1 /*
2  * Mesa 3-D graphics library
3  * Version:  6.3
4  *
5  * Copyright (C) 1999-2005  Brian Paul   All Rights Reserved.
6  *
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:
13  *
14  * The above copyright notice and this permission notice shall be included
15  * in all copies or substantial portions of the Software.
16  *
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.
23  */
24 
25 
26 /**
27  * \file m_matrix.c
28  * Matrix operations.
29  *
30  * \note
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
34  */
35 
36 
37 #include "main/glheader.h"
38 #include "main/imports.h"
39 #include "main/macros.h"
40 
41 #include "m_matrix.h"
42 
43 
44 /**
45  * \defgroup MatFlags MAT_FLAG_XXX-flags
46  *
47  * Bitmasks to indicate different kinds of 4x4 matrices in GLmatrix::flags
48  */
49 /*@{*/
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.)
54                                        */
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 */
66 
67 /** angle preserving matrix flags mask */
68 #define MAT_FLAGS_ANGLE_PRESERVING (MAT_FLAG_ROTATION | \
69 				    MAT_FLAG_TRANSLATION | \
70 				    MAT_FLAG_UNIFORM_SCALE)
71 
72 /** geometry related matrix flags mask */
73 #define MAT_FLAGS_GEOMETRY (MAT_FLAG_GENERAL | \
74 			    MAT_FLAG_ROTATION | \
75 			    MAT_FLAG_TRANSLATION | \
76 			    MAT_FLAG_UNIFORM_SCALE | \
77 			    MAT_FLAG_GENERAL_SCALE | \
78 			    MAT_FLAG_GENERAL_3D | \
79 			    MAT_FLAG_PERSPECTIVE | \
80 	                    MAT_FLAG_SINGULAR)
81 
82 /** length preserving matrix flags mask */
83 #define MAT_FLAGS_LENGTH_PRESERVING (MAT_FLAG_ROTATION | \
84 				     MAT_FLAG_TRANSLATION)
85 
86 
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 | \
92 		      MAT_FLAG_GENERAL_3D)
93 
94 /** dirty matrix flags mask */
95 #define MAT_DIRTY          (MAT_DIRTY_TYPE | \
96 			    MAT_DIRTY_FLAGS | \
97 			    MAT_DIRTY_INVERSE)
98 
99 /*@}*/
100 
101 
102 /**
103  * Test geometry related matrix flags.
104  *
105  * \param mat a pointer to a GLmatrix structure.
106  * \param a flags mask.
107  *
108  * \returns non-zero if all geometry related matrix flags are contained within
109  * the mask, or zero otherwise.
110  */
111 #define TEST_MAT_FLAGS(mat, a)  \
112     ((MAT_FLAGS_GEOMETRY & (~(a)) & ((mat)->flags) ) == 0)
113 
114 
115 
116 /**
117  * Names of the corresponding GLmatrixtype values.
118  */
119 static const char *types[] = {
120    "MATRIX_GENERAL",
121    "MATRIX_IDENTITY",
122    "MATRIX_3D_NO_ROT",
123    "MATRIX_PERSPECTIVE",
124    "MATRIX_2D",
125    "MATRIX_2D_NO_ROT",
126    "MATRIX_3D"
127 };
128 
129 
130 /**
131  * Identity matrix.
132  */
133 static GLfloat Identity[16] = {
134    1.0, 0.0, 0.0, 0.0,
135    0.0, 1.0, 0.0, 0.0,
136    0.0, 0.0, 1.0, 0.0,
137    0.0, 0.0, 0.0, 1.0
138 };
139 
140 
141 
142 /**********************************************************************/
143 /** \name Matrix multiplication */
144 /*@{*/
145 
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]
149 
150 /**
151  * Perform a full 4x4 matrix multiplication.
152  *
153  * \param a matrix.
154  * \param b matrix.
155  * \param product will receive the product of \p a and \p b.
156  *
157  * \warning Is assumed that \p product != \p b. \p product == \p a is allowed.
158  *
159  * \note KW: 4*16 = 64 multiplications
160  *
161  * \author This \c matmul was contributed by Thomas Malik
162  */
matmul4(GLfloat * product,const GLfloat * a,const GLfloat * b)163 static void matmul4( GLfloat *product, const GLfloat *a, const GLfloat *b )
164 {
165    GLint i;
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);
172    }
173 }
174 
175 /**
176  * Multiply two matrices known to occupy only the top three rows, such
177  * as typical model matrices, and orthogonal matrices.
178  *
179  * \param a matrix.
180  * \param b matrix.
181  * \param product will receive the product of \p a and \p b.
182  */
matmul34(GLfloat * product,const GLfloat * a,const GLfloat * b)183 static void matmul34( GLfloat *product, const GLfloat *a, const GLfloat *b )
184 {
185    GLint i;
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;
192    }
193    P(3,0) = 0;
194    P(3,1) = 0;
195    P(3,2) = 0;
196    P(3,3) = 1;
197 }
198 
199 #undef A
200 #undef B
201 #undef P
202 
203 /**
204  * Multiply a matrix by an array of floats with known properties.
205  *
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.
210  *
211  * Joins both flags and marks the type and inverse as dirty.  Calls matmul34()
212  * if both matrices are 3D, or matmul4() otherwise.
213  */
matrix_multf(GLmatrix * mat,const GLfloat * m,GLuint flags)214 static void matrix_multf( GLmatrix *mat, const GLfloat *m, GLuint flags )
215 {
216    mat->flags |= (flags | MAT_DIRTY_TYPE | MAT_DIRTY_INVERSE);
217 
218    if (TEST_MAT_FLAGS(mat, MAT_FLAGS_3D))
219       matmul34( mat->m, mat->m, m );
220    else
221       matmul4( mat->m, mat->m, m );
222 }
223 
224 /**
225  * Matrix multiplication.
226  *
227  * \param dest destination matrix.
228  * \param a left matrix.
229  * \param b right matrix.
230  *
231  * Joins both flags and marks the type and inverse as dirty.  Calls matmul34()
232  * if both matrices are 3D, or matmul4() otherwise.
233  */
234 void
_math_matrix_mul_matrix(GLmatrix * dest,const GLmatrix * a,const GLmatrix * b)235 _math_matrix_mul_matrix( GLmatrix *dest, const GLmatrix *a, const GLmatrix *b )
236 {
237    dest->flags = (a->flags |
238 		  b->flags |
239 		  MAT_DIRTY_TYPE |
240 		  MAT_DIRTY_INVERSE);
241 
242    if (TEST_MAT_FLAGS(dest, MAT_FLAGS_3D))
243       matmul34( dest->m, a->m, b->m );
244    else
245       matmul4( dest->m, a->m, b->m );
246 }
247 
248 /**
249  * Matrix multiplication.
250  *
251  * \param dest left and destination matrix.
252  * \param m right matrix array.
253  *
254  * Marks the matrix flags with general flag, and type and inverse dirty flags.
255  * Calls matmul4() for the multiplication.
256  */
257 void
_math_matrix_mul_floats(GLmatrix * dest,const GLfloat * m)258 _math_matrix_mul_floats( GLmatrix *dest, const GLfloat *m )
259 {
260    dest->flags |= (MAT_FLAG_GENERAL |
261 		   MAT_DIRTY_TYPE |
262 		   MAT_DIRTY_INVERSE |
263                    MAT_DIRTY_FLAGS);
264 
265    matmul4( dest->m, dest->m, m );
266 }
267 
268 /*@}*/
269 
270 
271 /**********************************************************************/
272 /** \name Matrix output */
273 /*@{*/
274 
275 /**
276  * Print a matrix array.
277  *
278  * \param m matrix array.
279  *
280  * Called by _math_matrix_print() to print a matrix or its inverse.
281  */
print_matrix_floats(const GLfloat m[16])282 static void print_matrix_floats( const GLfloat m[16] )
283 {
284    int i;
285    for (i=0;i<4;i++) {
286       _mesa_debug(NULL,"\t%f %f %f %f\n", m[i], m[4+i], m[8+i], m[12+i] );
287    }
288 }
289 
290 /**
291  * Dumps the contents of a GLmatrix structure.
292  *
293  * \param m pointer to the GLmatrix structure.
294  */
295 void
_math_matrix_print(const GLmatrix * m)296 _math_matrix_print( const GLmatrix *m )
297 {
298    GLfloat prod[16];
299 
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);
307 }
308 
309 /*@}*/
310 
311 
312 /**
313  * References an element of 4x4 matrix.
314  *
315  * \param m matrix array.
316  * \param c column of the desired element.
317  * \param r row of the desired element.
318  *
319  * \return value of the desired element.
320  *
321  * Calculate the linear storage index of the element and references it.
322  */
323 #define MAT(m,r,c) (m)[(c)*4+(r)]
324 
325 
326 /**********************************************************************/
327 /** \name Matrix inversion */
328 /*@{*/
329 
330 /**
331  * Swaps the values of two floating point variables.
332  *
333  * Used by invert_matrix_general() to swap the row pointers.
334  */
335 #define SWAP_ROWS(a, b) { GLfloat *_tmp = a; (a)=(b); (b)=_tmp; }
336 
337 /**
338  * Compute inverse of 4x4 transformation matrix.
339  *
340  * \param mat pointer to a GLmatrix structure. The matrix inverse will be
341  * stored in the GLmatrix::inv attribute.
342  *
343  * \return GL_TRUE for success, GL_FALSE for failure (\p singular matrix).
344  *
345  * \author
346  * Code contributed by Jacques Leroy jle@star.be
347  *
348  * Calculates the inverse matrix by performing the gaussian matrix reduction
349  * with partial pivoting followed by back/substitution with the loops manually
350  * unrolled.
351  */
invert_matrix_general(GLmatrix * mat)352 static GLboolean invert_matrix_general( GLmatrix *mat )
353 {
354    const GLfloat *m = mat->m;
355    GLfloat *out = mat->inv;
356    GLfloat wtmp[4][8];
357    GLfloat m0, m1, m2, m3, s;
358    GLfloat *r0, *r1, *r2, *r3;
359 
360    r0 = wtmp[0], r1 = wtmp[1], r2 = wtmp[2], r3 = wtmp[3];
361 
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,
365 
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,
369 
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,
373 
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;
377 
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;
383 
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;
389    s = r0[4];
390    if (s != 0.0) { r1[4] -= m1 * s; r2[4] -= m2 * s; r3[4] -= m3 * s; }
391    s = r0[5];
392    if (s != 0.0) { r1[5] -= m1 * s; r2[5] -= m2 * s; r3[5] -= m3 * s; }
393    s = r0[6];
394    if (s != 0.0) { r1[6] -= m1 * s; r2[6] -= m2 * s; r3[6] -= m3 * s; }
395    s = r0[7];
396    if (s != 0.0) { r1[7] -= m1 * s; r2[7] -= m2 * s; r3[7] -= m3 * s; }
397 
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;
402 
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; }
411 
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;
415 
416    /* eliminate third variable */
417    m3 = r3[2]/r2[2];
418    r3[3] -= m3 * r2[3], r3[4] -= m3 * r2[4],
419    r3[5] -= m3 * r2[5], r3[6] -= m3 * r2[6],
420    r3[7] -= m3 * r2[7];
421 
422    /* last check */
423    if (0.0 == r3[3]) return GL_FALSE;
424 
425    s = 1.0F/r3[3];             /* now back substitute row 3 */
426    r3[4] *= s; r3[5] *= s; r3[6] *= s; r3[7] *= s;
427 
428    m2 = r2[3];                 /* now back substitute row 2 */
429    s  = 1.0F/r2[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);
432    m1 = r1[3];
433    r1[4] -= r3[4] * m1, r1[5] -= r3[5] * m1,
434    r1[6] -= r3[6] * m1, r1[7] -= r3[7] * m1;
435    m0 = r0[3];
436    r0[4] -= r3[4] * m0, r0[5] -= r3[5] * m0,
437    r0[6] -= r3[6] * m0, r0[7] -= r3[7] * m0;
438 
439    m1 = r1[2];                 /* now back substitute row 1 */
440    s  = 1.0F/r1[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);
443    m0 = r0[2];
444    r0[4] -= r2[4] * m0, r0[5] -= r2[5] * m0,
445    r0[6] -= r2[6] * m0, r0[7] -= r2[7] * m0;
446 
447    m0 = r0[1];                 /* now back substitute row 0 */
448    s  = 1.0F/r0[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);
451 
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];
460 
461    return GL_TRUE;
462 }
463 #undef SWAP_ROWS
464 
465 /**
466  * Compute inverse of a general 3d transformation matrix.
467  *
468  * \param mat pointer to a GLmatrix structure. The matrix inverse will be
469  * stored in the GLmatrix::inv attribute.
470  *
471  * \return GL_TRUE for success, GL_FALSE for failure (\p singular matrix).
472  *
473  * \author Adapted from graphics gems II.
474  *
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.
479  */
invert_matrix_3d_general(GLmatrix * mat)480 static GLboolean invert_matrix_3d_general( GLmatrix *mat )
481 {
482    const GLfloat *in = mat->m;
483    GLfloat *out = mat->inv;
484    GLfloat pos, neg, t;
485    GLfloat det;
486 
487    /* Calculate the determinant of upper left 3x3 submatrix and
488     * determine if the matrix is singular.
489     */
490    pos = neg = 0.0;
491    t =  MAT(in,0,0) * MAT(in,1,1) * MAT(in,2,2);
492    if (t >= 0.0) pos += t; else neg += t;
493 
494    t =  MAT(in,1,0) * MAT(in,2,1) * MAT(in,0,2);
495    if (t >= 0.0) pos += t; else neg += t;
496 
497    t =  MAT(in,2,0) * MAT(in,0,1) * MAT(in,1,2);
498    if (t >= 0.0) pos += t; else neg += t;
499 
500    t = -MAT(in,2,0) * MAT(in,1,1) * MAT(in,0,2);
501    if (t >= 0.0) pos += t; else neg += t;
502 
503    t = -MAT(in,1,0) * MAT(in,0,1) * MAT(in,2,2);
504    if (t >= 0.0) pos += t; else neg += t;
505 
506    t = -MAT(in,0,0) * MAT(in,2,1) * MAT(in,1,2);
507    if (t >= 0.0) pos += t; else neg += t;
508 
509    det = pos + neg;
510 
511    if (FABSF(det) < 1e-25)
512       return GL_FALSE;
513 
514    det = 1.0F / det;
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);
524 
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) );
535 
536    return GL_TRUE;
537 }
538 
539 /**
540  * Compute inverse of a 3d transformation matrix.
541  *
542  * \param mat pointer to a GLmatrix structure. The matrix inverse will be
543  * stored in the GLmatrix::inv attribute.
544  *
545  * \return GL_TRUE for success, GL_FALSE for failure (\p singular matrix).
546  *
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
550  * translation parts.
551  */
invert_matrix_3d(GLmatrix * mat)552 static GLboolean invert_matrix_3d( GLmatrix *mat )
553 {
554    const GLfloat *in = mat->m;
555    GLfloat *out = mat->inv;
556 
557    if (!TEST_MAT_FLAGS(mat, MAT_FLAGS_ANGLE_PRESERVING)) {
558       return invert_matrix_3d_general( mat );
559    }
560 
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));
565 
566       if (scale == 0.0)
567          return GL_FALSE;
568 
569       scale = 1.0F / scale;
570 
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);
581    }
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);
593    }
594    else {
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);
600       return GL_TRUE;
601    }
602 
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) );
614    }
615    else {
616       MAT(out,0,3) = MAT(out,1,3) = MAT(out,2,3) = 0.0;
617    }
618 
619    return GL_TRUE;
620 }
621 
622 /**
623  * Compute inverse of an identity transformation matrix.
624  *
625  * \param mat pointer to a GLmatrix structure. The matrix inverse will be
626  * stored in the GLmatrix::inv attribute.
627  *
628  * \return always GL_TRUE.
629  *
630  * Simply copies Identity into GLmatrix::inv.
631  */
invert_matrix_identity(GLmatrix * mat)632 static GLboolean invert_matrix_identity( GLmatrix *mat )
633 {
634    memcpy( mat->inv, Identity, sizeof(Identity) );
635    return GL_TRUE;
636 }
637 
638 /**
639  * Compute inverse of a no-rotation 3d transformation matrix.
640  *
641  * \param mat pointer to a GLmatrix structure. The matrix inverse will be
642  * stored in the GLmatrix::inv attribute.
643  *
644  * \return GL_TRUE for success, GL_FALSE for failure (\p singular matrix).
645  *
646  * Calculates the
647  */
invert_matrix_3d_no_rot(GLmatrix * mat)648 static GLboolean invert_matrix_3d_no_rot( GLmatrix *mat )
649 {
650    const GLfloat *in = mat->m;
651    GLfloat *out = mat->inv;
652 
653    if (MAT(in,0,0) == 0 || MAT(in,1,1) == 0 || MAT(in,2,2) == 0 )
654       return GL_FALSE;
655 
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);
660 
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));
665    }
666 
667    return GL_TRUE;
668 }
669 
670 /**
671  * Compute inverse of a no-rotation 2d transformation matrix.
672  *
673  * \param mat pointer to a GLmatrix structure. The matrix inverse will be
674  * stored in the GLmatrix::inv attribute.
675  *
676  * \return GL_TRUE for success, GL_FALSE for failure (\p singular matrix).
677  *
678  * Calculates the inverse matrix by applying the inverse scaling and
679  * translation to the identity matrix.
680  */
invert_matrix_2d_no_rot(GLmatrix * mat)681 static GLboolean invert_matrix_2d_no_rot( GLmatrix *mat )
682 {
683    const GLfloat *in = mat->m;
684    GLfloat *out = mat->inv;
685 
686    if (MAT(in,0,0) == 0 || MAT(in,1,1) == 0)
687       return GL_FALSE;
688 
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);
692 
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));
696    }
697 
698    return GL_TRUE;
699 }
700 
701 #if 0
702 /* broken */
703 static GLboolean invert_matrix_perspective( GLmatrix *mat )
704 {
705    const GLfloat *in = mat->m;
706    GLfloat *out = mat->inv;
707 
708    if (MAT(in,2,3) == 0)
709       return GL_FALSE;
710 
711    memcpy( out, Identity, 16 * sizeof(GLfloat) );
712 
713    MAT(out,0,0) = 1.0F / MAT(in,0,0);
714    MAT(out,1,1) = 1.0F / MAT(in,1,1);
715 
716    MAT(out,0,3) = MAT(in,0,2);
717    MAT(out,1,3) = MAT(in,1,2);
718 
719    MAT(out,2,2) = 0;
720    MAT(out,2,3) = -1;
721 
722    MAT(out,3,2) = 1.0F / MAT(in,2,3);
723    MAT(out,3,3) = MAT(in,2,2) * MAT(out,3,2);
724 
725    return GL_TRUE;
726 }
727 #endif
728 
729 /**
730  * Matrix inversion function pointer type.
731  */
732 typedef GLboolean (*inv_mat_func)( GLmatrix *mat );
733 
734 /**
735  * Table of the matrix inversion functions according to the matrix type.
736  */
737 static inv_mat_func inv_mat_tab[7] = {
738    invert_matrix_general,
739    invert_matrix_identity,
740    invert_matrix_3d_no_rot,
741 #if 0
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).
744     */
745    invert_matrix_perspective,
746 #else
747    invert_matrix_general,
748 #endif
749    invert_matrix_3d,		/* lazy! */
750    invert_matrix_2d_no_rot,
751    invert_matrix_3d
752 };
753 
754 /**
755  * Compute inverse of a transformation matrix.
756  *
757  * \param mat pointer to a GLmatrix structure. The matrix inverse will be
758  * stored in the GLmatrix::inv attribute.
759  *
760  * \return GL_TRUE for success, GL_FALSE for failure (\p singular matrix).
761  *
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.
765  */
matrix_invert(GLmatrix * mat)766 static GLboolean matrix_invert( GLmatrix *mat )
767 {
768    if (inv_mat_tab[mat->type](mat)) {
769       mat->flags &= ~MAT_FLAG_SINGULAR;
770       return GL_TRUE;
771    } else {
772       mat->flags |= MAT_FLAG_SINGULAR;
773       memcpy( mat->inv, Identity, sizeof(Identity) );
774       return GL_FALSE;
775    }
776 }
777 
778 /*@}*/
779 
780 
781 /**********************************************************************/
782 /** \name Matrix generation */
783 /*@{*/
784 
785 /**
786  * Generate a 4x4 transformation matrix from glRotate parameters, and
787  * post-multiply the input matrix by it.
788  *
789  * \author
790  * This function was contributed by Erich Boleyn (erich@uruk.org).
791  * Optimizations contributed by Rudolf Opalla (rudi@khm.de).
792  */
793 void
_math_matrix_rotate(GLmatrix * mat,GLfloat angle,GLfloat x,GLfloat y,GLfloat z)794 _math_matrix_rotate( GLmatrix *mat,
795 		     GLfloat angle, GLfloat x, GLfloat y, GLfloat z )
796 {
797    GLfloat xx, yy, zz, xy, yz, zx, xs, ys, zs, one_c, s, c;
798    GLfloat m[16];
799    GLboolean optimized;
800 
801    s = (GLfloat) sin( angle * DEG2RAD );
802    c = (GLfloat) cos( angle * DEG2RAD );
803 
804    memcpy(m, Identity, sizeof(GLfloat)*16);
805    optimized = GL_FALSE;
806 
807 #define M(row,col)  m[col*4+row]
808 
809    if (x == 0.0F) {
810       if (y == 0.0F) {
811          if (z != 0.0F) {
812             optimized = GL_TRUE;
813             /* rotate only around z-axis */
814             M(0,0) = c;
815             M(1,1) = c;
816             if (z < 0.0F) {
817                M(0,1) = s;
818                M(1,0) = -s;
819             }
820             else {
821                M(0,1) = -s;
822                M(1,0) = s;
823             }
824          }
825       }
826       else if (z == 0.0F) {
827          optimized = GL_TRUE;
828          /* rotate only around y-axis */
829          M(0,0) = c;
830          M(2,2) = c;
831          if (y < 0.0F) {
832             M(0,2) = -s;
833             M(2,0) = s;
834          }
835          else {
836             M(0,2) = s;
837             M(2,0) = -s;
838          }
839       }
840    }
841    else if (y == 0.0F) {
842       if (z == 0.0F) {
843          optimized = GL_TRUE;
844          /* rotate only around x-axis */
845          M(1,1) = c;
846          M(2,2) = c;
847          if (x < 0.0F) {
848             M(1,2) = s;
849             M(2,1) = -s;
850          }
851          else {
852             M(1,2) = -s;
853             M(2,1) = s;
854          }
855       }
856    }
857 
858    if (!optimized) {
859       const GLfloat mag = SQRTF(x * x + y * y + z * z);
860 
861       if (mag <= 1.0e-4) {
862          /* no rotation, leave mat as-is */
863          return;
864       }
865 
866       x /= mag;
867       y /= mag;
868       z /= mag;
869 
870 
871       /*
872        *     Arbitrary axis rotation matrix.
873        *
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.
880        *
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.
890        *
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)
896        *  as follows:
897        *
898        *  cos ( theta ) = x / sqrt ( 1 - z^2 )
899        *  sin ( theta ) = y / sqrt ( 1 - z^2 )
900        *
901        *  cos ( phi ) = sqrt ( 1 - z^2 )
902        *  sin ( phi ) = z
903        *
904        *  Note that cos ( phi ) can further be inserted to the above
905        *  formulas:
906        *
907        *  cos ( theta ) = x / cos ( phi )
908        *  sin ( theta ) = y / sin ( phi )
909        *
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.
914        *
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.
922        */
923 
924       xx = x * x;
925       yy = y * y;
926       zz = z * z;
927       xy = x * y;
928       yz = y * z;
929       zx = z * x;
930       xs = x * s;
931       ys = y * s;
932       zs = z * s;
933       one_c = 1.0F - c;
934 
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;
939 /*    M(0,3) = 0.0F; */
940 
941       M(1,0) = (one_c * xy) + zs;
942       M(1,1) = (one_c * yy) + c;
943       M(1,2) = (one_c * yz) - xs;
944 /*    M(1,3) = 0.0F; */
945 
946       M(2,0) = (one_c * zx) - ys;
947       M(2,1) = (one_c * yz) + xs;
948       M(2,2) = (one_c * zz) + c;
949 /*    M(2,3) = 0.0F; */
950 
951 /*
952       M(3,0) = 0.0F;
953       M(3,1) = 0.0F;
954       M(3,2) = 0.0F;
955       M(3,3) = 1.0F;
956 */
957    }
958 #undef M
959 
960    matrix_multf( mat, m, MAT_FLAG_ROTATION );
961 }
962 
963 /**
964  * Apply a perspective projection matrix.
965  *
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.
973  *
974  * Creates the projection matrix and multiplies it with \p mat, marking the
975  * MAT_FLAG_PERSPECTIVE flag.
976  */
977 void
_math_matrix_frustum(GLmatrix * mat,GLfloat left,GLfloat right,GLfloat bottom,GLfloat top,GLfloat nearval,GLfloat farval)978 _math_matrix_frustum( GLmatrix *mat,
979 		      GLfloat left, GLfloat right,
980 		      GLfloat bottom, GLfloat top,
981 		      GLfloat nearval, GLfloat farval )
982 {
983    GLfloat x, y, a, b, c, d;
984    GLfloat m[16];
985 
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? */
992 
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;
998 #undef M
999 
1000    matrix_multf( mat, m, MAT_FLAG_PERSPECTIVE );
1001 }
1002 
1003 /**
1004  * Apply an orthographic projection matrix.
1005  *
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.
1013  *
1014  * Creates the projection matrix and multiplies it with \p mat, marking the
1015  * MAT_FLAG_GENERAL_SCALE and MAT_FLAG_TRANSLATION flags.
1016  */
1017 void
_math_matrix_ortho(GLmatrix * mat,GLfloat left,GLfloat right,GLfloat bottom,GLfloat top,GLfloat nearval,GLfloat farval)1018 _math_matrix_ortho( GLmatrix *mat,
1019 		    GLfloat left, GLfloat right,
1020 		    GLfloat bottom, GLfloat top,
1021 		    GLfloat nearval, GLfloat farval )
1022 {
1023    GLfloat m[16];
1024 
1025 #define M(row,col)  m[col*4+row]
1026    M(0,0) = 2.0F / (right-left);
1027    M(0,1) = 0.0F;
1028    M(0,2) = 0.0F;
1029    M(0,3) = -(right+left) / (right-left);
1030 
1031    M(1,0) = 0.0F;
1032    M(1,1) = 2.0F / (top-bottom);
1033    M(1,2) = 0.0F;
1034    M(1,3) = -(top+bottom) / (top-bottom);
1035 
1036    M(2,0) = 0.0F;
1037    M(2,1) = 0.0F;
1038    M(2,2) = -2.0F / (farval-nearval);
1039    M(2,3) = -(farval+nearval) / (farval-nearval);
1040 
1041    M(3,0) = 0.0F;
1042    M(3,1) = 0.0F;
1043    M(3,2) = 0.0F;
1044    M(3,3) = 1.0F;
1045 #undef M
1046 
1047    matrix_multf( mat, m, (MAT_FLAG_GENERAL_SCALE|MAT_FLAG_TRANSLATION));
1048 }
1049 
1050 /**
1051  * Multiply a matrix with a general scaling matrix.
1052  *
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.
1057  *
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.
1062  */
1063 void
_math_matrix_scale(GLmatrix * mat,GLfloat x,GLfloat y,GLfloat z)1064 _math_matrix_scale( GLmatrix *mat, GLfloat x, GLfloat y, GLfloat z )
1065 {
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;
1071 
1072    if (FABSF(x - y) < 1e-8 && FABSF(x - z) < 1e-8)
1073       mat->flags |= MAT_FLAG_UNIFORM_SCALE;
1074    else
1075       mat->flags |= MAT_FLAG_GENERAL_SCALE;
1076 
1077    mat->flags |= (MAT_DIRTY_TYPE |
1078 		  MAT_DIRTY_INVERSE);
1079 }
1080 
1081 /**
1082  * Multiply a matrix with a translation matrix.
1083  *
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.
1088  *
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
1091  * dirty flags.
1092  */
1093 void
_math_matrix_translate(GLmatrix * mat,GLfloat x,GLfloat y,GLfloat z)1094 _math_matrix_translate( GLmatrix *mat, GLfloat x, GLfloat y, GLfloat z )
1095 {
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];
1101 
1102    mat->flags |= (MAT_FLAG_TRANSLATION |
1103 		  MAT_DIRTY_TYPE |
1104 		  MAT_DIRTY_INVERSE);
1105 }
1106 
1107 
1108 /**
1109  * Set matrix to do viewport and depthrange mapping.
1110  * Transforms Normalized Device Coords to window/Z values.
1111  */
1112 void
_math_matrix_viewport(GLmatrix * m,GLint x,GLint y,GLint width,GLint height,GLfloat zNear,GLfloat zFar,GLfloat depthMax)1113 _math_matrix_viewport(GLmatrix *m, GLint x, GLint y, GLint width, GLint height,
1114                       GLfloat zNear, GLfloat zFar, GLfloat depthMax)
1115 {
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;
1124 }
1125 
1126 
1127 /**
1128  * Set a matrix to the identity matrix.
1129  *
1130  * \param mat matrix.
1131  *
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.
1134  */
1135 void
_math_matrix_set_identity(GLmatrix * mat)1136 _math_matrix_set_identity( GLmatrix *mat )
1137 {
1138    memcpy( mat->m, Identity, 16*sizeof(GLfloat) );
1139    memcpy( mat->inv, Identity, 16*sizeof(GLfloat) );
1140 
1141    mat->type = MATRIX_IDENTITY;
1142    mat->flags &= ~(MAT_DIRTY_FLAGS|
1143 		   MAT_DIRTY_TYPE|
1144 		   MAT_DIRTY_INVERSE);
1145 }
1146 
1147 /*@}*/
1148 
1149 
1150 /**********************************************************************/
1151 /** \name Matrix analysis */
1152 /*@{*/
1153 
1154 #define ZERO(x) (1<<x)
1155 #define ONE(x)  (1<<(x+16))
1156 
1157 #define MASK_NO_TRX      (ZERO(12) | ZERO(13) | ZERO(14))
1158 #define MASK_NO_2D_SCALE ( ONE(0)  | ONE(5))
1159 
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) )
1164 
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) )
1169 
1170 #define MASK_2D          (                      ZERO(8)  |           \
1171 			                        ZERO(9)  |           \
1172 			  ZERO(2)  | ZERO(6)  |  ONE(10) | ZERO(14) |\
1173 			  ZERO(3)  | ZERO(7)  | ZERO(11) |  ONE(15) )
1174 
1175 
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) )
1180 
1181 #define MASK_3D          (                                           \
1182 			                                             \
1183 			                                             \
1184 			  ZERO(3)  | ZERO(7)  | ZERO(11) |  ONE(15) )
1185 
1186 
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) )
1191 
1192 #define SQ(x) ((x)*(x))
1193 
1194 /**
1195  * Determine type and flags from scratch.
1196  *
1197  * \param mat matrix.
1198  *
1199  * This is expensive enough to only want to do it once.
1200  */
analyse_from_scratch(GLmatrix * mat)1201 static void analyse_from_scratch( GLmatrix *mat )
1202 {
1203    const GLfloat *m = mat->m;
1204    GLuint mask = 0;
1205    GLuint i;
1206 
1207    for (i = 0 ; i < 16 ; i++) {
1208       if (m[i] == 0.0) mask |= (1<<i);
1209    }
1210 
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);
1215 
1216    mat->flags &= ~MAT_FLAGS_GEOMETRY;
1217 
1218    /* Check for translation - no-one really cares
1219     */
1220    if ((mask & MASK_NO_TRX) != MASK_NO_TRX)
1221       mat->flags |= MAT_FLAG_TRANSLATION;
1222 
1223    /* Do the real work
1224     */
1225    if (mask == (GLuint) MASK_IDENTITY) {
1226       mat->type = MATRIX_IDENTITY;
1227    }
1228    else if ((mask & MASK_2D_NO_ROT) == (GLuint) MASK_2D_NO_ROT) {
1229       mat->type = MATRIX_2D_NO_ROT;
1230 
1231       if ((mask & MASK_NO_2D_SCALE) != MASK_NO_2D_SCALE)
1232 	 mat->flags |= MAT_FLAG_GENERAL_SCALE;
1233    }
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);
1238 
1239       mat->type = MATRIX_2D;
1240 
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;
1245 
1246       /* Check for rotation */
1247       if (SQ(mm4) > SQ(1e-6))
1248 	 mat->flags |= MAT_FLAG_GENERAL_3D;
1249       else
1250 	 mat->flags |= MAT_FLAG_ROTATION;
1251 
1252    }
1253    else if ((mask & MASK_3D_NO_ROT) == (GLuint) MASK_3D_NO_ROT) {
1254       mat->type = MATRIX_3D_NO_ROT;
1255 
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;
1261          }
1262       }
1263       else {
1264 	 mat->flags |= MAT_FLAG_GENERAL_SCALE;
1265       }
1266    }
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);
1272       GLfloat cp[3];
1273 
1274       mat->type = MATRIX_3D;
1275 
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 */
1281       }
1282       else {
1283 	 mat->flags |= MAT_FLAG_GENERAL_SCALE;
1284       }
1285 
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;
1292 	 else
1293 	    mat->flags |= MAT_FLAG_GENERAL_3D;
1294       }
1295       else {
1296 	 mat->flags |= MAT_FLAG_GENERAL_3D; /* shear, etc */
1297       }
1298    }
1299    else if ((mask & MASK_PERSPECTIVE) == MASK_PERSPECTIVE && m[11]==-1.0F) {
1300       mat->type = MATRIX_PERSPECTIVE;
1301       mat->flags |= MAT_FLAG_GENERAL;
1302    }
1303    else {
1304       mat->type = MATRIX_GENERAL;
1305       mat->flags |= MAT_FLAG_GENERAL;
1306    }
1307 }
1308 
1309 /**
1310  * Analyze a matrix given that its flags are accurate.
1311  *
1312  * This is the more common operation, hopefully.
1313  */
analyse_from_flags(GLmatrix * mat)1314 static void analyse_from_flags( GLmatrix *mat )
1315 {
1316    const GLfloat *m = mat->m;
1317 
1318    if (TEST_MAT_FLAGS(mat, 0)) {
1319       mat->type = MATRIX_IDENTITY;
1320    }
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;
1326       }
1327       else {
1328 	 mat->type = MATRIX_3D_NO_ROT;
1329       }
1330    }
1331    else if (TEST_MAT_FLAGS(mat, MAT_FLAGS_3D)) {
1332       if (                                 m[ 8]==0.0F
1333             &&                             m[ 9]==0.0F
1334             && m[2]==0.0F && m[6]==0.0F && m[10]==1.0F && m[14]==0.0F) {
1335 	 mat->type = MATRIX_2D;
1336       }
1337       else {
1338 	 mat->type = MATRIX_3D;
1339       }
1340    }
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;
1346    }
1347    else {
1348       mat->type = MATRIX_GENERAL;
1349    }
1350 }
1351 
1352 /**
1353  * Analyze and update a matrix.
1354  *
1355  * \param mat matrix.
1356  *
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.
1361  */
1362 void
_math_matrix_analyse(GLmatrix * mat)1363 _math_matrix_analyse( GLmatrix *mat )
1364 {
1365    if (mat->flags & MAT_DIRTY_TYPE) {
1366       if (mat->flags & MAT_DIRTY_FLAGS)
1367 	 analyse_from_scratch( mat );
1368       else
1369 	 analyse_from_flags( mat );
1370    }
1371 
1372    if (mat->inv && (mat->flags & MAT_DIRTY_INVERSE)) {
1373       matrix_invert( mat );
1374       mat->flags &= ~MAT_DIRTY_INVERSE;
1375    }
1376 
1377    mat->flags &= ~(MAT_DIRTY_FLAGS | MAT_DIRTY_TYPE);
1378 }
1379 
1380 /*@}*/
1381 
1382 
1383 /**
1384  * Test if the given matrix preserves vector lengths.
1385  */
1386 GLboolean
_math_matrix_is_length_preserving(const GLmatrix * m)1387 _math_matrix_is_length_preserving( const GLmatrix *m )
1388 {
1389    return TEST_MAT_FLAGS( m, MAT_FLAGS_LENGTH_PRESERVING);
1390 }
1391 
1392 
1393 /**
1394  * Test if the given matrix does any rotation.
1395  * (or perhaps if the upper-left 3x3 is non-identity)
1396  */
1397 GLboolean
_math_matrix_has_rotation(const GLmatrix * m)1398 _math_matrix_has_rotation( const GLmatrix *m )
1399 {
1400    if (m->flags & (MAT_FLAG_GENERAL |
1401                    MAT_FLAG_ROTATION |
1402                    MAT_FLAG_GENERAL_3D |
1403                    MAT_FLAG_PERSPECTIVE))
1404       return GL_TRUE;
1405    else
1406       return GL_FALSE;
1407 }
1408 
1409 
1410 GLboolean
_math_matrix_is_general_scale(const GLmatrix * m)1411 _math_matrix_is_general_scale( const GLmatrix *m )
1412 {
1413    return (m->flags & MAT_FLAG_GENERAL_SCALE) ? GL_TRUE : GL_FALSE;
1414 }
1415 
1416 
1417 GLboolean
_math_matrix_is_dirty(const GLmatrix * m)1418 _math_matrix_is_dirty( const GLmatrix *m )
1419 {
1420    return (m->flags & MAT_DIRTY) ? GL_TRUE : GL_FALSE;
1421 }
1422 
1423 
1424 /**********************************************************************/
1425 /** \name Matrix setup */
1426 /*@{*/
1427 
1428 /**
1429  * Copy a matrix.
1430  *
1431  * \param to destination matrix.
1432  * \param from source matrix.
1433  *
1434  * Copies all fields in GLmatrix, creating an inverse array if necessary.
1435  */
1436 void
_math_matrix_copy(GLmatrix * to,const GLmatrix * from)1437 _math_matrix_copy( GLmatrix *to, const GLmatrix *from )
1438 {
1439    memcpy( to->m, from->m, sizeof(Identity) );
1440    memcpy(to->inv, from->inv, 16 * sizeof(GLfloat));
1441    to->flags = from->flags;
1442    to->type = from->type;
1443 }
1444 
1445 /**
1446  * Loads a matrix array into GLmatrix.
1447  *
1448  * \param m matrix array.
1449  * \param mat matrix.
1450  *
1451  * Copies \p m into GLmatrix::m and marks the MAT_FLAG_GENERAL and MAT_DIRTY
1452  * flags.
1453  */
1454 void
_math_matrix_loadf(GLmatrix * mat,const GLfloat * m)1455 _math_matrix_loadf( GLmatrix *mat, const GLfloat *m )
1456 {
1457    memcpy( mat->m, m, 16*sizeof(GLfloat) );
1458    mat->flags = (MAT_FLAG_GENERAL | MAT_DIRTY);
1459 }
1460 
1461 /**
1462  * Matrix constructor.
1463  *
1464  * \param m matrix.
1465  *
1466  * Initialize the GLmatrix fields.
1467  */
1468 void
_math_matrix_ctr(GLmatrix * m)1469 _math_matrix_ctr( GLmatrix *m )
1470 {
1471    m->m = (GLfloat *) _mesa_align_malloc( 16 * sizeof(GLfloat), 16 );
1472    if (m->m)
1473       memcpy( m->m, Identity, sizeof(Identity) );
1474    m->inv = (GLfloat *) _mesa_align_malloc( 16 * sizeof(GLfloat), 16 );
1475    if (m->inv)
1476       memcpy( m->inv, Identity, sizeof(Identity) );
1477    m->type = MATRIX_IDENTITY;
1478    m->flags = 0;
1479 }
1480 
1481 /**
1482  * Matrix destructor.
1483  *
1484  * \param m matrix.
1485  *
1486  * Frees the data in a GLmatrix.
1487  */
1488 void
_math_matrix_dtr(GLmatrix * m)1489 _math_matrix_dtr( GLmatrix *m )
1490 {
1491    if (m->m) {
1492       _mesa_align_free( m->m );
1493       m->m = NULL;
1494    }
1495    if (m->inv) {
1496       _mesa_align_free( m->inv );
1497       m->inv = NULL;
1498    }
1499 }
1500 
1501 /*@}*/
1502 
1503 
1504 /**********************************************************************/
1505 /** \name Matrix transpose */
1506 /*@{*/
1507 
1508 /**
1509  * Transpose a GLfloat matrix.
1510  *
1511  * \param to destination array.
1512  * \param from source array.
1513  */
1514 void
_math_transposef(GLfloat to[16],const GLfloat from[16])1515 _math_transposef( GLfloat to[16], const GLfloat from[16] )
1516 {
1517    to[0] = from[0];
1518    to[1] = from[4];
1519    to[2] = from[8];
1520    to[3] = from[12];
1521    to[4] = from[1];
1522    to[5] = from[5];
1523    to[6] = from[9];
1524    to[7] = from[13];
1525    to[8] = from[2];
1526    to[9] = from[6];
1527    to[10] = from[10];
1528    to[11] = from[14];
1529    to[12] = from[3];
1530    to[13] = from[7];
1531    to[14] = from[11];
1532    to[15] = from[15];
1533 }
1534 
1535 /**
1536  * Transpose a GLdouble matrix.
1537  *
1538  * \param to destination array.
1539  * \param from source array.
1540  */
1541 void
_math_transposed(GLdouble to[16],const GLdouble from[16])1542 _math_transposed( GLdouble to[16], const GLdouble from[16] )
1543 {
1544    to[0] = from[0];
1545    to[1] = from[4];
1546    to[2] = from[8];
1547    to[3] = from[12];
1548    to[4] = from[1];
1549    to[5] = from[5];
1550    to[6] = from[9];
1551    to[7] = from[13];
1552    to[8] = from[2];
1553    to[9] = from[6];
1554    to[10] = from[10];
1555    to[11] = from[14];
1556    to[12] = from[3];
1557    to[13] = from[7];
1558    to[14] = from[11];
1559    to[15] = from[15];
1560 }
1561 
1562 /**
1563  * Transpose a GLdouble matrix and convert to GLfloat.
1564  *
1565  * \param to destination array.
1566  * \param from source array.
1567  */
1568 void
_math_transposefd(GLfloat to[16],const GLdouble from[16])1569 _math_transposefd( GLfloat to[16], const GLdouble from[16] )
1570 {
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];
1587 }
1588 
1589 /*@}*/
1590 
1591 
1592 /**
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
1595  * directions.
1596  * Mathematically,  u = v * m.
1597  * Input:  v - input vector
1598  *         m - transformation matrix
1599  * Output:  u - transformed vector
1600  */
1601 void
_mesa_transform_vector(GLfloat u[4],const GLfloat v[4],const GLfloat m[16])1602 _mesa_transform_vector( GLfloat u[4], const GLfloat v[4], const GLfloat m[16] )
1603 {
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);
1610 #undef M
1611 }
1612