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 #include "colortab.h"
  35 #include "context.h"
  36 #include "enums.h"
  37 #include "macros.h"
  38 #include "texobj.h"
  39 #include "teximage.h"
  40 #include "texstate.h"
  41 #include "mtypes.h"
  42
  43
  44
  45 /**
  46  * Default texture combine environment state.  This is used to initialize
  47  * a context's texture units and as the basis for converting "classic"
  48  * texture environmnets to ARB_texture_env_combine style values.
  49  */
  50 static const struct gl_tex_env_combine_state default_combine_state = {
  51    GL_MODULATE, GL_MODULATE,
  52    { GL_TEXTURE, GL_PREVIOUS, GL_CONSTANT, GL_CONSTANT },
  53    { GL_TEXTURE, GL_PREVIOUS, GL_CONSTANT, GL_CONSTANT },
  54    { GL_SRC_COLOR, GL_SRC_COLOR, GL_SRC_ALPHA, GL_SRC_ALPHA },
  55    { GL_SRC_ALPHA, GL_SRC_ALPHA, GL_SRC_ALPHA, GL_SRC_ALPHA },
  56    0, 0,
  57    2, 2
  58 };
  59
  60
  61
  62 /**
  63  * Used by glXCopyContext to copy texture state from one context to another.
  64  */
  65 void
  66 _mesa_copy_texture_state( const GLcontext *src, GLcontext *dst )
  67 {
  68    GLuint u, tex;
  69
  70    ASSERT(src);
  71    ASSERT(dst);
  72
  73    dst->Texture.CurrentUnit = src->Texture.CurrentUnit;
  74    dst->Texture._GenFlags = src->Texture._GenFlags;
  75    dst->Texture._TexGenEnabled = src->Texture._TexGenEnabled;
  76    dst->Texture._TexMatEnabled = src->Texture._TexMatEnabled;
  77    dst->Texture.SharedPalette = src->Texture.SharedPalette;
  78
  79    /* per-unit state */
  80    for (u = 0; u < src->Const.MaxCombinedTextureImageUnits; u++) {
  81       dst->Texture.Unit[u].Enabled = src->Texture.Unit[u].Enabled;
  82       dst->Texture.Unit[u].EnvMode = src->Texture.Unit[u].EnvMode;
  83       COPY_4V(dst->Texture.Unit[u].EnvColor, src->Texture.Unit[u].EnvColor);
  84       dst->Texture.Unit[u].TexGenEnabled = src->Texture.Unit[u].TexGenEnabled;
  85       dst->Texture.Unit[u].GenS = src->Texture.Unit[u].GenS;
  86       dst->Texture.Unit[u].GenT = src->Texture.Unit[u].GenT;
  87       dst->Texture.Unit[u].GenR = src->Texture.Unit[u].GenR;
  88       dst->Texture.Unit[u].GenQ = src->Texture.Unit[u].GenQ;
  89       dst->Texture.Unit[u].LodBias = src->Texture.Unit[u].LodBias;
  90
  91       /* GL_EXT_texture_env_combine */
  92       dst->Texture.Unit[u].Combine = src->Texture.Unit[u].Combine;
  93
  94       /* GL_ATI_envmap_bumpmap - need this? */
  95       dst->Texture.Unit[u].BumpTarget = src->Texture.Unit[u].BumpTarget;
  96       COPY_4V(dst->Texture.Unit[u].RotMatrix, src->Texture.Unit[u].RotMatrix);
  97
  98       /*
  99        * XXX strictly speaking, we should compare texture names/ids and
 100        * bind textures in the dest context according to id.  For now, only
 101        * copy bindings if the contexts share the same pool of textures to
 102        * avoid refcounting bugs.
 103        */
 104       if (dst->Shared == src->Shared) {
 105          /* copy texture object bindings, not contents of texture objects */
 106          _mesa_lock_context_textures(dst);
 107
 108          for (tex = 0; tex < NUM_TEXTURE_TARGETS; tex++) {
 109             _mesa_reference_texobj(&dst->Texture.Unit[u].CurrentTex[tex],
 110                                    src->Texture.Unit[u].CurrentTex[tex]);
 111          }
 112          _mesa_unlock_context_textures(dst);
 113       }
 114    }
 115 }
 116
 117
 118 /*
 119  * For debugging
 120  */
 121 void
 122 _mesa_print_texunit_state( GLcontext *ctx, GLuint unit )
 123 {
 124    const struct gl_texture_unit *texUnit = ctx->Texture.Unit + unit;
 125    printf("Texture Unit %d\n", unit);
 126    printf("  GL_TEXTURE_ENV_MODE = %s\n", _mesa_lookup_enum_by_nr(texUnit->EnvMode));
 127    printf("  GL_COMBINE_RGB = %s\n", _mesa_lookup_enum_by_nr(texUnit->Combine.ModeRGB));
 128    printf("  GL_COMBINE_ALPHA = %s\n", _mesa_lookup_enum_by_nr(texUnit->Combine.ModeA));
 129    printf("  GL_SOURCE0_RGB = %s\n", _mesa_lookup_enum_by_nr(texUnit->Combine.SourceRGB[0]));
 130    printf("  GL_SOURCE1_RGB = %s\n", _mesa_lookup_enum_by_nr(texUnit->Combine.SourceRGB[1]));
 131    printf("  GL_SOURCE2_RGB = %s\n", _mesa_lookup_enum_by_nr(texUnit->Combine.SourceRGB[2]));
 132    printf("  GL_SOURCE0_ALPHA = %s\n", _mesa_lookup_enum_by_nr(texUnit->Combine.SourceA[0]));
 133    printf("  GL_SOURCE1_ALPHA = %s\n", _mesa_lookup_enum_by_nr(texUnit->Combine.SourceA[1]));
 134    printf("  GL_SOURCE2_ALPHA = %s\n", _mesa_lookup_enum_by_nr(texUnit->Combine.SourceA[2]));
 135    printf("  GL_OPERAND0_RGB = %s\n", _mesa_lookup_enum_by_nr(texUnit->Combine.OperandRGB[0]));
 136    printf("  GL_OPERAND1_RGB = %s\n", _mesa_lookup_enum_by_nr(texUnit->Combine.OperandRGB[1]));
 137    printf("  GL_OPERAND2_RGB = %s\n", _mesa_lookup_enum_by_nr(texUnit->Combine.OperandRGB[2]));
 138    printf("  GL_OPERAND0_ALPHA = %s\n", _mesa_lookup_enum_by_nr(texUnit->Combine.OperandA[0]));
 139    printf("  GL_OPERAND1_ALPHA = %s\n", _mesa_lookup_enum_by_nr(texUnit->Combine.OperandA[1]));
 140    printf("  GL_OPERAND2_ALPHA = %s\n", _mesa_lookup_enum_by_nr(texUnit->Combine.OperandA[2]));
 141    printf("  GL_RGB_SCALE = %d\n", 1 << texUnit->Combine.ScaleShiftRGB);
 142    printf("  GL_ALPHA_SCALE = %d\n", 1 << texUnit->Combine.ScaleShiftA);
 143    printf("  GL_TEXTURE_ENV_COLOR = (%f, %f, %f, %f)\n", texUnit->EnvColor[0], texUnit->EnvColor[1], texUnit->EnvColor[2], texUnit->EnvColor[3]);
 144 }
 145
 146
 147
 148 /**********************************************************************/
 149 /*                       Texture Environment                          */
 150 /**********************************************************************/
 151
 152 /**
 153  * Convert "classic" texture environment to ARB_texture_env_combine style
 154  * environments.
 155  *
 156  * \param state  texture_env_combine state vector to be filled-in.
 157  * \param mode   Classic texture environment mode (i.e., \c GL_REPLACE,
 158  *               \c GL_BLEND, \c GL_DECAL, etc.).
 159  * \param texBaseFormat  Base format of the texture associated with the
 160  *               texture unit.
 161  */
 162 static void
 163 calculate_derived_texenv( struct gl_tex_env_combine_state *state,
 164                           GLenum mode, GLenum texBaseFormat )
 165 {
 166    GLenum mode_rgb;
 167    GLenum mode_a;
 168
 169    *state = default_combine_state;
 170
 171    switch (texBaseFormat) {
 172    case GL_ALPHA:
 173       state->SourceRGB[0] = GL_PREVIOUS;
 174       break;
 175
 176    case GL_LUMINANCE_ALPHA:
 177    case GL_INTENSITY:
 178    case GL_RGBA:
 179       break;
 180
 181    case GL_LUMINANCE:
 182    case GL_RGB:
 183    case GL_YCBCR_MESA:
 184    case GL_DUDV_ATI:
 185       state->SourceA[0] = GL_PREVIOUS;
 186       break;
 187
 188    default:
 189       _mesa_problem(NULL,
 190                     "Invalid texBaseFormat 0x%x in calculate_derived_texenv",
 191                     texBaseFormat);
 192       return;
 193    }
 194
 195    if (mode == GL_REPLACE_EXT)
 196       mode = GL_REPLACE;
 197
 198    switch (mode) {
 199    case GL_REPLACE:
 200    case GL_MODULATE:
 201       mode_rgb = (texBaseFormat == GL_ALPHA) ? GL_REPLACE : mode;
 202       mode_a   = mode;
 203       break;
 204
 205    case GL_DECAL:
 206       mode_rgb = GL_INTERPOLATE;
 207       mode_a   = GL_REPLACE;
 208
 209       state->SourceA[0] = GL_PREVIOUS;
 210
 211       /* Having alpha / luminance / intensity textures replace using the
 212        * incoming fragment color matches the definition in NV_texture_shader.
 213        * The 1.5 spec simply marks these as "undefined".
 214        */
 215       switch (texBaseFormat) {
 216       case GL_ALPHA:
 217       case GL_LUMINANCE:
 218       case GL_LUMINANCE_ALPHA:
 219       case GL_INTENSITY:
 220          state->SourceRGB[0] = GL_PREVIOUS;
 221          break;
 222       case GL_RGB:
 223       case GL_YCBCR_MESA:
 224       case GL_DUDV_ATI:
 225          mode_rgb = GL_REPLACE;
 226          break;
 227       case GL_RGBA:
 228          state->SourceRGB[2] = GL_TEXTURE;
 229          break;
 230       }
 231       break;
 232
 233    case GL_BLEND:
 234       mode_rgb = GL_INTERPOLATE;
 235       mode_a   = GL_MODULATE;
 236
 237       switch (texBaseFormat) {
 238       case GL_ALPHA:
 239          mode_rgb = GL_REPLACE;
 240          break;
 241       case GL_INTENSITY:
 242          mode_a = GL_INTERPOLATE;
 243          state->SourceA[0] = GL_CONSTANT;
 244          state->OperandA[2] = GL_SRC_ALPHA;
 245          /* FALLTHROUGH */
 246       case GL_LUMINANCE:
 247       case GL_RGB:
 248       case GL_LUMINANCE_ALPHA:
 249       case GL_RGBA:
 250       case GL_YCBCR_MESA:
 251       case GL_DUDV_ATI:
 252          state->SourceRGB[2] = GL_TEXTURE;
 253          state->SourceA[2]   = GL_TEXTURE;
 254          state->SourceRGB[0] = GL_CONSTANT;
 255          state->OperandRGB[2] = GL_SRC_COLOR;
 256          break;
 257       }
 258       break;
 259
 260    case GL_ADD:
 261       mode_rgb = (texBaseFormat == GL_ALPHA) ? GL_REPLACE : GL_ADD;
 262       mode_a   = (texBaseFormat == GL_INTENSITY) ? GL_ADD : GL_MODULATE;
 263       break;
 264
 265    default:
 266       _mesa_problem(NULL,
 267                     "Invalid texture env mode 0x%x in calculate_derived_texenv",
 268                     mode);
 269       return;
 270    }
 271
 272    state->ModeRGB = (state->SourceRGB[0] != GL_PREVIOUS)
 273        ? mode_rgb : GL_REPLACE;
 274    state->ModeA   = (state->SourceA[0]   != GL_PREVIOUS)
 275        ? mode_a   : GL_REPLACE;
 276 }
 277
 278
 279
 280
 281 /* GL_ARB_multitexture */
 282 void GLAPIENTRY
 283 _mesa_ActiveTextureARB(GLenum texture)
 284 {
 285    const GLuint texUnit = texture - GL_TEXTURE0;
 286    GLuint k;
 287    GET_CURRENT_CONTEXT(ctx);
 288
 289    /* See OpenGL spec for glActiveTexture: */
 290    k = MAX2(ctx->Const.MaxCombinedTextureImageUnits,
 291             ctx->Const.MaxTextureCoordUnits);
 292
 293    ASSERT(k <= Elements(ctx->Texture.Unit));
 294
 295    ASSERT_OUTSIDE_BEGIN_END(ctx);
 296
 297    if (MESA_VERBOSE & (VERBOSE_API|VERBOSE_TEXTURE))
 298       _mesa_debug(ctx, "glActiveTexture %s\n",
 299                   _mesa_lookup_enum_by_nr(texture));
 300
 301    if (texUnit >= k) {
 302       _mesa_error(ctx, GL_INVALID_ENUM, "glActiveTexture(texture=%s)",
 303                   _mesa_lookup_enum_by_nr(texture));
 304       return;
 305    }
 306
 307    if (ctx->Texture.CurrentUnit == texUnit)
 308       return;
 309
 310    FLUSH_VERTICES(ctx, _NEW_TEXTURE);
 311
 312    ctx->Texture.CurrentUnit = texUnit;
 313    if (ctx->Transform.MatrixMode == GL_TEXTURE) {
 314       /* update current stack pointer */
 315       ctx->CurrentStack = &ctx->TextureMatrixStack[texUnit];
 316    }
 317 }
 318
 319
 320 /* GL_ARB_multitexture */
 321 void GLAPIENTRY
 322 _mesa_ClientActiveTextureARB(GLenum texture)
 323 {
 324    GET_CURRENT_CONTEXT(ctx);
 325    GLuint texUnit = texture - GL_TEXTURE0;
 326    ASSERT_OUTSIDE_BEGIN_END(ctx);
 327
 328    if (MESA_VERBOSE & (VERBOSE_API | VERBOSE_TEXTURE))
 329       _mesa_debug(ctx, "glClientActiveTexture %s\n",
 330                   _mesa_lookup_enum_by_nr(texture));
 331
 332    if (texUnit >= ctx->Const.MaxTextureCoordUnits) {
 333       _mesa_error(ctx, GL_INVALID_ENUM, "glClientActiveTexture(texture)");
 334       return;
 335    }
 336
 337    if (ctx->Array.ActiveTexture == texUnit)
 338       return;
 339
 340    FLUSH_VERTICES(ctx, _NEW_ARRAY);
 341    ctx->Array.ActiveTexture = texUnit;
 342 }
 343
 344
 345
 346 /**********************************************************************/
 347 /*****                    State management                        *****/
 348 /**********************************************************************/
 349
 350
 351 /**
 352  * \note This routine refers to derived texture attribute values to
 353  * compute the ENABLE_TEXMAT flags, but is only called on
 354  * _NEW_TEXTURE_MATRIX.  On changes to _NEW_TEXTURE, the ENABLE_TEXMAT
 355  * flags are updated by _mesa_update_textures(), below.
 356  *
 357  * \param ctx GL context.
 358  */
 359 static void
 360 update_texture_matrices( GLcontext *ctx )
 361 {
 362    GLuint u;
 363
 364    ctx->Texture._TexMatEnabled = 0x0;
 365
 366    for (u = 0; u < ctx->Const.MaxTextureCoordUnits; u++) {
 367       ASSERT(u < Elements(ctx->TextureMatrixStack));
 368       if (_math_matrix_is_dirty(ctx->TextureMatrixStack[u].Top)) {
 369          _math_matrix_analyse( ctx->TextureMatrixStack[u].Top );
 370
 371          if (ctx->Texture.Unit[u]._ReallyEnabled &&
 372              ctx->TextureMatrixStack[u].Top->type != MATRIX_IDENTITY)
 373             ctx->Texture._TexMatEnabled |= ENABLE_TEXMAT(u);
 374       }
 375    }
 376 }
 377
 378
 379 /**
 380  * Examine texture unit's combine/env state to update derived state.
 381  */
 382 static void
 383 update_tex_combine(GLcontext *ctx, struct gl_texture_unit *texUnit)
 384 {
 385    struct gl_tex_env_combine_state *combine;
 386
 387    /* Set the texUnit->_CurrentCombine field to point to the user's combiner
 388     * state, or the combiner state which is derived from traditional texenv
 389     * mode.
 390     */
 391    if (texUnit->EnvMode == GL_COMBINE ||
 392        texUnit->EnvMode == GL_COMBINE4_NV) {
 393       texUnit->_CurrentCombine = & texUnit->Combine;
 394    }
 395    else {
 396       const struct gl_texture_object *texObj = texUnit->_Current;
 397       GLenum format = texObj->Image[0][texObj->BaseLevel]->_BaseFormat;
 398       if (format == GL_COLOR_INDEX) {
 399          format = GL_RGBA;  /* a bit of a hack */
 400       }
 401       else if (format == GL_DEPTH_COMPONENT ||
 402                format == GL_DEPTH_STENCIL_EXT) {
 403          format = texObj->DepthMode;
 404       }
 405       calculate_derived_texenv(&texUnit->_EnvMode, texUnit->EnvMode, format);
 406       texUnit->_CurrentCombine = & texUnit->_EnvMode;
 407    }
 408
 409    combine = texUnit->_CurrentCombine;
 410
 411    /* Determine number of source RGB terms in the combiner function */
 412    switch (combine->ModeRGB) {
 413    case GL_REPLACE:
 414       combine->_NumArgsRGB = 1;
 415       break;
 416    case GL_ADD:
 417    case GL_ADD_SIGNED:
 418       if (texUnit->EnvMode == GL_COMBINE4_NV)
 419          combine->_NumArgsRGB = 4;
 420       else
 421          combine->_NumArgsRGB = 2;
 422       break;
 423    case GL_MODULATE:
 424    case GL_SUBTRACT:
 425    case GL_DOT3_RGB:
 426    case GL_DOT3_RGBA:
 427    case GL_DOT3_RGB_EXT:
 428    case GL_DOT3_RGBA_EXT:
 429       combine->_NumArgsRGB = 2;
 430       break;
 431    case GL_INTERPOLATE:
 432    case GL_MODULATE_ADD_ATI:
 433    case GL_MODULATE_SIGNED_ADD_ATI:
 434    case GL_MODULATE_SUBTRACT_ATI:
 435       combine->_NumArgsRGB = 3;
 436       break;
 437    case GL_BUMP_ENVMAP_ATI:
 438       /* no real arguments for this case */
 439       combine->_NumArgsRGB = 0;
 440       break;
 441    default:
 442       combine->_NumArgsRGB = 0;
 443       _mesa_problem(ctx, "invalid RGB combine mode in update_texture_state");
 444       return;
 445    }
 446
 447    /* Determine number of source Alpha terms in the combiner function */
 448    switch (combine->ModeA) {
 449    case GL_REPLACE:
 450       combine->_NumArgsA = 1;
 451       break;
 452    case GL_ADD:
 453    case GL_ADD_SIGNED:
 454       if (texUnit->EnvMode == GL_COMBINE4_NV)
 455          combine->_NumArgsA = 4;
 456       else
 457          combine->_NumArgsA = 2;
 458       break;
 459    case GL_MODULATE:
 460    case GL_SUBTRACT:
 461       combine->_NumArgsA = 2;
 462       break;
 463    case GL_INTERPOLATE:
 464    case GL_MODULATE_ADD_ATI:
 465    case GL_MODULATE_SIGNED_ADD_ATI:
 466    case GL_MODULATE_SUBTRACT_ATI:
 467       combine->_NumArgsA = 3;
 468       break;
 469    default:
 470       combine->_NumArgsA = 0;
 471       _mesa_problem(ctx, "invalid Alpha combine mode in update_texture_state");
 472       break;
 473    }
 474 }
 475
 476
 477 /**
 478  * \note This routine refers to derived texture matrix values to
 479  * compute the ENABLE_TEXMAT flags, but is only called on
 480  * _NEW_TEXTURE.  On changes to _NEW_TEXTURE_MATRIX, the ENABLE_TEXMAT
 481  * flags are updated by _mesa_update_texture_matrices, above.
 482  *
 483  * \param ctx GL context.
 484  */
 485 static void
 486 update_texture_state( GLcontext *ctx )
 487 {
 488    GLuint unit;
 489    struct gl_fragment_program *fprog = NULL;
 490    struct gl_vertex_program *vprog = NULL;
 491    GLbitfield enabledFragUnits = 0x0;
 492
 493    if (ctx->Shader.CurrentProgram &&
 494        ctx->Shader.CurrentProgram->LinkStatus) {
 495       fprog = ctx->Shader.CurrentProgram->FragmentProgram;
 496       vprog = ctx->Shader.CurrentProgram->VertexProgram;
 497    }
 498    else {
 499       if (ctx->FragmentProgram._Enabled) {
 500          fprog = ctx->FragmentProgram.Current;
 501       }
 502       if (ctx->VertexProgram._Enabled) {
 503          /* XXX enable this if/when non-shader vertex programs get
 504           * texture fetches:
 505          vprog = ctx->VertexProgram.Current;
 506          */
 507       }
 508    }
 509
 510    /* TODO: only set this if there are actual changes */
 511    ctx->NewState |= _NEW_TEXTURE;
 512
 513    ctx->Texture._EnabledUnits = 0x0;
 514    ctx->Texture._GenFlags = 0x0;
 515    ctx->Texture._TexMatEnabled = 0x0;
 516    ctx->Texture._TexGenEnabled = 0x0;
 517
 518    /*
 519     * Update texture unit state.
 520     */
 521    for (unit = 0; unit < ctx->Const.MaxCombinedTextureImageUnits; unit++) {
 522       struct gl_texture_unit *texUnit = &ctx->Texture.Unit[unit];
 523       GLbitfield enabledVertTargets = 0x0;
 524       GLbitfield enabledFragTargets = 0x0;
 525       GLbitfield enabledTargets = 0x0;
 526       GLuint texIndex;
 527
 528       /* Get the bitmask of texture target enables.
 529        * enableBits will be a mask of the TEXTURE_*_BIT flags indicating
 530        * which texture targets are enabled (fixed function) or referenced
 531        * by a fragment shader/program.  When multiple flags are set, we'll
 532        * settle on the one with highest priority (see below).
 533        */
 534       if (vprog) {
 535          enabledVertTargets |= vprog->Base.TexturesUsed[unit];
 536       }
 537
 538       if (fprog) {
 539          enabledFragTargets |= fprog->Base.TexturesUsed[unit];
 540       }
 541       else {
 542          /* fixed-function fragment program */
 543          enabledFragTargets |= texUnit->Enabled;
 544       }
 545
 546       enabledTargets = enabledVertTargets | enabledFragTargets;
 547
 548       texUnit->_ReallyEnabled = 0x0;
 549
 550       if (enabledTargets == 0x0) {
 551          /* neither vertex nor fragment processing uses this unit */
 552          continue;
 553       }
 554
 555       /* Look for the highest priority texture target that's enabled (or used
 556        * by the vert/frag shaders) and "complete".  That's the one we'll use
 557        * for texturing.  If we're using vert/frag program we're guaranteed
 558        * that bitcount(enabledBits) <= 1.
 559        * Note that the TEXTURE_x_INDEX values are in high to low priority.
 560        */
 561       for (texIndex = 0; texIndex < NUM_TEXTURE_TARGETS; texIndex++) {
 562          if (enabledTargets & (1 << texIndex)) {
 563             struct gl_texture_object *texObj = texUnit->CurrentTex[texIndex];
 564             if (!texObj->_Complete) {
 565                _mesa_test_texobj_completeness(ctx, texObj);
 566             }
 567             if (texObj->_Complete) {
 568                texUnit->_ReallyEnabled = 1 << texIndex;
 569                _mesa_reference_texobj(&texUnit->_Current, texObj);
 570                break;
 571             }
 572          }
 573       }
 574
 575       if (!texUnit->_ReallyEnabled) {
 576          if (fprog) {
 577             /* If we get here it means the shader is expecting a texture
 578              * object, but there isn't one (or it's incomplete).  Use the
 579              * fallback texture.
 580              */
 581             struct gl_texture_object *texObj = _mesa_get_fallback_texture(ctx);
 582             texUnit->_ReallyEnabled = 1 << TEXTURE_2D_INDEX;
 583             _mesa_reference_texobj(&texUnit->_Current, texObj);
 584          }
 585          else {
 586             /* fixed-function: texture unit is really disabled */
 587             continue;
 588          }
 589       }
 590
 591       /* if we get here, we know this texture unit is enabled */
 592
 593       ctx->Texture._EnabledUnits |= (1 << unit);
 594
 595       if (enabledFragTargets)
 596          enabledFragUnits |= (1 << unit);
 597
 598       update_tex_combine(ctx, texUnit);
 599    }
 600
 601
 602    /* Determine which texture coordinate sets are actually needed */
 603    if (fprog) {
 604       const GLuint coordMask = (1 << MAX_TEXTURE_COORD_UNITS) - 1;
 605       ctx->Texture._EnabledCoordUnits
 606          = (fprog->Base.InputsRead >> FRAG_ATTRIB_TEX0) & coordMask;
 607    }
 608    else {
 609       ctx->Texture._EnabledCoordUnits = enabledFragUnits;
 610    }
 611
 612    /* Setup texgen for those texture coordinate sets that are in use */
 613    for (unit = 0; unit < ctx->Const.MaxTextureCoordUnits; unit++) {
 614       struct gl_texture_unit *texUnit = &ctx->Texture.Unit[unit];
 615
 616       texUnit->_GenFlags = 0x0;
 617
 618       if (!(ctx->Texture._EnabledCoordUnits & (1 << unit)))
 619          continue;
 620
 621       if (texUnit->TexGenEnabled) {
 622          if (texUnit->TexGenEnabled & S_BIT) {
 623             texUnit->_GenFlags |= texUnit->GenS._ModeBit;
 624          }
 625          if (texUnit->TexGenEnabled & T_BIT) {
 626             texUnit->_GenFlags |= texUnit->GenT._ModeBit;
 627          }
 628          if (texUnit->TexGenEnabled & R_BIT) {
 629             texUnit->_GenFlags |= texUnit->GenR._ModeBit;
 630          }
 631          if (texUnit->TexGenEnabled & Q_BIT) {
 632             texUnit->_GenFlags |= texUnit->GenQ._ModeBit;
 633          }
 634
 635          ctx->Texture._TexGenEnabled |= ENABLE_TEXGEN(unit);
 636          ctx->Texture._GenFlags |= texUnit->_GenFlags;
 637       }
 638
 639       ASSERT(unit < Elements(ctx->TextureMatrixStack));
 640       if (ctx->TextureMatrixStack[unit].Top->type != MATRIX_IDENTITY)
 641          ctx->Texture._TexMatEnabled |= ENABLE_TEXMAT(unit);
 642    }
 643 }
 644
 645
 646 /**
 647  * Update texture-related derived state.
 648  */
 649 void
 650 _mesa_update_texture( GLcontext *ctx, GLuint new_state )
 651 {
 652    if (new_state & _NEW_TEXTURE_MATRIX)
 653       update_texture_matrices( ctx );
 654
 655    if (new_state & (_NEW_TEXTURE | _NEW_PROGRAM))
 656       update_texture_state( ctx );
 657 }
 658
 659
 660 /**********************************************************************/
 661 /*****                      Initialization                        *****/
 662 /**********************************************************************/
 663
 664 /**
 665  * Allocate the proxy textures for the given context.
 666  *
 667  * \param ctx the context to allocate proxies for.
 668  *
 669  * \return GL_TRUE on success, or GL_FALSE on failure
 670  *
 671  * If run out of memory part way through the allocations, clean up and return
 672  * GL_FALSE.
 673  */
 674 static GLboolean
 675 alloc_proxy_textures( GLcontext *ctx )
 676 {
 677    static const GLenum targets[] = {
 678       GL_TEXTURE_1D,
 679       GL_TEXTURE_2D,
 680       GL_TEXTURE_3D,
 681       GL_TEXTURE_CUBE_MAP_ARB,
 682       GL_TEXTURE_RECTANGLE_NV,
 683       GL_TEXTURE_1D_ARRAY_EXT,
 684       GL_TEXTURE_2D_ARRAY_EXT
 685    };
 686    GLint tgt;
 687
 688    ASSERT(Elements(targets) == NUM_TEXTURE_TARGETS);
 689
 690    for (tgt = 0; tgt < NUM_TEXTURE_TARGETS; tgt++) {
 691       if (!(ctx->Texture.ProxyTex[tgt]
 692             = ctx->Driver.NewTextureObject(ctx, 0, targets[tgt]))) {
 693          /* out of memory, free what we did allocate */
 694          while (--tgt >= 0) {
 695             ctx->Driver.DeleteTexture(ctx, ctx->Texture.ProxyTex[tgt]);
 696          }
 697          return GL_FALSE;
 698       }
 699    }
 700
 701    assert(ctx->Texture.ProxyTex[0]->RefCount == 1); /* sanity check */
 702    return GL_TRUE;
 703 }
 704
 705
 706 /**
 707  * Initialize a texture unit.
 708  *
 709  * \param ctx GL context.
 710  * \param unit texture unit number to be initialized.
 711  */
 712 static void
 713 init_texture_unit( GLcontext *ctx, GLuint unit )
 714 {
 715    struct gl_texture_unit *texUnit = &ctx->Texture.Unit[unit];
 716    GLuint tex;
 717
 718    texUnit->EnvMode = GL_MODULATE;
 719    ASSIGN_4V( texUnit->EnvColor, 0.0, 0.0, 0.0, 0.0 );
 720
 721    texUnit->Combine = default_combine_state;
 722    texUnit->_EnvMode = default_combine_state;
 723    texUnit->_CurrentCombine = & texUnit->_EnvMode;
 724    texUnit->BumpTarget = GL_TEXTURE0;
 725
 726    texUnit->TexGenEnabled = 0x0;
 727    texUnit->GenS.Mode = GL_EYE_LINEAR;
 728    texUnit->GenT.Mode = GL_EYE_LINEAR;
 729    texUnit->GenR.Mode = GL_EYE_LINEAR;
 730    texUnit->GenQ.Mode = GL_EYE_LINEAR;
 731    texUnit->GenS._ModeBit = TEXGEN_EYE_LINEAR;
 732    texUnit->GenT._ModeBit = TEXGEN_EYE_LINEAR;
 733    texUnit->GenR._ModeBit = TEXGEN_EYE_LINEAR;
 734    texUnit->GenQ._ModeBit = TEXGEN_EYE_LINEAR;
 735
 736    /* Yes, these plane coefficients are correct! */
 737    ASSIGN_4V( texUnit->GenS.ObjectPlane, 1.0, 0.0, 0.0, 0.0 );
 738    ASSIGN_4V( texUnit->GenT.ObjectPlane, 0.0, 1.0, 0.0, 0.0 );
 739    ASSIGN_4V( texUnit->GenR.ObjectPlane, 0.0, 0.0, 0.0, 0.0 );
 740    ASSIGN_4V( texUnit->GenQ.ObjectPlane, 0.0, 0.0, 0.0, 0.0 );
 741    ASSIGN_4V( texUnit->GenS.EyePlane, 1.0, 0.0, 0.0, 0.0 );
 742    ASSIGN_4V( texUnit->GenT.EyePlane, 0.0, 1.0, 0.0, 0.0 );
 743    ASSIGN_4V( texUnit->GenR.EyePlane, 0.0, 0.0, 0.0, 0.0 );
 744    ASSIGN_4V( texUnit->GenQ.EyePlane, 0.0, 0.0, 0.0, 0.0 );
 745
 746    /* no mention of this in spec, but maybe id matrix expected? */
 747    ASSIGN_4V( texUnit->RotMatrix, 1.0, 0.0, 0.0, 1.0 );
 748
 749    /* initialize current texture object ptrs to the shared default objects */
 750    for (tex = 0; tex < NUM_TEXTURE_TARGETS; tex++) {
 751       _mesa_reference_texobj(&texUnit->CurrentTex[tex],
 752                              ctx->Shared->DefaultTex[tex]);
 753    }
 754 }
 755
 756
 757 /**
 758  * Initialize texture state for the given context.
 759  */
 760 GLboolean
 761 _mesa_init_texture(GLcontext *ctx)
 762 {
 763    GLuint u;
 764
 765    /* Texture group */
 766    ctx->Texture.CurrentUnit = 0;      /* multitexture */
 767    ctx->Texture._EnabledUnits = 0x0;
 768    ctx->Texture.SharedPalette = GL_FALSE;
 769    _mesa_init_colortable(&ctx->Texture.Palette);
 770
 771    for (u = 0; u < Elements(ctx->Texture.Unit); u++)
 772       init_texture_unit(ctx, u);
 773
 774    /* After we're done initializing the context's texture state the default
 775     * texture objects' refcounts should be at least
 776     * MAX_COMBINED_TEXTURE_IMAGE_UNITS + 1.
 777     */
 778    assert(ctx->Shared->DefaultTex[TEXTURE_1D_INDEX]->RefCount
 779           >= MAX_COMBINED_TEXTURE_IMAGE_UNITS + 1);
 780
 781    /* Allocate proxy textures */
 782    if (!alloc_proxy_textures( ctx ))
 783       return GL_FALSE;
 784
 785    return GL_TRUE;
 786 }
 787
 788
 789 /**
 790  * Free dynamically-allocted texture data attached to the given context.
 791  */
 792 void
 793 _mesa_free_texture_data(GLcontext *ctx)
 794 {
 795    GLuint u, tgt;
 796
 797    /* unreference current textures */
 798    for (u = 0; u < Elements(ctx->Texture.Unit); u++) {
 799       /* The _Current texture could account for another reference */
 800       _mesa_reference_texobj(&ctx->Texture.Unit[u]._Current, NULL);
 801
 802       for (tgt = 0; tgt < NUM_TEXTURE_TARGETS; tgt++) {
 803          _mesa_reference_texobj(&ctx->Texture.Unit[u].CurrentTex[tgt], NULL);
 804       }
 805    }
 806
 807    /* Free proxy texture objects */
 808    for (tgt = 0; tgt < NUM_TEXTURE_TARGETS; tgt++)
 809       ctx->Driver.DeleteTexture(ctx, ctx->Texture.ProxyTex[tgt]);
 810
 811    for (u = 0; u < Elements(ctx->Texture.Unit); u++)
 812       _mesa_free_colortable_data(&ctx->Texture.Unit[u].ColorTable);
 813 }
 814
 815
 816 /**
 817  * Update the default texture objects in the given context to reference those
 818  * specified in the shared state and release those referencing the old
 819  * shared state.
 820  */
 821 void
 822 _mesa_update_default_objects_texture(GLcontext *ctx)
 823 {
 824    GLuint u, tex;
 825
 826    for (u = 0; u < Elements(ctx->Texture.Unit); u++) {
 827       struct gl_texture_unit *texUnit = &ctx->Texture.Unit[u];
 828       for (tex = 0; tex < NUM_TEXTURE_TARGETS; tex++) {
 829          _mesa_reference_texobj(&texUnit->CurrentTex[tex],
 830                                 ctx->Shared->DefaultTex[tex]);
 831       }
 832    }
 833 }