src/mesa/main/context.c

   1 /*
   2  * Mesa 3-D graphics library
   3  * Version:  7.3
   4  *
   5  * Copyright (C) 1999-2007  Brian Paul   All Rights Reserved.
   6  * Copyright (C) 2008  VMware, Inc.  All Rights Reserved.
   7  *
   8  * Permission is hereby granted, free of charge, to any person obtaining a
   9  * copy of this software and associated documentation files (the "Software"),
  10  * to deal in the Software without restriction, including without limitation
  11  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  12  * and/or sell copies of the Software, and to permit persons to whom the
  13  * Software is furnished to do so, subject to the following conditions:
  14  *
  15  * The above copyright notice and this permission notice shall be included
  16  * in all copies or substantial portions of the Software.
  17  *
  18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  19  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  20  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  21  * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
  22  * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  23  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  24  */
  25
  26 /**
  27  * \file context.c
  28  * Mesa context/visual/framebuffer management functions.
  29  * \author Brian Paul
  30  */
  31
  32 /**
  33  * \mainpage Mesa Main Module
  34  *
  35  * \section MainIntroduction Introduction
  36  *
  37  * The Mesa Main module consists of all the files in the main/ directory.
  38  * Among the features of this module are:
  39  * <UL>
  40  * <LI> Structures to represent most GL state </LI>
  41  * <LI> State set/get functions </LI>
  42  * <LI> Display lists </LI>
  43  * <LI> Texture unit, object and image handling </LI>
  44  * <LI> Matrix and attribute stacks </LI>
  45  * </UL>
  46  *
  47  * Other modules are responsible for API dispatch, vertex transformation,
  48  * point/line/triangle setup, rasterization, vertex array caching,
  49  * vertex/fragment programs/shaders, etc.
  50  *
  51  *
  52  * \section AboutDoxygen About Doxygen
  53  *
  54  * If you're viewing this information as Doxygen-generated HTML you'll
  55  * see the documentation index at the top of this page.
  56  *
  57  * The first line lists the Mesa source code modules.
  58  * The second line lists the indexes available for viewing the documentation
  59  * for each module.
  60  *
  61  * Selecting the <b>Main page</b> link will display a summary of the module
  62  * (this page).
  63  *
  64  * Selecting <b>Data Structures</b> will list all C structures.
  65  *
  66  * Selecting the <b>File List</b> link will list all the source files in
  67  * the module.
  68  * Selecting a filename will show a list of all functions defined in that file.
  69  *
  70  * Selecting the <b>Data Fields</b> link will display a list of all
  71  * documented structure members.
  72  *
  73  * Selecting the <b>Globals</b> link will display a list
  74  * of all functions, structures, global variables and macros in the module.
  75  *
  76  */
  77
  78
  79 #include "glheader.h"
  80 #include "mfeatures.h"
  81 #include "imports.h"
  82 #include "accum.h"
  83 #include "api_exec.h"
  84 #include "arrayobj.h"
  85 #include "attrib.h"
  86 #include "blend.h"
  87 #include "buffers.h"
  88 #include "bufferobj.h"
  89 #include "colortab.h"
  90 #include "context.h"
  91 #include "cpuinfo.h"
  92 #include "debug.h"
  93 #include "depth.h"
  94 #include "dlist.h"
  95 #include "eval.h"
  96 #include "extensions.h"
  97 #include "fbobject.h"
  98 #include "feedback.h"
  99 #include "fog.h"
 100 #include "framebuffer.h"
 101 #include "histogram.h"
 102 #include "hint.h"
 103 #include "hash.h"
 104 #include "light.h"
 105 #include "lines.h"
 106 #include "macros.h"
 107 #include "matrix.h"
 108 #include "multisample.h"
 109 #include "pixel.h"
 110 #include "pixelstore.h"
 111 #include "points.h"
 112 #include "polygon.h"
 113 #include "queryobj.h"
 114 #if FEATURE_ARB_sync
 115 #include "syncobj.h"
 116 #endif
 117 #include "rastpos.h"
 118 #include "remap.h"
 119 #include "scissor.h"
 120 #include "shared.h"
 121 #include "simple_list.h"
 122 #include "state.h"
 123 #include "stencil.h"
 124 #include "texcompress_s3tc.h"
 125 #include "texstate.h"
 126 #include "mtypes.h"
 127 #include "varray.h"
 128 #include "version.h"
 129 #include "viewport.h"
 130 #include "vtxfmt.h"
 131 #include "glapi/glthread.h"
 132 #include "glapi/glapitable.h"
 133 #include "shader/program.h"
 134 #include "shader/prog_print.h"
 135 #include "shader/shader_api.h"
 136 #if _HAVE_FULL_GL
 137 #include "math/m_matrix.h"
 138 #endif
 139
 140 #ifdef USE_SPARC_ASM
 141 #include "sparc/sparc.h"
 142 #endif
 143
 144 #ifndef MESA_VERBOSE
 145 int MESA_VERBOSE = 0;
 146 #endif
 147
 148 #ifndef MESA_DEBUG_FLAGS
 149 int MESA_DEBUG_FLAGS = 0;
 150 #endif
 151
 152
 153 /* ubyte -> float conversion */
 154 GLfloat _mesa_ubyte_to_float_color_tab[256];
 155
 156
 157
 158 /**
 159  * Swap buffers notification callback.
 160  *
 161  * \param ctx GL context.
 162  *
 163  * Called by window system just before swapping buffers.
 164  * We have to finish any pending rendering.
 165  */
 166 void
 167 _mesa_notifySwapBuffers(__GLcontext *ctx)
 168 {
 169    if (MESA_VERBOSE & VERBOSE_SWAPBUFFERS)
 170       _mesa_debug(ctx, "SwapBuffers\n");
 171    FLUSH_CURRENT( ctx, 0 );
 172    if (ctx->Driver.Flush) {
 173       ctx->Driver.Flush(ctx);
 174    }
 175 }
 176
 177
 178 /**********************************************************************/
 179 /** \name GL Visual allocation/destruction                            */
 180 /**********************************************************************/
 181 /*@{*/
 182
 183 /**
 184  * Allocates a GLvisual structure and initializes it via
 185  * _mesa_initialize_visual().
 186  *
 187  * \param rgbFlag GL_TRUE for RGB(A) mode, GL_FALSE for Color Index mode.
 188  * \param dbFlag double buffering
 189  * \param stereoFlag stereo buffer
 190  * \param depthBits requested bits per depth buffer value. Any value in [0, 32]
 191  * is acceptable but the actual depth type will be GLushort or GLuint as
 192  * needed.
 193  * \param stencilBits requested minimum bits per stencil buffer value
 194  * \param accumRedBits, accumGreenBits, accumBlueBits, accumAlphaBits number of bits per color component in accum buffer.
 195  * \param indexBits number of bits per pixel if \p rgbFlag is GL_FALSE
 196  * \param redBits number of bits per color component in frame buffer for RGB(A)
 197  * mode.  We always use 8 in core Mesa though.
 198  * \param greenBits same as above.
 199  * \param blueBits same as above.
 200  * \param alphaBits same as above.
 201  * \param numSamples not really used.
 202  *
 203  * \return pointer to new GLvisual or NULL if requested parameters can't be
 204  * met.
 205  *
 206  * \note Need to add params for level and numAuxBuffers (at least)
 207  */
 208 GLvisual *
 209 _mesa_create_visual( GLboolean rgbFlag,
 210                      GLboolean dbFlag,
 211                      GLboolean stereoFlag,
 212                      GLint redBits,
 213                      GLint greenBits,
 214                      GLint blueBits,
 215                      GLint alphaBits,
 216                      GLint indexBits,
 217                      GLint depthBits,
 218                      GLint stencilBits,
 219                      GLint accumRedBits,
 220                      GLint accumGreenBits,
 221                      GLint accumBlueBits,
 222                      GLint accumAlphaBits,
 223                      GLint numSamples )
 224 {
 225    GLvisual *vis = (GLvisual *) _mesa_calloc(sizeof(GLvisual));
 226    if (vis) {
 227       if (!_mesa_initialize_visual(vis, rgbFlag, dbFlag, stereoFlag,
 228                                    redBits, greenBits, blueBits, alphaBits,
 229                                    indexBits, depthBits, stencilBits,
 230                                    accumRedBits, accumGreenBits,
 231                                    accumBlueBits, accumAlphaBits,
 232                                    numSamples)) {
 233          _mesa_free(vis);
 234          return NULL;
 235       }
 236    }
 237    return vis;
 238 }
 239
 240 /**
 241  * Makes some sanity checks and fills in the fields of the
 242  * GLvisual object with the given parameters.  If the caller needs
 243  * to set additional fields, he should just probably init the whole GLvisual
 244  * object himself.
 245  * \return GL_TRUE on success, or GL_FALSE on failure.
 246  *
 247  * \sa _mesa_create_visual() above for the parameter description.
 248  */
 249 GLboolean
 250 _mesa_initialize_visual( GLvisual *vis,
 251                          GLboolean rgbFlag,
 252                          GLboolean dbFlag,
 253                          GLboolean stereoFlag,
 254                          GLint redBits,
 255                          GLint greenBits,
 256                          GLint blueBits,
 257                          GLint alphaBits,
 258                          GLint indexBits,
 259                          GLint depthBits,
 260                          GLint stencilBits,
 261                          GLint accumRedBits,
 262                          GLint accumGreenBits,
 263                          GLint accumBlueBits,
 264                          GLint accumAlphaBits,
 265                          GLint numSamples )
 266 {
 267    assert(vis);
 268
 269    if (depthBits < 0 || depthBits > 32) {
 270       return GL_FALSE;
 271    }
 272    if (stencilBits < 0 || stencilBits > STENCIL_BITS) {
 273       return GL_FALSE;
 274    }
 275    assert(accumRedBits >= 0);
 276    assert(accumGreenBits >= 0);
 277    assert(accumBlueBits >= 0);
 278    assert(accumAlphaBits >= 0);
 279
 280    vis->rgbMode          = rgbFlag;
 281    vis->doubleBufferMode = dbFlag;
 282    vis->stereoMode       = stereoFlag;
 283
 284    vis->redBits          = redBits;
 285    vis->greenBits        = greenBits;
 286    vis->blueBits         = blueBits;
 287    vis->alphaBits        = alphaBits;
 288    vis->rgbBits          = redBits + greenBits + blueBits;
 289
 290    vis->indexBits      = indexBits;
 291    vis->depthBits      = depthBits;
 292    vis->stencilBits    = stencilBits;
 293
 294    vis->accumRedBits   = accumRedBits;
 295    vis->accumGreenBits = accumGreenBits;
 296    vis->accumBlueBits  = accumBlueBits;
 297    vis->accumAlphaBits = accumAlphaBits;
 298
 299    vis->haveAccumBuffer   = accumRedBits > 0;
 300    vis->haveDepthBuffer   = depthBits > 0;
 301    vis->haveStencilBuffer = stencilBits > 0;
 302
 303    vis->numAuxBuffers = 0;
 304    vis->level = 0;
 305    vis->pixmapMode = 0;
 306    vis->sampleBuffers = numSamples > 0 ? 1 : 0;
 307    vis->samples = numSamples;
 308
 309    return GL_TRUE;
 310 }
 311
 312
 313 /**
 314  * Destroy a visual and free its memory.
 315  *
 316  * \param vis visual.
 317  *
 318  * Frees the visual structure.
 319  */
 320 void
 321 _mesa_destroy_visual( GLvisual *vis )
 322 {
 323    _mesa_free(vis);
 324 }
 325
 326 /*@}*/
 327
 328
 329 /**********************************************************************/
 330 /** \name Context allocation, initialization, destroying
 331  *
 332  * The purpose of the most initialization functions here is to provide the
 333  * default state values according to the OpenGL specification.
 334  */
 335 /**********************************************************************/
 336 /*@{*/
 337
 338
 339 /**
 340  * This is lame.  gdb only seems to recognize enum types that are
 341  * actually used somewhere.  We want to be able to print/use enum
 342  * values such as TEXTURE_2D_INDEX in gdb.  But we don't actually use
 343  * the gl_texture_index type anywhere.  Thus, this lame function.
 344  */
 345 static void
 346 dummy_enum_func(void)
 347 {
 348    gl_buffer_index bi;
 349    gl_colortable_index ci;
 350    gl_face_index fi;
 351    gl_frag_attrib fa;
 352    gl_frag_result fr;
 353    gl_texture_index ti;
 354    gl_vert_attrib va;
 355    gl_vert_result vr;
 356
 357    (void) bi;
 358    (void) ci;
 359    (void) fi;
 360    (void) fa;
 361    (void) fr;
 362    (void) ti;
 363    (void) va;
 364    (void) vr;
 365 }
 366
 367
 368 /**
 369  * One-time initialization mutex lock.
 370  *
 371  * \sa Used by one_time_init().
 372  */
 373 _glthread_DECLARE_STATIC_MUTEX(OneTimeLock);
 374
 375 /**
 376  * Calls all the various one-time-init functions in Mesa.
 377  *
 378  * While holding a global mutex lock, calls several initialization functions,
 379  * and sets the glapi callbacks if the \c MESA_DEBUG environment variable is
 380  * defined.
 381  *
 382  * \sa _math_init().
 383  */
 384 static void
 385 one_time_init( GLcontext *ctx )
 386 {
 387    static GLboolean alreadyCalled = GL_FALSE;
 388    (void) ctx;
 389    _glthread_LOCK_MUTEX(OneTimeLock);
 390    if (!alreadyCalled) {
 391       GLuint i;
 392
 393       /* do some implementation tests */
 394       assert( sizeof(GLbyte) == 1 );
 395       assert( sizeof(GLubyte) == 1 );
 396       assert( sizeof(GLshort) == 2 );
 397       assert( sizeof(GLushort) == 2 );
 398       assert( sizeof(GLint) == 4 );
 399       assert( sizeof(GLuint) == 4 );
 400
 401       _mesa_get_cpu_features();
 402
 403       _mesa_init_remap_table();
 404
 405       _mesa_init_sqrt_table();
 406
 407       for (i = 0; i < 256; i++) {
 408          _mesa_ubyte_to_float_color_tab[i] = (float) i / 255.0F;
 409       }
 410
 411 #if defined(DEBUG) && defined(__DATE__) && defined(__TIME__)
 412       _mesa_debug(ctx, "Mesa %s DEBUG build %s %s\n",
 413                   MESA_VERSION_STRING, __DATE__, __TIME__);
 414 #endif
 415
 416       alreadyCalled = GL_TRUE;
 417    }
 418    _glthread_UNLOCK_MUTEX(OneTimeLock);
 419
 420    dummy_enum_func();
 421 }
 422
 423
 424 /**
 425  * Initialize fields of gl_current_attrib (aka ctx->Current.*)
 426  */
 427 static void
 428 _mesa_init_current(GLcontext *ctx)
 429 {
 430    GLuint i;
 431
 432    /* Init all to (0,0,0,1) */
 433    for (i = 0; i < Elements(ctx->Current.Attrib); i++) {
 434       ASSIGN_4V( ctx->Current.Attrib[i], 0.0, 0.0, 0.0, 1.0 );
 435    }
 436
 437    /* redo special cases: */
 438    ASSIGN_4V( ctx->Current.Attrib[VERT_ATTRIB_WEIGHT], 1.0, 0.0, 0.0, 0.0 );
 439    ASSIGN_4V( ctx->Current.Attrib[VERT_ATTRIB_NORMAL], 0.0, 0.0, 1.0, 1.0 );
 440    ASSIGN_4V( ctx->Current.Attrib[VERT_ATTRIB_COLOR0], 1.0, 1.0, 1.0, 1.0 );
 441    ASSIGN_4V( ctx->Current.Attrib[VERT_ATTRIB_COLOR1], 0.0, 0.0, 0.0, 1.0 );
 442    ASSIGN_4V( ctx->Current.Attrib[VERT_ATTRIB_COLOR_INDEX], 1.0, 0.0, 0.0, 1.0 );
 443    ASSIGN_4V( ctx->Current.Attrib[VERT_ATTRIB_EDGEFLAG], 1.0, 0.0, 0.0, 1.0 );
 444 }
 445
 446
 447 /**
 448  * Init vertex/fragment program limits.
 449  * Important: drivers should override these with actual limits.
 450  */
 451 static void
 452 init_program_limits(GLenum type, struct gl_program_constants *prog)
 453 {
 454    prog->MaxInstructions = MAX_PROGRAM_INSTRUCTIONS;
 455    prog->MaxAluInstructions = MAX_PROGRAM_INSTRUCTIONS;
 456    prog->MaxTexInstructions = MAX_PROGRAM_INSTRUCTIONS;
 457    prog->MaxTexIndirections = MAX_PROGRAM_INSTRUCTIONS;
 458    prog->MaxTemps = MAX_PROGRAM_TEMPS;
 459    prog->MaxEnvParams = MAX_PROGRAM_ENV_PARAMS;
 460    prog->MaxLocalParams = MAX_PROGRAM_LOCAL_PARAMS;
 461    prog->MaxUniformComponents = 4 * MAX_UNIFORMS;
 462
 463    if (type == GL_VERTEX_PROGRAM_ARB) {
 464       prog->MaxParameters = MAX_VERTEX_PROGRAM_PARAMS;
 465       prog->MaxAttribs = MAX_NV_VERTEX_PROGRAM_INPUTS;
 466       prog->MaxAddressRegs = MAX_VERTEX_PROGRAM_ADDRESS_REGS;
 467    }
 468    else {
 469       prog->MaxParameters = MAX_NV_FRAGMENT_PROGRAM_PARAMS;
 470       prog->MaxAttribs = MAX_NV_FRAGMENT_PROGRAM_INPUTS;
 471       prog->MaxAddressRegs = MAX_FRAGMENT_PROGRAM_ADDRESS_REGS;
 472    }
 473
 474    /* Set the native limits to zero.  This implies that there is no native
 475     * support for shaders.  Let the drivers fill in the actual values.
 476     */
 477    prog->MaxNativeInstructions = 0;
 478    prog->MaxNativeAluInstructions = 0;
 479    prog->MaxNativeTexInstructions = 0;
 480    prog->MaxNativeTexIndirections = 0;
 481    prog->MaxNativeAttribs = 0;
 482    prog->MaxNativeTemps = 0;
 483    prog->MaxNativeAddressRegs = 0;
 484    prog->MaxNativeParameters = 0;
 485 }
 486
 487
 488 /**
 489  * Initialize fields of gl_constants (aka ctx->Const.*).
 490  * Use defaults from config.h.  The device drivers will often override
 491  * some of these values (such as number of texture units).
 492  */
 493 static void
 494 _mesa_init_constants(GLcontext *ctx)
 495 {
 496    assert(ctx);
 497
 498    assert(MAX_TEXTURE_LEVELS >= MAX_3D_TEXTURE_LEVELS);
 499    assert(MAX_TEXTURE_LEVELS >= MAX_CUBE_TEXTURE_LEVELS);
 500
 501    /* Max texture size should be <= max viewport size (render to texture) */
 502    assert((1 << (MAX_TEXTURE_LEVELS - 1)) <= MAX_WIDTH);
 503
 504    /* Constants, may be overriden (usually only reduced) by device drivers */
 505    ctx->Const.MaxTextureLevels = MAX_TEXTURE_LEVELS;
 506    ctx->Const.Max3DTextureLevels = MAX_3D_TEXTURE_LEVELS;
 507    ctx->Const.MaxCubeTextureLevels = MAX_CUBE_TEXTURE_LEVELS;
 508    ctx->Const.MaxTextureRectSize = MAX_TEXTURE_RECT_SIZE;
 509    ctx->Const.MaxArrayTextureLayers = MAX_ARRAY_TEXTURE_LAYERS;
 510    ctx->Const.MaxTextureCoordUnits = MAX_TEXTURE_COORD_UNITS;
 511    ctx->Const.MaxTextureImageUnits = MAX_TEXTURE_IMAGE_UNITS;
 512    ctx->Const.MaxTextureUnits = MIN2(ctx->Const.MaxTextureCoordUnits,
 513                                      ctx->Const.MaxTextureImageUnits);
 514    ctx->Const.MaxTextureMaxAnisotropy = MAX_TEXTURE_MAX_ANISOTROPY;
 515    ctx->Const.MaxTextureLodBias = MAX_TEXTURE_LOD_BIAS;
 516    ctx->Const.MaxArrayLockSize = MAX_ARRAY_LOCK_SIZE;
 517    ctx->Const.SubPixelBits = SUB_PIXEL_BITS;
 518    ctx->Const.MinPointSize = MIN_POINT_SIZE;
 519    ctx->Const.MaxPointSize = MAX_POINT_SIZE;
 520    ctx->Const.MinPointSizeAA = MIN_POINT_SIZE;
 521    ctx->Const.MaxPointSizeAA = MAX_POINT_SIZE;
 522    ctx->Const.PointSizeGranularity = (GLfloat) POINT_SIZE_GRANULARITY;
 523    ctx->Const.MinLineWidth = MIN_LINE_WIDTH;
 524    ctx->Const.MaxLineWidth = MAX_LINE_WIDTH;
 525    ctx->Const.MinLineWidthAA = MIN_LINE_WIDTH;
 526    ctx->Const.MaxLineWidthAA = MAX_LINE_WIDTH;
 527    ctx->Const.LineWidthGranularity = (GLfloat) LINE_WIDTH_GRANULARITY;
 528    ctx->Const.MaxColorTableSize = MAX_COLOR_TABLE_SIZE;
 529    ctx->Const.MaxConvolutionWidth = MAX_CONVOLUTION_WIDTH;
 530    ctx->Const.MaxConvolutionHeight = MAX_CONVOLUTION_HEIGHT;
 531    ctx->Const.MaxClipPlanes = MAX_CLIP_PLANES;
 532    ctx->Const.MaxLights = MAX_LIGHTS;
 533    ctx->Const.MaxShininess = 128.0;
 534    ctx->Const.MaxSpotExponent = 128.0;
 535    ctx->Const.MaxViewportWidth = MAX_WIDTH;
 536    ctx->Const.MaxViewportHeight = MAX_HEIGHT;
 537 #if FEATURE_ARB_vertex_program
 538    init_program_limits(GL_VERTEX_PROGRAM_ARB, &ctx->Const.VertexProgram);
 539 #endif
 540 #if FEATURE_ARB_fragment_program
 541    init_program_limits(GL_FRAGMENT_PROGRAM_ARB, &ctx->Const.FragmentProgram);
 542 #endif
 543    ctx->Const.MaxProgramMatrices = MAX_PROGRAM_MATRICES;
 544    ctx->Const.MaxProgramMatrixStackDepth = MAX_PROGRAM_MATRIX_STACK_DEPTH;
 545
 546    /* CheckArrayBounds is overriden by drivers/x11 for X server */
 547    ctx->Const.CheckArrayBounds = GL_FALSE;
 548
 549    /* GL_ARB_draw_buffers */
 550    ctx->Const.MaxDrawBuffers = MAX_DRAW_BUFFERS;
 551
 552 #if FEATURE_EXT_framebuffer_object
 553    ctx->Const.MaxColorAttachments = MAX_COLOR_ATTACHMENTS;
 554    ctx->Const.MaxRenderbufferSize = MAX_WIDTH;
 555 #endif
 556
 557 #if FEATURE_ARB_vertex_shader
 558    ctx->Const.MaxVertexTextureImageUnits = MAX_VERTEX_TEXTURE_IMAGE_UNITS;
 559    ctx->Const.MaxCombinedTextureImageUnits = MAX_COMBINED_TEXTURE_IMAGE_UNITS;
 560    ctx->Const.MaxVarying = MAX_VARYING;
 561 #endif
 562
 563    /* GL_ARB_framebuffer_object */
 564    ctx->Const.MaxSamples = 0;
 565
 566    /* GL_ARB_sync */
 567    ctx->Const.MaxServerWaitTimeout = (GLuint64) ~0;
 568
 569    /* GL_ATI_envmap_bumpmap */
 570    ctx->Const.SupportedBumpUnits = SUPPORTED_ATI_BUMP_UNITS;
 571
 572    /* GL_EXT_provoking_vertex */
 573    ctx->Const.QuadsFollowProvokingVertexConvention = GL_TRUE;
 574
 575    /* sanity checks */
 576    ASSERT(ctx->Const.MaxTextureUnits == MIN2(ctx->Const.MaxTextureImageUnits,
 577                                              ctx->Const.MaxTextureCoordUnits));
 578    ASSERT(ctx->Const.FragmentProgram.MaxLocalParams <= MAX_PROGRAM_LOCAL_PARAMS);
 579    ASSERT(ctx->Const.VertexProgram.MaxLocalParams <= MAX_PROGRAM_LOCAL_PARAMS);
 580
 581    ASSERT(MAX_NV_FRAGMENT_PROGRAM_TEMPS <= MAX_PROGRAM_TEMPS);
 582    ASSERT(MAX_NV_VERTEX_PROGRAM_TEMPS <= MAX_PROGRAM_TEMPS);
 583    ASSERT(MAX_NV_VERTEX_PROGRAM_INPUTS <= VERT_ATTRIB_MAX);
 584    ASSERT(MAX_NV_VERTEX_PROGRAM_OUTPUTS <= VERT_RESULT_MAX);
 585
 586    /* check that we don't exceed the size of various bitfields */
 587    ASSERT(VERT_RESULT_MAX <=
 588           (8 * sizeof(ctx->VertexProgram._Current->Base.OutputsWritten)));
 589    ASSERT(FRAG_ATTRIB_MAX <=
 590           (8 * sizeof(ctx->FragmentProgram._Current->Base.InputsRead)));
 591 }
 592
 593
 594 /**
 595  * Do some sanity checks on the limits/constants for the given context.
 596  * Only called the first time a context is bound.
 597  */
 598 static void
 599 check_context_limits(GLcontext *ctx)
 600 {
 601    /* Many context limits/constants are limited by the size of
 602     * internal arrays.
 603     */
 604    assert(ctx->Const.MaxTextureImageUnits <= MAX_TEXTURE_IMAGE_UNITS);
 605    assert(ctx->Const.MaxTextureCoordUnits <= MAX_TEXTURE_COORD_UNITS);
 606    assert(ctx->Const.MaxTextureUnits <= MAX_TEXTURE_IMAGE_UNITS);
 607    assert(ctx->Const.MaxTextureUnits <= MAX_TEXTURE_COORD_UNITS);
 608
 609    /* number of coord units cannot be greater than number of image units */
 610    assert(ctx->Const.MaxTextureCoordUnits <= ctx->Const.MaxTextureImageUnits);
 611
 612    assert(ctx->Const.MaxTextureLevels <= MAX_TEXTURE_LEVELS);
 613    assert(ctx->Const.Max3DTextureLevels <= MAX_3D_TEXTURE_LEVELS);
 614    assert(ctx->Const.MaxCubeTextureLevels <= MAX_CUBE_TEXTURE_LEVELS);
 615    assert(ctx->Const.MaxTextureRectSize <= MAX_TEXTURE_RECT_SIZE);
 616
 617    /* make sure largest texture image is <= MAX_WIDTH in size */
 618    assert((1 << (ctx->Const.MaxTextureLevels - 1)) <= MAX_WIDTH);
 619    assert((1 << (ctx->Const.MaxCubeTextureLevels - 1)) <= MAX_WIDTH);
 620    assert((1 << (ctx->Const.Max3DTextureLevels - 1)) <= MAX_WIDTH);
 621
 622    assert(ctx->Const.MaxViewportWidth <= MAX_WIDTH);
 623    assert(ctx->Const.MaxViewportHeight <= MAX_WIDTH);
 624
 625    assert(ctx->Const.MaxDrawBuffers <= MAX_DRAW_BUFFERS);
 626
 627    /* XXX probably add more tests */
 628 }
 629
 630
 631 /**
 632  * Initialize the attribute groups in a GL context.
 633  *
 634  * \param ctx GL context.
 635  *
 636  * Initializes all the attributes, calling the respective <tt>init*</tt>
 637  * functions for the more complex data structures.
 638  */
 639 static GLboolean
 640 init_attrib_groups(GLcontext *ctx)
 641 {
 642    assert(ctx);
 643
 644    /* Constants */
 645    _mesa_init_constants( ctx );
 646
 647    /* Extensions */
 648    _mesa_init_extensions( ctx );
 649
 650    /* Attribute Groups */
 651    _mesa_init_accum( ctx );
 652    _mesa_init_attrib( ctx );
 653    _mesa_init_buffer_objects( ctx );
 654    _mesa_init_color( ctx );
 655    _mesa_init_colortables( ctx );
 656    _mesa_init_current( ctx );
 657    _mesa_init_depth( ctx );
 658    _mesa_init_debug( ctx );
 659    _mesa_init_display_list( ctx );
 660    _mesa_init_eval( ctx );
 661    _mesa_init_fbobjects( ctx );
 662    _mesa_init_feedback( ctx );
 663    _mesa_init_fog( ctx );
 664    _mesa_init_histogram( ctx );
 665    _mesa_init_hint( ctx );
 666    _mesa_init_line( ctx );
 667    _mesa_init_lighting( ctx );
 668    _mesa_init_matrix( ctx );
 669    _mesa_init_multisample( ctx );
 670    _mesa_init_pixel( ctx );
 671    _mesa_init_pixelstore( ctx );
 672    _mesa_init_point( ctx );
 673    _mesa_init_polygon( ctx );
 674    _mesa_init_program( ctx );
 675    _mesa_init_queryobj( ctx );
 676 #if FEATURE_ARB_sync
 677    _mesa_init_sync( ctx );
 678 #endif
 679    _mesa_init_rastpos( ctx );
 680    _mesa_init_scissor( ctx );
 681    _mesa_init_shader_state( ctx );
 682    _mesa_init_stencil( ctx );
 683    _mesa_init_transform( ctx );
 684    _mesa_init_varray( ctx );
 685    _mesa_init_viewport( ctx );
 686
 687    if (!_mesa_init_texture( ctx ))
 688       return GL_FALSE;
 689
 690    _mesa_init_texture_s3tc( ctx );
 691
 692    /* Miscellaneous */
 693    ctx->NewState = _NEW_ALL;
 694    ctx->ErrorValue = (GLenum) GL_NO_ERROR;
 695    ctx->varying_vp_inputs = ~0;
 696
 697    return GL_TRUE;
 698 }
 699
 700
 701 /**
 702  * Update default objects in a GL context with respect to shared state.
 703  *
 704  * \param ctx GL context.
 705  *
 706  * Removes references to old default objects, (texture objects, program
 707  * objects, etc.) and changes to reference those from the current shared
 708  * state.
 709  */
 710 static GLboolean
 711 update_default_objects(GLcontext *ctx)
 712 {
 713    assert(ctx);
 714
 715    _mesa_update_default_objects_program(ctx);
 716    _mesa_update_default_objects_texture(ctx);
 717    _mesa_update_default_objects_buffer_objects(ctx);
 718
 719    return GL_TRUE;
 720 }
 721
 722
 723 /**
 724  * This is the default function we plug into all dispatch table slots
 725  * This helps prevents a segfault when someone calls a GL function without
 726  * first checking if the extension's supported.
 727  */
 728 static int
 729 generic_nop(void)
 730 {
 731    _mesa_warning(NULL, "User called no-op dispatch function (an unsupported extension function?)");
 732    return 0;
 733 }
 734
 735
 736 /**
 737  * Allocate and initialize a new dispatch table.
 738  */
 739 static struct _glapi_table *
 740 alloc_dispatch_table(void)
 741 {
 742    /* Find the larger of Mesa's dispatch table and libGL's dispatch table.
 743     * In practice, this'll be the same for stand-alone Mesa.  But for DRI
 744     * Mesa we do this to accomodate different versions of libGL and various
 745     * DRI drivers.
 746     */
 747    GLint numEntries = MAX2(_glapi_get_dispatch_table_size(),
 748                            sizeof(struct _glapi_table) / sizeof(_glapi_proc));
 749    struct _glapi_table *table =
 750       (struct _glapi_table *) _mesa_malloc(numEntries * sizeof(_glapi_proc));
 751    if (table) {
 752       _glapi_proc *entry = (_glapi_proc *) table;
 753       GLint i;
 754       for (i = 0; i < numEntries; i++) {
 755          entry[i] = (_glapi_proc) generic_nop;
 756       }
 757    }
 758    return table;
 759 }
 760
 761
 762 /**
 763  * Initialize a GLcontext struct (rendering context).
 764  *
 765  * This includes allocating all the other structs and arrays which hang off of
 766  * the context by pointers.
 767  * Note that the driver needs to pass in its dd_function_table here since
 768  * we need to at least call driverFunctions->NewTextureObject to create the
 769  * default texture objects.
 770  *
 771  * Called by _mesa_create_context().
 772  *
 773  * Performs the imports and exports callback tables initialization, and
 774  * miscellaneous one-time initializations. If no shared context is supplied one
 775  * is allocated, and increase its reference count.  Setups the GL API dispatch
 776  * tables.  Initialize the TNL module. Sets the maximum Z buffer depth.
 777  * Finally queries the \c MESA_DEBUG and \c MESA_VERBOSE environment variables
 778  * for debug flags.
 779  *
 780  * \param ctx the context to initialize
 781  * \param visual describes the visual attributes for this context
 782  * \param share_list points to context to share textures, display lists,
 783  *        etc with, or NULL
 784  * \param driverFunctions table of device driver functions for this context
 785  *        to use
 786  * \param driverContext pointer to driver-specific context data
 787  */
 788 GLboolean
 789 _mesa_initialize_context(GLcontext *ctx,
 790                          const GLvisual *visual,
 791                          GLcontext *share_list,
 792                          const struct dd_function_table *driverFunctions,
 793                          void *driverContext)
 794 {
 795    struct gl_shared_state *shared;
 796
 797    /*ASSERT(driverContext);*/
 798    assert(driverFunctions->NewTextureObject);
 799    assert(driverFunctions->FreeTexImageData);
 800
 801    /* misc one-time initializations */
 802    one_time_init(ctx);
 803
 804    ctx->Visual = *visual;
 805    ctx->DrawBuffer = NULL;
 806    ctx->ReadBuffer = NULL;
 807    ctx->WinSysDrawBuffer = NULL;
 808    ctx->WinSysReadBuffer = NULL;
 809
 810    /* Plug in driver functions and context pointer here.
 811     * This is important because when we call alloc_shared_state() below
 812     * we'll call ctx->Driver.NewTextureObject() to create the default
 813     * textures.
 814     */
 815    ctx->Driver = *driverFunctions;
 816    ctx->DriverCtx = driverContext;
 817
 818    if (share_list) {
 819       /* share state with another context */
 820       shared = share_list->Shared;
 821    }
 822    else {
 823       /* allocate new, unshared state */
 824       shared = _mesa_alloc_shared_state(ctx);
 825       if (!shared)
 826          return GL_FALSE;
 827    }
 828
 829    _glthread_LOCK_MUTEX(shared->Mutex);
 830    ctx->Shared = shared;
 831    shared->RefCount++;
 832    _glthread_UNLOCK_MUTEX(shared->Mutex);
 833
 834    if (!init_attrib_groups( ctx )) {
 835       _mesa_free_shared_state(ctx, ctx->Shared);
 836       return GL_FALSE;
 837    }
 838
 839    /* setup the API dispatch tables */
 840    ctx->Exec = alloc_dispatch_table();
 841    ctx->Save = alloc_dispatch_table();
 842    if (!ctx->Exec || !ctx->Save) {
 843       _mesa_free_shared_state(ctx, ctx->Shared);
 844       if (ctx->Exec)
 845          _mesa_free(ctx->Exec);
 846       return GL_FALSE;
 847    }
 848 #if FEATURE_dispatch
 849    _mesa_init_exec_table(ctx->Exec);
 850 #endif
 851    ctx->CurrentDispatch = ctx->Exec;
 852
 853 #if FEATURE_dlist
 854    _mesa_init_save_table(ctx->Save);
 855    _mesa_install_save_vtxfmt( ctx, &ctx->ListState.ListVtxfmt );
 856 #endif
 857
 858    /* Neutral tnl module stuff */
 859    _mesa_init_exec_vtxfmt( ctx );
 860    ctx->TnlModule.Current = NULL;
 861    ctx->TnlModule.SwapCount = 0;
 862
 863    ctx->FragmentProgram._MaintainTexEnvProgram
 864       = (_mesa_getenv("MESA_TEX_PROG") != NULL);
 865
 866    ctx->VertexProgram._MaintainTnlProgram
 867       = (_mesa_getenv("MESA_TNL_PROG") != NULL);
 868    if (ctx->VertexProgram._MaintainTnlProgram) {
 869       /* this is required... */
 870       ctx->FragmentProgram._MaintainTexEnvProgram = GL_TRUE;
 871    }
 872
 873 #ifdef FEATURE_extra_context_init
 874    _mesa_initialize_context_extra(ctx);
 875 #endif
 876
 877    ctx->FirstTimeCurrent = GL_TRUE;
 878
 879    return GL_TRUE;
 880 }
 881
 882
 883 /**
 884  * Allocate and initialize a GLcontext structure.
 885  * Note that the driver needs to pass in its dd_function_table here since
 886  * we need to at least call driverFunctions->NewTextureObject to initialize
 887  * the rendering context.
 888  *
 889  * \param visual a GLvisual pointer (we copy the struct contents)
 890  * \param share_list another context to share display lists with or NULL
 891  * \param driverFunctions points to the dd_function_table into which the
 892  *        driver has plugged in all its special functions.
 893  * \param driverContext points to the device driver's private context state
 894  *
 895  * \return pointer to a new __GLcontextRec or NULL if error.
 896  */
 897 GLcontext *
 898 _mesa_create_context(const GLvisual *visual,
 899                      GLcontext *share_list,
 900                      const struct dd_function_table *driverFunctions,
 901                      void *driverContext)
 902 {
 903    GLcontext *ctx;
 904
 905    ASSERT(visual);
 906    /*ASSERT(driverContext);*/
 907
 908    ctx = (GLcontext *) _mesa_calloc(sizeof(GLcontext));
 909    if (!ctx)
 910       return NULL;
 911
 912    if (_mesa_initialize_context(ctx, visual, share_list,
 913                                 driverFunctions, driverContext)) {
 914       return ctx;
 915    }
 916    else {
 917       _mesa_free(ctx);
 918       return NULL;
 919    }
 920 }
 921
 922
 923 /**
 924  * Free the data associated with the given context.
 925  *
 926  * But doesn't free the GLcontext struct itself.
 927  *
 928  * \sa _mesa_initialize_context() and init_attrib_groups().
 929  */
 930 void
 931 _mesa_free_context_data( GLcontext *ctx )
 932 {
 933    GLint RefCount;
 934
 935    if (!_mesa_get_current_context()){
 936       /* No current context, but we may need one in order to delete
 937        * texture objs, etc.  So temporarily bind the context now.
 938        */
 939       _mesa_make_current(ctx, NULL, NULL);
 940    }
 941
 942    /* unreference WinSysDraw/Read buffers */
 943    _mesa_reference_framebuffer(&ctx->WinSysDrawBuffer, NULL);
 944    _mesa_reference_framebuffer(&ctx->WinSysReadBuffer, NULL);
 945    _mesa_reference_framebuffer(&ctx->DrawBuffer, NULL);
 946    _mesa_reference_framebuffer(&ctx->ReadBuffer, NULL);
 947
 948    _mesa_reference_vertprog(ctx, &ctx->VertexProgram.Current, NULL);
 949    _mesa_reference_vertprog(ctx, &ctx->VertexProgram._Current, NULL);
 950    _mesa_reference_vertprog(ctx, &ctx->VertexProgram._TnlProgram, NULL);
 951
 952    _mesa_reference_fragprog(ctx, &ctx->FragmentProgram.Current, NULL);
 953    _mesa_reference_fragprog(ctx, &ctx->FragmentProgram._Current, NULL);
 954    _mesa_reference_fragprog(ctx, &ctx->FragmentProgram._TexEnvProgram, NULL);
 955
 956    _mesa_free_attrib_data(ctx);
 957    _mesa_free_lighting_data( ctx );
 958    _mesa_free_eval_data( ctx );
 959    _mesa_free_texture_data( ctx );
 960    _mesa_free_matrix_data( ctx );
 961    _mesa_free_viewport_data( ctx );
 962    _mesa_free_colortables_data( ctx );
 963    _mesa_free_program_data(ctx);
 964    _mesa_free_shader_state(ctx);
 965    _mesa_free_queryobj_data(ctx);
 966 #if FEATURE_ARB_sync
 967    _mesa_free_sync_data(ctx);
 968 #endif
 969    _mesa_free_varray_data(ctx);
 970
 971    _mesa_delete_array_object(ctx, ctx->Array.DefaultArrayObj);
 972
 973 #if FEATURE_ARB_pixel_buffer_object
 974    _mesa_reference_buffer_object(ctx, &ctx->Pack.BufferObj, NULL);
 975    _mesa_reference_buffer_object(ctx, &ctx->Unpack.BufferObj, NULL);
 976 #endif
 977
 978 #if FEATURE_ARB_vertex_buffer_object
 979    _mesa_reference_buffer_object(ctx, &ctx->Array.ArrayBufferObj, NULL);
 980    _mesa_reference_buffer_object(ctx, &ctx->Array.ElementArrayBufferObj, NULL);
 981 #endif
 982
 983    /* free dispatch tables */
 984    _mesa_free(ctx->Exec);
 985    _mesa_free(ctx->Save);
 986
 987    /* Shared context state (display lists, textures, etc) */
 988    _glthread_LOCK_MUTEX(ctx->Shared->Mutex);
 989    RefCount = --ctx->Shared->RefCount;
 990    _glthread_UNLOCK_MUTEX(ctx->Shared->Mutex);
 991    assert(RefCount >= 0);
 992    if (RefCount == 0) {
 993       /* free shared state */
 994       _mesa_free_shared_state( ctx, ctx->Shared );
 995    }
 996
 997    /* needs to be after freeing shared state */
 998    _mesa_free_display_list_data(ctx);
 999
1000    if (ctx->Extensions.String)
1001       _mesa_free((void *) ctx->Extensions.String);
1002
1003    if (ctx->VersionString)
1004       _mesa_free(ctx->VersionString);
1005
1006    /* unbind the context if it's currently bound */
1007    if (ctx == _mesa_get_current_context()) {
1008       _mesa_make_current(NULL, NULL, NULL);
1009    }
1010 }
1011
1012
1013 /**
1014  * Destroy a GLcontext structure.
1015  *
1016  * \param ctx GL context.
1017  *
1018  * Calls _mesa_free_context_data() and frees the GLcontext structure itself.
1019  */
1020 void
1021 _mesa_destroy_context( GLcontext *ctx )
1022 {
1023    if (ctx) {
1024       _mesa_free_context_data(ctx);
1025       _mesa_free( (void *) ctx );
1026    }
1027 }
1028
1029
1030 #if _HAVE_FULL_GL
1031 /**
1032  * Copy attribute groups from one context to another.
1033  *
1034  * \param src source context
1035  * \param dst destination context
1036  * \param mask bitwise OR of GL_*_BIT flags
1037  *
1038  * According to the bits specified in \p mask, copies the corresponding
1039  * attributes from \p src into \p dst.  For many of the attributes a simple \c
1040  * memcpy is not enough due to the existence of internal pointers in their data
1041  * structures.
1042  */
1043 void
1044 _mesa_copy_context( const GLcontext *src, GLcontext *dst, GLuint mask )
1045 {
1046    if (mask & GL_ACCUM_BUFFER_BIT) {
1047       /* OK to memcpy */
1048       dst->Accum = src->Accum;
1049    }
1050    if (mask & GL_COLOR_BUFFER_BIT) {
1051       /* OK to memcpy */
1052       dst->Color = src->Color;
1053    }
1054    if (mask & GL_CURRENT_BIT) {
1055       /* OK to memcpy */
1056       dst->Current = src->Current;
1057    }
1058    if (mask & GL_DEPTH_BUFFER_BIT) {
1059       /* OK to memcpy */
1060       dst->Depth = src->Depth;
1061    }
1062    if (mask & GL_ENABLE_BIT) {
1063       /* no op */
1064    }
1065    if (mask & GL_EVAL_BIT) {
1066       /* OK to memcpy */
1067       dst->Eval = src->Eval;
1068    }
1069    if (mask & GL_FOG_BIT) {
1070       /* OK to memcpy */
1071       dst->Fog = src->Fog;
1072    }
1073    if (mask & GL_HINT_BIT) {
1074       /* OK to memcpy */
1075       dst->Hint = src->Hint;
1076    }
1077    if (mask & GL_LIGHTING_BIT) {
1078       GLuint i;
1079       /* begin with memcpy */
1080       dst->Light = src->Light;
1081       /* fixup linked lists to prevent pointer insanity */
1082       make_empty_list( &(dst->Light.EnabledList) );
1083       for (i = 0; i < MAX_LIGHTS; i++) {
1084          if (dst->Light.Light[i].Enabled) {
1085             insert_at_tail(&(dst->Light.EnabledList), &(dst->Light.Light[i]));
1086          }
1087       }
1088    }
1089    if (mask & GL_LINE_BIT) {
1090       /* OK to memcpy */
1091       dst->Line = src->Line;
1092    }
1093    if (mask & GL_LIST_BIT) {
1094       /* OK to memcpy */
1095       dst->List = src->List;
1096    }
1097    if (mask & GL_PIXEL_MODE_BIT) {
1098       /* OK to memcpy */
1099       dst->Pixel = src->Pixel;
1100    }
1101    if (mask & GL_POINT_BIT) {
1102       /* OK to memcpy */
1103       dst->Point = src->Point;
1104    }
1105    if (mask & GL_POLYGON_BIT) {
1106       /* OK to memcpy */
1107       dst->Polygon = src->Polygon;
1108    }
1109    if (mask & GL_POLYGON_STIPPLE_BIT) {
1110       /* Use loop instead of MEMCPY due to problem with Portland Group's
1111        * C compiler.  Reported by John Stone.
1112        */
1113       GLuint i;
1114       for (i = 0; i < 32; i++) {
1115          dst->PolygonStipple[i] = src->PolygonStipple[i];
1116       }
1117    }
1118    if (mask & GL_SCISSOR_BIT) {
1119       /* OK to memcpy */
1120       dst->Scissor = src->Scissor;
1121    }
1122    if (mask & GL_STENCIL_BUFFER_BIT) {
1123       /* OK to memcpy */
1124       dst->Stencil = src->Stencil;
1125    }
1126    if (mask & GL_TEXTURE_BIT) {
1127       /* Cannot memcpy because of pointers */
1128       _mesa_copy_texture_state(src, dst);
1129    }
1130    if (mask & GL_TRANSFORM_BIT) {
1131       /* OK to memcpy */
1132       dst->Transform = src->Transform;
1133    }
1134    if (mask & GL_VIEWPORT_BIT) {
1135       /* Cannot use memcpy, because of pointers in GLmatrix _WindowMap */
1136       dst->Viewport.X = src->Viewport.X;
1137       dst->Viewport.Y = src->Viewport.Y;
1138       dst->Viewport.Width = src->Viewport.Width;
1139       dst->Viewport.Height = src->Viewport.Height;
1140       dst->Viewport.Near = src->Viewport.Near;
1141       dst->Viewport.Far = src->Viewport.Far;
1142       _math_matrix_copy(&dst->Viewport._WindowMap, &src->Viewport._WindowMap);
1143    }
1144
1145    /* XXX FIXME:  Call callbacks?
1146     */
1147    dst->NewState = _NEW_ALL;
1148 }
1149 #endif
1150
1151
1152 /**
1153  * Check if the given context can render into the given framebuffer
1154  * by checking visual attributes.
1155  *
1156  * Most of these tests could go away because Mesa is now pretty flexible
1157  * in terms of mixing rendering contexts with framebuffers.  As long
1158  * as RGB vs. CI mode agree, we're probably good.
1159  *
1160  * \return GL_TRUE if compatible, GL_FALSE otherwise.
1161  */
1162 static GLboolean
1163 check_compatible(const GLcontext *ctx, const GLframebuffer *buffer)
1164 {
1165    const GLvisual *ctxvis = &ctx->Visual;
1166    const GLvisual *bufvis = &buffer->Visual;
1167
1168    if (ctxvis == bufvis)
1169       return GL_TRUE;
1170
1171    if (ctxvis->rgbMode != bufvis->rgbMode)
1172       return GL_FALSE;
1173 #if 0
1174    /* disabling this fixes the fgl_glxgears pbuffer demo */
1175    if (ctxvis->doubleBufferMode && !bufvis->doubleBufferMode)
1176       return GL_FALSE;
1177 #endif
1178    if (ctxvis->stereoMode && !bufvis->stereoMode)
1179       return GL_FALSE;
1180    if (ctxvis->haveAccumBuffer && !bufvis->haveAccumBuffer)
1181       return GL_FALSE;
1182    if (ctxvis->haveDepthBuffer && !bufvis->haveDepthBuffer)
1183       return GL_FALSE;
1184    if (ctxvis->haveStencilBuffer && !bufvis->haveStencilBuffer)
1185       return GL_FALSE;
1186    if (ctxvis->redMask && ctxvis->redMask != bufvis->redMask)
1187       return GL_FALSE;
1188    if (ctxvis->greenMask && ctxvis->greenMask != bufvis->greenMask)
1189       return GL_FALSE;
1190    if (ctxvis->blueMask && ctxvis->blueMask != bufvis->blueMask)
1191       return GL_FALSE;
1192 #if 0
1193    /* disabled (see bug 11161) */
1194    if (ctxvis->depthBits && ctxvis->depthBits != bufvis->depthBits)
1195       return GL_FALSE;
1196 #endif
1197    if (ctxvis->stencilBits && ctxvis->stencilBits != bufvis->stencilBits)
1198       return GL_FALSE;
1199
1200    return GL_TRUE;
1201 }
1202
1203
1204 /**
1205  * Do one-time initialization for the given framebuffer.  Specifically,
1206  * ask the driver for the window's current size and update the framebuffer
1207  * object to match.
1208  * Really, the device driver should totally take care of this.
1209  */
1210 static void
1211 initialize_framebuffer_size(GLcontext *ctx, GLframebuffer *fb)
1212 {
1213    GLuint width, height;
1214    if (ctx->Driver.GetBufferSize) {
1215       ctx->Driver.GetBufferSize(fb, &width, &height);
1216       if (ctx->Driver.ResizeBuffers)
1217          ctx->Driver.ResizeBuffers(ctx, fb, width, height);
1218       fb->Initialized = GL_TRUE;
1219    }
1220 }
1221
1222
1223 /**
1224  * Check if the viewport/scissor size has not yet been initialized.
1225  * Initialize the size if the given width and height are non-zero.
1226  */
1227 void
1228 _mesa_check_init_viewport(GLcontext *ctx, GLuint width, GLuint height)
1229 {
1230    if (!ctx->ViewportInitialized && width > 0 && height > 0) {
1231       /* Note: set flag here, before calling _mesa_set_viewport(), to prevent
1232        * potential infinite recursion.
1233        */
1234       ctx->ViewportInitialized = GL_TRUE;
1235       _mesa_set_viewport(ctx, 0, 0, width, height);
1236       _mesa_set_scissor(ctx, 0, 0, width, height);
1237    }
1238 }
1239
1240
1241 /**
1242  * Bind the given context to the given drawBuffer and readBuffer and
1243  * make it the current context for the calling thread.
1244  * We'll render into the drawBuffer and read pixels from the
1245  * readBuffer (i.e. glRead/CopyPixels, glCopyTexImage, etc).
1246  *
1247  * We check that the context's and framebuffer's visuals are compatible
1248  * and return immediately if they're not.
1249  *
1250  * \param newCtx  the new GL context. If NULL then there will be no current GL
1251  *                context.
1252  * \param drawBuffer  the drawing framebuffer
1253  * \param readBuffer  the reading framebuffer
1254  */
1255 GLboolean
1256 _mesa_make_current( GLcontext *newCtx, GLframebuffer *drawBuffer,
1257                     GLframebuffer *readBuffer )
1258 {
1259    if (MESA_VERBOSE & VERBOSE_API)
1260       _mesa_debug(newCtx, "_mesa_make_current()\n");
1261
1262    /* Check that the context's and framebuffer's visuals are compatible.
1263     */
1264    if (newCtx && drawBuffer && newCtx->WinSysDrawBuffer != drawBuffer) {
1265       if (!check_compatible(newCtx, drawBuffer)) {
1266          _mesa_warning(newCtx,
1267               "MakeCurrent: incompatible visuals for context and drawbuffer");
1268          return GL_FALSE;
1269       }
1270    }
1271    if (newCtx && readBuffer && newCtx->WinSysReadBuffer != readBuffer) {
1272       if (!check_compatible(newCtx, readBuffer)) {
1273          _mesa_warning(newCtx,
1274               "MakeCurrent: incompatible visuals for context and readbuffer");
1275          return GL_FALSE;
1276       }
1277    }
1278
1279    /* We used to call _glapi_check_multithread() here.  Now do it in drivers */
1280    _glapi_set_context((void *) newCtx);
1281    ASSERT(_mesa_get_current_context() == newCtx);
1282
1283    if (!newCtx) {
1284       _glapi_set_dispatch(NULL);  /* none current */
1285    }
1286    else {
1287       _glapi_set_dispatch(newCtx->CurrentDispatch);
1288
1289       if (drawBuffer && readBuffer) {
1290          /* TODO: check if newCtx and buffer's visual match??? */
1291
1292          ASSERT(drawBuffer->Name == 0);
1293          ASSERT(readBuffer->Name == 0);
1294          _mesa_reference_framebuffer(&newCtx->WinSysDrawBuffer, drawBuffer);
1295          _mesa_reference_framebuffer(&newCtx->WinSysReadBuffer, readBuffer);
1296
1297          /*
1298           * Only set the context's Draw/ReadBuffer fields if they're NULL
1299           * or not bound to a user-created FBO.
1300           */
1301          if (!newCtx->DrawBuffer || newCtx->DrawBuffer->Name == 0) {
1302             /* KW: merge conflict here, revisit.
1303              */
1304             /* fix up the fb fields - these will end up wrong otherwise
1305              * if the DRIdrawable changes, and everything relies on them.
1306              * This is a bit messy (same as needed in _mesa_BindFramebufferEXT)
1307              */
1308             unsigned int i;
1309             GLenum buffers[MAX_DRAW_BUFFERS];
1310
1311             _mesa_reference_framebuffer(&newCtx->DrawBuffer, drawBuffer);
1312
1313             for(i = 0; i < newCtx->Const.MaxDrawBuffers; i++) {
1314                buffers[i] = newCtx->Color.DrawBuffer[i];
1315             }
1316
1317             _mesa_drawbuffers(newCtx, newCtx->Const.MaxDrawBuffers, buffers, NULL);
1318          }
1319          if (!newCtx->ReadBuffer || newCtx->ReadBuffer->Name == 0) {
1320             _mesa_reference_framebuffer(&newCtx->ReadBuffer, readBuffer);
1321          }
1322
1323          /* XXX only set this flag if we're really changing the draw/read
1324           * framebuffer bindings.
1325           */
1326          newCtx->NewState |= _NEW_BUFFERS;
1327
1328 #if 1
1329          /* We want to get rid of these lines: */
1330
1331 #if _HAVE_FULL_GL
1332          if (!drawBuffer->Initialized) {
1333             initialize_framebuffer_size(newCtx, drawBuffer);
1334          }
1335          if (readBuffer != drawBuffer && !readBuffer->Initialized) {
1336             initialize_framebuffer_size(newCtx, readBuffer);
1337          }
1338
1339          _mesa_resizebuffers(newCtx);
1340 #endif
1341
1342 #else
1343          /* We want the drawBuffer and readBuffer to be initialized by
1344           * the driver.
1345           * This generally means the Width and Height match the actual
1346           * window size and the renderbuffers (both hardware and software
1347           * based) are allocated to match.  The later can generally be
1348           * done with a call to _mesa_resize_framebuffer().
1349           *
1350           * It's theoretically possible for a buffer to have zero width
1351           * or height, but for now, assert check that the driver did what's
1352           * expected of it.
1353           */
1354          ASSERT(drawBuffer->Width > 0);
1355          ASSERT(drawBuffer->Height > 0);
1356 #endif
1357
1358          if (drawBuffer) {
1359             _mesa_check_init_viewport(newCtx,
1360                                       drawBuffer->Width, drawBuffer->Height);
1361          }
1362       }
1363
1364       if (newCtx->FirstTimeCurrent) {
1365          _mesa_compute_version(newCtx);
1366
1367          check_context_limits(newCtx);
1368
1369          /* We can use this to help debug user's problems.  Tell them to set
1370           * the MESA_INFO env variable before running their app.  Then the
1371           * first time each context is made current we'll print some useful
1372           * information.
1373           */
1374          if (_mesa_getenv("MESA_INFO")) {
1375             _mesa_print_info();
1376          }
1377
1378          newCtx->FirstTimeCurrent = GL_FALSE;
1379       }
1380    }
1381
1382    return GL_TRUE;
1383 }
1384
1385
1386 /**
1387  * Make context 'ctx' share the display lists, textures and programs
1388  * that are associated with 'ctxToShare'.
1389  * Any display lists, textures or programs associated with 'ctx' will
1390  * be deleted if nobody else is sharing them.
1391  */
1392 GLboolean
1393 _mesa_share_state(GLcontext *ctx, GLcontext *ctxToShare)
1394 {
1395    if (ctx && ctxToShare && ctx->Shared && ctxToShare->Shared) {
1396       struct gl_shared_state *oldSharedState = ctx->Shared;
1397       GLint RefCount;
1398
1399       ctx->Shared = ctxToShare->Shared;
1400
1401       _glthread_LOCK_MUTEX(ctx->Shared->Mutex);
1402       ctx->Shared->RefCount++;
1403       _glthread_UNLOCK_MUTEX(ctx->Shared->Mutex);
1404
1405       update_default_objects(ctx);
1406
1407       _glthread_LOCK_MUTEX(oldSharedState->Mutex);
1408       RefCount = --oldSharedState->RefCount;
1409       _glthread_UNLOCK_MUTEX(oldSharedState->Mutex);
1410
1411       if (RefCount == 0) {
1412          _mesa_free_shared_state(ctx, oldSharedState);
1413       }
1414
1415       return GL_TRUE;
1416    }
1417    else {
1418       return GL_FALSE;
1419    }
1420 }
1421
1422
1423
1424 /**
1425  * \return pointer to the current GL context for this thread.
1426  *
1427  * Calls _glapi_get_context(). This isn't the fastest way to get the current
1428  * context.  If you need speed, see the #GET_CURRENT_CONTEXT macro in
1429  * context.h.
1430  */
1431 GLcontext *
1432 _mesa_get_current_context( void )
1433 {
1434    return (GLcontext *) _glapi_get_context();
1435 }
1436
1437
1438 /**
1439  * Get context's current API dispatch table.
1440  *
1441  * It'll either be the immediate-mode execute dispatcher or the display list
1442  * compile dispatcher.
1443  *
1444  * \param ctx GL context.
1445  *
1446  * \return pointer to dispatch_table.
1447  *
1448  * Simply returns __GLcontextRec::CurrentDispatch.
1449  */
1450 struct _glapi_table *
1451 _mesa_get_dispatch(GLcontext *ctx)
1452 {
1453    return ctx->CurrentDispatch;
1454 }
1455
1456 /*@}*/
1457
1458
1459 /**********************************************************************/
1460 /** \name Miscellaneous functions                                     */
1461 /**********************************************************************/
1462 /*@{*/
1463
1464 /**
1465  * Record an error.
1466  *
1467  * \param ctx GL context.
1468  * \param error error code.
1469  *
1470  * Records the given error code and call the driver's dd_function_table::Error
1471  * function if defined.
1472  *
1473  * \sa
1474  * This is called via _mesa_error().
1475  */
1476 void
1477 _mesa_record_error(GLcontext *ctx, GLenum error)
1478 {
1479    if (!ctx)
1480       return;
1481
1482    if (ctx->ErrorValue == GL_NO_ERROR) {
1483       ctx->ErrorValue = error;
1484    }
1485
1486    /* Call device driver's error handler, if any.  This is used on the Mac. */
1487    if (ctx->Driver.Error) {
1488       ctx->Driver.Error(ctx);
1489    }
1490 }
1491
1492
1493 /**
1494  * Flush commands and wait for completion.
1495  */
1496 void
1497 _mesa_finish(GLcontext *ctx)
1498 {
1499    FLUSH_CURRENT( ctx, 0 );
1500    if (ctx->Driver.Finish) {
1501       ctx->Driver.Finish(ctx);
1502    }
1503 }
1504
1505
1506 /**
1507  * Flush commands.
1508  */
1509 void
1510 _mesa_flush(GLcontext *ctx)
1511 {
1512    FLUSH_CURRENT( ctx, 0 );
1513    if (ctx->Driver.Flush) {
1514       ctx->Driver.Flush(ctx);
1515    }
1516 }
1517
1518
1519
1520 /**
1521  * Execute glFinish().
1522  *
1523  * Calls the #ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH macro and the
1524  * dd_function_table::Finish driver callback, if not NULL.
1525  */
1526 void GLAPIENTRY
1527 _mesa_Finish(void)
1528 {
1529    GET_CURRENT_CONTEXT(ctx);
1530    ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(ctx);
1531    _mesa_finish(ctx);
1532 }
1533
1534
1535 /**
1536  * Execute glFlush().
1537  *
1538  * Calls the #ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH macro and the
1539  * dd_function_table::Flush driver callback, if not NULL.
1540  */
1541 void GLAPIENTRY
1542 _mesa_Flush(void)
1543 {
1544    GET_CURRENT_CONTEXT(ctx);
1545    ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(ctx);
1546    _mesa_flush(ctx);
1547 }
1548
1549
1550 /**
1551  * Set mvp_with_dp4 flag.  If a driver has a preference for DP4 over
1552  * MUL/MAD, or vice versa, call this function to register that.
1553  * Otherwise we default to MUL/MAD.
1554  */
1555 void
1556 _mesa_set_mvp_with_dp4( GLcontext *ctx,
1557                         GLboolean flag )
1558 {
1559    ctx->mvp_with_dp4 = flag;
1560 }
1561
1562
1563
1564 /**
1565  * Prior to drawing anything with glBegin, glDrawArrays, etc. this function
1566  * is called to see if it's valid to render.  This involves checking that
1567  * the current shader is valid and the framebuffer is complete.
1568  * If an error is detected it'll be recorded here.
1569  * \return GL_TRUE if OK to render, GL_FALSE if not
1570  */
1571 GLboolean
1572 _mesa_valid_to_render(GLcontext *ctx, const char *where)
1573 {
1574    /* This depends on having up to date derived state (shaders) */
1575    if (ctx->NewState)
1576       _mesa_update_state(ctx);
1577
1578    if (ctx->Shader.CurrentProgram) {
1579       /* using shaders */
1580       if (!ctx->Shader.CurrentProgram->LinkStatus) {
1581          _mesa_error(ctx, GL_INVALID_OPERATION,
1582                      "%s(shader not linked), where");
1583          return GL_FALSE;
1584       }
1585 #if 0 /* not normally enabled */
1586       {
1587          char errMsg[100];
1588          if (!_mesa_validate_shader_program(ctx, ctx->Shader.CurrentProgram,
1589                                             errMsg)) {
1590             _mesa_warning(ctx, "Shader program %u is invalid: %s",
1591                           ctx->Shader.CurrentProgram->Name, errMsg);
1592          }
1593       }
1594 #endif
1595    }
1596    else {
1597       if (ctx->VertexProgram.Enabled && !ctx->VertexProgram._Enabled) {
1598          _mesa_error(ctx, GL_INVALID_OPERATION,
1599                      "%s(vertex program not valid)", where);
1600          return GL_FALSE;
1601       }
1602       if (ctx->FragmentProgram.Enabled && !ctx->FragmentProgram._Enabled) {
1603          _mesa_error(ctx, GL_INVALID_OPERATION,
1604                      "%s(fragment program not valid)", where);
1605          return GL_FALSE;
1606       }
1607    }
1608
1609    if (ctx->DrawBuffer->_Status != GL_FRAMEBUFFER_COMPLETE_EXT) {
1610       _mesa_error(ctx, GL_INVALID_FRAMEBUFFER_OPERATION_EXT,
1611                   "%s(incomplete framebuffer)", where);
1612       return GL_FALSE;
1613    }
1614
1615 #ifdef DEBUG
1616    if (ctx->Shader.Flags & GLSL_LOG) {
1617       struct gl_shader_program *shProg = ctx->Shader.CurrentProgram;
1618       if (shProg) {
1619          if (!shProg->_Used) {
1620             /* This is the first time this shader is being used.
1621              * Append shader's constants/uniforms to log file.
1622              */
1623             GLuint i;
1624             for (i = 0; i < shProg->NumShaders; i++) {
1625                struct gl_shader *sh = shProg->Shaders[i];
1626                if (sh->Type == GL_VERTEX_SHADER) {
1627                   _mesa_append_uniforms_to_file(sh,
1628                                                 &shProg->VertexProgram->Base);
1629                }
1630                else if (sh->Type == GL_FRAGMENT_SHADER) {
1631                   _mesa_append_uniforms_to_file(sh,
1632                                                 &shProg->FragmentProgram->Base);
1633                }
1634             }
1635             shProg->_Used = GL_TRUE;
1636          }
1637       }
1638    }
1639 #endif
1640
1641    return GL_TRUE;
1642 }
1643
1644
1645 /*@}*/