATION;
1225 if (mask == (GLuint) MASK_IDENTITY) {
1226 mat->type = MATRIX_IDENTITY;
1228 else if ((mask & MASK_2D_NO_ROT) == (GLuint) MASK_2D_NO_ROT) {
1229 mat->type = MATRIX_2D_NO_ROT;
1231 if ((mask & MASK_NO_2D_SCALE) != MASK_NO_2D_SCALE)
1232 mat->flags |= MAT_FLAG_GENERAL_SCALE;
1234 else if ((mask & MASK_2D) == (GLuint) MASK_2D) {
1235 GLfloat mm = DOT2(m, m);
1236 GLfloat m4m4 = DOT2(m+4,m+4);
1237 GLfloat mm4 = DOT2(m,m+4);
1239 mat->type = MATRIX_2D;
1241 /* Check for scale */
1242 if (SQ(mm-1) > SQ(1e-6) ||
1243 SQ(m4m4-1) > SQ(1e-6))
1244 mat->flags |= MAT_FLAG_GENERAL_SCALE;
1246 /* Check for rotation */
1247 if (SQ(mm4) > SQ(1e-6))
1248 mat->flags |= MAT_FLAG_GENERAL_3D;
1250 mat->flags |= MAT_FLAG_ROTATION;
1253 else if ((mask & MASK_3D_NO_ROT) == (GLuint) MASK_3D_NO_ROT) {
1254 mat->type = MATRIX_3D_NO_ROT;
1256 /* Check for scale */
1257 if (SQ(m[0]-m[5]) < SQ(1e-6) &&
1258 SQ(m[0]-m[10]) < SQ(1e-6)) {
1259 if (SQ(m[0]-1.0) > SQ(1e-6)) {
1260 mat->flags |= MAT_FLAG_UNIFORM_SCALE;
1264 mat->flags |= MAT_FLAG_GENERAL_SCALE;
1267 else if ((mask & MASK_3D) == (GLuint) MASK_3D) {
1268 GLfloat c1 = DOT3(m,m);
1269 GLfloat c2 = DOT3(m+4,m+4);
1270 GLfloat c3 = DOT3(m+8,m+8);
1271 GLfloat d1 = DOT3(m, m+4);
1274 mat->type = MATRIX_3D;
1276 /* Check for scale */
1277 if (SQ(c1-c2) < SQ(1e-6) && SQ(c1-c3) < SQ(1e-6)) {
1278 if (SQ(c1-1.0) > SQ(1e-6))
1279 mat->flags |= MAT_FLAG_UNIFORM_SCALE;
1280 /* else no scale at all */
1283 mat->flags |= MAT_FLAG_GENERAL_SCALE;
1286 /* Check for rotation */
1287 if (SQ(d1) < SQ(1e-6)) {
1288 CROSS3( cp, m, m+4 );
1289 SUB_3V( cp, cp, (m+8) );
1290 if (LEN_SQUARED_3FV(cp) < SQ(1e-6))
1291 mat->flags |= MAT_FLAG_ROTATION;
1293 mat->flags |= MAT_FLAG_GENERAL_3D;
1296 mat->flags |= MAT_FLAG_GENERAL_3D; /* shear, etc */
1299 else if ((mask & MASK_PERSPECTIVE) == MASK_PERSPECTIVE && m[11]==-1.0F) {
1300 mat->type = MATRIX_PERSPECTIVE;
1301 mat->flags |= MAT_FLAG_GENERAL;
1304 mat->type = MATRIX_GENERAL;
1305 mat->flags |= MAT_FLAG_GENERAL;
1310 * Analyze a matrix given that its flags are accurate.
1312 * This is the more common operation, hopefully.
1314 static void analyse_from_flags( GLmatrix *mat )
1316 const GLfloat *m = mat->m;
1318 if (TEST_MAT_FLAGS(mat, 0)) {
1319 mat->type = MATRIX_IDENTITY;
1321 else if (TEST_MAT_FLAGS(mat, (MAT_FLAG_TRANSLATION |
1322 MAT_FLAG_UNIFORM_SCALE |
1323 MAT_FLAG_GENERAL_SCALE))) {
1324 if ( m[10]==1.0F && m[14]==0.0F ) {
1325 mat->type = MATRIX_2D_NO_ROT;
1328 mat->type = MATRIX_3D_NO_ROT;
1331 else if (TEST_MAT_FLAGS(mat, MAT_FLAGS_3D)) {
1334 && m[2]==0.0F && m[6]==0.0F && m[10]==1.0F && m[14]==0.0F) {
1335 mat->type = MATRIX_2D;
1338 mat->type = MATRIX_3D;
1341 else if ( m[4]==0.0F && m[12]==0.0F
1342 && m[1]==0.0F && m[13]==0.0F
1343 && m[2]==0.0F && m[6]==0.0F
1344 && m[3]==0.0F && m[7]==0.0F && m[11]==-1.0F && m[15]==0.0F) {
1345 mat->type = MATRIX_PERSPECTIVE;
1348 mat->type = MATRIX_GENERAL;
1353 * Analyze and update a matrix.
1355 * \param mat matrix.
1357 * If the matrix type is dirty then calls either analyse_from_scratch() or
1358 * analyse_from_flags() to determine its type, according to whether the flags
1359 * are dirty or not, respectively. If the matrix has an inverse and it's dirty
1360 * then calls matrix_invert(). Finally clears the dirty flags.
1363 _math_matrix_analyse( GLmatrix *mat )
1365 if (mat->flags & MAT_DIRTY_TYPE) {
1366 if (mat->flags & MAT_DIRTY_FLAGS)
1367 analyse_from_scratch( mat );
1369 analyse_from_flags( mat );
1372 if (mat->inv && (mat->flags & MAT_DIRTY_INVERSE)) {
1373 matrix_invert( mat );
1374 mat->flags &= ~MAT_DIRTY_INVERSE;
1377 mat->flags &= ~(MAT_DIRTY_FLAGS | MAT_DIRTY_TYPE);
1384 * Test if the given matrix preserves vector lengths.
1387 _math_matrix_is_length_preserving( const GLmatrix *m )
1389 return TEST_MAT_FLAGS( m, MAT_FLAGS_LENGTH_PRESERVING);
1394 * Test if the given matrix does any rotation.
1395 * (or perhaps if the upper-left 3x3 is non-identity)
1398 _math_matrix_has_rotation( const GLmatrix *m )
1400 if (m->flags & (MAT_FLAG_GENERAL |
1402 MAT_FLAG_GENERAL_3D |
1403 MAT_FLAG_PERSPECTIVE))
1411 _math_matrix_is_general_scale( const GLmatrix *m )
1413 return (m->flags & MAT_FLAG_GENERAL_SCALE) ? GL_TRUE : GL_FALSE;
1418 _math_matrix_is_dirty( const GLmatrix *m )
1420 return (m->flags & MAT_DIRTY) ? GL_TRUE : GL_FALSE;
1424 /**********************************************************************/
1425 /** \name Matrix setup */
1431 * \param to destination matrix.
1432 * \param from source matrix.
1434 * Copies all fields in GLmatrix, creating an inverse array if necessary.
1437 _math_matrix_copy( GLmatrix *to, const GLmatrix *from )
1439 memcpy( to->m, from->m, sizeof(Identity) );
1440 memcpy(to->inv, from->inv, sizeof(*from->inv));
1441 to->flags = from->flags;
1442 to->type = from->type;
1446 * Loads a matrix array into GLmatrix.
1448 * \param m matrix array.
1449 * \param mat matrix.
1451 * Copies \p m into GLmatrix::m and marks the MAT_FLAG_GENERAL and MAT_DIRTY
1455 _math_matrix_loadf( GLmatrix *mat, const GLfloat *m )
1457 memcpy( mat->m, m, 16*sizeof(GLfloat) );
1458 mat->flags = (MAT_FLAG_GENERAL | MAT_DIRTY);
1462 * Matrix constructor.
1466 * Initialize the GLmatrix fields.
1469 _math_matrix_ctr( GLmatrix *m )
1471 m->m = (GLfloat *) _mesa_align_malloc( 16 * sizeof(GLfloat), 16 );
1473 memcpy( m->m, Identity, sizeof(Identity) );
1474 m->inv = (GLfloat *) _mesa_align_malloc( 16 * sizeof(GLfloat), 16 );
1476 memcpy( m->inv, Identity, sizeof(Identity) );
1477 m->type = MATRIX_IDENTITY;
1482 * Matrix destructor.
1486 * Frees the data in a GLmatrix.
1489 _math_matrix_dtr( GLmatrix *m )
1492 _mesa_align_free( m->m );
1496 _mesa_align_free( m->inv );
1504 /**********************************************************************/
1505 /** \name Matrix transpose */
1509 * Transpose a GLfloat matrix.
1511 * \param to destination array.
1512 * \param from source array.
1515 _math_transposef( GLfloat to[16], const GLfloat from[16] )
1536 * Transpose a GLdouble matrix.
1538 * \param to destination array.
1539 * \param from source array.
1542 _math_transposed( GLdouble to[16], const GLdouble from[16] )
1563 * Transpose a GLdouble matrix and convert to GLfloat.
1565 * \param to destination array.
1566 * \param from source array.
1569 _math_transposefd( GLfloat to[16], const GLdouble from[16] )
1571 to[0] = (GLfloat) from[0];
1572 to[1] = (GLfloat) from[4];
1573 to[2] = (GLfloat) from[8];
1574 to[3] = (GLfloat) from[12];
1575 to[4] = (GLfloat) from[1];
1576 to[5] = (GLfloat) from[5];
1577 to[6] = (GLfloat) from[9];
1578 to[7] = (GLfloat) from[13];
1579 to[8] = (GLfloat) from[2];
1580 to[9] = (GLfloat) from[6];
1581 to[10] = (GLfloat) from[10];
1582 to[11] = (GLfloat) from[14];
1583 to[12] = (GLfloat) from[3];
1584 to[13] = (GLfloat) from[7];
1585 to[14] = (GLfloat) from[11];
1586 to[15] = (GLfloat) from[15];
1593 * Transform a 4-element row vector (1x4 matrix) by a 4x4 matrix. This
1594 * function is used for transforming clipping plane equations and spotlight
1596 * Mathematically, u = v * m.
1597 * Input: v - input vector
1598 * m - transformation matrix
1599 * Output: u - transformed vector
1602 _mesa_transform_vector( GLfloat u[4], const GLfloat v[4], const GLfloat m[16] )
1604 const GLfloat v0 = v[0], v1 = v[1], v2 = v[2], v3 = v[3];
1605 #define M(row,col) m[row + col*4]
1606 u[0] = v0 * M(0,0) + v1 * M(1,0) + v2 * M(2,0) + v3 * M(3,0);
1607 u[1] = v0 * M(0,1) + v1 * M(1,1) + v2 * M(2,1) + v3 * M(3,1);
1608 u[2] = v0 * M(0,2) + v1 * M(1,2) + v2 * M(2,2) + v3 * M(3,2);
1609 u[3] = v0 * M(0,3) + v1 * M(1,3) + v2 * M(2,3) + v3 * M(3,3);