src/mesa/main/texstate.c

   1 /*
   2  * Mesa 3-D graphics library
   3  * Version:  7.1
   4  *
   5  * Copyright (C) 1999-2007  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  * \file texstate.c
  27  *
  28  * Texture state handling.
  29  */
  30
  31 #include "glheader.h"
  32 #include "colormac.h"
  33 #if FEATURE_colortable
  34 #include "colortab.h"
  35 #endif
  36 #include "context.h"
  37 #include "enums.h"
  38 #include "macros.h"
  39 #include "texcompress.h"
  40 #include "texobj.h"
  41 #include "teximage.h"
  42 #include "texstate.h"
  43 #include "texenvprogram.h"
  44 #include "mtypes.h"
  45
  46
  47
  48 /**
  49  * Default texture combine environment state.  This is used to initialize
  50  * a context's texture units and as the basis for converting "classic"
  51  * texture environmnets to ARB_texture_env_combine style values.
  52  */
  53 static const struct gl_tex_env_combine_state default_combine_state = {
  54    GL_MODULATE, GL_MODULATE,
  55    { GL_TEXTURE, GL_PREVIOUS, GL_CONSTANT, GL_CONSTANT },
  56    { GL_TEXTURE, GL_PREVIOUS, GL_CONSTANT, GL_CONSTANT },
  57    { GL_SRC_COLOR, GL_SRC_COLOR, GL_SRC_ALPHA, GL_SRC_ALPHA },
  58    { GL_SRC_ALPHA, GL_SRC_ALPHA, GL_SRC_ALPHA, GL_SRC_ALPHA },
  59    0, 0,
  60    2, 2
  61 };
  62
  63
  64
  65 /**
  66  * Used by glXCopyContext to copy texture state from one context to another.
  67  */
  68 void
  69 _mesa_copy_texture_state( const GLcontext *src, GLcontext *dst )
  70 {
  71    GLuint i, tex;
  72
  73    ASSERT(src);
  74    ASSERT(dst);
  75
  76    dst->Texture.CurrentUnit = src->Texture.CurrentUnit;
  77    dst->Texture._GenFlags = src->Texture._GenFlags;
  78    dst->Texture._TexGenEnabled = src->Texture._TexGenEnabled;
  79    dst->Texture._TexMatEnabled = src->Texture._TexMatEnabled;
  80    dst->Texture.SharedPalette = src->Texture.SharedPalette;
  81
  82    /* per-unit state */
  83    for (i = 0; i < src->Const.MaxTextureImageUnits; i++) {
  84       dst->Texture.Unit[i].Enabled = src->Texture.Unit[i].Enabled;
  85       dst->Texture.Unit[i].EnvMode = src->Texture.Unit[i].EnvMode;
  86       COPY_4V(dst->Texture.Unit[i].EnvColor, src->Texture.Unit[i].EnvColor);
  87       dst->Texture.Unit[i].TexGenEnabled = src->Texture.Unit[i].TexGenEnabled;
  88       dst->Texture.Unit[i].GenS = src->Texture.Unit[i].GenS;
  89       dst->Texture.Unit[i].GenT = src->Texture.Unit[i].GenT;
  90       dst->Texture.Unit[i].GenR = src->Texture.Unit[i].GenR;
  91       dst->Texture.Unit[i].GenQ = src->Texture.Unit[i].GenQ;
  92       dst->Texture.Unit[i].LodBias = src->Texture.Unit[i].LodBias;
  93
  94       /* GL_EXT_texture_env_combine */
  95       dst->Texture.Unit[i].Combine = src->Texture.Unit[i].Combine;
  96
  97       /* copy texture object bindings, not contents of texture objects */
  98       _mesa_lock_context_textures(dst);
  99
 100       for (tex = 0; tex < NUM_TEXTURE_TARGETS; tex++) {
 101          _mesa_reference_texobj(&dst->Texture.Unit[i].CurrentTex[tex],
 102                                 src->Texture.Unit[i].CurrentTex[tex]);
 103       }
 104
 105       _mesa_unlock_context_textures(dst);
 106    }
 107 }
 108
 109
 110 /*
 111  * For debugging
 112  */
 113 void
 114 _mesa_print_texunit_state( GLcontext *ctx, GLuint unit )
 115 {
 116    const struct gl_texture_unit *texUnit = ctx->Texture.Unit + unit;
 117    _mesa_printf("Texture Unit %d\n", unit);
 118    _mesa_printf("  GL_TEXTURE_ENV_MODE = %s\n", _mesa_lookup_enum_by_nr(texUnit->EnvMode));
 119    _mesa_printf("  GL_COMBINE_RGB = %s\n", _mesa_lookup_enum_by_nr(texUnit->Combine.ModeRGB));
 120    _mesa_printf("  GL_COMBINE_ALPHA = %s\n", _mesa_lookup_enum_by_nr(texUnit->Combine.ModeA));
 121    _mesa_printf("  GL_SOURCE0_RGB = %s\n", _mesa_lookup_enum_by_nr(texUnit->Combine.SourceRGB[0]));
 122    _mesa_printf("  GL_SOURCE1_RGB = %s\n", _mesa_lookup_enum_by_nr(texUnit->Combine.SourceRGB[1]));
 123    _mesa_printf("  GL_SOURCE2_RGB = %s\n", _mesa_lookup_enum_by_nr(texUnit->Combine.SourceRGB[2]));
 124    _mesa_printf("  GL_SOURCE0_ALPHA = %s\n", _mesa_lookup_enum_by_nr(texUnit->Combine.SourceA[0]));
 125    _mesa_printf("  GL_SOURCE1_ALPHA = %s\n", _mesa_lookup_enum_by_nr(texUnit->Combine.SourceA[1]));
 126    _mesa_printf("  GL_SOURCE2_ALPHA = %s\n", _mesa_lookup_enum_by_nr(texUnit->Combine.SourceA[2]));
 127    _mesa_printf("  GL_OPERAND0_RGB = %s\n", _mesa_lookup_enum_by_nr(texUnit->Combine.OperandRGB[0]));
 128    _mesa_printf("  GL_OPERAND1_RGB = %s\n", _mesa_lookup_enum_by_nr(texUnit->Combine.OperandRGB[1]));
 129    _mesa_printf("  GL_OPERAND2_RGB = %s\n", _mesa_lookup_enum_by_nr(texUnit->Combine.OperandRGB[2]));
 130    _mesa_printf("  GL_OPERAND0_ALPHA = %s\n", _mesa_lookup_enum_by_nr(texUnit->Combine.OperandA[0]));
 131    _mesa_printf("  GL_OPERAND1_ALPHA = %s\n", _mesa_lookup_enum_by_nr(texUnit->Combine.OperandA[1]));
 132    _mesa_printf("  GL_OPERAND2_ALPHA = %s\n", _mesa_lookup_enum_by_nr(texUnit->Combine.OperandA[2]));
 133    _mesa_printf("  GL_RGB_SCALE = %d\n", 1 << texUnit->Combine.ScaleShiftRGB);
 134    _mesa_printf("  GL_ALPHA_SCALE = %d\n", 1 << texUnit->Combine.ScaleShiftA);
 135    _mesa_printf("  GL_TEXTURE_ENV_COLOR = (%f, %f, %f, %f)\n", texUnit->EnvColor[0], texUnit->EnvColor[1], texUnit->EnvColor[2], texUnit->EnvColor[3]);
 136 }
 137
 138
 139
 140 /**********************************************************************/
 141 /*                       Texture Environment                          */
 142 /**********************************************************************/
 143
 144 /**
 145  * Convert "classic" texture environment to ARB_texture_env_combine style
 146  * environments.
 147  *
 148  * \param state  texture_env_combine state vector to be filled-in.
 149  * \param mode   Classic texture environment mode (i.e., \c GL_REPLACE,
 150  *               \c GL_BLEND, \c GL_DECAL, etc.).
 151  * \param texBaseFormat  Base format of the texture associated with the
 152  *               texture unit.
 153  */
 154 static void
 155 calculate_derived_texenv( struct gl_tex_env_combine_state *state,
 156                           GLenum mode, GLenum texBaseFormat )
 157 {
 158    GLenum mode_rgb;
 159    GLenum mode_a;
 160
 161    *state = default_combine_state;
 162
 163    switch (texBaseFormat) {
 164    case GL_ALPHA:
 165       state->SourceRGB[0] = GL_PREVIOUS;
 166       break;
 167
 168    case GL_LUMINANCE_ALPHA:
 169    case GL_INTENSITY:
 170    case GL_RGBA:
 171       break;
 172
 173    case GL_LUMINANCE:
 174    case GL_RGB:
 175    case GL_YCBCR_MESA:
 176       state->SourceA[0] = GL_PREVIOUS;
 177       break;
 178
 179    default:
 180       _mesa_problem(NULL, "Invalid texBaseFormat in calculate_derived_texenv");
 181       return;
 182    }
 183
 184    if (mode == GL_REPLACE_EXT)
 185       mode = GL_REPLACE;
 186
 187    switch (mode) {
 188    case GL_REPLACE:
 189    case GL_MODULATE:
 190       mode_rgb = (texBaseFormat == GL_ALPHA) ? GL_REPLACE : mode;
 191       mode_a   = mode;
 192       break;
 193
 194    case GL_DECAL:
 195       mode_rgb = GL_INTERPOLATE;
 196       mode_a   = GL_REPLACE;
 197
 198       state->SourceA[0] = GL_PREVIOUS;
 199
 200       /* Having alpha / luminance / intensity textures replace using the
 201        * incoming fragment color matches the definition in NV_texture_shader.
 202        * The 1.5 spec simply marks these as "undefined".
 203        */
 204       switch (texBaseFormat) {
 205       case GL_ALPHA:
 206       case GL_LUMINANCE:
 207       case GL_LUMINANCE_ALPHA:
 208       case GL_INTENSITY:
 209          state->SourceRGB[0] = GL_PREVIOUS;
 210          break;
 211       case GL_RGB:
 212       case GL_YCBCR_MESA:
 213          mode_rgb = GL_REPLACE;
 214          break;
 215       case GL_RGBA:
 216          state->SourceRGB[2] = GL_TEXTURE;
 217          break;
 218       }
 219       break;
 220
 221    case GL_BLEND:
 222       mode_rgb = GL_INTERPOLATE;
 223       mode_a   = GL_MODULATE;
 224
 225       switch (texBaseFormat) {
 226       case GL_ALPHA:
 227          mode_rgb = GL_REPLACE;
 228          break;
 229       case GL_INTENSITY:
 230          mode_a = GL_INTERPOLATE;
 231          state->SourceA[0] = GL_CONSTANT;
 232          state->OperandA[2] = GL_SRC_ALPHA;
 233          /* FALLTHROUGH */
 234       case GL_LUMINANCE:
 235       case GL_RGB:
 236       case GL_LUMINANCE_ALPHA:
 237       case GL_RGBA:
 238       case GL_YCBCR_MESA:
 239          state->SourceRGB[2] = GL_TEXTURE;
 240          state->SourceA[2]   = GL_TEXTURE;
 241          state->SourceRGB[0] = GL_CONSTANT;
 242          state->OperandRGB[2] = GL_SRC_COLOR;
 243          break;
 244       }
 245       break;
 246
 247    case GL_ADD:
 248       mode_rgb = (texBaseFormat == GL_ALPHA) ? GL_REPLACE : GL_ADD;
 249       mode_a   = (texBaseFormat == GL_INTENSITY) ? GL_ADD : GL_MODULATE;
 250       break;
 251
 252    default:
 253       _mesa_problem(NULL,
 254                     "Invalid texture env mode in calculate_derived_texenv");
 255       return;
 256    }
 257
 258    state->ModeRGB = (state->SourceRGB[0] != GL_PREVIOUS)
 259        ? mode_rgb : GL_REPLACE;
 260    state->ModeA   = (state->SourceA[0]   != GL_PREVIOUS)
 261        ? mode_a   : GL_REPLACE;
 262 }
 263
 264
 265
 266
 267 /* GL_ARB_multitexture */
 268 void GLAPIENTRY
 269 _mesa_ActiveTextureARB(GLenum texture)
 270 {
 271    GET_CURRENT_CONTEXT(ctx);
 272    const GLuint texUnit = texture - GL_TEXTURE0;
 273    ASSERT_OUTSIDE_BEGIN_END(ctx);
 274
 275    if (MESA_VERBOSE & (VERBOSE_API|VERBOSE_TEXTURE))
 276       _mesa_debug(ctx, "glActiveTexture %s\n",
 277                   _mesa_lookup_enum_by_nr(texture));
 278
 279    if (texUnit >= ctx->Const.MaxTextureImageUnits) {
 280       _mesa_error(ctx, GL_INVALID_ENUM, "glActiveTexture(texture)");
 281       return;
 282    }
 283
 284    if (ctx->Texture.CurrentUnit == texUnit)
 285       return;
 286
 287    FLUSH_VERTICES(ctx, _NEW_TEXTURE);
 288
 289    ctx->Texture.CurrentUnit = texUnit;
 290    if (ctx->Transform.MatrixMode == GL_TEXTURE) {
 291       /* update current stack pointer */
 292       ctx->CurrentStack = &ctx->TextureMatrixStack[texUnit];
 293    }
 294
 295    if (ctx->Driver.ActiveTexture) {
 296       (*ctx->Driver.ActiveTexture)( ctx, (GLuint) texUnit );
 297    }
 298 }
 299
 300
 301 /* GL_ARB_multitexture */
 302 void GLAPIENTRY
 303 _mesa_ClientActiveTextureARB(GLenum texture)
 304 {
 305    GET_CURRENT_CONTEXT(ctx);
 306    GLuint texUnit = texture - GL_TEXTURE0;
 307    ASSERT_OUTSIDE_BEGIN_END(ctx);
 308
 309    if (texUnit >= ctx->Const.MaxTextureCoordUnits) {
 310       _mesa_error(ctx, GL_INVALID_ENUM, "glClientActiveTexture(texture)");
 311       return;
 312    }
 313
 314    FLUSH_VERTICES(ctx, _NEW_ARRAY);
 315    ctx->Array.ActiveTexture = texUnit;
 316 }
 317
 318
 319
 320 /**********************************************************************/
 321 /*****                    State management                        *****/
 322 /**********************************************************************/
 323
 324
 325 /**
 326  * \note This routine refers to derived texture attribute values to
 327  * compute the ENABLE_TEXMAT flags, but is only called on
 328  * _NEW_TEXTURE_MATRIX.  On changes to _NEW_TEXTURE, the ENABLE_TEXMAT
 329  * flags are updated by _mesa_update_textures(), below.
 330  *
 331  * \param ctx GL context.
 332  */
 333 static void
 334 update_texture_matrices( GLcontext *ctx )
 335 {
 336    GLuint i;
 337
 338    ctx->Texture._TexMatEnabled = 0;
 339
 340    for (i=0; i < ctx->Const.MaxTextureCoordUnits; i++) {
 341       if (_math_matrix_is_dirty(ctx->TextureMatrixStack[i].Top)) {
 342          _math_matrix_analyse( ctx->TextureMatrixStack[i].Top );
 343
 344          if (ctx->Texture.Unit[i]._ReallyEnabled &&
 345              ctx->TextureMatrixStack[i].Top->type != MATRIX_IDENTITY)
 346             ctx->Texture._TexMatEnabled |= ENABLE_TEXMAT(i);
 347
 348          if (ctx->Driver.TextureMatrix)
 349             ctx->Driver.TextureMatrix( ctx, i, ctx->TextureMatrixStack[i].Top);
 350       }
 351    }
 352 }
 353
 354
 355 /**
 356  * Update texture object's _Function field.  We need to do this
 357  * whenever any of the texture object's shadow-related fields change
 358  * or when we start/stop using a fragment program.
 359  *
 360  * This function could be expanded someday to update additional per-object
 361  * fields that depend on assorted state changes.
 362  */
 363 static void
 364 update_texture_compare_function(GLcontext *ctx,
 365                                 struct gl_texture_object *tObj)
 366 {
 367    /* XXX temporarily disable this test since it breaks the GLSL
 368     * shadow2D(), etc. functions.
 369     */
 370    if (0 /*ctx->FragmentProgram._Current*/) {
 371       /* Texel/coordinate comparison is ignored for programs.
 372        * See GL_ARB_fragment_program/shader spec for details.
 373        */
 374       tObj->_Function = GL_NONE;
 375    }
 376    else if (tObj->CompareMode == GL_COMPARE_R_TO_TEXTURE_ARB) {
 377       /* GL_ARB_shadow */
 378       tObj->_Function = tObj->CompareFunc;
 379    }
 380    else {
 381       tObj->_Function = GL_NONE;  /* pass depth through as grayscale */
 382    }
 383 }
 384
 385
 386 /**
 387  * Helper function for determining which texture object (1D, 2D, cube, etc)
 388  * should actually be used.
 389  */
 390 static void
 391 texture_override(GLcontext *ctx,
 392                  struct gl_texture_unit *texUnit, GLbitfield enableBits,
 393                  struct gl_texture_object *texObj, GLuint textureBit)
 394 {
 395    if (!texUnit->_ReallyEnabled && (enableBits & textureBit)) {
 396       if (!texObj->_Complete) {
 397          _mesa_test_texobj_completeness(ctx, texObj);
 398       }
 399       if (texObj->_Complete) {
 400          texUnit->_ReallyEnabled = textureBit;
 401          texUnit->_Current = texObj;
 402          update_texture_compare_function(ctx, texObj);
 403       }
 404    }
 405 }
 406
 407
 408 /**
 409  * Examine texture unit's combine/env state to update derived state.
 410  */
 411 static void
 412 update_tex_combine(GLcontext *ctx, struct gl_texture_unit *texUnit)
 413 {
 414    /* Set the texUnit->_CurrentCombine field to point to the user's combiner
 415     * state, or the combiner state which is derived from traditional texenv
 416     * mode.
 417     */
 418    if (texUnit->EnvMode == GL_COMBINE ||
 419        texUnit->EnvMode == GL_COMBINE4_NV) {
 420       texUnit->_CurrentCombine = & texUnit->Combine;
 421    }
 422    else {
 423       const struct gl_texture_object *texObj = texUnit->_Current;
 424       GLenum format = texObj->Image[0][texObj->BaseLevel]->_BaseFormat;
 425       if (format == GL_COLOR_INDEX) {
 426          format = GL_RGBA;  /* a bit of a hack */
 427       }
 428       else if (format == GL_DEPTH_COMPONENT ||
 429                format == GL_DEPTH_STENCIL_EXT) {
 430          format = texObj->DepthMode;
 431       }
 432       calculate_derived_texenv(&texUnit->_EnvMode, texUnit->EnvMode, format);
 433       texUnit->_CurrentCombine = & texUnit->_EnvMode;
 434    }
 435
 436    /* Determine number of source RGB terms in the combiner function */
 437    switch (texUnit->_CurrentCombine->ModeRGB) {
 438    case GL_REPLACE:
 439       texUnit->_CurrentCombine->_NumArgsRGB = 1;
 440       break;
 441    case GL_ADD:
 442    case GL_ADD_SIGNED:
 443       if (texUnit->EnvMode == GL_COMBINE4_NV)
 444          texUnit->_CurrentCombine->_NumArgsRGB = 4;
 445       else
 446          texUnit->_CurrentCombine->_NumArgsRGB = 2;
 447       break;
 448    case GL_MODULATE:
 449    case GL_SUBTRACT:
 450    case GL_DOT3_RGB:
 451    case GL_DOT3_RGBA:
 452    case GL_DOT3_RGB_EXT:
 453    case GL_DOT3_RGBA_EXT:
 454       texUnit->_CurrentCombine->_NumArgsRGB = 2;
 455       break;
 456    case GL_INTERPOLATE:
 457    case GL_MODULATE_ADD_ATI:
 458    case GL_MODULATE_SIGNED_ADD_ATI:
 459    case GL_MODULATE_SUBTRACT_ATI:
 460       texUnit->_CurrentCombine->_NumArgsRGB = 3;
 461       break;
 462    default:
 463       texUnit->_CurrentCombine->_NumArgsRGB = 0;
 464       _mesa_problem(ctx, "invalid RGB combine mode in update_texture_state");
 465       return;
 466    }
 467
 468    /* Determine number of source Alpha terms in the combiner function */
 469    switch (texUnit->_CurrentCombine->ModeA) {
 470    case GL_REPLACE:
 471       texUnit->_CurrentCombine->_NumArgsA = 1;
 472       break;
 473    case GL_ADD:
 474    case GL_ADD_SIGNED:
 475       if (texUnit->EnvMode == GL_COMBINE4_NV)
 476          texUnit->_CurrentCombine->_NumArgsA = 4;
 477       else
 478          texUnit->_CurrentCombine->_NumArgsA = 2;
 479       break;
 480    case GL_MODULATE:
 481    case GL_SUBTRACT:
 482       texUnit->_CurrentCombine->_NumArgsA = 2;
 483       break;
 484    case GL_INTERPOLATE:
 485    case GL_MODULATE_ADD_ATI:
 486    case GL_MODULATE_SIGNED_ADD_ATI:
 487    case GL_MODULATE_SUBTRACT_ATI:
 488       texUnit->_CurrentCombine->_NumArgsA = 3;
 489       break;
 490    default:
 491       texUnit->_CurrentCombine->_NumArgsA = 0;
 492       _mesa_problem(ctx, "invalid Alpha combine mode in update_texture_state");
 493       break;
 494    }
 495 }
 496
 497
 498 /**
 499  * \note This routine refers to derived texture matrix values to
 500  * compute the ENABLE_TEXMAT flags, but is only called on
 501  * _NEW_TEXTURE.  On changes to _NEW_TEXTURE_MATRIX, the ENABLE_TEXMAT
 502  * flags are updated by _mesa_update_texture_matrices, above.
 503  *
 504  * \param ctx GL context.
 505  */
 506 static void
 507 update_texture_state( GLcontext *ctx )
 508 {
 509    GLuint unit;
 510    struct gl_fragment_program *fprog = NULL;
 511    struct gl_vertex_program *vprog = NULL;
 512
 513    if (ctx->Shader.CurrentProgram &&
 514        ctx->Shader.CurrentProgram->LinkStatus) {
 515       fprog = ctx->Shader.CurrentProgram->FragmentProgram;
 516       vprog = ctx->Shader.CurrentProgram->VertexProgram;
 517    }
 518    else {
 519       if (ctx->FragmentProgram._Enabled) {
 520          fprog = ctx->FragmentProgram.Current;
 521       }
 522       if (ctx->VertexProgram._Enabled) {
 523          /* XXX enable this if/when non-shader vertex programs get
 524           * texture fetches:
 525          vprog = ctx->VertexProgram.Current;
 526          */
 527       }
 528    }
 529
 530    /* TODO: only set this if there are actual changes */
 531    ctx->NewState |= _NEW_TEXTURE;
 532
 533    ctx->Texture._EnabledUnits = 0;
 534    ctx->Texture._GenFlags = 0;
 535    ctx->Texture._TexMatEnabled = 0;
 536    ctx->Texture._TexGenEnabled = 0;
 537
 538    /*
 539     * Update texture unit state.
 540     */
 541    for (unit = 0; unit < ctx->Const.MaxTextureImageUnits; unit++) {
 542       struct gl_texture_unit *texUnit = &ctx->Texture.Unit[unit];
 543       GLbitfield enableBits;
 544       GLuint texIndex;
 545
 546       texUnit->_Current = NULL;
 547       texUnit->_ReallyEnabled = 0;
 548       texUnit->_GenFlags = 0;
 549
 550       /* Get the bitmask of texture target enables.
 551        * enableBits will be a mask of the TEXTURE_*_BIT flags indicating
 552        * which texture targets are enabled (fixed function) or referenced
 553        * by a fragment shader/program.  When multiple flags are set, we'll
 554        * settle on the one with highest priority (see texture_override below).
 555        */
 556       enableBits = 0x0;
 557       if (vprog) {
 558          enableBits |= vprog->Base.TexturesUsed[unit];
 559       }
 560       if (fprog) {
 561          enableBits |= fprog->Base.TexturesUsed[unit];
 562       }
 563       else {
 564          /* fixed-function fragment program */
 565          enableBits |= texUnit->Enabled;
 566       }
 567
 568       if (enableBits == 0x0)
 569          continue;
 570
 571       /* Look for the highest-priority texture target that's enabled and
 572        * complete.  That's the one we'll use for texturing.  If we're using
 573        * a fragment program we're guaranteed that bitcount(enabledBits) <= 1.
 574        * Note that the TEXTURE_x_INDEX values are in high to low priority.
 575        */
 576       for (texIndex = 0; texIndex < NUM_TEXTURE_TARGETS; texIndex++) {
 577          texture_override(ctx, texUnit, enableBits,
 578                           texUnit->CurrentTex[texIndex], 1 << texIndex);
 579       }
 580
 581       if (!texUnit->_ReallyEnabled) {
 582          continue;
 583       }
 584
 585       /* if we get here, we know this texture unit is enabled */
 586
 587       ctx->Texture._EnabledUnits |= (1 << unit);
 588
 589       update_tex_combine(ctx, texUnit);
 590    }
 591
 592
 593    /* Determine which texture coordinate sets are actually needed */
 594    if (fprog) {
 595       const GLuint coordMask = (1 << MAX_TEXTURE_COORD_UNITS) - 1;
 596       ctx->Texture._EnabledCoordUnits
 597          = (fprog->Base.InputsRead >> FRAG_ATTRIB_TEX0) & coordMask;
 598    }
 599    else {
 600       ctx->Texture._EnabledCoordUnits = ctx->Texture._EnabledUnits;
 601    }
 602
 603    /* Setup texgen for those texture coordinate sets that are in use */
 604    for (unit = 0; unit < ctx->Const.MaxTextureCoordUnits; unit++) {
 605       struct gl_texture_unit *texUnit = &ctx->Texture.Unit[unit];
 606
 607       if (!(ctx->Texture._EnabledCoordUnits & (1 << unit)))
 608          continue;
 609
 610       if (texUnit->TexGenEnabled) {
 611          if (texUnit->TexGenEnabled & S_BIT) {
 612             texUnit->_GenFlags |= texUnit->GenS._ModeBit;
 613          }
 614          if (texUnit->TexGenEnabled & T_BIT) {
 615             texUnit->_GenFlags |= texUnit->GenT._ModeBit;
 616          }
 617          if (texUnit->TexGenEnabled & R_BIT) {
 618             texUnit->_GenFlags |= texUnit->GenR._ModeBit;
 619          }
 620          if (texUnit->TexGenEnabled & Q_BIT) {
 621             texUnit->_GenFlags |= texUnit->GenQ._ModeBit;
 622          }
 623
 624          ctx->Texture._TexGenEnabled |= ENABLE_TEXGEN(unit);
 625          ctx->Texture._GenFlags |= texUnit->_GenFlags;
 626       }
 627
 628       if (ctx->TextureMatrixStack[unit].Top->type != MATRIX_IDENTITY)
 629          ctx->Texture._TexMatEnabled |= ENABLE_TEXMAT(unit);
 630    }
 631 }
 632
 633
 634 /**
 635  * Update texture-related derived state.
 636  */
 637 void
 638 _mesa_update_texture( GLcontext *ctx, GLuint new_state )
 639 {
 640    if (new_state & _NEW_TEXTURE_MATRIX)
 641       update_texture_matrices( ctx );
 642
 643    if (new_state & (_NEW_TEXTURE | _NEW_PROGRAM))
 644       update_texture_state( ctx );
 645 }
 646
 647
 648 /**********************************************************************/
 649 /*****                      Initialization                        *****/
 650 /**********************************************************************/
 651
 652 /**
 653  * Allocate the proxy textures for the given context.
 654  *
 655  * \param ctx the context to allocate proxies for.
 656  *
 657  * \return GL_TRUE on success, or GL_FALSE on failure
 658  *
 659  * If run out of memory part way through the allocations, clean up and return
 660  * GL_FALSE.
 661  */
 662 static GLboolean
 663 alloc_proxy_textures( GLcontext *ctx )
 664 {
 665    static const GLenum targets[] = {
 666       GL_TEXTURE_1D,
 667       GL_TEXTURE_2D,
 668       GL_TEXTURE_3D,
 669       GL_TEXTURE_CUBE_MAP_ARB,
 670       GL_TEXTURE_RECTANGLE_NV,
 671       GL_TEXTURE_1D_ARRAY_EXT,
 672       GL_TEXTURE_2D_ARRAY_EXT
 673    };
 674    GLint tgt;
 675
 676    ASSERT(Elements(targets) == NUM_TEXTURE_TARGETS);
 677
 678    for (tgt = 0; tgt < NUM_TEXTURE_TARGETS; tgt++) {
 679       if (!(ctx->Texture.ProxyTex[tgt]
 680             = ctx->Driver.NewTextureObject(ctx, 0, targets[tgt]))) {
 681          /* out of memory, free what we did allocate */
 682          while (--tgt >= 0) {
 683             ctx->Driver.DeleteTexture(ctx, ctx->Texture.ProxyTex[tgt]);
 684          }
 685          return GL_FALSE;
 686       }
 687    }
 688
 689    assert(ctx->Texture.ProxyTex[0]->RefCount == 1); /* sanity check */
 690    return GL_TRUE;
 691 }
 692
 693
 694 /**
 695  * Initialize a texture unit.
 696  *
 697  * \param ctx GL context.
 698  * \param unit texture unit number to be initialized.
 699  */
 700 static void
 701 init_texture_unit( GLcontext *ctx, GLuint unit )
 702 {
 703    struct gl_texture_unit *texUnit = &ctx->Texture.Unit[unit];
 704    GLuint tex;
 705
 706    texUnit->EnvMode = GL_MODULATE;
 707    ASSIGN_4V( texUnit->EnvColor, 0.0, 0.0, 0.0, 0.0 );
 708
 709    texUnit->Combine = default_combine_state;
 710    texUnit->_EnvMode = default_combine_state;
 711    texUnit->_CurrentCombine = & texUnit->_EnvMode;
 712
 713    texUnit->TexGenEnabled = 0;
 714    texUnit->GenS.Mode = GL_EYE_LINEAR;
 715    texUnit->GenT.Mode = GL_EYE_LINEAR;
 716    texUnit->GenR.Mode = GL_EYE_LINEAR;
 717    texUnit->GenQ.Mode = GL_EYE_LINEAR;
 718    texUnit->GenS._ModeBit = TEXGEN_EYE_LINEAR;
 719    texUnit->GenT._ModeBit = TEXGEN_EYE_LINEAR;
 720    texUnit->GenR._ModeBit = TEXGEN_EYE_LINEAR;
 721    texUnit->GenQ._ModeBit = TEXGEN_EYE_LINEAR;
 722
 723    /* Yes, these plane coefficients are correct! */
 724    ASSIGN_4V( texUnit->GenS.ObjectPlane, 1.0, 0.0, 0.0, 0.0 );
 725    ASSIGN_4V( texUnit->GenT.ObjectPlane, 0.0, 1.0, 0.0, 0.0 );
 726    ASSIGN_4V( texUnit->GenR.ObjectPlane, 0.0, 0.0, 0.0, 0.0 );
 727    ASSIGN_4V( texUnit->GenQ.ObjectPlane, 0.0, 0.0, 0.0, 0.0 );
 728    ASSIGN_4V( texUnit->GenS.EyePlane, 1.0, 0.0, 0.0, 0.0 );
 729    ASSIGN_4V( texUnit->GenT.EyePlane, 0.0, 1.0, 0.0, 0.0 );
 730    ASSIGN_4V( texUnit->GenR.EyePlane, 0.0, 0.0, 0.0, 0.0 );
 731    ASSIGN_4V( texUnit->GenQ.EyePlane, 0.0, 0.0, 0.0, 0.0 );
 732
 733    /* initialize current texture object ptrs to the shared default objects */
 734    for (tex = 0; tex < NUM_TEXTURE_TARGETS; tex++) {
 735       _mesa_reference_texobj(&texUnit->CurrentTex[tex],
 736                              ctx->Shared->DefaultTex[tex]);
 737    }
 738 }
 739
 740
 741 /**
 742  * Initialize texture state for the given context.
 743  */
 744 GLboolean
 745 _mesa_init_texture(GLcontext *ctx)
 746 {
 747    GLuint i;
 748
 749    /* Texture group */
 750    ctx->Texture.CurrentUnit = 0;      /* multitexture */
 751    ctx->Texture._EnabledUnits = 0;
 752    ctx->Texture.SharedPalette = GL_FALSE;
 753 #if FEATURE_colortable
 754    _mesa_init_colortable(&ctx->Texture.Palette);
 755 #endif
 756
 757    for (i = 0; i < MAX_TEXTURE_UNITS; i++)
 758       init_texture_unit( ctx, i );
 759
 760    /* After we're done initializing the context's texture state the default
 761     * texture objects' refcounts should be at least MAX_TEXTURE_UNITS + 1.
 762     */
 763    assert(ctx->Shared->DefaultTex[TEXTURE_1D_INDEX]->RefCount
 764           >= MAX_TEXTURE_UNITS + 1);
 765
 766    /* Allocate proxy textures */
 767    if (!alloc_proxy_textures( ctx ))
 768       return GL_FALSE;
 769
 770    return GL_TRUE;
 771 }
 772
 773
 774 /**
 775  * Free dynamically-allocted texture data attached to the given context.
 776  */
 777 void
 778 _mesa_free_texture_data(GLcontext *ctx)
 779 {
 780    GLuint u, tgt;
 781
 782    /* unreference current textures */
 783    for (u = 0; u < MAX_TEXTURE_IMAGE_UNITS; u++) {
 784       struct gl_texture_unit *unit = ctx->Texture.Unit + u;
 785       for (tgt = 0; tgt < NUM_TEXTURE_TARGETS; tgt++) {
 786          _mesa_reference_texobj(&unit->CurrentTex[tgt], NULL);
 787       }
 788    }
 789
 790    /* Free proxy texture objects */
 791    for (tgt = 0; tgt < NUM_TEXTURE_TARGETS; tgt++)
 792       ctx->Driver.DeleteTexture(ctx, ctx->Texture.ProxyTex[tgt]);
 793
 794 #if FEATURE_colortable
 795    {
 796       GLuint i;
 797       for (i = 0; i < MAX_TEXTURE_IMAGE_UNITS; i++)
 798          _mesa_free_colortable_data( &ctx->Texture.Unit[i].ColorTable );
 799    }
 800 #endif
 801 }
 802
 803
 804 /**
 805  * Update the default texture objects in the given context to reference those
 806  * specified in the shared state and release those referencing the old
 807  * shared state.
 808  */
 809 void
 810 _mesa_update_default_objects_texture(GLcontext *ctx)
 811 {
 812    GLuint i, tex;
 813
 814    for (i = 0; i < MAX_TEXTURE_UNITS; i++) {
 815       struct gl_texture_unit *texUnit = &ctx->Texture.Unit[i];
 816       for (tex = 0; tex < NUM_TEXTURE_TARGETS; tex++) {
 817          _mesa_reference_texobj(&texUnit->CurrentTex[tex],
 818                                 ctx->Shared->DefaultTex[tex]);
 819       }
 820    }
 821 }