src/mesa/main/texstate.c

   1 /*
   2  * Mesa 3-D graphics library
   3  * Version:  7.5
   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 "mfeatures.h"
  33 #include "colormac.h"
  34 #if FEATURE_colortable
  35 #include "colortab.h"
  36 #endif
  37 #include "context.h"
  38 #include "enums.h"
  39 #include "macros.h"
  40 #include "texcompress.h"
  41 #include "texobj.h"
  42 #include "teximage.h"
  43 #include "texstate.h"
  44 #include "texenvprogram.h"
  45 #include "mtypes.h"
  46
  47
  48
  49 /**
  50  * Default texture combine environment state.  This is used to initialize
  51  * a context's texture units and as the basis for converting "classic"
  52  * texture environmnets to ARB_texture_env_combine style values.
  53  */
  54 static const struct gl_tex_env_combine_state default_combine_state = {
  55    GL_MODULATE, GL_MODULATE,
  56    { GL_TEXTURE, GL_PREVIOUS, GL_CONSTANT, GL_CONSTANT },
  57    { GL_TEXTURE, GL_PREVIOUS, GL_CONSTANT, GL_CONSTANT },
  58    { GL_SRC_COLOR, GL_SRC_COLOR, GL_SRC_ALPHA, GL_SRC_ALPHA },
  59    { GL_SRC_ALPHA, GL_SRC_ALPHA, GL_SRC_ALPHA, GL_SRC_ALPHA },
  60    0, 0,
  61    2, 2
  62 };
  63
  64
  65
  66 /**
  67  * Used by glXCopyContext to copy texture state from one context to another.
  68  */
  69 void
  70 _mesa_copy_texture_state( const GLcontext *src, GLcontext *dst )
  71 {
  72    GLuint u, tex;
  73
  74    ASSERT(src);
  75    ASSERT(dst);
  76
  77    dst->Texture.CurrentUnit = src->Texture.CurrentUnit;
  78    dst->Texture._GenFlags = src->Texture._GenFlags;
  79    dst->Texture._TexGenEnabled = src->Texture._TexGenEnabled;
  80    dst->Texture._TexMatEnabled = src->Texture._TexMatEnabled;
  81    dst->Texture.SharedPalette = src->Texture.SharedPalette;
  82
  83    /* per-unit state */
  84    for (u = 0; u < src->Const.MaxTextureImageUnits; u++) {
  85       dst->Texture.Unit[u].Enabled = src->Texture.Unit[u].Enabled;
  86       dst->Texture.Unit[u].EnvMode = src->Texture.Unit[u].EnvMode;
  87       COPY_4V(dst->Texture.Unit[u].EnvColor, src->Texture.Unit[u].EnvColor);
  88       dst->Texture.Unit[u].TexGenEnabled = src->Texture.Unit[u].TexGenEnabled;
  89       dst->Texture.Unit[u].GenS = src->Texture.Unit[u].GenS;
  90       dst->Texture.Unit[u].GenT = src->Texture.Unit[u].GenT;
  91       dst->Texture.Unit[u].GenR = src->Texture.Unit[u].GenR;
  92       dst->Texture.Unit[u].GenQ = src->Texture.Unit[u].GenQ;
  93       dst->Texture.Unit[u].LodBias = src->Texture.Unit[u].LodBias;
  94
  95       /* GL_EXT_texture_env_combine */
  96       dst->Texture.Unit[u].Combine = src->Texture.Unit[u].Combine;
  97
  98       /* GL_ATI_envmap_bumpmap - need this? */
  99       dst->Texture.Unit[u].BumpTarget = src->Texture.Unit[u].BumpTarget;
 100       COPY_4V(dst->Texture.Unit[u].RotMatrix, src->Texture.Unit[u].RotMatrix);
 101
 102       /*
 103        * XXX strictly speaking, we should compare texture names/ids and
 104        * bind textures in the dest context according to id.  For now, only
 105        * copy bindings if the contexts share the same pool of textures to
 106        * avoid refcounting bugs.
 107        */
 108       if (dst->Shared == src->Shared) {
 109          /* copy texture object bindings, not contents of texture objects */
 110          _mesa_lock_context_textures(dst);
 111
 112          for (tex = 0; tex < NUM_TEXTURE_TARGETS; tex++) {
 113             _mesa_reference_texobj(&dst->Texture.Unit[u].CurrentTex[tex],
 114                                    src->Texture.Unit[u].CurrentTex[tex]);
 115          }
 116          _mesa_unlock_context_textures(dst);
 117       }
 118    }
 119 }
 120
 121
 122 /*
 123  * For debugging
 124  */
 125 void
 126 _mesa_print_texunit_state( GLcontext *ctx, GLuint unit )
 127 {
 128    const struct gl_texture_unit *texUnit = ctx->Texture.Unit + unit;
 129    _mesa_printf("Texture Unit %d\n", unit);
 130    _mesa_printf("  GL_TEXTURE_ENV_MODE = %s\n", _mesa_lookup_enum_by_nr(texUnit->EnvMode));
 131    _mesa_printf("  GL_COMBINE_RGB = %s\n", _mesa_lookup_enum_by_nr(texUnit->Combine.ModeRGB));
 132    _mesa_printf("  GL_COMBINE_ALPHA = %s\n", _mesa_lookup_enum_by_nr(texUnit->Combine.ModeA));
 133    _mesa_printf("  GL_SOURCE0_RGB = %s\n", _mesa_lookup_enum_by_nr(texUnit->Combine.SourceRGB[0]));
 134    _mesa_printf("  GL_SOURCE1_RGB = %s\n", _mesa_lookup_enum_by_nr(texUnit->Combine.SourceRGB[1]));
 135    _mesa_printf("  GL_SOURCE2_RGB = %s\n", _mesa_lookup_enum_by_nr(texUnit->Combine.SourceRGB[2]));
 136    _mesa_printf("  GL_SOURCE0_ALPHA = %s\n", _mesa_lookup_enum_by_nr(texUnit->Combine.SourceA[0]));
 137    _mesa_printf("  GL_SOURCE1_ALPHA = %s\n", _mesa_lookup_enum_by_nr(texUnit->Combine.SourceA[1]));
 138    _mesa_printf("  GL_SOURCE2_ALPHA = %s\n", _mesa_lookup_enum_by_nr(texUnit->Combine.SourceA[2]));
 139    _mesa_printf("  GL_OPERAND0_RGB = %s\n", _mesa_lookup_enum_by_nr(texUnit->Combine.OperandRGB[0]));
 140    _mesa_printf("  GL_OPERAND1_RGB = %s\n", _mesa_lookup_enum_by_nr(texUnit->Combine.OperandRGB[1]));
 141    _mesa_printf("  GL_OPERAND2_RGB = %s\n", _mesa_lookup_enum_by_nr(texUnit->Combine.OperandRGB[2]));
 142    _mesa_printf("  GL_OPERAND0_ALPHA = %s\n", _mesa_lookup_enum_by_nr(texUnit->Combine.OperandA[0]));
 143    _mesa_printf("  GL_OPERAND1_ALPHA = %s\n", _mesa_lookup_enum_by_nr(texUnit->Combine.OperandA[1]));
 144    _mesa_printf("  GL_OPERAND2_ALPHA = %s\n", _mesa_lookup_enum_by_nr(texUnit->Combine.OperandA[2]));
 145    _mesa_printf("  GL_RGB_SCALE = %d\n", 1 << texUnit->Combine.ScaleShiftRGB);
 146    _mesa_printf("  GL_ALPHA_SCALE = %d\n", 1 << texUnit->Combine.ScaleShiftA);
 147    _mesa_printf("  GL_TEXTURE_ENV_COLOR = (%f, %f, %f, %f)\n", texUnit->EnvColor[0], texUnit->EnvColor[1], texUnit->EnvColor[2], texUnit->EnvColor[3]);
 148 }
 149
 150
 151
 152 /**********************************************************************/
 153 /*                       Texture Environment                          */
 154 /**********************************************************************/
 155
 156 /**
 157  * Convert "classic" texture environment to ARB_texture_env_combine style
 158  * environments.
 159  *
 160  * \param state  texture_env_combine state vector to be filled-in.
 161  * \param mode   Classic texture environment mode (i.e., \c GL_REPLACE,
 162  *               \c GL_BLEND, \c GL_DECAL, etc.).
 163  * \param texBaseFormat  Base format of the texture associated with the
 164  *               texture unit.
 165  */
 166 static void
 167 calculate_derived_texenv( struct gl_tex_env_combine_state *state,
 168                           GLenum mode, GLenum texBaseFormat )
 169 {
 170    GLenum mode_rgb;
 171    GLenum mode_a;
 172
 173    *state = default_combine_state;
 174
 175    switch (texBaseFormat) {
 176    case GL_ALPHA:
 177       state->SourceRGB[0] = GL_PREVIOUS;
 178       break;
 179
 180    case GL_LUMINANCE_ALPHA:
 181    case GL_INTENSITY:
 182    case GL_RGBA:
 183       break;
 184
 185    case GL_LUMINANCE:
 186    case GL_RGB:
 187    case GL_YCBCR_MESA:
 188    case GL_DUDV_ATI:
 189       state->SourceA[0] = GL_PREVIOUS;
 190       break;
 191
 192    default:
 193       _mesa_problem(NULL,
 194                     "Invalid texBaseFormat 0x%x in calculate_derived_texenv",
 195                     texBaseFormat);
 196       return;
 197    }
 198
 199    if (mode == GL_REPLACE_EXT)
 200       mode = GL_REPLACE;
 201
 202    switch (mode) {
 203    case GL_REPLACE:
 204    case GL_MODULATE:
 205       mode_rgb = (texBaseFormat == GL_ALPHA) ? GL_REPLACE : mode;
 206       mode_a   = mode;
 207       break;
 208
 209    case GL_DECAL:
 210       mode_rgb = GL_INTERPOLATE;
 211       mode_a   = GL_REPLACE;
 212
 213       state->SourceA[0] = GL_PREVIOUS;
 214
 215       /* Having alpha / luminance / intensity textures replace using the
 216        * incoming fragment color matches the definition in NV_texture_shader.
 217        * The 1.5 spec simply marks these as "undefined".
 218        */
 219       switch (texBaseFormat) {
 220       case GL_ALPHA:
 221       case GL_LUMINANCE:
 222       case GL_LUMINANCE_ALPHA:
 223       case GL_INTENSITY:
 224          state->SourceRGB[0] = GL_PREVIOUS;
 225          break;
 226       case GL_RGB:
 227       case GL_YCBCR_MESA:
 228       case GL_DUDV_ATI:
 229          mode_rgb = GL_REPLACE;
 230          break;
 231       case GL_RGBA:
 232          state->SourceRGB[2] = GL_TEXTURE;
 233          break;
 234       }
 235       break;
 236
 237    case GL_BLEND:
 238       mode_rgb = GL_INTERPOLATE;
 239       mode_a   = GL_MODULATE;
 240
 241       switch (texBaseFormat) {
 242       case GL_ALPHA:
 243          mode_rgb = GL_REPLACE;
 244          break;
 245       case GL_INTENSITY:
 246          mode_a = GL_INTERPOLATE;
 247          state->SourceA[0] = GL_CONSTANT;
 248          state->OperandA[2] = GL_SRC_ALPHA;
 249          /* FALLTHROUGH */
 250       case GL_LUMINANCE:
 251       case GL_RGB:
 252       case GL_LUMINANCE_ALPHA:
 253       case GL_RGBA:
 254       case GL_YCBCR_MESA:
 255       case GL_DUDV_ATI:
 256          state->SourceRGB[2] = GL_TEXTURE;
 257          state->SourceA[2]   = GL_TEXTURE;
 258          state->SourceRGB[0] = GL_CONSTANT;
 259          state->OperandRGB[2] = GL_SRC_COLOR;
 260          break;
 261       }
 262       break;
 263
 264    case GL_ADD:
 265       mode_rgb = (texBaseFormat == GL_ALPHA) ? GL_REPLACE : GL_ADD;
 266       mode_a   = (texBaseFormat == GL_INTENSITY) ? GL_ADD : GL_MODULATE;
 267       break;
 268
 269    default:
 270       _mesa_problem(NULL,
 271                     "Invalid texture env mode 0x%x in calculate_derived_texenv",
 272                     mode);
 273       return;
 274    }
 275
 276    state->ModeRGB = (state->SourceRGB[0] != GL_PREVIOUS)
 277        ? mode_rgb : GL_REPLACE;
 278    state->ModeA   = (state->SourceA[0]   != GL_PREVIOUS)
 279        ? mode_a   : GL_REPLACE;
 280 }
 281
 282
 283
 284
 285 /* GL_ARB_multitexture */
 286 void GLAPIENTRY
 287 _mesa_ActiveTextureARB(GLenum texture)
 288 {
 289    GET_CURRENT_CONTEXT(ctx);
 290    const GLuint texUnit = texture - GL_TEXTURE0;
 291    ASSERT_OUTSIDE_BEGIN_END(ctx);
 292
 293    if (MESA_VERBOSE & (VERBOSE_API|VERBOSE_TEXTURE))
 294       _mesa_debug(ctx, "glActiveTexture %s\n",
 295                   _mesa_lookup_enum_by_nr(texture));
 296
 297    if (texUnit >= ctx->Const.MaxTextureImageUnits) {
 298       _mesa_error(ctx, GL_INVALID_ENUM, "glActiveTexture(texture)");
 299       return;
 300    }
 301
 302    if (ctx->Texture.CurrentUnit == texUnit)
 303       return;
 304
 305    FLUSH_VERTICES(ctx, _NEW_TEXTURE);
 306
 307    ctx->Texture.CurrentUnit = texUnit;
 308    if (ctx->Transform.MatrixMode == GL_TEXTURE) {
 309       /* update current stack pointer */
 310       ctx->CurrentStack = &ctx->TextureMatrixStack[texUnit];
 311    }
 312
 313    if (ctx->Driver.ActiveTexture) {
 314       (*ctx->Driver.ActiveTexture)( ctx, (GLuint) texUnit );
 315    }
 316 }
 317
 318
 319 /* GL_ARB_multitexture */
 320 void GLAPIENTRY
 321 _mesa_ClientActiveTextureARB(GLenum texture)
 322 {
 323    GET_CURRENT_CONTEXT(ctx);
 324    GLuint texUnit = texture - GL_TEXTURE0;
 325    ASSERT_OUTSIDE_BEGIN_END(ctx);
 326
 327    if (texUnit >= ctx->Const.MaxTextureCoordUnits) {
 328       _mesa_error(ctx, GL_INVALID_ENUM, "glClientActiveTexture(texture)");
 329       return;
 330    }
 331
 332    FLUSH_VERTICES(ctx, _NEW_ARRAY);
 333    ctx->Array.ActiveTexture = texUnit;
 334 }
 335
 336
 337
 338 /**********************************************************************/
 339 /*****                    State management                        *****/
 340 /**********************************************************************/
 341
 342
 343 /**
 344  * \note This routine refers to derived texture attribute values to
 345  * compute the ENABLE_TEXMAT flags, but is only called on
 346  * _NEW_TEXTURE_MATRIX.  On changes to _NEW_TEXTURE, the ENABLE_TEXMAT
 347  * flags are updated by _mesa_update_textures(), below.
 348  *
 349  * \param ctx GL context.
 350  */
 351 static void
 352 update_texture_matrices( GLcontext *ctx )
 353 {
 354    GLuint u;
 355
 356    ctx->Texture._TexMatEnabled = 0x0;
 357
 358    for (u = 0; u < ctx->Const.MaxTextureCoordUnits; u++) {
 359       if (_math_matrix_is_dirty(ctx->TextureMatrixStack[u].Top)) {
 360          _math_matrix_analyse( ctx->TextureMatrixStack[u].Top );
 361
 362          if (ctx->Texture.Unit[u]._ReallyEnabled &&
 363              ctx->TextureMatrixStack[u].Top->type != MATRIX_IDENTITY)
 364             ctx->Texture._TexMatEnabled |= ENABLE_TEXMAT(u);
 365
 366          if (ctx->Driver.TextureMatrix)
 367             ctx->Driver.TextureMatrix( ctx, u, ctx->TextureMatrixStack[u].Top);
 368       }
 369    }
 370 }
 371
 372
 373 /**
 374  * Examine texture unit's combine/env state to update derived state.
 375  */
 376 static void
 377 update_tex_combine(GLcontext *ctx, struct gl_texture_unit *texUnit)
 378 {
 379    struct gl_tex_env_combine_state *combine;
 380
 381    /* Set the texUnit->_CurrentCombine field to point to the user's combiner
 382     * state, or the combiner state which is derived from traditional texenv
 383     * mode.
 384     */
 385    if (texUnit->EnvMode == GL_COMBINE ||
 386        texUnit->EnvMode == GL_COMBINE4_NV) {
 387       texUnit->_CurrentCombine = & texUnit->Combine;
 388    }
 389    else {
 390       const struct gl_texture_object *texObj = texUnit->_Current;
 391       GLenum format = texObj->Image[0][texObj->BaseLevel]->_BaseFormat;
 392       if (format == GL_COLOR_INDEX) {
 393          format = GL_RGBA;  /* a bit of a hack */
 394       }
 395       else if (format == GL_DEPTH_COMPONENT ||
 396                format == GL_DEPTH_STENCIL_EXT) {
 397          format = texObj->DepthMode;
 398       }
 399       calculate_derived_texenv(&texUnit->_EnvMode, texUnit->EnvMode, format);
 400       texUnit->_CurrentCombine = & texUnit->_EnvMode;
 401    }
 402
 403    combine = texUnit->_CurrentCombine;
 404
 405    /* Determine number of source RGB terms in the combiner function */
 406    switch (combine->ModeRGB) {
 407    case GL_REPLACE:
 408       combine->_NumArgsRGB = 1;
 409       break;
 410    case GL_ADD:
 411    case GL_ADD_SIGNED:
 412       if (texUnit->EnvMode == GL_COMBINE4_NV)
 413          combine->_NumArgsRGB = 4;
 414       else
 415          combine->_NumArgsRGB = 2;
 416       break;
 417    case GL_MODULATE:
 418    case GL_SUBTRACT:
 419    case GL_DOT3_RGB:
 420    case GL_DOT3_RGBA:
 421    case GL_DOT3_RGB_EXT:
 422    case GL_DOT3_RGBA_EXT:
 423       combine->_NumArgsRGB = 2;
 424       break;
 425    case GL_INTERPOLATE:
 426    case GL_MODULATE_ADD_ATI:
 427    case GL_MODULATE_SIGNED_ADD_ATI:
 428    case GL_MODULATE_SUBTRACT_ATI:
 429       combine->_NumArgsRGB = 3;
 430       break;
 431    case GL_BUMP_ENVMAP_ATI:
 432       /* no real arguments for this case */
 433       combine->_NumArgsRGB = 0;
 434       break;
 435    default:
 436       combine->_NumArgsRGB = 0;
 437       _mesa_problem(ctx, "invalid RGB combine mode in update_texture_state");
 438       return;
 439    }
 440
 441    /* Determine number of source Alpha terms in the combiner function */
 442    switch (combine->ModeA) {
 443    case GL_REPLACE:
 444       combine->_NumArgsA = 1;
 445       break;
 446    case GL_ADD:
 447    case GL_ADD_SIGNED:
 448       if (texUnit->EnvMode == GL_COMBINE4_NV)
 449          combine->_NumArgsA = 4;
 450       else
 451          combine->_NumArgsA = 2;
 452       break;
 453    case GL_MODULATE:
 454    case GL_SUBTRACT:
 455       combine->_NumArgsA = 2;
 456       break;
 457    case GL_INTERPOLATE:
 458    case GL_MODULATE_ADD_ATI:
 459    case GL_MODULATE_SIGNED_ADD_ATI:
 460    case GL_MODULATE_SUBTRACT_ATI:
 461       combine->_NumArgsA = 3;
 462       break;
 463    default:
 464       combine->_NumArgsA = 0;
 465       _mesa_problem(ctx, "invalid Alpha combine mode in update_texture_state");
 466       break;
 467    }
 468 }
 469
 470
 471 /**
 472  * \note This routine refers to derived texture matrix values to
 473  * compute the ENABLE_TEXMAT flags, but is only called on
 474  * _NEW_TEXTURE.  On changes to _NEW_TEXTURE_MATRIX, the ENABLE_TEXMAT
 475  * flags are updated by _mesa_update_texture_matrices, above.
 476  *
 477  * \param ctx GL context.
 478  */
 479 static void
 480 update_texture_state( GLcontext *ctx )
 481 {
 482    GLuint unit;
 483    struct gl_fragment_program *fprog = NULL;
 484    struct gl_vertex_program *vprog = NULL;
 485    GLbitfield enabledFragUnits = 0x0;
 486
 487    if (ctx->Shader.CurrentProgram &&
 488        ctx->Shader.CurrentProgram->LinkStatus) {
 489       fprog = ctx->Shader.CurrentProgram->FragmentProgram;
 490       vprog = ctx->Shader.CurrentProgram->VertexProgram;
 491    }
 492    else {
 493       if (ctx->FragmentProgram._Enabled) {
 494          fprog = ctx->FragmentProgram.Current;
 495       }
 496       if (ctx->VertexProgram._Enabled) {
 497          /* XXX enable this if/when non-shader vertex programs get
 498           * texture fetches:
 499          vprog = ctx->VertexProgram.Current;
 500          */
 501       }
 502    }
 503
 504    /* TODO: only set this if there are actual changes */
 505    ctx->NewState |= _NEW_TEXTURE;
 506
 507    ctx->Texture._EnabledUnits = 0x0;
 508    ctx->Texture._GenFlags = 0x0;
 509    ctx->Texture._TexMatEnabled = 0x0;
 510    ctx->Texture._TexGenEnabled = 0x0;
 511
 512    /*
 513     * Update texture unit state.
 514     */
 515    for (unit = 0; unit < ctx->Const.MaxTextureImageUnits; unit++) {
 516       struct gl_texture_unit *texUnit = &ctx->Texture.Unit[unit];
 517       GLbitfield enabledVertTargets = 0x0;
 518       GLbitfield enabledFragTargets = 0x0;
 519       GLbitfield enabledTargets = 0x0;
 520       GLuint texIndex;
 521
 522       /* Get the bitmask of texture target enables.
 523        * enableBits will be a mask of the TEXTURE_*_BIT flags indicating
 524        * which texture targets are enabled (fixed function) or referenced
 525        * by a fragment shader/program.  When multiple flags are set, we'll
 526        * settle on the one with highest priority (see below).
 527        */
 528       if (vprog) {
 529          enabledVertTargets |= vprog->Base.TexturesUsed[unit];
 530       }
 531
 532       if (fprog) {
 533          enabledFragTargets |= fprog->Base.TexturesUsed[unit];
 534       }
 535       else {
 536          /* fixed-function fragment program */
 537          enabledFragTargets |= texUnit->Enabled;
 538       }
 539
 540       enabledTargets = enabledVertTargets | enabledFragTargets;
 541
 542       texUnit->_ReallyEnabled = 0x0;
 543
 544       if (enabledTargets == 0x0) {
 545          /* neither vertex nor fragment processing uses this unit */
 546          continue;
 547       }
 548
 549       /* Look for the highest priority texture target that's enabled (or used
 550        * by the vert/frag shaders) and "complete".  That's the one we'll use
 551        * for texturing.  If we're using vert/frag program we're guaranteed
 552        * that bitcount(enabledBits) <= 1.
 553        * Note that the TEXTURE_x_INDEX values are in high to low priority.
 554        */
 555       for (texIndex = 0; texIndex < NUM_TEXTURE_TARGETS; texIndex++) {
 556          if (enabledTargets & (1 << texIndex)) {
 557             struct gl_texture_object *texObj = texUnit->CurrentTex[texIndex];
 558             if (!texObj->_Complete) {
 559                _mesa_test_texobj_completeness(ctx, texObj);
 560             }
 561             if (texObj->_Complete) {
 562                texUnit->_ReallyEnabled = 1 << texIndex;
 563                _mesa_reference_texobj(&texUnit->_Current, texObj);
 564                break;
 565             }
 566          }
 567       }
 568
 569       if (!texUnit->_ReallyEnabled) {
 570          if (fprog) {
 571             /* If we get here it means the shader is expecting a texture
 572              * object, but there isn't one (or it's incomplete).  Use the
 573              * fallback texture.
 574              */
 575             struct gl_texture_object *texObj = _mesa_get_fallback_texture(ctx);
 576             texUnit->_ReallyEnabled = 1 << TEXTURE_2D_INDEX;
 577             _mesa_reference_texobj(&texUnit->_Current, texObj);
 578          }
 579          else {
 580             /* fixed-function: texture unit is really disabled */
 581             continue;
 582          }
 583       }
 584
 585       /* if we get here, we know this texture unit is enabled */
 586
 587       ctx->Texture._EnabledUnits |= (1 << unit);
 588
 589       if (enabledFragTargets)
 590          enabledFragUnits |= (1 << unit);
 591
 592       update_tex_combine(ctx, texUnit);
 593    }
 594
 595
 596    /* Determine which texture coordinate sets are actually needed */
 597    if (fprog) {
 598       const GLuint coordMask = (1 << MAX_TEXTURE_COORD_UNITS) - 1;
 599       ctx->Texture._EnabledCoordUnits
 600          = (fprog->Base.InputsRead >> FRAG_ATTRIB_TEX0) & coordMask;
 601    }
 602    else {
 603       ctx->Texture._EnabledCoordUnits = enabledFragUnits;
 604    }
 605
 606    /* Setup texgen for those texture coordinate sets that are in use */
 607    for (unit = 0; unit < ctx->Const.MaxTextureCoordUnits; unit++) {
 608       struct gl_texture_unit *texUnit = &ctx->Texture.Unit[unit];
 609
 610       texUnit->_GenFlags = 0x0;
 611
 612       if (!(ctx->Texture._EnabledCoordUnits & (1 << unit)))
 613          continue;
 614
 615       if (texUnit->TexGenEnabled) {
 616          if (texUnit->TexGenEnabled & S_BIT) {
 617             texUnit->_GenFlags |= texUnit->GenS._ModeBit;
 618          }
 619          if (texUnit->TexGenEnabled & T_BIT) {
 620             texUnit->_GenFlags |= texUnit->GenT._ModeBit;
 621          }
 622          if (texUnit->TexGenEnabled & R_BIT) {
 623             texUnit->_GenFlags |= texUnit->GenR._ModeBit;
 624          }
 625          if (texUnit->TexGenEnabled & Q_BIT) {
 626             texUnit->_GenFlags |= texUnit->GenQ._ModeBit;
 627          }
 628
 629          ctx->Texture._TexGenEnabled |= ENABLE_TEXGEN(unit);
 630          ctx->Texture._GenFlags |= texUnit->_GenFlags;
 631       }
 632
 633       if (ctx->TextureMatrixStack[unit].Top->type != MATRIX_IDENTITY)
 634          ctx->Texture._TexMatEnabled |= ENABLE_TEXMAT(unit);
 635    }
 636 }
 637
 638
 639 /**
 640  * Update texture-related derived state.
 641  */
 642 void
 643 _mesa_update_texture( GLcontext *ctx, GLuint new_state )
 644 {
 645    if (new_state & _NEW_TEXTURE_MATRIX)
 646       update_texture_matrices( ctx );
 647
 648    if (new_state & (_NEW_TEXTURE | _NEW_PROGRAM))
 649       update_texture_state( ctx );
 650 }
 651
 652
 653 /**********************************************************************/
 654 /*****                      Initialization                        *****/
 655 /**********************************************************************/
 656
 657 /**
 658  * Allocate the proxy textures for the given context.
 659  *
 660  * \param ctx the context to allocate proxies for.
 661  *
 662  * \return GL_TRUE on success, or GL_FALSE on failure
 663  *
 664  * If run out of memory part way through the allocations, clean up and return
 665  * GL_FALSE.
 666  */
 667 static GLboolean
 668 alloc_proxy_textures( GLcontext *ctx )
 669 {
 670    static const GLenum targets[] = {
 671       GL_TEXTURE_1D,
 672       GL_TEXTURE_2D,
 673       GL_TEXTURE_3D,
 674       GL_TEXTURE_CUBE_MAP_ARB,
 675       GL_TEXTURE_RECTANGLE_NV,
 676       GL_TEXTURE_1D_ARRAY_EXT,
 677       GL_TEXTURE_2D_ARRAY_EXT
 678    };
 679    GLint tgt;
 680
 681    ASSERT(Elements(targets) == NUM_TEXTURE_TARGETS);
 682
 683    for (tgt = 0; tgt < NUM_TEXTURE_TARGETS; tgt++) {
 684       if (!(ctx->Texture.ProxyTex[tgt]
 685             = ctx->Driver.NewTextureObject(ctx, 0, targets[tgt]))) {
 686          /* out of memory, free what we did allocate */
 687          while (--tgt >= 0) {
 688             ctx->Driver.DeleteTexture(ctx, ctx->Texture.ProxyTex[tgt]);
 689          }
 690          return GL_FALSE;
 691       }
 692    }
 693
 694    assert(ctx->Texture.ProxyTex[0]->RefCount == 1); /* sanity check */
 695    return GL_TRUE;
 696 }
 697
 698
 699 /**
 700  * Initialize a texture unit.
 701  *
 702  * \param ctx GL context.
 703  * \param unit texture unit number to be initialized.
 704  */
 705 static void
 706 init_texture_unit( GLcontext *ctx, GLuint unit )
 707 {
 708    struct gl_texture_unit *texUnit = &ctx->Texture.Unit[unit];
 709    GLuint tex;
 710
 711    texUnit->EnvMode = GL_MODULATE;
 712    ASSIGN_4V( texUnit->EnvColor, 0.0, 0.0, 0.0, 0.0 );
 713
 714    texUnit->Combine = default_combine_state;
 715    texUnit->_EnvMode = default_combine_state;
 716    texUnit->_CurrentCombine = & texUnit->_EnvMode;
 717    texUnit->BumpTarget = GL_TEXTURE0;
 718
 719    texUnit->TexGenEnabled = 0x0;
 720    texUnit->GenS.Mode = GL_EYE_LINEAR;
 721    texUnit->GenT.Mode = GL_EYE_LINEAR;
 722    texUnit->GenR.Mode = GL_EYE_LINEAR;
 723    texUnit->GenQ.Mode = GL_EYE_LINEAR;
 724    texUnit->GenS._ModeBit = TEXGEN_EYE_LINEAR;
 725    texUnit->GenT._ModeBit = TEXGEN_EYE_LINEAR;
 726    texUnit->GenR._ModeBit = TEXGEN_EYE_LINEAR;
 727    texUnit->GenQ._ModeBit = TEXGEN_EYE_LINEAR;
 728
 729    /* Yes, these plane coefficients are correct! */
 730    ASSIGN_4V( texUnit->GenS.ObjectPlane, 1.0, 0.0, 0.0, 0.0 );
 731    ASSIGN_4V( texUnit->GenT.ObjectPlane, 0.0, 1.0, 0.0, 0.0 );
 732    ASSIGN_4V( texUnit->GenR.ObjectPlane, 0.0, 0.0, 0.0, 0.0 );
 733    ASSIGN_4V( texUnit->GenQ.ObjectPlane, 0.0, 0.0, 0.0, 0.0 );
 734    ASSIGN_4V( texUnit->GenS.EyePlane, 1.0, 0.0, 0.0, 0.0 );
 735    ASSIGN_4V( texUnit->GenT.EyePlane, 0.0, 1.0, 0.0, 0.0 );
 736    ASSIGN_4V( texUnit->GenR.EyePlane, 0.0, 0.0, 0.0, 0.0 );
 737    ASSIGN_4V( texUnit->GenQ.EyePlane, 0.0, 0.0, 0.0, 0.0 );
 738
 739    /* no mention of this in spec, but maybe id matrix expected? */
 740    ASSIGN_4V( texUnit->RotMatrix, 1.0, 0.0, 0.0, 1.0 );
 741
 742    /* initialize current texture object ptrs to the shared default objects */
 743    for (tex = 0; tex < NUM_TEXTURE_TARGETS; tex++) {
 744       _mesa_reference_texobj(&texUnit->CurrentTex[tex],
 745                              ctx->Shared->DefaultTex[tex]);
 746    }
 747 }
 748
 749
 750 /**
 751  * Initialize texture state for the given context.
 752  */
 753 GLboolean
 754 _mesa_init_texture(GLcontext *ctx)
 755 {
 756    GLuint u;
 757
 758    /* Texture group */
 759    ctx->Texture.CurrentUnit = 0;      /* multitexture */
 760    ctx->Texture._EnabledUnits = 0x0;
 761    ctx->Texture.SharedPalette = GL_FALSE;
 762 #if FEATURE_colortable
 763    _mesa_init_colortable(&ctx->Texture.Palette);
 764 #endif
 765
 766    for (u = 0; u < MAX_TEXTURE_UNITS; u++)
 767       init_texture_unit(ctx, u);
 768
 769    /* After we're done initializing the context's texture state the default
 770     * texture objects' refcounts should be at least MAX_TEXTURE_UNITS + 1.
 771     */
 772    assert(ctx->Shared->DefaultTex[TEXTURE_1D_INDEX]->RefCount
 773           >= MAX_TEXTURE_UNITS + 1);
 774
 775    /* Allocate proxy textures */
 776    if (!alloc_proxy_textures( ctx ))
 777       return GL_FALSE;
 778
 779    return GL_TRUE;
 780 }
 781
 782
 783 /**
 784  * Free dynamically-allocted texture data attached to the given context.
 785  */
 786 void
 787 _mesa_free_texture_data(GLcontext *ctx)
 788 {
 789    GLuint u, tgt;
 790
 791    /* unreference current textures */
 792    for (u = 0; u < MAX_TEXTURE_IMAGE_UNITS; u++) {
 793       /* The _Current texture could account for another reference */
 794       _mesa_reference_texobj(&ctx->Texture.Unit[u]._Current, NULL);
 795
 796       for (tgt = 0; tgt < NUM_TEXTURE_TARGETS; tgt++) {
 797          _mesa_reference_texobj(&ctx->Texture.Unit[u].CurrentTex[tgt], NULL);
 798       }
 799    }
 800
 801    /* Free proxy texture objects */
 802    for (tgt = 0; tgt < NUM_TEXTURE_TARGETS; tgt++)
 803       ctx->Driver.DeleteTexture(ctx, ctx->Texture.ProxyTex[tgt]);
 804
 805 #if FEATURE_colortable
 806    for (u = 0; u < MAX_TEXTURE_IMAGE_UNITS; u++)
 807       _mesa_free_colortable_data(&ctx->Texture.Unit[u].ColorTable);
 808 #endif
 809 }
 810
 811
 812 /**
 813  * Update the default texture objects in the given context to reference those
 814  * specified in the shared state and release those referencing the old
 815  * shared state.
 816  */
 817 void
 818 _mesa_update_default_objects_texture(GLcontext *ctx)
 819 {
 820    GLuint u, tex;
 821
 822    for (u = 0; u < MAX_TEXTURE_UNITS; u++) {
 823       struct gl_texture_unit *texUnit = &ctx->Texture.Unit[u];
 824       for (tex = 0; tex < NUM_TEXTURE_TARGETS; tex++) {
 825          _mesa_reference_texobj(&texUnit->CurrentTex[tex],
 826                                 ctx->Shared->DefaultTex[tex]);
 827       }
 828    }
 829 }