src/mesa/main/texenvprogram.c

   1 /**************************************************************************
   2  *
   3  * Copyright 2003 Tungsten Graphics, Inc., Cedar Park, Texas.
   4  * All Rights Reserved.
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a
   7  * copy of this software and associated documentation files (the
   8  * "Software"), to deal in the Software without restriction, including
   9  * without limitation the rights to use, copy, modify, merge, publish,
  10  * distribute, sub license, and/or sell copies of the Software, and to
  11  * permit persons to whom the Software is furnished to do so, subject to
  12  * the following conditions:
  13  *
  14  * The above copyright notice and this permission notice (including the
  15  * next paragraph) shall be included in all copies or substantial portions
  16  * 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
  20  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
  21  * IN NO EVENT SHALL TUNGSTEN GRAPHICS AND/OR ITS SUPPLIERS BE LIABLE FOR
  22  * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
  23  * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
  24  * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  25  *
  26  **************************************************************************/
  27
  28 #include "glheader.h"
  29 #include "macros.h"
  30 #include "enums.h"
  31 #include "texenvprogram.h"
  32
  33 #include "shader/program.h"
  34 #include "shader/program_instruction.h"
  35
  36 /**
  37  * According to Glean's texCombine test, no more than 21 instructions
  38  * are needed.  Allow a few extra just in case.
  39  */
  40 #define MAX_INSTRUCTIONS 24
  41
  42 #define DISASSEM (MESA_VERBOSE & VERBOSE_DISASSEM)
  43
  44 struct mode_opt {
  45    GLuint Source:4;
  46    GLuint Operand:3;
  47 };
  48
  49 struct state_key {
  50    GLbitfield enabled_units;
  51    GLuint separate_specular:1;
  52    GLuint fog_enabled:1;
  53    GLuint fog_mode:2;
  54
  55    struct {
  56       GLuint enabled:1;
  57       GLuint source_index:3;   /* one of TEXTURE_1D/2D/3D/CUBE/RECT_INDEX */
  58       GLuint ScaleShiftRGB:2;
  59       GLuint ScaleShiftA:2;
  60
  61       GLuint NumArgsRGB:2;
  62       GLuint ModeRGB:4;
  63       struct mode_opt OptRGB[3];
  64
  65       GLuint NumArgsA:2;
  66       GLuint ModeA:4;
  67       struct mode_opt OptA[3];
  68    } unit[8];
  69 };
  70
  71 #define FOG_LINEAR  0
  72 #define FOG_EXP     1
  73 #define FOG_EXP2    2
  74 #define FOG_UNKNOWN 3
  75
  76 static GLuint translate_fog_mode( GLenum mode )
  77 {
  78    switch (mode) {
  79    case GL_LINEAR: return FOG_LINEAR;
  80    case GL_EXP: return FOG_EXP;
  81    case GL_EXP2: return FOG_EXP2;
  82    default: return FOG_UNKNOWN;
  83    }
  84 }
  85
  86 #define OPR_SRC_COLOR           0
  87 #define OPR_ONE_MINUS_SRC_COLOR 1
  88 #define OPR_SRC_ALPHA           2
  89 #define OPR_ONE_MINUS_SRC_ALPHA 3
  90 #define OPR_ZERO                4
  91 #define OPR_ONE                 5
  92 #define OPR_UNKNOWN             7
  93
  94 static GLuint translate_operand( GLenum operand )
  95 {
  96    switch (operand) {
  97    case GL_SRC_COLOR: return OPR_SRC_COLOR;
  98    case GL_ONE_MINUS_SRC_COLOR: return OPR_ONE_MINUS_SRC_COLOR;
  99    case GL_SRC_ALPHA: return OPR_SRC_ALPHA;
 100    case GL_ONE_MINUS_SRC_ALPHA: return OPR_ONE_MINUS_SRC_ALPHA;
 101    case GL_ZERO: return OPR_ZERO;
 102    case GL_ONE: return OPR_ONE;
 103    default:     return OPR_UNKNOWN;
 104    }
 105 }
 106
 107 #define SRC_TEXTURE  0
 108 #define SRC_TEXTURE0 1
 109 #define SRC_TEXTURE1 2
 110 #define SRC_TEXTURE2 3
 111 #define SRC_TEXTURE3 4
 112 #define SRC_TEXTURE4 5
 113 #define SRC_TEXTURE5 6
 114 #define SRC_TEXTURE6 7
 115 #define SRC_TEXTURE7 8
 116 #define SRC_CONSTANT 9
 117 #define SRC_PRIMARY_COLOR 10
 118 #define SRC_PREVIOUS 11
 119 #define SRC_UNKNOWN  15
 120
 121 static GLuint translate_source( GLenum src )
 122 {
 123    switch (src) {
 124    case GL_TEXTURE: return SRC_TEXTURE;
 125    case GL_TEXTURE0:
 126    case GL_TEXTURE1:
 127    case GL_TEXTURE2:
 128    case GL_TEXTURE3:
 129    case GL_TEXTURE4:
 130    case GL_TEXTURE5:
 131    case GL_TEXTURE6:
 132    case GL_TEXTURE7: return SRC_TEXTURE0 + (src - GL_TEXTURE0);
 133    case GL_CONSTANT: return SRC_CONSTANT;
 134    case GL_PRIMARY_COLOR: return SRC_PRIMARY_COLOR;
 135    case GL_PREVIOUS: return SRC_PREVIOUS;
 136    default: return SRC_UNKNOWN;
 137    }
 138 }
 139
 140 #define MODE_REPLACE       0
 141 #define MODE_MODULATE      1
 142 #define MODE_ADD           2
 143 #define MODE_ADD_SIGNED    3
 144 #define MODE_INTERPOLATE   4
 145 #define MODE_SUBTRACT      5
 146 #define MODE_DOT3_RGB      6
 147 #define MODE_DOT3_RGB_EXT  7
 148 #define MODE_DOT3_RGBA     8
 149 #define MODE_DOT3_RGBA_EXT 9
 150 #define MODE_MODULATE_ADD_ATI           10
 151 #define MODE_MODULATE_SIGNED_ADD_ATI    11
 152 #define MODE_MODULATE_SUBTRACT_ATI      12
 153 #define MODE_UNKNOWN       15
 154
 155 static GLuint translate_mode( GLenum mode )
 156 {
 157    switch (mode) {
 158    case GL_REPLACE: return MODE_REPLACE;
 159    case GL_MODULATE: return MODE_MODULATE;
 160    case GL_ADD: return MODE_ADD;
 161    case GL_ADD_SIGNED: return MODE_ADD_SIGNED;
 162    case GL_INTERPOLATE: return MODE_INTERPOLATE;
 163    case GL_SUBTRACT: return MODE_SUBTRACT;
 164    case GL_DOT3_RGB: return MODE_DOT3_RGB;
 165    case GL_DOT3_RGB_EXT: return MODE_DOT3_RGB_EXT;
 166    case GL_DOT3_RGBA: return MODE_DOT3_RGBA;
 167    case GL_DOT3_RGBA_EXT: return MODE_DOT3_RGBA_EXT;
 168    case GL_MODULATE_ADD_ATI: return MODE_MODULATE_ADD_ATI;
 169    case GL_MODULATE_SIGNED_ADD_ATI: return MODE_MODULATE_SIGNED_ADD_ATI;
 170    case GL_MODULATE_SUBTRACT_ATI: return MODE_MODULATE_SUBTRACT_ATI;
 171    default: return MODE_UNKNOWN;
 172    }
 173 }
 174
 175 #define TEXTURE_UNKNOWN_INDEX 7
 176 static GLuint translate_tex_src_bit( GLbitfield bit )
 177 {
 178    switch (bit) {
 179    case TEXTURE_1D_BIT:   return TEXTURE_1D_INDEX;
 180    case TEXTURE_2D_BIT:   return TEXTURE_2D_INDEX;
 181    case TEXTURE_RECT_BIT: return TEXTURE_RECT_INDEX;
 182    case TEXTURE_3D_BIT:   return TEXTURE_3D_INDEX;
 183    case TEXTURE_CUBE_BIT: return TEXTURE_CUBE_INDEX;
 184    default: return TEXTURE_UNKNOWN_INDEX;
 185    }
 186 }
 187
 188 /**
 189  * Examine current texture environment state and generate a unique
 190  * key to identify it.
 191  */
 192 static void make_state_key( GLcontext *ctx,  struct state_key *key )
 193 {
 194    GLuint i, j;
 195
 196    memset(key, 0, sizeof(*key));
 197
 198    for (i=0;i<MAX_TEXTURE_UNITS;i++) {
 199       const struct gl_texture_unit *texUnit = &ctx->Texture.Unit[i];
 200
 201       if (!texUnit->_ReallyEnabled)
 202          continue;
 203
 204       key->unit[i].enabled = 1;
 205       key->enabled_units |= (1<<i);
 206
 207       key->unit[i].source_index =
 208          translate_tex_src_bit(texUnit->_ReallyEnabled);
 209
 210       key->unit[i].NumArgsRGB = texUnit->_CurrentCombine->_NumArgsRGB;
 211       key->unit[i].NumArgsA = texUnit->_CurrentCombine->_NumArgsA;
 212
 213       key->unit[i].ModeRGB =
 214          translate_mode(texUnit->_CurrentCombine->ModeRGB);
 215       key->unit[i].ModeA =
 216          translate_mode(texUnit->_CurrentCombine->ModeA);
 217
 218       key->unit[i].ScaleShiftRGB = texUnit->_CurrentCombine->ScaleShiftRGB;
 219       key->unit[i].ScaleShiftA = texUnit->_CurrentCombine->ScaleShiftA;
 220
 221       for (j=0;j<3;j++) {
 222          key->unit[i].OptRGB[j].Operand =
 223             translate_operand(texUnit->_CurrentCombine->OperandRGB[j]);
 224          key->unit[i].OptA[j].Operand =
 225             translate_operand(texUnit->_CurrentCombine->OperandA[j]);
 226          key->unit[i].OptRGB[j].Source =
 227             translate_source(texUnit->_CurrentCombine->SourceRGB[j]);
 228          key->unit[i].OptA[j].Source =
 229             translate_source(texUnit->_CurrentCombine->SourceA[j]);
 230       }
 231    }
 232
 233    if (ctx->_TriangleCaps & DD_SEPARATE_SPECULAR)
 234       key->separate_specular = 1;
 235
 236    if (ctx->Fog.Enabled) {
 237       key->fog_enabled = 1;
 238       key->fog_mode = translate_fog_mode(ctx->Fog.Mode);
 239    }
 240 }
 241
 242 /* Use uregs to represent registers internally, translate to Mesa's
 243  * expected formats on emit.
 244  *
 245  * NOTE: These are passed by value extensively in this file rather
 246  * than as usual by pointer reference.  If this disturbs you, try
 247  * remembering they are just 32bits in size.
 248  *
 249  * GCC is smart enough to deal with these dword-sized structures in
 250  * much the same way as if I had defined them as dwords and was using
 251  * macros to access and set the fields.  This is much nicer and easier
 252  * to evolve.
 253  */
 254 struct ureg {
 255    GLuint file:4;
 256    GLuint idx:8;
 257    GLuint negatebase:1;
 258    GLuint abs:1;
 259    GLuint negateabs:1;
 260    GLuint swz:12;
 261    GLuint pad:5;
 262 };
 263
 264 static const struct ureg undef = {
 265    PROGRAM_UNDEFINED,
 266    ~0,
 267    0,
 268    0,
 269    0,
 270    0,
 271    0
 272 };
 273
 274
 275 /* State used to build the fragment program:
 276  */
 277 struct texenv_fragment_program {
 278    struct gl_fragment_program *program;
 279    GLcontext *ctx;
 280    struct state_key *state;
 281
 282    GLbitfield alu_temps;        /* Track texture indirections, see spec. */
 283    GLbitfield temps_output;     /* Track texture indirections, see spec. */
 284    GLbitfield temp_in_use;      /* Tracks temporary regs which are in use. */
 285    GLboolean error;
 286
 287    struct ureg src_texture[MAX_TEXTURE_UNITS];
 288    /* Reg containing each texture unit's sampled texture color,
 289     * else undef.
 290     */
 291
 292    struct ureg src_previous;    /* Reg containing color from previous
 293                                  * stage.  May need to be decl'd.
 294                                  */
 295
 296    GLuint last_tex_stage;       /* Number of last enabled texture unit */
 297
 298    struct ureg half;
 299    struct ureg one;
 300    struct ureg zero;
 301 };
 302
 303
 304
 305 static struct ureg make_ureg(GLuint file, GLuint idx)
 306 {
 307    struct ureg reg;
 308    reg.file = file;
 309    reg.idx = idx;
 310    reg.negatebase = 0;
 311    reg.abs = 0;
 312    reg.negateabs = 0;
 313    reg.swz = SWIZZLE_NOOP;
 314    reg.pad = 0;
 315    return reg;
 316 }
 317
 318 static struct ureg swizzle( struct ureg reg, int x, int y, int z, int w )
 319 {
 320    reg.swz = MAKE_SWIZZLE4(GET_SWZ(reg.swz, x),
 321                            GET_SWZ(reg.swz, y),
 322                            GET_SWZ(reg.swz, z),
 323                            GET_SWZ(reg.swz, w));
 324
 325    return reg;
 326 }
 327
 328 static struct ureg swizzle1( struct ureg reg, int x )
 329 {
 330    return swizzle(reg, x, x, x, x);
 331 }
 332
 333 static struct ureg negate( struct ureg reg )
 334 {
 335    reg.negatebase ^= 1;
 336    return reg;
 337 }
 338
 339 static GLboolean is_undef( struct ureg reg )
 340 {
 341    return reg.file == PROGRAM_UNDEFINED;
 342 }
 343
 344
 345 static struct ureg get_temp( struct texenv_fragment_program *p )
 346 {
 347    GLint bit;
 348
 349    /* First try and reuse temps which have been used already:
 350     */
 351    bit = _mesa_ffs( ~p->temp_in_use & p->alu_temps );
 352
 353    /* Then any unused temporary:
 354     */
 355    if (!bit)
 356       bit = _mesa_ffs( ~p->temp_in_use );
 357
 358    if (!bit) {
 359       _mesa_problem(NULL, "%s: out of temporaries\n", __FILE__);
 360       _mesa_exit(1);
 361    }
 362
 363    if ((GLuint) bit > p->program->Base.NumTemporaries)
 364       p->program->Base.NumTemporaries = bit;
 365
 366    p->temp_in_use |= 1<<(bit-1);
 367    return make_ureg(PROGRAM_TEMPORARY, (bit-1));
 368 }
 369
 370 static struct ureg get_tex_temp( struct texenv_fragment_program *p )
 371 {
 372    int bit;
 373
 374    /* First try to find availble temp not previously used (to avoid
 375     * starting a new texture indirection).  According to the spec, the
 376     * ~p->temps_output isn't necessary, but will keep it there for
 377     * now:
 378     */
 379    bit = _mesa_ffs( ~p->temp_in_use & ~p->alu_temps & ~p->temps_output );
 380
 381    /* Then any unused temporary:
 382     */
 383    if (!bit)
 384       bit = _mesa_ffs( ~p->temp_in_use );
 385
 386    if (!bit) {
 387       _mesa_problem(NULL, "%s: out of temporaries\n", __FILE__);
 388       _mesa_exit(1);
 389    }
 390
 391    if ((GLuint) bit > p->program->Base.NumTemporaries)
 392       p->program->Base.NumTemporaries = bit;
 393
 394    p->temp_in_use |= 1<<(bit-1);
 395    return make_ureg(PROGRAM_TEMPORARY, (bit-1));
 396 }
 397
 398
 399 static void release_temps( struct texenv_fragment_program *p )
 400 {
 401    GLuint max_temp = p->ctx->Const.FragmentProgram.MaxTemps;
 402
 403    /* KW: To support tex_env_crossbar, don't release the registers in
 404     * temps_output.
 405     */
 406    if (max_temp >= sizeof(int) * 8)
 407       p->temp_in_use = p->temps_output;
 408    else
 409       p->temp_in_use = ~((1<<max_temp)-1) | p->temps_output;
 410 }
 411
 412
 413 static struct ureg register_param6( struct texenv_fragment_program *p,
 414                                     GLint s0,
 415                                     GLint s1,
 416                                     GLint s2,
 417                                     GLint s3,
 418                                     GLint s4,
 419                                     GLint s5)
 420 {
 421    GLint tokens[6];
 422    GLuint idx;
 423    tokens[0] = s0;
 424    tokens[1] = s1;
 425    tokens[2] = s2;
 426    tokens[3] = s3;
 427    tokens[4] = s4;
 428    tokens[5] = s5;
 429    idx = _mesa_add_state_reference( p->program->Base.Parameters, tokens );
 430    return make_ureg(PROGRAM_STATE_VAR, idx);
 431 }
 432
 433
 434 #define register_param1(p,s0)          register_param6(p,s0,0,0,0,0,0)
 435 #define register_param2(p,s0,s1)       register_param6(p,s0,s1,0,0,0,0)
 436 #define register_param3(p,s0,s1,s2)    register_param6(p,s0,s1,s2,0,0,0)
 437 #define register_param4(p,s0,s1,s2,s3) register_param6(p,s0,s1,s2,s3,0,0)
 438
 439
 440 static struct ureg register_input( struct texenv_fragment_program *p, GLuint input )
 441 {
 442    p->program->Base.InputsRead |= (1 << input);
 443    return make_ureg(PROGRAM_INPUT, input);
 444 }
 445
 446
 447 static void emit_arg( struct prog_src_register *reg,
 448                       struct ureg ureg )
 449 {
 450    reg->File = ureg.file;
 451    reg->Index = ureg.idx;
 452    reg->Swizzle = ureg.swz;
 453    reg->NegateBase = ureg.negatebase ? 0xf : 0x0;
 454    reg->Abs = ureg.abs;
 455    reg->NegateAbs = ureg.negateabs;
 456 }
 457
 458 static void emit_dst( struct prog_dst_register *dst,
 459                       struct ureg ureg, GLuint mask )
 460 {
 461    dst->File = ureg.file;
 462    dst->Index = ureg.idx;
 463    dst->WriteMask = mask;
 464    dst->CondMask = 0;
 465    dst->CondSwizzle = 0;
 466 }
 467
 468 static struct prog_instruction *
 469 emit_op(struct texenv_fragment_program *p,
 470         enum prog_opcode op,
 471         struct ureg dest,
 472         GLuint mask,
 473         GLboolean saturate,
 474         struct ureg src0,
 475         struct ureg src1,
 476         struct ureg src2 )
 477 {
 478    GLuint nr = p->program->Base.NumInstructions++;
 479    struct prog_instruction *inst = &p->program->Base.Instructions[nr];
 480
 481    _mesa_init_instructions(inst, 1);
 482    inst->Opcode = op;
 483
 484    emit_arg( &inst->SrcReg[0], src0 );
 485    emit_arg( &inst->SrcReg[1], src1 );
 486    emit_arg( &inst->SrcReg[2], src2 );
 487
 488    inst->SaturateMode = saturate ? SATURATE_ZERO_ONE : SATURATE_OFF;
 489
 490    emit_dst( &inst->DstReg, dest, mask );
 491
 492    /* Accounting for indirection tracking:
 493     */
 494    if (dest.file == PROGRAM_TEMPORARY)
 495       p->temps_output |= 1 << dest.idx;
 496
 497    return inst;
 498 }
 499
 500
 501 static struct ureg emit_arith( struct texenv_fragment_program *p,
 502                                enum prog_opcode op,
 503                                struct ureg dest,
 504                                GLuint mask,
 505                                GLboolean saturate,
 506                                struct ureg src0,
 507                                struct ureg src1,
 508                                struct ureg src2 )
 509 {
 510    emit_op(p, op, dest, mask, saturate, src0, src1, src2);
 511
 512    /* Accounting for indirection tracking:
 513     */
 514    if (src0.file == PROGRAM_TEMPORARY)
 515       p->alu_temps |= 1 << src0.idx;
 516
 517    if (!is_undef(src1) && src1.file == PROGRAM_TEMPORARY)
 518       p->alu_temps |= 1 << src1.idx;
 519
 520    if (!is_undef(src2) && src2.file == PROGRAM_TEMPORARY)
 521       p->alu_temps |= 1 << src2.idx;
 522
 523    if (dest.file == PROGRAM_TEMPORARY)
 524       p->alu_temps |= 1 << dest.idx;
 525
 526    p->program->NumAluInstructions++;
 527    return dest;
 528 }
 529
 530 static struct ureg emit_texld( struct texenv_fragment_program *p,
 531                                enum prog_opcode op,
 532                                struct ureg dest,
 533                                GLuint destmask,
 534                                GLuint tex_unit,
 535                                GLuint tex_idx,
 536                                struct ureg coord )
 537 {
 538    struct prog_instruction *inst = emit_op( p, op,
 539                                           dest, destmask,
 540                                           GL_FALSE,     /* don't saturate? */
 541                                           coord,        /* arg 0? */
 542                                           undef,
 543                                           undef);
 544
 545    inst->TexSrcTarget = tex_idx;
 546    inst->TexSrcUnit = tex_unit;
 547
 548    p->program->NumTexInstructions++;
 549
 550    /* Is this a texture indirection?
 551     */
 552    if ((coord.file == PROGRAM_TEMPORARY &&
 553         (p->temps_output & (1<<coord.idx))) ||
 554        (dest.file == PROGRAM_TEMPORARY &&
 555         (p->alu_temps & (1<<dest.idx)))) {
 556       p->program->NumTexIndirections++;
 557       p->temps_output = 1<<coord.idx;
 558       p->alu_temps = 0;
 559       assert(0);                /* KW: texture env crossbar */
 560    }
 561
 562    return dest;
 563 }
 564
 565
 566 static struct ureg register_const4f( struct texenv_fragment_program *p,
 567                                      GLfloat s0,
 568                                      GLfloat s1,
 569                                      GLfloat s2,
 570                                      GLfloat s3)
 571 {
 572    GLfloat values[4];
 573    GLuint idx;
 574    values[0] = s0;
 575    values[1] = s1;
 576    values[2] = s2;
 577    values[3] = s3;
 578    idx = _mesa_add_unnamed_constant( p->program->Base.Parameters, values, 4 );
 579    return make_ureg(PROGRAM_STATE_VAR, idx);
 580 }
 581
 582 #define register_scalar_const(p, s0)    register_const4f(p, s0, s0, s0, s0)
 583 #define register_const1f(p, s0)         register_const4f(p, s0, 0, 0, 1)
 584 #define register_const2f(p, s0, s1)     register_const4f(p, s0, s1, 0, 1)
 585 #define register_const3f(p, s0, s1, s2) register_const4f(p, s0, s1, s2, 1)
 586
 587
 588 static struct ureg get_one( struct texenv_fragment_program *p )
 589 {
 590    if (is_undef(p->one))
 591       p->one = register_scalar_const(p, 1.0);
 592    return p->one;
 593 }
 594
 595 static struct ureg get_half( struct texenv_fragment_program *p )
 596 {
 597    if (is_undef(p->half))
 598       p->half = register_scalar_const(p, 0.5);
 599    return p->half;
 600 }
 601
 602 static struct ureg get_zero( struct texenv_fragment_program *p )
 603 {
 604    if (is_undef(p->zero))
 605       p->zero = register_scalar_const(p, 0.0);
 606    return p->zero;
 607 }
 608
 609
 610 static void program_error( struct texenv_fragment_program *p, const char *msg )
 611 {
 612    _mesa_problem(NULL, msg);
 613    p->error = 1;
 614 }
 615
 616 static struct ureg get_source( struct texenv_fragment_program *p,
 617                                GLuint src, GLuint unit )
 618 {
 619    switch (src) {
 620    case SRC_TEXTURE:
 621       assert(!is_undef(p->src_texture[unit]));
 622       return p->src_texture[unit];
 623
 624    case SRC_TEXTURE0:
 625    case SRC_TEXTURE1:
 626    case SRC_TEXTURE2:
 627    case SRC_TEXTURE3:
 628    case SRC_TEXTURE4:
 629    case SRC_TEXTURE5:
 630    case SRC_TEXTURE6:
 631    case SRC_TEXTURE7:
 632       assert(!is_undef(p->src_texture[src - SRC_TEXTURE0]));
 633       return p->src_texture[src - SRC_TEXTURE0];
 634
 635    case SRC_CONSTANT:
 636       return register_param2(p, STATE_TEXENV_COLOR, unit);
 637
 638    case SRC_PRIMARY_COLOR:
 639       return register_input(p, FRAG_ATTRIB_COL0);
 640
 641    case SRC_PREVIOUS:
 642    default:
 643       if (is_undef(p->src_previous))
 644          return register_input(p, FRAG_ATTRIB_COL0);
 645       else
 646          return p->src_previous;
 647    }
 648 }
 649
 650 static struct ureg emit_combine_source( struct texenv_fragment_program *p,
 651                                         GLuint mask,
 652                                         GLuint unit,
 653                                         GLuint source,
 654                                         GLuint operand )
 655 {
 656    struct ureg arg, src, one;
 657
 658    src = get_source(p, source, unit);
 659
 660    switch (operand) {
 661    case OPR_ONE_MINUS_SRC_COLOR:
 662       /* Get unused tmp,
 663        * Emit tmp = 1.0 - arg.xyzw
 664        */
 665       arg = get_temp( p );
 666       one = get_one( p );
 667       return emit_arith( p, OPCODE_SUB, arg, mask, 0, one, src, undef);
 668
 669    case OPR_SRC_ALPHA:
 670       if (mask == WRITEMASK_W)
 671          return src;
 672       else
 673          return swizzle1( src, SWIZZLE_W );
 674    case OPR_ONE_MINUS_SRC_ALPHA:
 675       /* Get unused tmp,
 676        * Emit tmp = 1.0 - arg.wwww
 677        */
 678       arg = get_temp(p);
 679       one = get_one(p);
 680       return emit_arith(p, OPCODE_SUB, arg, mask, 0,
 681                         one, swizzle1(src, SWIZZLE_W), undef);
 682    case OPR_ZERO:
 683       return get_zero(p);
 684    case OPR_ONE:
 685       return get_one(p);
 686    case OPR_SRC_COLOR:
 687    default:
 688       return src;
 689    }
 690 }
 691
 692 static GLboolean args_match( struct state_key *key, GLuint unit )
 693 {
 694    GLuint i, nr = key->unit[unit].NumArgsRGB;
 695
 696    for (i = 0 ; i < nr ; i++) {
 697       if (key->unit[unit].OptA[i].Source != key->unit[unit].OptRGB[i].Source)
 698          return GL_FALSE;
 699
 700       switch(key->unit[unit].OptA[i].Operand) {
 701       case OPR_SRC_ALPHA:
 702          switch(key->unit[unit].OptRGB[i].Operand) {
 703          case OPR_SRC_COLOR:
 704          case OPR_SRC_ALPHA:
 705             break;
 706          default:
 707             return GL_FALSE;
 708          }
 709          break;
 710       case OPR_ONE_MINUS_SRC_ALPHA:
 711          switch(key->unit[unit].OptRGB[i].Operand) {
 712          case OPR_ONE_MINUS_SRC_COLOR:
 713          case OPR_ONE_MINUS_SRC_ALPHA:
 714             break;
 715          default:
 716             return GL_FALSE;
 717          }
 718          break;
 719       default:
 720          return GL_FALSE;       /* impossible */
 721       }
 722    }
 723
 724    return GL_TRUE;
 725 }
 726
 727 static struct ureg emit_combine( struct texenv_fragment_program *p,
 728                                  struct ureg dest,
 729                                  GLuint mask,
 730                                  GLboolean saturate,
 731                                  GLuint unit,
 732                                  GLuint nr,
 733                                  GLuint mode,
 734                                  const struct mode_opt *opt)
 735 {
 736    struct ureg src[3];
 737    struct ureg tmp, half;
 738    GLuint i;
 739
 740    tmp = undef; /* silence warning (bug 5318) */
 741
 742    for (i = 0; i < nr; i++)
 743       src[i] = emit_combine_source( p, mask, unit, opt[i].Source, opt[i].Operand );
 744
 745    switch (mode) {
 746    case MODE_REPLACE:
 747       if (mask == WRITEMASK_XYZW && !saturate)
 748          return src[0];
 749       else
 750          return emit_arith( p, OPCODE_MOV, dest, mask, saturate, src[0], undef, undef );
 751    case MODE_MODULATE:
 752       return emit_arith( p, OPCODE_MUL, dest, mask, saturate,
 753                          src[0], src[1], undef );
 754    case MODE_ADD:
 755       return emit_arith( p, OPCODE_ADD, dest, mask, saturate,
 756                          src[0], src[1], undef );
 757    case MODE_ADD_SIGNED:
 758       /* tmp = arg0 + arg1
 759        * result = tmp - .5
 760        */
 761       half = get_half(p);
 762       tmp = get_temp( p );
 763       emit_arith( p, OPCODE_ADD, tmp, mask, 0, src[0], src[1], undef );
 764       emit_arith( p, OPCODE_SUB, dest, mask, saturate, tmp, half, undef );
 765       return dest;
 766    case MODE_INTERPOLATE:
 767       /* Arg0 * (Arg2) + Arg1 * (1-Arg2) -- note arguments are reordered:
 768        */
 769       return emit_arith( p, OPCODE_LRP, dest, mask, saturate, src[2], src[0], src[1] );
 770
 771    case MODE_SUBTRACT:
 772       return emit_arith( p, OPCODE_SUB, dest, mask, saturate, src[0], src[1], undef );
 773
 774    case MODE_DOT3_RGBA:
 775    case MODE_DOT3_RGBA_EXT:
 776    case MODE_DOT3_RGB_EXT:
 777    case MODE_DOT3_RGB: {
 778       struct ureg tmp0 = get_temp( p );
 779       struct ureg tmp1 = get_temp( p );
 780       struct ureg neg1 = register_scalar_const(p, -1);
 781       struct ureg two  = register_scalar_const(p, 2);
 782
 783       /* tmp0 = 2*src0 - 1
 784        * tmp1 = 2*src1 - 1
 785        *
 786        * dst = tmp0 dot3 tmp1
 787        */
 788       emit_arith( p, OPCODE_MAD, tmp0, WRITEMASK_XYZW, 0,
 789                   two, src[0], neg1);
 790
 791       if (_mesa_memcmp(&src[0], &src[1], sizeof(struct ureg)) == 0)
 792          tmp1 = tmp0;
 793       else
 794          emit_arith( p, OPCODE_MAD, tmp1, WRITEMASK_XYZW, 0,
 795                      two, src[1], neg1);
 796       emit_arith( p, OPCODE_DP3, dest, mask, saturate, tmp0, tmp1, undef);
 797       return dest;
 798    }
 799    case MODE_MODULATE_ADD_ATI:
 800       /* Arg0 * Arg2 + Arg1 */
 801       return emit_arith( p, OPCODE_MAD, dest, mask, saturate,
 802                          src[0], src[2], src[1] );
 803    case MODE_MODULATE_SIGNED_ADD_ATI: {
 804       /* Arg0 * Arg2 + Arg1 - 0.5 */
 805       struct ureg tmp0 = get_temp(p);
 806       half = get_half(p);
 807       emit_arith( p, OPCODE_MAD, tmp0, mask, 0, src[0], src[2], src[1] );
 808       emit_arith( p, OPCODE_SUB, dest, mask, saturate, tmp0, half, undef );
 809       return dest;
 810    }
 811    case MODE_MODULATE_SUBTRACT_ATI:
 812       /* Arg0 * Arg2 - Arg1 */
 813       emit_arith( p, OPCODE_MAD, dest, mask, 0, src[0], src[2], negate(src[1]) );
 814       return dest;
 815    default:
 816       return src[0];
 817    }
 818 }
 819
 820
 821 /**
 822  * Generate instructions for one texture unit's env/combiner mode.
 823  */
 824 static struct ureg
 825 emit_texenv(struct texenv_fragment_program *p, GLuint unit)
 826 {
 827    struct state_key *key = p->state;
 828    GLboolean saturate = (unit < p->last_tex_stage);
 829    GLuint rgb_shift, alpha_shift;
 830    struct ureg out, shift;
 831    struct ureg dest;
 832
 833    if (!key->unit[unit].enabled) {
 834       return get_source(p, SRC_PREVIOUS, 0);
 835    }
 836
 837    switch (key->unit[unit].ModeRGB) {
 838    case MODE_DOT3_RGB_EXT:
 839       alpha_shift = key->unit[unit].ScaleShiftA;
 840       rgb_shift = 0;
 841       break;
 842    case MODE_DOT3_RGBA_EXT:
 843       alpha_shift = 0;
 844       rgb_shift = 0;
 845       break;
 846    default:
 847       rgb_shift = key->unit[unit].ScaleShiftRGB;
 848       alpha_shift = key->unit[unit].ScaleShiftA;
 849       break;
 850    }
 851
 852    /* If this is the very last calculation, emit direct to output reg:
 853     */
 854    if (key->separate_specular ||
 855        unit != p->last_tex_stage ||
 856        alpha_shift ||
 857        rgb_shift)
 858       dest = get_temp( p );
 859    else
 860       dest = make_ureg(PROGRAM_OUTPUT, FRAG_RESULT_COLR);
 861
 862    /* Emit the RGB and A combine ops
 863     */
 864    if (key->unit[unit].ModeRGB == key->unit[unit].ModeA &&
 865        args_match(key, unit)) {
 866       out = emit_combine( p, dest, WRITEMASK_XYZW, saturate,
 867                           unit,
 868                           key->unit[unit].NumArgsRGB,
 869                           key->unit[unit].ModeRGB,
 870                           key->unit[unit].OptRGB);
 871    }
 872    else if (key->unit[unit].ModeRGB == MODE_DOT3_RGBA_EXT ||
 873             key->unit[unit].ModeA == MODE_DOT3_RGBA) {
 874
 875       out = emit_combine( p, dest, WRITEMASK_XYZW, saturate,
 876                           unit,
 877                           key->unit[unit].NumArgsRGB,
 878                           key->unit[unit].ModeRGB,
 879                           key->unit[unit].OptRGB);
 880    }
 881    else {
 882       /* Need to do something to stop from re-emitting identical
 883        * argument calculations here:
 884        */
 885       out = emit_combine( p, dest, WRITEMASK_XYZ, saturate,
 886                           unit,
 887                           key->unit[unit].NumArgsRGB,
 888                           key->unit[unit].ModeRGB,
 889                           key->unit[unit].OptRGB);
 890       out = emit_combine( p, dest, WRITEMASK_W, saturate,
 891                           unit,
 892                           key->unit[unit].NumArgsA,
 893                           key->unit[unit].ModeA,
 894                           key->unit[unit].OptA);
 895    }
 896
 897    /* Deal with the final shift:
 898     */
 899    if (alpha_shift || rgb_shift) {
 900       if (rgb_shift == alpha_shift) {
 901          shift = register_scalar_const(p, 1<<rgb_shift);
 902       }
 903       else {
 904          shift = register_const4f(p,
 905                                   1<<rgb_shift,
 906                                   1<<rgb_shift,
 907                                   1<<rgb_shift,
 908                                   1<<alpha_shift);
 909       }
 910       return emit_arith( p, OPCODE_MUL, dest, WRITEMASK_XYZW,
 911                          saturate, out, shift, undef );
 912    }
 913    else
 914       return out;
 915 }
 916
 917
 918 /**
 919  * Generate instruction for getting a texture source term.
 920  */
 921 static void load_texture( struct texenv_fragment_program *p, GLuint unit )
 922 {
 923    if (is_undef(p->src_texture[unit])) {
 924       GLuint dim = p->state->unit[unit].source_index;
 925       struct ureg texcoord = register_input(p, FRAG_ATTRIB_TEX0+unit);
 926       struct ureg tmp = get_tex_temp( p );
 927
 928       if (dim == TEXTURE_UNKNOWN_INDEX)
 929          program_error(p, "TexSrcBit");
 930
 931       /* TODO: Use D0_MASK_XY where possible.
 932        */
 933       if (p->state->unit[unit].enabled)
 934          p->src_texture[unit] = emit_texld( p, OPCODE_TXP,
 935                                             tmp, WRITEMASK_XYZW,
 936                                             unit, dim, texcoord );
 937       else
 938          p->src_texture[unit] = get_zero(p);
 939    }
 940 }
 941
 942 static GLboolean load_texenv_source( struct texenv_fragment_program *p,
 943                                      GLuint src, GLuint unit )
 944 {
 945    switch (src) {
 946    case SRC_TEXTURE:
 947       load_texture(p, unit);
 948       break;
 949
 950    case SRC_TEXTURE0:
 951    case SRC_TEXTURE1:
 952    case SRC_TEXTURE2:
 953    case SRC_TEXTURE3:
 954    case SRC_TEXTURE4:
 955    case SRC_TEXTURE5:
 956    case SRC_TEXTURE6:
 957    case SRC_TEXTURE7:
 958       load_texture(p, src - SRC_TEXTURE0);
 959       break;
 960
 961    default:
 962       break;
 963    }
 964
 965    return GL_TRUE;
 966 }
 967
 968
 969 /**
 970  * Generate instructions for loading all texture source terms.
 971  */
 972 static GLboolean
 973 load_texunit_sources( struct texenv_fragment_program *p, int unit )
 974 {
 975    struct state_key *key = p->state;
 976    GLuint i;
 977
 978    for (i = 0; i < key->unit[unit].NumArgsRGB; i++) {
 979       load_texenv_source( p, key->unit[unit].OptRGB[i].Source, unit);
 980    }
 981
 982    for (i = 0; i < key->unit[unit].NumArgsA; i++) {
 983       load_texenv_source( p, key->unit[unit].OptA[i].Source, unit );
 984    }
 985
 986    return GL_TRUE;
 987 }
 988
 989
 990 /**
 991  * Generate a new fragment program which implements the context's
 992  * current texture env/combine mode.
 993  */
 994 static void
 995 create_new_program(GLcontext *ctx, struct state_key *key,
 996                    struct gl_fragment_program *program)
 997 {
 998    struct prog_instruction instBuffer[MAX_INSTRUCTIONS];
 999    struct texenv_fragment_program p;
1000    GLuint unit;
1001    struct ureg cf, out;
1002
1003    _mesa_memset(&p, 0, sizeof(p));
1004    p.ctx = ctx;
1005    p.state = key;
1006    p.program = program;
1007
1008    /* During code generation, use locally-allocated instruction buffer,
1009     * then alloc dynamic storage below.
1010     */
1011    p.program->Base.Instructions = instBuffer;
1012    p.program->Base.Target = GL_FRAGMENT_PROGRAM_ARB;
1013    p.program->NumTexIndirections = 1;   /* correct? */
1014    p.program->NumTexInstructions = 0;
1015    p.program->NumAluInstructions = 0;
1016    p.program->Base.String = 0;
1017    p.program->Base.NumInstructions =
1018    p.program->Base.NumTemporaries =
1019    p.program->Base.NumParameters =
1020    p.program->Base.NumAttributes = p.program->Base.NumAddressRegs = 0;
1021    p.program->Base.Parameters = _mesa_new_parameter_list();
1022
1023    p.program->Base.InputsRead = 0;
1024    p.program->Base.OutputsWritten = 1 << FRAG_RESULT_COLR;
1025
1026    for (unit = 0; unit < MAX_TEXTURE_UNITS; unit++)
1027       p.src_texture[unit] = undef;
1028
1029    p.src_previous = undef;
1030    p.half = undef;
1031    p.zero = undef;
1032    p.one = undef;
1033
1034    p.last_tex_stage = 0;
1035    release_temps(&p);
1036
1037    if (key->enabled_units) {
1038       /* First pass - to support texture_env_crossbar, first identify
1039        * all referenced texture sources and emit texld instructions
1040        * for each:
1041        */
1042       for (unit = 0 ; unit < ctx->Const.MaxTextureUnits ; unit++)
1043          if (key->unit[unit].enabled) {
1044             load_texunit_sources( &p, unit );
1045             p.last_tex_stage = unit;
1046          }
1047
1048       /* Second pass - emit combine instructions to build final color:
1049        */
1050       for (unit = 0 ; unit < ctx->Const.MaxTextureUnits; unit++)
1051          if (key->enabled_units & (1<<unit)) {
1052             p.src_previous = emit_texenv( &p, unit );
1053             release_temps(&p);  /* release all temps */
1054          }
1055    }
1056
1057    cf = get_source( &p, SRC_PREVIOUS, 0 );
1058    out = make_ureg( PROGRAM_OUTPUT, FRAG_RESULT_COLR );
1059
1060    if (key->separate_specular) {
1061       /* Emit specular add.
1062        */
1063       struct ureg s = register_input(&p, FRAG_ATTRIB_COL1);
1064       emit_arith( &p, OPCODE_ADD, out, WRITEMASK_XYZ, 0, cf, s, undef );
1065       emit_arith( &p, OPCODE_MOV, out, WRITEMASK_W, 0, cf, undef, undef );
1066    }
1067    else if (_mesa_memcmp(&cf, &out, sizeof(cf)) != 0) {
1068       /* Will wind up in here if no texture enabled or a couple of
1069        * other scenarios (GL_REPLACE for instance).
1070        */
1071       emit_arith( &p, OPCODE_MOV, out, WRITEMASK_XYZW, 0, cf, undef, undef );
1072    }
1073
1074    /* Finish up:
1075     */
1076    emit_arith( &p, OPCODE_END, undef, WRITEMASK_XYZW, 0, undef, undef, undef);
1077
1078    if (key->fog_enabled) {
1079       /* Pull fog mode from GLcontext, the value in the state key is
1080        * a reduced value and not what is expected in FogOption
1081        */
1082       p.program->FogOption = ctx->Fog.Mode;
1083    } else
1084       p.program->FogOption = GL_NONE;
1085
1086    if (p.program->NumTexIndirections > ctx->Const.FragmentProgram.MaxTexIndirections)
1087       program_error(&p, "Exceeded max nr indirect texture lookups");
1088
1089    if (p.program->NumTexInstructions > ctx->Const.FragmentProgram.MaxTexInstructions)
1090       program_error(&p, "Exceeded max TEX instructions");
1091
1092    if (p.program->NumAluInstructions > ctx->Const.FragmentProgram.MaxAluInstructions)
1093       program_error(&p, "Exceeded max ALU instructions");
1094
1095    ASSERT(p.program->Base.NumInstructions <= MAX_INSTRUCTIONS);
1096
1097    /* Allocate final instruction array */
1098    program->Base.Instructions
1099       = _mesa_alloc_instructions(program->Base.NumInstructions);
1100    if (!program->Base.Instructions) {
1101       _mesa_error(ctx, GL_OUT_OF_MEMORY,
1102                   "generating tex env program");
1103       return;
1104    }
1105    _mesa_memcpy(program->Base.Instructions, instBuffer,
1106                 sizeof(struct prog_instruction)
1107                 * program->Base.NumInstructions);
1108
1109    /* Notify driver the fragment program has (actually) changed.
1110     */
1111    if (ctx->Driver.ProgramStringNotify) {
1112       ctx->Driver.ProgramStringNotify( ctx, GL_FRAGMENT_PROGRAM_ARB,
1113                                        &p.program->Base );
1114    }
1115
1116    if (DISASSEM) {
1117       _mesa_print_program(&p.program->Base);
1118       _mesa_printf("\n");
1119    }
1120 }
1121
1122
1123 static struct gl_fragment_program *
1124 search_cache(const struct texenvprog_cache *cache,
1125              GLuint hash,
1126              const void *key,
1127              GLuint keysize)
1128 {
1129    struct texenvprog_cache_item *c;
1130
1131    for (c = cache->items[hash % cache->size]; c; c = c->next) {
1132       if (c->hash == hash && memcmp(c->key, key, keysize) == 0)
1133          return (struct gl_fragment_program *) c->data;
1134    }
1135
1136    return NULL;
1137 }
1138
1139 static void rehash( struct texenvprog_cache *cache )
1140 {
1141    struct texenvprog_cache_item **items;
1142    struct texenvprog_cache_item *c, *next;
1143    GLuint size, i;
1144
1145    size = cache->size * 3;
1146    items = (struct texenvprog_cache_item**) _mesa_malloc(size * sizeof(*items));
1147    _mesa_memset(items, 0, size * sizeof(*items));
1148
1149    for (i = 0; i < cache->size; i++)
1150       for (c = cache->items[i]; c; c = next) {
1151          next = c->next;
1152          c->next = items[c->hash % size];
1153          items[c->hash % size] = c;
1154       }
1155
1156    _mesa_free(cache->items);
1157    cache->items = items;
1158    cache->size = size;
1159 }
1160
1161 static void clear_cache( struct texenvprog_cache *cache )
1162 {
1163    struct texenvprog_cache_item *c, *next;
1164    GLuint i;
1165
1166    for (i = 0; i < cache->size; i++) {
1167       for (c = cache->items[i]; c; c = next) {
1168          next = c->next;
1169          _mesa_free(c->key);
1170          cache->ctx->Driver.DeleteProgram(cache->ctx,
1171                                           (struct gl_program *) c->data);
1172          _mesa_free(c);
1173       }
1174       cache->items[i] = NULL;
1175    }
1176
1177
1178    cache->n_items = 0;
1179 }
1180
1181
1182 static void cache_item( struct texenvprog_cache *cache,
1183                         GLuint hash,
1184                         const struct state_key *key,
1185                         void *data )
1186 {
1187    struct texenvprog_cache_item *c
1188       = (struct texenvprog_cache_item *) MALLOC(sizeof(*c));
1189    c->hash = hash;
1190
1191    c->key = _mesa_malloc(sizeof(*key));
1192    memcpy(c->key, key, sizeof(*key));
1193
1194    c->data = (struct gl_fragment_program *) data;
1195
1196    if (cache->n_items > cache->size * 1.5) {
1197       if (cache->size < 1000)
1198          rehash(cache);
1199       else
1200          clear_cache(cache);
1201    }
1202
1203    cache->n_items++;
1204    c->next = cache->items[hash % cache->size];
1205    cache->items[hash % cache->size] = c;
1206 }
1207
1208 static GLuint hash_key( const struct state_key *key )
1209 {
1210    GLuint *ikey = (GLuint *)key;
1211    GLuint hash = 0, i;
1212
1213    /* Make a slightly better attempt at a hash function:
1214     */
1215    for (i = 0; i < sizeof(*key)/sizeof(*ikey); i++)
1216    {
1217       hash += ikey[i];
1218       hash += (hash << 10);
1219       hash ^= (hash >> 6);
1220    }
1221
1222    return hash;
1223 }
1224
1225 void _mesa_UpdateTexEnvProgram( GLcontext *ctx )
1226 {
1227    struct state_key key;
1228    GLuint hash;
1229    const struct gl_fragment_program *prev = ctx->FragmentProgram._Current;
1230
1231    if (!ctx->FragmentProgram._Enabled) {
1232       make_state_key(ctx, &key);
1233       hash = hash_key(&key);
1234
1235       ctx->FragmentProgram._Current =
1236       ctx->_TexEnvProgram =
1237          search_cache(&ctx->Texture.env_fp_cache, hash, &key, sizeof(key));
1238
1239       if (!ctx->_TexEnvProgram) {
1240          if (0) _mesa_printf("Building new texenv proggy for key %x\n", hash);
1241
1242          ctx->FragmentProgram._Current = ctx->_TexEnvProgram =
1243             (struct gl_fragment_program *)
1244             ctx->Driver.NewProgram(ctx, GL_FRAGMENT_PROGRAM_ARB, 0);
1245
1246          create_new_program(ctx, &key, ctx->_TexEnvProgram);
1247
1248          cache_item(&ctx->Texture.env_fp_cache, hash, &key, ctx->_TexEnvProgram);
1249       } else {
1250          if (0) _mesa_printf("Found existing texenv program for key %x\n", hash);
1251       }
1252    }
1253    else {
1254       ctx->FragmentProgram._Current = ctx->FragmentProgram.Current;
1255    }
1256
1257    /* Tell the driver about the change.  Could define a new target for
1258     * this?
1259     */
1260    if (ctx->FragmentProgram._Current != prev && ctx->Driver.BindProgram) {
1261       ctx->Driver.BindProgram(ctx, GL_FRAGMENT_PROGRAM_ARB,
1262                              (struct gl_program *) ctx->FragmentProgram._Current);
1263    }
1264 }
1265
1266
1267 void _mesa_TexEnvProgramCacheInit( GLcontext *ctx )
1268 {
1269    ctx->Texture.env_fp_cache.ctx = ctx;
1270    ctx->Texture.env_fp_cache.size = 17;
1271    ctx->Texture.env_fp_cache.n_items = 0;
1272    ctx->Texture.env_fp_cache.items = (struct texenvprog_cache_item **)
1273       _mesa_calloc(ctx->Texture.env_fp_cache.size *
1274                    sizeof(struct texenvprog_cache_item));
1275 }
1276
1277
1278 void _mesa_TexEnvProgramCacheDestroy( GLcontext *ctx )
1279 {
1280    clear_cache(&ctx->Texture.env_fp_cache);
1281    _mesa_free(ctx->Texture.env_fp_cache.items);
1282 }