summaryrefslogtreecommitdiff
path: root/src/mesa/main/matrix.c
blob: a775a9a36a27c0789b25e6be60ed569d6f638d77 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
/*
 * Mesa 3-D graphics library
 * Version:  7.5
 *
 * Copyright (C) 1999-2008  Brian Paul   All Rights Reserved.
 * Copyright (C) 2009  VMware, Inc.  All Rights Reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included
 * in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
 * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */


/**
 * \file matrix.c
 * Matrix operations.
 *
 * \note
 * -# 4x4 transformation matrices are stored in memory in column major order.
 * -# Points/vertices are to be thought of as column vectors.
 * -# Transformation of a point p by a matrix M is: p' = M * p
 */


#include "glheader.h"
#include "imports.h"
#include "context.h"
#include "enums.h"
#include "macros.h"
#include "mfeatures.h"
#include "matrix.h"
#include "mtypes.h"
#include "math/m_matrix.h"


/**
 * Apply a perspective projection matrix.
 *
 * \param left left clipping plane coordinate.
 * \param right right clipping plane coordinate.
 * \param bottom bottom clipping plane coordinate.
 * \param top top clipping plane coordinate.
 * \param nearval distance to the near clipping plane.
 * \param farval distance to the far clipping plane.
 *
 * \sa glFrustum().
 *
 * Flushes vertices and validates parameters. Calls _math_matrix_frustum() with
 * the top matrix of the current matrix stack and sets
 * __struct gl_contextRec::NewState.
 */
void GLAPIENTRY
_mesa_Frustum( GLdouble left, GLdouble right,
               GLdouble bottom, GLdouble top,
               GLdouble nearval, GLdouble farval )
{
   GET_CURRENT_CONTEXT(ctx);
   ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(ctx);

   if (nearval <= 0.0 ||
       farval <= 0.0 ||
       nearval == farval ||
       left == right ||
       top == bottom)
   {
      _mesa_error( ctx,  GL_INVALID_VALUE, "glFrustum" );
      return;
   }

   _math_matrix_frustum( ctx->CurrentStack->Top,
                         (GLfloat) left, (GLfloat) right, 
			 (GLfloat) bottom, (GLfloat) top, 
			 (GLfloat) nearval, (GLfloat) farval );
   ctx->NewState |= ctx->CurrentStack->DirtyFlag;
}


/**
 * Apply an orthographic projection matrix.
 *
 * \param left left clipping plane coordinate.
 * \param right right clipping plane coordinate.
 * \param bottom bottom clipping plane coordinate.
 * \param top top clipping plane coordinate.
 * \param nearval distance to the near clipping plane.
 * \param farval distance to the far clipping plane.
 *
 * \sa glOrtho().
 *
 * Flushes vertices and validates parameters. Calls _math_matrix_ortho() with
 * the top matrix of the current matrix stack and sets
 * __struct gl_contextRec::NewState.
 */
void GLAPIENTRY
_mesa_Ortho( GLdouble left, GLdouble right,
             GLdouble bottom, GLdouble top,
             GLdouble nearval, GLdouble farval )
{
   GET_CURRENT_CONTEXT(ctx);
   ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(ctx);

   if (MESA_VERBOSE & VERBOSE_API)
      _mesa_debug(ctx, "glOrtho(%f, %f, %f, %f, %f, %f)\n",
                  left, right, bottom, top, nearval, farval);

   if (left == right ||
       bottom == top ||
       nearval == farval)
   {
      _mesa_error( ctx,  GL_INVALID_VALUE, "glOrtho" );
      return;
   }

   _math_matrix_ortho( ctx->CurrentStack->Top,
                       (GLfloat) left, (GLfloat) right, 
		       (GLfloat) bottom, (GLfloat) top, 
		       (GLfloat) nearval, (GLfloat) farval );
   ctx->NewState |= ctx->CurrentStack->DirtyFlag;
}


/**
 * Set the current matrix stack.
 *
 * \param mode matrix stack.
 *
 * \sa glMatrixMode().
 *
 * Flushes the vertices, validates the parameter and updates
 * __struct gl_contextRec::CurrentStack and gl_transform_attrib::MatrixMode
 * with the specified matrix stack.
 */
void GLAPIENTRY
_mesa_MatrixMode( GLenum mode )
{
   GET_CURRENT_CONTEXT(ctx);
   ASSERT_OUTSIDE_BEGIN_END(ctx);

   if (ctx->Transform.MatrixMode == mode && mode != GL_TEXTURE)
      return;
   FLUSH_VERTICES(ctx, _NEW_TRANSFORM);

   switch (mode) {
   case GL_MODELVIEW:
      ctx->CurrentStack = &ctx->ModelviewMatrixStack;
      break;
   case GL_PROJECTION:
      ctx->CurrentStack = &ctx->ProjectionMatrixStack;
      break;
   case GL_TEXTURE:
      /* This error check is disabled because if we're called from
       * glPopAttrib() when the active texture unit is >= MaxTextureCoordUnits
       * we'll generate an unexpected error.
       * From the GL_ARB_vertex_shader spec it sounds like we should instead
       * do error checking in other places when we actually try to access
       * texture matrices beyond MaxTextureCoordUnits.
       */
#if 0
      if (ctx->Texture.CurrentUnit >= ctx->Const.MaxTextureCoordUnits) {
         _mesa_error(ctx, GL_INVALID_OPERATION,
                     "glMatrixMode(invalid tex unit %d)",
                     ctx->Texture.CurrentUnit);
         return;
      }
#endif
      ASSERT(ctx->Texture.CurrentUnit < Elements(ctx->TextureMatrixStack));
      ctx->CurrentStack = &ctx->TextureMatrixStack[ctx->Texture.CurrentUnit];
      break;
   case GL_MATRIX0_NV:
   case GL_MATRIX1_NV:
   case GL_MATRIX2_NV:
   case GL_MATRIX3_NV:
   case GL_MATRIX4_NV:
   case GL_MATRIX5_NV:
   case GL_MATRIX6_NV:
   case GL_MATRIX7_NV:
      if (ctx->API == API_OPENGL && ctx->Extensions.NV_vertex_program) {
         ctx->CurrentStack = &ctx->ProgramMatrixStack[mode - GL_MATRIX0_NV];
      }
      else {
         _mesa_error( ctx,  GL_INVALID_ENUM, "glMatrixMode(mode)" );
         return;
      }
      break;
   case GL_MATRIX0_ARB:
   case GL_MATRIX1_ARB:
   case GL_MATRIX2_ARB:
   case GL_MATRIX3_ARB:
   case GL_MATRIX4_ARB:
   case GL_MATRIX5_ARB:
   case GL_MATRIX6_ARB:
   case GL_MATRIX7_ARB:
      if (ctx->API == API_OPENGL
          && (ctx->Extensions.ARB_vertex_program ||
              ctx->Extensions.ARB_fragment_program)) {
         const GLuint m = mode - GL_MATRIX0_ARB;
         if (m > ctx->Const.MaxProgramMatrices) {
            _mesa_error(ctx, GL_INVALID_ENUM,
                        "glMatrixMode(GL_MATRIX%d_ARB)", m);
            return;
         }
         ctx->CurrentStack = &ctx->ProgramMatrixStack[m];
      }
      else {
         _mesa_error( ctx,  GL_INVALID_ENUM, "glMatrixMode(mode)" );
         return;
      }
      break;
   default:
      _mesa_error( ctx,  GL_INVALID_ENUM, "glMatrixMode(mode)" );
      return;
   }

   ctx->Transform.MatrixMode = mode;
}


/**
 * Push the current matrix stack.
 *
 * \sa glPushMatrix().
 * 
 * Verifies the current matrix stack is not full, and duplicates the top-most
 * matrix in the stack.
 * Marks __struct gl_contextRec::NewState with the stack dirty flag.
 */
void GLAPIENTRY
_mesa_PushMatrix( void )
{
   GET_CURRENT_CONTEXT(ctx);
   struct gl_matrix_stack *stack = ctx->CurrentStack;
   ASSERT_OUTSIDE_BEGIN_END(ctx);

   if (MESA_VERBOSE&VERBOSE_API)
      _mesa_debug(ctx, "glPushMatrix %s\n",
                  _mesa_lookup_enum_by_nr(ctx->Transform.MatrixMode));

   if (stack->Depth + 1 >= stack->MaxDepth) {
      if (ctx->Transform.MatrixMode == GL_TEXTURE) {
         _mesa_error(ctx,  GL_STACK_OVERFLOW,
                     "glPushMatrix(mode=GL_TEXTURE, unit=%d)",
                      ctx->Texture.CurrentUnit);
      }
      else {
         _mesa_error(ctx,  GL_STACK_OVERFLOW, "glPushMatrix(mode=%s)",
                     _mesa_lookup_enum_by_nr(ctx->Transform.MatrixMode));
      }
      return;
   }
   _math_matrix_copy( &stack->Stack[stack->Depth + 1],
                      &stack->Stack[stack->Depth] );
   stack->Depth++;
   stack->Top = &(stack->Stack[stack->Depth]);
   ctx->NewState |= stack->DirtyFlag;
}


/**
 * Pop the current matrix stack.
 *
 * \sa glPopMatrix().
 * 
 * Flushes the vertices, verifies the current matrix stack is not empty, and
 * moves the stack head down.
 * Marks __struct gl_contextRec::NewState with the dirty stack flag.
 */
void GLAPIENTRY
_mesa_PopMatrix( void )
{
   GET_CURRENT_CONTEXT(ctx);
   struct gl_matrix_stack *stack = ctx->CurrentStack;
   ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(ctx);

   if (MESA_VERBOSE&VERBOSE_API)
      _mesa_debug(ctx, "glPopMatrix %s\n",
                  _mesa_lookup_enum_by_nr(ctx->Transform.MatrixMode));

   if (stack->Depth == 0) {
      if (ctx->Transform.MatrixMode == GL_TEXTURE) {
         _mesa_error(ctx,  GL_STACK_UNDERFLOW,
                     "glPopMatrix(mode=GL_TEXTURE, unit=%d)",
                      ctx->Texture.CurrentUnit);
      }
      else {
         _mesa_error(ctx,  GL_STACK_UNDERFLOW, "glPopMatrix(mode=%s)",
                     _mesa_lookup_enum_by_nr(ctx->Transform.MatrixMode));
      }
      return;
   }
   stack->Depth--;
   stack->Top = &(stack->Stack[stack->Depth]);
   ctx->NewState |= stack->DirtyFlag;
}


/**
 * Replace the current matrix with the identity matrix.
 *
 * \sa glLoadIdentity().
 *
 * Flushes the vertices and calls _math_matrix_set_identity() with the
 * top-most matrix in the current stack.
 * Marks __struct gl_contextRec::NewState with the stack dirty flag.
 */
void GLAPIENTRY
_mesa_LoadIdentity( void )
{
   GET_CURRENT_CONTEXT(ctx);
   ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(ctx);

   if (MESA_VERBOSE & VERBOSE_API)
      _mesa_debug(ctx, "glLoadIdentity()\n");

   _math_matrix_set_identity( ctx->CurrentStack->Top );
   ctx->NewState |= ctx->CurrentStack->DirtyFlag;
}


/**
 * Replace the current matrix with a given matrix.
 *
 * \param m matrix.
 *
 * \sa glLoadMatrixf().
 *
 * Flushes the vertices and calls _math_matrix_loadf() with the top-most
 * matrix in the current stack and the given matrix.
 * Marks __struct gl_contextRec::NewState with the dirty stack flag.
 */
void GLAPIENTRY
_mesa_LoadMatrixf( const GLfloat *m )
{
   GET_CURRENT_CONTEXT(ctx);
   if (!m) return;
   if (MESA_VERBOSE & VERBOSE_API)
      _mesa_debug(ctx,
          "glLoadMatrix(%f %f %f %f, %f %f %f %f, %f %f %f %f, %f %f %f %f\n",
          m[0], m[4], m[8], m[12],
          m[1], m[5], m[9], m[13],
          m[2], m[6], m[10], m[14],
          m[3], m[7], m[11], m[15]);

   ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(ctx);
   _math_matrix_loadf( ctx->CurrentStack->Top, m );
   ctx->NewState |= ctx->CurrentStack->DirtyFlag;
}


/**
 * Multiply the current matrix with a given matrix.
 *
 * \param m matrix.
 *
 * \sa glMultMatrixf().
 *
 * Flushes the vertices and calls _math_matrix_mul_floats() with the top-most
 * matrix in the current stack and the given matrix. Marks
 * __struct gl_contextRec::NewState with the dirty stack flag.
 */
void GLAPIENTRY
_mesa_MultMatrixf( const GLfloat *m )
{
   GET_CURRENT_CONTEXT(ctx);
   if (!m) return;
   if (MESA_VERBOSE & VERBOSE_API)
      _mesa_debug(ctx,
          "glMultMatrix(%f %f %f %f, %f %f %f %f, %f %f %f %f, %f %f %f %f\n",
          m[0], m[4], m[8], m[12],
          m[1], m[5], m[9], m[13],
          m[2], m[6], m[10], m[14],
          m[3], m[7], m[11], m[15]);
   ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(ctx);
   _math_matrix_mul_floats( ctx->CurrentStack->Top, m );
   ctx->NewState |= ctx->CurrentStack->DirtyFlag;
}


/**
 * Multiply the current matrix with a rotation matrix.
 *
 * \param angle angle of rotation, in degrees.
 * \param x rotation vector x coordinate.
 * \param y rotation vector y coordinate.
 * \param z rotation vector z coordinate.
 *
 * \sa glRotatef().
 *
 * Flushes the vertices and calls _math_matrix_rotate() with the top-most
 * matrix in the current stack and the given parameters. Marks
 * __struct gl_contextRec::NewState with the dirty stack flag.
 */
void GLAPIENTRY
_mesa_Rotatef( GLfloat angle, GLfloat x, GLfloat y, GLfloat z )
{
   GET_CURRENT_CONTEXT(ctx);
   ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(ctx);
   if (angle != 0.0F) {
      _math_matrix_rotate( ctx->CurrentStack->Top, angle, x, y, z);
      ctx->NewState |= ctx->CurrentStack->DirtyFlag;
   }
}


/**
 * Multiply the current matrix with a general scaling matrix.
 *
 * \param x x axis scale factor.
 * \param y y axis scale factor.
 * \param z z axis scale factor.
 *
 * \sa glScalef().
 *
 * Flushes the vertices and calls _math_matrix_scale() with the top-most
 * matrix in the current stack and the given parameters. Marks
 * __struct gl_contextRec::NewState with the dirty stack flag.
 */
void GLAPIENTRY
_mesa_Scalef( GLfloat x, GLfloat y, GLfloat z )
{
   GET_CURRENT_CONTEXT(ctx);
   ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(ctx);
   _math_matrix_scale( ctx->CurrentStack->Top, x, y, z);
   ctx->NewState |= ctx->CurrentStack->DirtyFlag;
}


/**
 * Multiply the current matrix with a translation matrix.
 *
 * \param x translation vector x coordinate.
 * \param y translation vector y coordinate.
 * \param z translation vector z coordinate.
 *
 * \sa glTranslatef().
 *
 * Flushes the vertices and calls _math_matrix_translate() with the top-most
 * matrix in the current stack and the given parameters. Marks
 * __struct gl_contextRec::NewState with the dirty stack flag.
 */
void GLAPIENTRY
_mesa_Translatef( GLfloat x, GLfloat y, GLfloat z )
{
   GET_CURRENT_CONTEXT(ctx);
   ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(ctx);
   _math_matrix_translate( ctx->CurrentStack->Top, x, y, z);
   ctx->NewState |= ctx->CurrentStack->DirtyFlag;
}

 
#if _HAVE_FULL_GL
void GLAPIENTRY
_mesa_LoadMatrixd( const GLdouble *m )
{
   GLint i;
   GLfloat f[16];
   if (!m) return;
   for (i = 0; i < 16; i++)
      f[i] = (GLfloat) m[i];
   _mesa_LoadMatrixf(f);
}

void GLAPIENTRY
_mesa_MultMatrixd( const GLdouble *m )
{
   GLint i;
   GLfloat f[16];
   if (!m) return;
   for (i = 0; i < 16; i++)
      f[i] = (GLfloat) m[i];
   _mesa_MultMatrixf( f );
}


void GLAPIENTRY
_mesa_Rotated( GLdouble angle, GLdouble x, GLdouble y, GLdouble z )
{
   _mesa_Rotatef((GLfloat) angle, (GLfloat) x, (GLfloat) y, (GLfloat) z);
}


void GLAPIENTRY
_mesa_Scaled( GLdouble x, GLdouble y, GLdouble z )
{
   _mesa_Scalef((GLfloat) x, (GLfloat) y, (GLfloat) z);
}


void GLAPIENTRY
_mesa_Translated( GLdouble x, GLdouble y, GLdouble z )
{
   _mesa_Translatef((GLfloat) x, (GLfloat) y, (GLfloat) z);
}
#endif


#if _HAVE_FULL_GL
void GLAPIENTRY
_mesa_LoadTransposeMatrixfARB( const GLfloat *m )
{
   GLfloat tm[16];
   if (!m) return;
   _math_transposef(tm, m);
   _mesa_LoadMatrixf(tm);
}


void GLAPIENTRY
_mesa_LoadTransposeMatrixdARB( const GLdouble *m )
{
   GLfloat tm[16];
   if (!m) return;
   _math_transposefd(tm, m);
   _mesa_LoadMatrixf(tm);
}


void GLAPIENTRY
_mesa_MultTransposeMatrixfARB( const GLfloat *m )
{
   GLfloat tm[16];
   if (!m) return;
   _math_transposef(tm, m);
   _mesa_MultMatrixf(tm);
}


void GLAPIENTRY
_mesa_MultTransposeMatrixdARB( const GLdouble *m )
{
   GLfloat tm[16];
   if (!m) return;
   _math_transposefd(tm, m);
   _mesa_MultMatrixf(tm);
}
#endif



/**********************************************************************/
/** \name State management */
/*@{*/


/**
 * Update the projection matrix stack.
 *
 * \param ctx GL context.
 *
 * Calls _math_matrix_analyse() with the top-matrix of the projection matrix
 * stack, and recomputes user clip positions if necessary.
 * 
 * \note This routine references __struct gl_contextRec::Tranform attribute
 * values to compute userclip positions in clip space, but is only called on
 * _NEW_PROJECTION.  The _mesa_ClipPlane() function keeps these values up to
 * date across changes to the __struct gl_contextRec::Transform attributes.
 */
static void
update_projection( struct gl_context *ctx )
{
   _math_matrix_analyse( ctx->ProjectionMatrixStack.Top );

#if FEATURE_userclip
   /* Recompute clip plane positions in clipspace.  This is also done
    * in _mesa_ClipPlane().
    */
   if (ctx->Transform.ClipPlanesEnabled) {
      GLuint p;
      for (p = 0; p < ctx->Const.MaxClipPlanes; p++) {
	 if (ctx->Transform.ClipPlanesEnabled & (1 << p)) {
	    _mesa_transform_vector( ctx->Transform._ClipUserPlane[p],
				 ctx->Transform.EyeUserPlane[p],
				 ctx->ProjectionMatrixStack.Top->inv );
	 }
      }
   }
#endif
}


/**
 * Calculate the combined modelview-projection matrix.
 *
 * \param ctx GL context.
 *
 * Multiplies the top matrices of the projection and model view stacks into
 * __struct gl_contextRec::_ModelProjectMatrix via _math_matrix_mul_matrix()
 * and analyzes the resulting matrix via _math_matrix_analyse().
 */
static void
calculate_model_project_matrix( struct gl_context *ctx )
{
   _math_matrix_mul_matrix( &ctx->_ModelProjectMatrix,
                            ctx->ProjectionMatrixStack.Top,
                            ctx->ModelviewMatrixStack.Top );

   _math_matrix_analyse( &ctx->_ModelProjectMatrix );
}


/**
 * Updates the combined modelview-projection matrix.
 *
 * \param ctx GL context.
 * \param new_state new state bit mask.
 *
 * If there is a new model view matrix then analyzes it. If there is a new
 * projection matrix, updates it. Finally calls
 * calculate_model_project_matrix() to recalculate the modelview-projection
 * matrix.
 */
void _mesa_update_modelview_project( struct gl_context *ctx, GLuint new_state )
{
   if (new_state & _NEW_MODELVIEW) {
      _math_matrix_analyse( ctx->ModelviewMatrixStack.Top );
    
      /* Bring cull position up to date.
       */
      TRANSFORM_POINT3( ctx->Transform.CullObjPos, 
			ctx->ModelviewMatrixStack.Top->inv,
			ctx->Transform.CullEyePos );
   }


   if (new_state & _NEW_PROJECTION)
      update_projection( ctx );

   /* Keep ModelviewProject up to date always to allow tnl
    * implementations that go model->clip even when eye is required.
    */
   calculate_model_project_matrix(ctx);
}

/*@}*/


/**********************************************************************/
/** Matrix stack initialization */
/*@{*/


/**
 * Initialize a matrix stack.
 *
 * \param stack matrix stack.
 * \param maxDepth maximum stack depth.
 * \param dirtyFlag dirty flag.
 * 
 * Allocates an array of \p maxDepth elements for the matrix stack and calls
 * _math_matrix_ctr() for each element to initialize it.
 */
static void
init_matrix_stack( struct gl_matrix_stack *stack,
                   GLuint maxDepth, GLuint dirtyFlag )
{
   GLuint i;

   stack->Depth = 0;
   stack->MaxDepth = maxDepth;
   stack->DirtyFlag = dirtyFlag;
   /* The stack */
   stack->Stack = (GLmatrix *) calloc(maxDepth, sizeof(GLmatrix));
   for (i = 0; i < maxDepth; i++) {
      _math_matrix_ctr(&stack->Stack[i]);
   }
   stack->Top = stack->Stack;
}

/**
 * Free matrix stack.
 * 
 * \param stack matrix stack.
 * 
 * Calls _math_matrix_dtr() for each element of the matrix stack and
 * frees the array.
 */
static void
free_matrix_stack( struct gl_matrix_stack *stack )
{
   GLuint i;
   for (i = 0; i < stack->MaxDepth; i++) {
      _math_matrix_dtr(&stack->Stack[i]);
   }
   FREE(stack->Stack);
   stack->Stack = stack->Top = NULL;
}

/*@}*/


/**********************************************************************/
/** \name Initialization */
/*@{*/


/**
 * Initialize the context matrix data.
 *
 * \param ctx GL context.
 *
 * Initializes each of the matrix stacks and the combined modelview-projection
 * matrix.
 */
void _mesa_init_matrix( struct gl_context * ctx )
{
   GLint i;

   /* Initialize matrix stacks */
   init_matrix_stack(&ctx->ModelviewMatrixStack, MAX_MODELVIEW_STACK_DEPTH,
                     _NEW_MODELVIEW);
   init_matrix_stack(&ctx->ProjectionMatrixStack, MAX_PROJECTION_STACK_DEPTH,
                     _NEW_PROJECTION);
   for (i = 0; i < Elements(ctx->TextureMatrixStack); i++)
      init_matrix_stack(&ctx->TextureMatrixStack[i], MAX_TEXTURE_STACK_DEPTH,
                        _NEW_TEXTURE_MATRIX);
   for (i = 0; i < Elements(ctx->ProgramMatrixStack); i++)
      init_matrix_stack(&ctx->ProgramMatrixStack[i], 
		        MAX_PROGRAM_MATRIX_STACK_DEPTH, _NEW_TRACK_MATRIX);
   ctx->CurrentStack = &ctx->ModelviewMatrixStack;

   /* Init combined Modelview*Projection matrix */
   _math_matrix_ctr( &ctx->_ModelProjectMatrix );
}


/**
 * Free the context matrix data.
 * 
 * \param ctx GL context.
 *
 * Frees each of the matrix stacks and the combined modelview-projection
 * matrix.
 */
void _mesa_free_matrix_data( struct gl_context *ctx )
{
   GLint i;

   free_matrix_stack(&ctx->ModelviewMatrixStack);
   free_matrix_stack(&ctx->ProjectionMatrixStack);
   for (i = 0; i < Elements(ctx->TextureMatrixStack); i++)
      free_matrix_stack(&ctx->TextureMatrixStack[i]);
   for (i = 0; i < Elements(ctx->ProgramMatrixStack); i++)
      free_matrix_stack(&ctx->ProgramMatrixStack[i]);
   /* combined Modelview*Projection matrix */
   _math_matrix_dtr( &ctx->_ModelProjectMatrix );

}


/** 
 * Initialize the context transform attribute group.
 *
 * \param ctx GL context.
 *
 * \todo Move this to a new file with other 'transform' routines.
 */
void _mesa_init_transform( struct gl_context *ctx )
{
   GLint i;

   /* Transformation group */
   ctx->Transform.MatrixMode = GL_MODELVIEW;
   ctx->Transform.Normalize = GL_FALSE;
   ctx->Transform.RescaleNormals = GL_FALSE;
   ctx->Transform.RasterPositionUnclipped = GL_FALSE;
   for (i=0;i<ctx->Const.MaxClipPlanes;i++) {
      ASSIGN_4V( ctx->Transform.EyeUserPlane[i], 0.0, 0.0, 0.0, 0.0 );
   }
   ctx->Transform.ClipPlanesEnabled = 0;

   ASSIGN_4V( ctx->Transform.CullObjPos, 0.0, 0.0, 1.0, 0.0 );
   ASSIGN_4V( ctx->Transform.CullEyePos, 0.0, 0.0, 1.0, 0.0 );
}


/*@}*/