src/mesa/main/texenvprogram.c

   1 /**************************************************************************
   2  *
   3  * Copyright 2007 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 "shader/prog_parameter.h"
  32 #include "shader/prog_cache.h"
  33 #include "shader/prog_instruction.h"
  34 #include "shader/prog_print.h"
  35 #include "shader/prog_statevars.h"
  36 #include "shader/programopt.h"
  37 #include "texenvprogram.h"
  38
  39 /**
  40  * Up to nine instructions per tex unit, plus fog, specular color.
  41  */
  42 #define MAX_INSTRUCTIONS ((MAX_TEXTURE_UNITS * 9) + 12)
  43
  44 #define DISASSEM (MESA_VERBOSE & VERBOSE_DISASSEM)
  45
  46 struct mode_opt {
  47    GLubyte Source:4;
  48    GLubyte Operand:3;
  49 };
  50
  51 struct state_key {
  52    GLuint nr_enabled_units:8;
  53    GLuint enabled_units:8;
  54    GLuint separate_specular:1;
  55    GLuint fog_enabled:1;
  56    GLuint fog_mode:2;
  57    GLuint inputs_available:12;
  58
  59    struct {
  60       GLuint enabled:1;
  61       GLuint source_index:3;   /* one of TEXTURE_1D/2D/3D/CUBE/RECT_INDEX */
  62       GLuint ScaleShiftRGB:2;
  63       GLuint ScaleShiftA:2;
  64
  65       GLuint NumArgsRGB:2;
  66       GLuint ModeRGB:4;
  67       GLuint NumArgsA:2;
  68       GLuint ModeA:4;
  69
  70       struct mode_opt OptRGB[3];
  71       struct mode_opt OptA[3];
  72    } unit[8];
  73 };
  74
  75 #define FOG_LINEAR  0
  76 #define FOG_EXP     1
  77 #define FOG_EXP2    2
  78 #define FOG_UNKNOWN 3
  79
  80 static GLuint translate_fog_mode( GLenum mode )
  81 {
  82    switch (mode) {
  83    case GL_LINEAR: return FOG_LINEAR;
  84    case GL_EXP: return FOG_EXP;
  85    case GL_EXP2: return FOG_EXP2;
  86    default: return FOG_UNKNOWN;
  87    }
  88 }
  89
  90 #define OPR_SRC_COLOR           0
  91 #define OPR_ONE_MINUS_SRC_COLOR 1
  92 #define OPR_SRC_ALPHA           2
  93 #define OPR_ONE_MINUS_SRC_ALPHA 3
  94 #define OPR_ZERO                4
  95 #define OPR_ONE                 5
  96 #define OPR_UNKNOWN             7
  97
  98 static GLuint translate_operand( GLenum operand )
  99 {
 100    switch (operand) {
 101    case GL_SRC_COLOR: return OPR_SRC_COLOR;
 102    case GL_ONE_MINUS_SRC_COLOR: return OPR_ONE_MINUS_SRC_COLOR;
 103    case GL_SRC_ALPHA: return OPR_SRC_ALPHA;
 104    case GL_ONE_MINUS_SRC_ALPHA: return OPR_ONE_MINUS_SRC_ALPHA;
 105    case GL_ZERO: return OPR_ZERO;
 106    case GL_ONE: return OPR_ONE;
 107    default:     return OPR_UNKNOWN;
 108    }
 109 }
 110
 111 #define SRC_TEXTURE  0
 112 #define SRC_TEXTURE0 1
 113 #define SRC_TEXTURE1 2
 114 #define SRC_TEXTURE2 3
 115 #define SRC_TEXTURE3 4
 116 #define SRC_TEXTURE4 5
 117 #define SRC_TEXTURE5 6
 118 #define SRC_TEXTURE6 7
 119 #define SRC_TEXTURE7 8
 120 #define SRC_CONSTANT 9
 121 #define SRC_PRIMARY_COLOR 10
 122 #define SRC_PREVIOUS 11
 123 #define SRC_UNKNOWN  15
 124
 125 static GLuint translate_source( GLenum src )
 126 {
 127    switch (src) {
 128    case GL_TEXTURE: return SRC_TEXTURE;
 129    case GL_TEXTURE0:
 130    case GL_TEXTURE1:
 131    case GL_TEXTURE2:
 132    case GL_TEXTURE3:
 133    case GL_TEXTURE4:
 134    case GL_TEXTURE5:
 135    case GL_TEXTURE6:
 136    case GL_TEXTURE7: return SRC_TEXTURE0 + (src - GL_TEXTURE0);
 137    case GL_CONSTANT: return SRC_CONSTANT;
 138    case GL_PRIMARY_COLOR: return SRC_PRIMARY_COLOR;
 139    case GL_PREVIOUS: return SRC_PREVIOUS;
 140    default: return SRC_UNKNOWN;
 141    }
 142 }
 143
 144 #define MODE_REPLACE       0
 145 #define MODE_MODULATE      1
 146 #define MODE_ADD           2
 147 #define MODE_ADD_SIGNED    3
 148 #define MODE_INTERPOLATE   4
 149 #define MODE_SUBTRACT      5
 150 #define MODE_DOT3_RGB      6
 151 #define MODE_DOT3_RGB_EXT  7
 152 #define MODE_DOT3_RGBA     8
 153 #define MODE_DOT3_RGBA_EXT 9
 154 #define MODE_MODULATE_ADD_ATI           10
 155 #define MODE_MODULATE_SIGNED_ADD_ATI    11
 156 #define MODE_MODULATE_SUBTRACT_ATI      12
 157 #define MODE_UNKNOWN       15
 158
 159 static GLuint translate_mode( GLenum mode )
 160 {
 161    switch (mode) {
 162    case GL_REPLACE: return MODE_REPLACE;
 163    case GL_MODULATE: return MODE_MODULATE;
 164    case GL_ADD: return MODE_ADD;
 165    case GL_ADD_SIGNED: return MODE_ADD_SIGNED;
 166    case GL_INTERPOLATE: return MODE_INTERPOLATE;
 167    case GL_SUBTRACT: return MODE_SUBTRACT;
 168    case GL_DOT3_RGB: return MODE_DOT3_RGB;
 169    case GL_DOT3_RGB_EXT: return MODE_DOT3_RGB_EXT;
 170    case GL_DOT3_RGBA: return MODE_DOT3_RGBA;
 171    case GL_DOT3_RGBA_EXT: return MODE_DOT3_RGBA_EXT;
 172    case GL_MODULATE_ADD_ATI: return MODE_MODULATE_ADD_ATI;
 173    case GL_MODULATE_SIGNED_ADD_ATI: return MODE_MODULATE_SIGNED_ADD_ATI;
 174    case GL_MODULATE_SUBTRACT_ATI: return MODE_MODULATE_SUBTRACT_ATI;
 175    default: return MODE_UNKNOWN;
 176    }
 177 }
 178
 179 #define TEXTURE_UNKNOWN_INDEX 7
 180 static GLuint translate_tex_src_bit( GLbitfield bit )
 181 {
 182    switch (bit) {
 183    case TEXTURE_1D_BIT:   return TEXTURE_1D_INDEX;
 184    case TEXTURE_2D_BIT:   return TEXTURE_2D_INDEX;
 185    case TEXTURE_RECT_BIT: return TEXTURE_RECT_INDEX;
 186    case TEXTURE_3D_BIT:   return TEXTURE_3D_INDEX;
 187    case TEXTURE_CUBE_BIT: return TEXTURE_CUBE_INDEX;
 188    default: return TEXTURE_UNKNOWN_INDEX;
 189    }
 190 }
 191
 192 #define VERT_BIT_TEX_ANY    (0xff << VERT_ATTRIB_TEX0)
 193 #define VERT_RESULT_TEX_ANY (0xff << VERT_RESULT_TEX0)
 194
 195 /* Identify all possible varying inputs.  The fragment program will
 196  * never reference non-varying inputs, but will track them via state
 197  * constants instead.
 198  *
 199  * This function figures out all the inputs that the fragment program
 200  * has access to.  The bitmask is later reduced to just those which
 201  * are actually referenced.
 202  */
 203 static GLuint get_fp_input_mask( GLcontext *ctx )
 204 {
 205    GLuint fp_inputs = 0;
 206
 207    if (1) {
 208       GLuint varying_inputs = ctx->varying_vp_inputs;
 209
 210       /* First look at what values may be computed by the generated
 211        * vertex program:
 212        */
 213       if (ctx->Light.Enabled) {
 214          fp_inputs |= FRAG_BIT_COL0;
 215
 216          if (ctx->_TriangleCaps & DD_SEPARATE_SPECULAR)
 217             fp_inputs |= FRAG_BIT_COL1;
 218       }
 219
 220       fp_inputs |= (ctx->Texture._TexGenEnabled |
 221                     ctx->Texture._TexMatEnabled) << FRAG_ATTRIB_TEX0;
 222
 223       /* Then look at what might be varying as a result of enabled
 224        * arrays, etc:
 225        */
 226       if (varying_inputs & VERT_BIT_COLOR0) fp_inputs |= FRAG_BIT_COL0;
 227       if (varying_inputs & VERT_BIT_COLOR1) fp_inputs |= FRAG_BIT_COL1;
 228
 229       fp_inputs |= (((varying_inputs & VERT_BIT_TEX_ANY) >> VERT_ATTRIB_TEX0)
 230                     << FRAG_ATTRIB_TEX0);
 231
 232    }
 233    else {
 234       /* calculate from vp->outputs */
 235       GLuint vp_outputs = 0;
 236
 237       if (vp_outputs & (1 << VERT_RESULT_COL0)) fp_inputs |= FRAG_BIT_COL0;
 238       if (vp_outputs & (1 << VERT_RESULT_COL1)) fp_inputs |= FRAG_BIT_COL1;
 239
 240       fp_inputs |= (((vp_outputs & VERT_RESULT_TEX_ANY)
 241                    << VERT_RESULT_TEX0)
 242                   >> FRAG_ATTRIB_TEX0);
 243    }
 244
 245    return fp_inputs;
 246 }
 247
 248
 249 /**
 250  * Examine current texture environment state and generate a unique
 251  * key to identify it.
 252  */
 253 static void make_state_key( GLcontext *ctx,  struct state_key *key )
 254 {
 255    GLuint i, j;
 256    GLuint inputs_referenced = FRAG_BIT_COL0;
 257    GLuint inputs_available = get_fp_input_mask( ctx );
 258
 259    memset(key, 0, sizeof(*key));
 260
 261    for (i=0;i<MAX_TEXTURE_UNITS;i++) {
 262       const struct gl_texture_unit *texUnit = &ctx->Texture.Unit[i];
 263
 264       if (!texUnit->_ReallyEnabled)
 265          continue;
 266
 267       key->unit[i].enabled = 1;
 268       key->enabled_units |= (1<<i);
 269       key->nr_enabled_units = i+1;
 270       inputs_referenced |= FRAG_BIT_TEX(i);
 271
 272       key->unit[i].source_index =
 273          translate_tex_src_bit(texUnit->_ReallyEnabled);
 274
 275       key->unit[i].NumArgsRGB = texUnit->_CurrentCombine->_NumArgsRGB;
 276       key->unit[i].NumArgsA = texUnit->_CurrentCombine->_NumArgsA;
 277
 278       key->unit[i].ModeRGB =
 279          translate_mode(texUnit->_CurrentCombine->ModeRGB);
 280       key->unit[i].ModeA =
 281          translate_mode(texUnit->_CurrentCombine->ModeA);
 282
 283       key->unit[i].ScaleShiftRGB = texUnit->_CurrentCombine->ScaleShiftRGB;
 284       key->unit[i].ScaleShiftA = texUnit->_CurrentCombine->ScaleShiftA;
 285
 286       for (j=0;j<3;j++) {
 287          key->unit[i].OptRGB[j].Operand =
 288             translate_operand(texUnit->_CurrentCombine->OperandRGB[j]);
 289          key->unit[i].OptA[j].Operand =
 290             translate_operand(texUnit->_CurrentCombine->OperandA[j]);
 291          key->unit[i].OptRGB[j].Source =
 292             translate_source(texUnit->_CurrentCombine->SourceRGB[j]);
 293          key->unit[i].OptA[j].Source =
 294             translate_source(texUnit->_CurrentCombine->SourceA[j]);
 295       }
 296    }
 297
 298    if (ctx->_TriangleCaps & DD_SEPARATE_SPECULAR) {
 299       key->separate_specular = 1;
 300       inputs_referenced |= FRAG_BIT_COL1;
 301    }
 302
 303    if (ctx->Fog.Enabled) {
 304       key->fog_enabled = 1;
 305       key->fog_mode = translate_fog_mode(ctx->Fog.Mode);
 306       inputs_referenced |= FRAG_BIT_FOGC; /* maybe */
 307    }
 308
 309    key->inputs_available = (inputs_available & inputs_referenced);
 310 }
 311
 312 /* Use uregs to represent registers internally, translate to Mesa's
 313  * expected formats on emit.
 314  *
 315  * NOTE: These are passed by value extensively in this file rather
 316  * than as usual by pointer reference.  If this disturbs you, try
 317  * remembering they are just 32bits in size.
 318  *
 319  * GCC is smart enough to deal with these dword-sized structures in
 320  * much the same way as if I had defined them as dwords and was using
 321  * macros to access and set the fields.  This is much nicer and easier
 322  * to evolve.
 323  */
 324 struct ureg {
 325    GLuint file:4;
 326    GLuint idx:8;
 327    GLuint negatebase:1;
 328    GLuint abs:1;
 329    GLuint negateabs:1;
 330    GLuint swz:12;
 331    GLuint pad:5;
 332 };
 333
 334 static const struct ureg undef = {
 335    PROGRAM_UNDEFINED,
 336    ~0,
 337    0,
 338    0,
 339    0,
 340    0,
 341    0
 342 };
 343
 344
 345 /* State used to build the fragment program:
 346  */
 347 struct texenv_fragment_program {
 348    struct gl_fragment_program *program;
 349    GLcontext *ctx;
 350    struct state_key *state;
 351
 352    GLbitfield alu_temps;        /* Track texture indirections, see spec. */
 353    GLbitfield temps_output;     /* Track texture indirections, see spec. */
 354    GLbitfield temp_in_use;      /* Tracks temporary regs which are in use. */
 355    GLboolean error;
 356
 357    struct ureg src_texture[MAX_TEXTURE_UNITS];
 358    /* Reg containing each texture unit's sampled texture color,
 359     * else undef.
 360     */
 361
 362    struct ureg src_previous;    /* Reg containing color from previous
 363                                  * stage.  May need to be decl'd.
 364                                  */
 365
 366    GLuint last_tex_stage;       /* Number of last enabled texture unit */
 367
 368    struct ureg half;
 369    struct ureg one;
 370    struct ureg zero;
 371 };
 372
 373
 374
 375 static struct ureg make_ureg(GLuint file, GLuint idx)
 376 {
 377    struct ureg reg;
 378    reg.file = file;
 379    reg.idx = idx;
 380    reg.negatebase = 0;
 381    reg.abs = 0;
 382    reg.negateabs = 0;
 383    reg.swz = SWIZZLE_NOOP;
 384    reg.pad = 0;
 385    return reg;
 386 }
 387
 388 static struct ureg swizzle( struct ureg reg, int x, int y, int z, int w )
 389 {
 390    reg.swz = MAKE_SWIZZLE4(GET_SWZ(reg.swz, x),
 391                            GET_SWZ(reg.swz, y),
 392                            GET_SWZ(reg.swz, z),
 393                            GET_SWZ(reg.swz, w));
 394
 395    return reg;
 396 }
 397
 398 static struct ureg swizzle1( struct ureg reg, int x )
 399 {
 400    return swizzle(reg, x, x, x, x);
 401 }
 402
 403 static struct ureg negate( struct ureg reg )
 404 {
 405    reg.negatebase ^= 1;
 406    return reg;
 407 }
 408
 409 static GLboolean is_undef( struct ureg reg )
 410 {
 411    return reg.file == PROGRAM_UNDEFINED;
 412 }
 413
 414
 415 static struct ureg get_temp( struct texenv_fragment_program *p )
 416 {
 417    GLint bit;
 418
 419    /* First try and reuse temps which have been used already:
 420     */
 421    bit = _mesa_ffs( ~p->temp_in_use & p->alu_temps );
 422
 423    /* Then any unused temporary:
 424     */
 425    if (!bit)
 426       bit = _mesa_ffs( ~p->temp_in_use );
 427
 428    if (!bit) {
 429       _mesa_problem(NULL, "%s: out of temporaries\n", __FILE__);
 430       _mesa_exit(1);
 431    }
 432
 433    if ((GLuint) bit > p->program->Base.NumTemporaries)
 434       p->program->Base.NumTemporaries = bit;
 435
 436    p->temp_in_use |= 1<<(bit-1);
 437    return make_ureg(PROGRAM_TEMPORARY, (bit-1));
 438 }
 439
 440 static struct ureg get_tex_temp( struct texenv_fragment_program *p )
 441 {
 442    int bit;
 443
 444    /* First try to find available temp not previously used (to avoid
 445     * starting a new texture indirection).  According to the spec, the
 446     * ~p->temps_output isn't necessary, but will keep it there for
 447     * now:
 448     */
 449    bit = _mesa_ffs( ~p->temp_in_use & ~p->alu_temps & ~p->temps_output );
 450
 451    /* Then any unused temporary:
 452     */
 453    if (!bit)
 454       bit = _mesa_ffs( ~p->temp_in_use );
 455
 456    if (!bit) {
 457       _mesa_problem(NULL, "%s: out of temporaries\n", __FILE__);
 458       _mesa_exit(1);
 459    }
 460
 461    if ((GLuint) bit > p->program->Base.NumTemporaries)
 462       p->program->Base.NumTemporaries = bit;
 463
 464    p->temp_in_use |= 1<<(bit-1);
 465    return make_ureg(PROGRAM_TEMPORARY, (bit-1));
 466 }
 467
 468
 469 /** Mark a temp reg as being no longer allocatable. */
 470 static void reserve_temp( struct texenv_fragment_program *p, struct ureg r )
 471 {
 472    if (r.file == PROGRAM_TEMPORARY)
 473       p->temps_output |= (1 << r.idx);
 474 }
 475
 476
 477 static void release_temps(GLcontext *ctx, struct texenv_fragment_program *p )
 478 {
 479    GLuint max_temp = ctx->Const.FragmentProgram.MaxTemps;
 480
 481    /* KW: To support tex_env_crossbar, don't release the registers in
 482     * temps_output.
 483     */
 484    if (max_temp >= sizeof(int) * 8)
 485       p->temp_in_use = p->temps_output;
 486    else
 487       p->temp_in_use = ~((1<<max_temp)-1) | p->temps_output;
 488 }
 489
 490
 491 static struct ureg register_param5( struct texenv_fragment_program *p,
 492                                     GLint s0,
 493                                     GLint s1,
 494                                     GLint s2,
 495                                     GLint s3,
 496                                     GLint s4)
 497 {
 498    gl_state_index tokens[STATE_LENGTH];
 499    GLuint idx;
 500    tokens[0] = s0;
 501    tokens[1] = s1;
 502    tokens[2] = s2;
 503    tokens[3] = s3;
 504    tokens[4] = s4;
 505    idx = _mesa_add_state_reference( p->program->Base.Parameters, tokens );
 506    return make_ureg(PROGRAM_STATE_VAR, idx);
 507 }
 508
 509
 510 #define register_param1(p,s0)          register_param5(p,s0,0,0,0,0)
 511 #define register_param2(p,s0,s1)       register_param5(p,s0,s1,0,0,0)
 512 #define register_param3(p,s0,s1,s2)    register_param5(p,s0,s1,s2,0,0)
 513 #define register_param4(p,s0,s1,s2,s3) register_param5(p,s0,s1,s2,s3,0)
 514
 515 static GLuint frag_to_vert_attrib( GLuint attrib )
 516 {
 517    switch (attrib) {
 518    case FRAG_ATTRIB_COL0: return VERT_ATTRIB_COLOR0;
 519    case FRAG_ATTRIB_COL1: return VERT_ATTRIB_COLOR1;
 520    default:
 521       assert(attrib >= FRAG_ATTRIB_TEX0);
 522       assert(attrib <= FRAG_ATTRIB_TEX7);
 523       return attrib - FRAG_ATTRIB_TEX0 + VERT_ATTRIB_TEX0;
 524    }
 525 }
 526
 527
 528 static struct ureg register_input( struct texenv_fragment_program *p, GLuint input )
 529 {
 530    if (p->state->inputs_available & (1<<input)) {
 531       p->program->Base.InputsRead |= (1 << input);
 532       return make_ureg(PROGRAM_INPUT, input);
 533    }
 534    else {
 535       GLuint idx = frag_to_vert_attrib( input );
 536       return register_param3( p, STATE_INTERNAL, STATE_CURRENT_ATTRIB, idx );
 537    }
 538 }
 539
 540
 541 static void emit_arg( struct prog_src_register *reg,
 542                       struct ureg ureg )
 543 {
 544    reg->File = ureg.file;
 545    reg->Index = ureg.idx;
 546    reg->Swizzle = ureg.swz;
 547    reg->NegateBase = ureg.negatebase ? 0xf : 0x0;
 548    reg->Abs = ureg.abs;
 549    reg->NegateAbs = ureg.negateabs;
 550 }
 551
 552 static void emit_dst( struct prog_dst_register *dst,
 553                       struct ureg ureg, GLuint mask )
 554 {
 555    dst->File = ureg.file;
 556    dst->Index = ureg.idx;
 557    dst->WriteMask = mask;
 558    dst->CondMask = COND_TR;  /* always pass cond test */
 559    dst->CondSwizzle = SWIZZLE_NOOP;
 560 }
 561
 562 static struct prog_instruction *
 563 emit_op(struct texenv_fragment_program *p,
 564         enum prog_opcode op,
 565         struct ureg dest,
 566         GLuint mask,
 567         GLboolean saturate,
 568         struct ureg src0,
 569         struct ureg src1,
 570         struct ureg src2 )
 571 {
 572    GLuint nr = p->program->Base.NumInstructions++;
 573    struct prog_instruction *inst = &p->program->Base.Instructions[nr];
 574
 575    assert(nr < MAX_INSTRUCTIONS);
 576
 577    _mesa_init_instructions(inst, 1);
 578    inst->Opcode = op;
 579
 580    emit_arg( &inst->SrcReg[0], src0 );
 581    emit_arg( &inst->SrcReg[1], src1 );
 582    emit_arg( &inst->SrcReg[2], src2 );
 583
 584    inst->SaturateMode = saturate ? SATURATE_ZERO_ONE : SATURATE_OFF;
 585
 586    emit_dst( &inst->DstReg, dest, mask );
 587
 588 #if 0
 589    /* Accounting for indirection tracking:
 590     */
 591    if (dest.file == PROGRAM_TEMPORARY)
 592       p->temps_output |= 1 << dest.idx;
 593 #endif
 594
 595    return inst;
 596 }
 597
 598
 599 static struct ureg emit_arith( struct texenv_fragment_program *p,
 600                                enum prog_opcode op,
 601                                struct ureg dest,
 602                                GLuint mask,
 603                                GLboolean saturate,
 604                                struct ureg src0,
 605                                struct ureg src1,
 606                                struct ureg src2 )
 607 {
 608    emit_op(p, op, dest, mask, saturate, src0, src1, src2);
 609
 610    /* Accounting for indirection tracking:
 611     */
 612    if (src0.file == PROGRAM_TEMPORARY)
 613       p->alu_temps |= 1 << src0.idx;
 614
 615    if (!is_undef(src1) && src1.file == PROGRAM_TEMPORARY)
 616       p->alu_temps |= 1 << src1.idx;
 617
 618    if (!is_undef(src2) && src2.file == PROGRAM_TEMPORARY)
 619       p->alu_temps |= 1 << src2.idx;
 620
 621    if (dest.file == PROGRAM_TEMPORARY)
 622       p->alu_temps |= 1 << dest.idx;
 623
 624    p->program->Base.NumAluInstructions++;
 625    return dest;
 626 }
 627
 628 static struct ureg emit_texld( struct texenv_fragment_program *p,
 629                                enum prog_opcode op,
 630                                struct ureg dest,
 631                                GLuint destmask,
 632                                GLuint tex_unit,
 633                                GLuint tex_idx,
 634                                struct ureg coord )
 635 {
 636    struct prog_instruction *inst = emit_op( p, op,
 637                                           dest, destmask,
 638                                           GL_FALSE,     /* don't saturate? */
 639                                           coord,        /* arg 0? */
 640                                           undef,
 641                                           undef);
 642
 643    inst->TexSrcTarget = tex_idx;
 644    inst->TexSrcUnit = tex_unit;
 645
 646    p->program->Base.NumTexInstructions++;
 647
 648    /* Accounting for indirection tracking:
 649     */
 650    reserve_temp(p, dest);
 651
 652    /* Is this a texture indirection?
 653     */
 654    if ((coord.file == PROGRAM_TEMPORARY &&
 655         (p->temps_output & (1<<coord.idx))) ||
 656        (dest.file == PROGRAM_TEMPORARY &&
 657         (p->alu_temps & (1<<dest.idx)))) {
 658       p->program->Base.NumTexIndirections++;
 659       p->temps_output = 1<<coord.idx;
 660       p->alu_temps = 0;
 661       assert(0);                /* KW: texture env crossbar */
 662    }
 663
 664    return dest;
 665 }
 666
 667
 668 static struct ureg register_const4f( struct texenv_fragment_program *p,
 669                                      GLfloat s0,
 670                                      GLfloat s1,
 671                                      GLfloat s2,
 672                                      GLfloat s3)
 673 {
 674    GLfloat values[4];
 675    GLuint idx, swizzle;
 676    struct ureg r;
 677    values[0] = s0;
 678    values[1] = s1;
 679    values[2] = s2;
 680    values[3] = s3;
 681    idx = _mesa_add_unnamed_constant( p->program->Base.Parameters, values, 4,
 682                                      &swizzle );
 683    r = make_ureg(PROGRAM_CONSTANT, idx);
 684    r.swz = swizzle;
 685    return r;
 686 }
 687
 688 #define register_scalar_const(p, s0)    register_const4f(p, s0, s0, s0, s0)
 689 #define register_const1f(p, s0)         register_const4f(p, s0, 0, 0, 1)
 690 #define register_const2f(p, s0, s1)     register_const4f(p, s0, s1, 0, 1)
 691 #define register_const3f(p, s0, s1, s2) register_const4f(p, s0, s1, s2, 1)
 692
 693
 694 static struct ureg get_one( struct texenv_fragment_program *p )
 695 {
 696    if (is_undef(p->one))
 697       p->one = register_scalar_const(p, 1.0);
 698    return p->one;
 699 }
 700
 701 static struct ureg get_half( struct texenv_fragment_program *p )
 702 {
 703    if (is_undef(p->half))
 704       p->half = register_scalar_const(p, 0.5);
 705    return p->half;
 706 }
 707
 708 static struct ureg get_zero( struct texenv_fragment_program *p )
 709 {
 710    if (is_undef(p->zero))
 711       p->zero = register_scalar_const(p, 0.0);
 712    return p->zero;
 713 }
 714
 715
 716 static void program_error( struct texenv_fragment_program *p, const char *msg )
 717 {
 718    _mesa_problem(NULL, msg);
 719    p->error = 1;
 720 }
 721
 722 static struct ureg get_source( struct texenv_fragment_program *p,
 723                                GLuint src, GLuint unit )
 724 {
 725    switch (src) {
 726    case SRC_TEXTURE:
 727       assert(!is_undef(p->src_texture[unit]));
 728       return p->src_texture[unit];
 729
 730    case SRC_TEXTURE0:
 731    case SRC_TEXTURE1:
 732    case SRC_TEXTURE2:
 733    case SRC_TEXTURE3:
 734    case SRC_TEXTURE4:
 735    case SRC_TEXTURE5:
 736    case SRC_TEXTURE6:
 737    case SRC_TEXTURE7:
 738       assert(!is_undef(p->src_texture[src - SRC_TEXTURE0]));
 739       return p->src_texture[src - SRC_TEXTURE0];
 740
 741    case SRC_CONSTANT:
 742       return register_param2(p, STATE_TEXENV_COLOR, unit);
 743
 744    case SRC_PRIMARY_COLOR:
 745       return register_input(p, FRAG_ATTRIB_COL0);
 746
 747    case SRC_PREVIOUS:
 748    default:
 749       if (is_undef(p->src_previous))
 750          return register_input(p, FRAG_ATTRIB_COL0);
 751       else
 752          return p->src_previous;
 753    }
 754 }
 755
 756 static struct ureg emit_combine_source( struct texenv_fragment_program *p,
 757                                         GLuint mask,
 758                                         GLuint unit,
 759                                         GLuint source,
 760                                         GLuint operand )
 761 {
 762    struct ureg arg, src, one;
 763
 764    src = get_source(p, source, unit);
 765
 766    switch (operand) {
 767    case OPR_ONE_MINUS_SRC_COLOR:
 768       /* Get unused tmp,
 769        * Emit tmp = 1.0 - arg.xyzw
 770        */
 771       arg = get_temp( p );
 772       one = get_one( p );
 773       return emit_arith( p, OPCODE_SUB, arg, mask, 0, one, src, undef);
 774
 775    case OPR_SRC_ALPHA:
 776       if (mask == WRITEMASK_W)
 777          return src;
 778       else
 779          return swizzle1( src, SWIZZLE_W );
 780    case OPR_ONE_MINUS_SRC_ALPHA:
 781       /* Get unused tmp,
 782        * Emit tmp = 1.0 - arg.wwww
 783        */
 784       arg = get_temp(p);
 785       one = get_one(p);
 786       return emit_arith(p, OPCODE_SUB, arg, mask, 0,
 787                         one, swizzle1(src, SWIZZLE_W), undef);
 788    case OPR_ZERO:
 789       return get_zero(p);
 790    case OPR_ONE:
 791       return get_one(p);
 792    case OPR_SRC_COLOR:
 793    default:
 794       return src;
 795    }
 796 }
 797
 798 static GLboolean args_match( struct state_key *key, GLuint unit )
 799 {
 800    GLuint i, nr = key->unit[unit].NumArgsRGB;
 801
 802    for (i = 0 ; i < nr ; i++) {
 803       if (key->unit[unit].OptA[i].Source != key->unit[unit].OptRGB[i].Source)
 804          return GL_FALSE;
 805
 806       switch(key->unit[unit].OptA[i].Operand) {
 807       case OPR_SRC_ALPHA:
 808          switch(key->unit[unit].OptRGB[i].Operand) {
 809          case OPR_SRC_COLOR:
 810          case OPR_SRC_ALPHA:
 811             break;
 812          default:
 813             return GL_FALSE;
 814          }
 815          break;
 816       case OPR_ONE_MINUS_SRC_ALPHA:
 817          switch(key->unit[unit].OptRGB[i].Operand) {
 818          case OPR_ONE_MINUS_SRC_COLOR:
 819          case OPR_ONE_MINUS_SRC_ALPHA:
 820             break;
 821          default:
 822             return GL_FALSE;
 823          }
 824          break;
 825       default:
 826          return GL_FALSE;       /* impossible */
 827       }
 828    }
 829
 830    return GL_TRUE;
 831 }
 832
 833 static struct ureg emit_combine( struct texenv_fragment_program *p,
 834                                  struct ureg dest,
 835                                  GLuint mask,
 836                                  GLboolean saturate,
 837                                  GLuint unit,
 838                                  GLuint nr,
 839                                  GLuint mode,
 840                                  const struct mode_opt *opt)
 841 {
 842    struct ureg src[3];
 843    struct ureg tmp, half;
 844    GLuint i;
 845
 846    tmp = undef; /* silence warning (bug 5318) */
 847
 848    for (i = 0; i < nr; i++)
 849       src[i] = emit_combine_source( p, mask, unit, opt[i].Source, opt[i].Operand );
 850
 851    switch (mode) {
 852    case MODE_REPLACE:
 853       if (mask == WRITEMASK_XYZW && !saturate)
 854          return src[0];
 855       else
 856          return emit_arith( p, OPCODE_MOV, dest, mask, saturate, src[0], undef, undef );
 857    case MODE_MODULATE:
 858       return emit_arith( p, OPCODE_MUL, dest, mask, saturate,
 859                          src[0], src[1], undef );
 860    case MODE_ADD:
 861       return emit_arith( p, OPCODE_ADD, dest, mask, saturate,
 862                          src[0], src[1], undef );
 863    case MODE_ADD_SIGNED:
 864       /* tmp = arg0 + arg1
 865        * result = tmp - .5
 866        */
 867       half = get_half(p);
 868       tmp = get_temp( p );
 869       emit_arith( p, OPCODE_ADD, tmp, mask, 0, src[0], src[1], undef );
 870       emit_arith( p, OPCODE_SUB, dest, mask, saturate, tmp, half, undef );
 871       return dest;
 872    case MODE_INTERPOLATE:
 873       /* Arg0 * (Arg2) + Arg1 * (1-Arg2) -- note arguments are reordered:
 874        */
 875       return emit_arith( p, OPCODE_LRP, dest, mask, saturate, src[2], src[0], src[1] );
 876
 877    case MODE_SUBTRACT:
 878       return emit_arith( p, OPCODE_SUB, dest, mask, saturate, src[0], src[1], undef );
 879
 880    case MODE_DOT3_RGBA:
 881    case MODE_DOT3_RGBA_EXT:
 882    case MODE_DOT3_RGB_EXT:
 883    case MODE_DOT3_RGB: {
 884       struct ureg tmp0 = get_temp( p );
 885       struct ureg tmp1 = get_temp( p );
 886       struct ureg neg1 = register_scalar_const(p, -1);
 887       struct ureg two  = register_scalar_const(p, 2);
 888
 889       /* tmp0 = 2*src0 - 1
 890        * tmp1 = 2*src1 - 1
 891        *
 892        * dst = tmp0 dot3 tmp1
 893        */
 894       emit_arith( p, OPCODE_MAD, tmp0, WRITEMASK_XYZW, 0,
 895                   two, src[0], neg1);
 896
 897       if (_mesa_memcmp(&src[0], &src[1], sizeof(struct ureg)) == 0)
 898          tmp1 = tmp0;
 899       else
 900          emit_arith( p, OPCODE_MAD, tmp1, WRITEMASK_XYZW, 0,
 901                      two, src[1], neg1);
 902       emit_arith( p, OPCODE_DP3, dest, mask, saturate, tmp0, tmp1, undef);
 903       return dest;
 904    }
 905    case MODE_MODULATE_ADD_ATI:
 906       /* Arg0 * Arg2 + Arg1 */
 907       return emit_arith( p, OPCODE_MAD, dest, mask, saturate,
 908                          src[0], src[2], src[1] );
 909    case MODE_MODULATE_SIGNED_ADD_ATI: {
 910       /* Arg0 * Arg2 + Arg1 - 0.5 */
 911       struct ureg tmp0 = get_temp(p);
 912       half = get_half(p);
 913       emit_arith( p, OPCODE_MAD, tmp0, mask, 0, src[0], src[2], src[1] );
 914       emit_arith( p, OPCODE_SUB, dest, mask, saturate, tmp0, half, undef );
 915       return dest;
 916    }
 917    case MODE_MODULATE_SUBTRACT_ATI:
 918       /* Arg0 * Arg2 - Arg1 */
 919       emit_arith( p, OPCODE_MAD, dest, mask, 0, src[0], src[2], negate(src[1]) );
 920       return dest;
 921    default:
 922       return src[0];
 923    }
 924 }
 925
 926
 927 /**
 928  * Generate instructions for one texture unit's env/combiner mode.
 929  */
 930 static struct ureg
 931 emit_texenv(struct texenv_fragment_program *p, GLuint unit)
 932 {
 933    struct state_key *key = p->state;
 934    GLboolean saturate = (unit < p->last_tex_stage);
 935    GLuint rgb_shift, alpha_shift;
 936    struct ureg out, shift;
 937    struct ureg dest;
 938
 939    if (!key->unit[unit].enabled) {
 940       return get_source(p, SRC_PREVIOUS, 0);
 941    }
 942
 943    switch (key->unit[unit].ModeRGB) {
 944    case MODE_DOT3_RGB_EXT:
 945       alpha_shift = key->unit[unit].ScaleShiftA;
 946       rgb_shift = 0;
 947       break;
 948    case MODE_DOT3_RGBA_EXT:
 949       alpha_shift = 0;
 950       rgb_shift = 0;
 951       break;
 952    default:
 953       rgb_shift = key->unit[unit].ScaleShiftRGB;
 954       alpha_shift = key->unit[unit].ScaleShiftA;
 955       break;
 956    }
 957
 958    /* If this is the very last calculation, emit direct to output reg:
 959     */
 960    if (key->separate_specular ||
 961        unit != p->last_tex_stage ||
 962        alpha_shift ||
 963        rgb_shift)
 964       dest = get_temp( p );
 965    else
 966       dest = make_ureg(PROGRAM_OUTPUT, FRAG_RESULT_COLR);
 967
 968    /* Emit the RGB and A combine ops
 969     */
 970    if (key->unit[unit].ModeRGB == key->unit[unit].ModeA &&
 971        args_match(key, unit)) {
 972       out = emit_combine( p, dest, WRITEMASK_XYZW, saturate,
 973                           unit,
 974                           key->unit[unit].NumArgsRGB,
 975                           key->unit[unit].ModeRGB,
 976                           key->unit[unit].OptRGB);
 977    }
 978    else if (key->unit[unit].ModeRGB == MODE_DOT3_RGBA_EXT ||
 979             key->unit[unit].ModeRGB == MODE_DOT3_RGBA) {
 980
 981       out = emit_combine( p, dest, WRITEMASK_XYZW, saturate,
 982                           unit,
 983                           key->unit[unit].NumArgsRGB,
 984                           key->unit[unit].ModeRGB,
 985                           key->unit[unit].OptRGB);
 986    }
 987    else {
 988       /* Need to do something to stop from re-emitting identical
 989        * argument calculations here:
 990        */
 991       out = emit_combine( p, dest, WRITEMASK_XYZ, saturate,
 992                           unit,
 993                           key->unit[unit].NumArgsRGB,
 994                           key->unit[unit].ModeRGB,
 995                           key->unit[unit].OptRGB);
 996       out = emit_combine( p, dest, WRITEMASK_W, saturate,
 997                           unit,
 998                           key->unit[unit].NumArgsA,
 999                           key->unit[unit].ModeA,
1000                           key->unit[unit].OptA);
1001    }
1002
1003    /* Deal with the final shift:
1004     */
1005    if (alpha_shift || rgb_shift) {
1006       if (rgb_shift == alpha_shift) {
1007          shift = register_scalar_const(p, (GLfloat)(1<<rgb_shift));
1008       }
1009       else {
1010          shift = register_const4f(p,
1011                                   (GLfloat)(1<<rgb_shift),
1012                                   (GLfloat)(1<<rgb_shift),
1013                                   (GLfloat)(1<<rgb_shift),
1014                                   (GLfloat)(1<<alpha_shift));
1015       }
1016       return emit_arith( p, OPCODE_MUL, dest, WRITEMASK_XYZW,
1017                          saturate, out, shift, undef );
1018    }
1019    else
1020       return out;
1021 }
1022
1023
1024 /**
1025  * Generate instruction for getting a texture source term.
1026  */
1027 static void load_texture( struct texenv_fragment_program *p, GLuint unit )
1028 {
1029    if (is_undef(p->src_texture[unit])) {
1030       GLuint dim = p->state->unit[unit].source_index;
1031       struct ureg texcoord = register_input(p, FRAG_ATTRIB_TEX0+unit);
1032       struct ureg tmp = get_tex_temp( p );
1033
1034       if (dim == TEXTURE_UNKNOWN_INDEX)
1035          program_error(p, "TexSrcBit");
1036
1037       /* TODO: Use D0_MASK_XY where possible.
1038        */
1039       if (p->state->unit[unit].enabled) {
1040          p->src_texture[unit] = emit_texld( p, OPCODE_TXP,
1041                                             tmp, WRITEMASK_XYZW,
1042                                             unit, dim, texcoord );
1043          p->program->Base.SamplersUsed |= (1 << unit);
1044          /* This identity mapping should already be in place
1045           * (see _mesa_init_program_struct()) but let's be safe.
1046           */
1047          p->program->Base.SamplerUnits[unit] = unit;
1048       }
1049       else
1050          p->src_texture[unit] = get_zero(p);
1051    }
1052 }
1053
1054 static GLboolean load_texenv_source( struct texenv_fragment_program *p,
1055                                      GLuint src, GLuint unit )
1056 {
1057    switch (src) {
1058    case SRC_TEXTURE:
1059       load_texture(p, unit);
1060       break;
1061
1062    case SRC_TEXTURE0:
1063    case SRC_TEXTURE1:
1064    case SRC_TEXTURE2:
1065    case SRC_TEXTURE3:
1066    case SRC_TEXTURE4:
1067    case SRC_TEXTURE5:
1068    case SRC_TEXTURE6:
1069    case SRC_TEXTURE7:
1070       load_texture(p, src - SRC_TEXTURE0);
1071       break;
1072
1073    default:
1074       break;
1075    }
1076
1077    return GL_TRUE;
1078 }
1079
1080
1081 /**
1082  * Generate instructions for loading all texture source terms.
1083  */
1084 static GLboolean
1085 load_texunit_sources( struct texenv_fragment_program *p, int unit )
1086 {
1087    struct state_key *key = p->state;
1088    GLuint i;
1089
1090    for (i = 0; i < key->unit[unit].NumArgsRGB; i++) {
1091       load_texenv_source( p, key->unit[unit].OptRGB[i].Source, unit);
1092    }
1093
1094    for (i = 0; i < key->unit[unit].NumArgsA; i++) {
1095       load_texenv_source( p, key->unit[unit].OptA[i].Source, unit );
1096    }
1097
1098    return GL_TRUE;
1099 }
1100
1101
1102 /**
1103  * Generate a new fragment program which implements the context's
1104  * current texture env/combine mode.
1105  */
1106 static void
1107 create_new_program(GLcontext *ctx, struct state_key *key,
1108                    struct gl_fragment_program *program)
1109 {
1110    struct prog_instruction instBuffer[MAX_INSTRUCTIONS];
1111    struct texenv_fragment_program p;
1112    GLuint unit;
1113    struct ureg cf, out;
1114
1115    _mesa_memset(&p, 0, sizeof(p));
1116    p.ctx = ctx;
1117    p.state = key;
1118    p.program = program;
1119
1120    /* During code generation, use locally-allocated instruction buffer,
1121     * then alloc dynamic storage below.
1122     */
1123    p.program->Base.Instructions = instBuffer;
1124    p.program->Base.Target = GL_FRAGMENT_PROGRAM_ARB;
1125    p.program->Base.NumTexIndirections = 1;      /* correct? */
1126    p.program->Base.NumTexInstructions = 0;
1127    p.program->Base.NumAluInstructions = 0;
1128    p.program->Base.String = NULL;
1129    p.program->Base.NumInstructions =
1130    p.program->Base.NumTemporaries =
1131    p.program->Base.NumParameters =
1132    p.program->Base.NumAttributes = p.program->Base.NumAddressRegs = 0;
1133    p.program->Base.Parameters = _mesa_new_parameter_list();
1134
1135    p.program->Base.InputsRead = 0;
1136    p.program->Base.OutputsWritten = 1 << FRAG_RESULT_COLR;
1137
1138    for (unit = 0; unit < MAX_TEXTURE_UNITS; unit++)
1139       p.src_texture[unit] = undef;
1140
1141    p.src_previous = undef;
1142    p.half = undef;
1143    p.zero = undef;
1144    p.one = undef;
1145
1146    p.last_tex_stage = 0;
1147    release_temps(ctx, &p);
1148
1149    if (key->enabled_units) {
1150       /* First pass - to support texture_env_crossbar, first identify
1151        * all referenced texture sources and emit texld instructions
1152        * for each:
1153        */
1154       for (unit = 0 ; unit < ctx->Const.MaxTextureUnits ; unit++)
1155          if (key->unit[unit].enabled) {
1156             load_texunit_sources( &p, unit );
1157             p.last_tex_stage = unit;
1158          }
1159
1160       /* Second pass - emit combine instructions to build final color:
1161        */
1162       for (unit = 0 ; unit < ctx->Const.MaxTextureUnits; unit++)
1163          if (key->enabled_units & (1<<unit)) {
1164             p.src_previous = emit_texenv( &p, unit );
1165             reserve_temp(&p, p.src_previous); /* don't re-use this temp reg */
1166             release_temps(ctx, &p);     /* release all temps */
1167          }
1168    }
1169
1170    cf = get_source( &p, SRC_PREVIOUS, 0 );
1171    out = make_ureg( PROGRAM_OUTPUT, FRAG_RESULT_COLR );
1172
1173    if (key->separate_specular) {
1174       /* Emit specular add.
1175        */
1176       struct ureg s = register_input(&p, FRAG_ATTRIB_COL1);
1177       emit_arith( &p, OPCODE_ADD, out, WRITEMASK_XYZ, 0, cf, s, undef );
1178       emit_arith( &p, OPCODE_MOV, out, WRITEMASK_W, 0, cf, undef, undef );
1179    }
1180    else if (_mesa_memcmp(&cf, &out, sizeof(cf)) != 0) {
1181       /* Will wind up in here if no texture enabled or a couple of
1182        * other scenarios (GL_REPLACE for instance).
1183        */
1184       emit_arith( &p, OPCODE_MOV, out, WRITEMASK_XYZW, 0, cf, undef, undef );
1185    }
1186
1187    /* Finish up:
1188     */
1189    emit_arith( &p, OPCODE_END, undef, WRITEMASK_XYZW, 0, undef, undef, undef);
1190
1191    if (key->fog_enabled) {
1192       /* Pull fog mode from GLcontext, the value in the state key is
1193        * a reduced value and not what is expected in FogOption
1194        */
1195       p.program->FogOption = ctx->Fog.Mode;
1196       p.program->Base.InputsRead |= FRAG_BIT_FOGC; /* XXX new */
1197    } else
1198       p.program->FogOption = GL_NONE;
1199
1200    if (p.program->Base.NumTexIndirections > ctx->Const.FragmentProgram.MaxTexIndirections)
1201       program_error(&p, "Exceeded max nr indirect texture lookups");
1202
1203    if (p.program->Base.NumTexInstructions > ctx->Const.FragmentProgram.MaxTexInstructions)
1204       program_error(&p, "Exceeded max TEX instructions");
1205
1206    if (p.program->Base.NumAluInstructions > ctx->Const.FragmentProgram.MaxAluInstructions)
1207       program_error(&p, "Exceeded max ALU instructions");
1208
1209    ASSERT(p.program->Base.NumInstructions <= MAX_INSTRUCTIONS);
1210
1211    /* Allocate final instruction array */
1212    p.program->Base.Instructions
1213       = _mesa_alloc_instructions(p.program->Base.NumInstructions);
1214    if (!p.program->Base.Instructions) {
1215       _mesa_error(ctx, GL_OUT_OF_MEMORY,
1216                   "generating tex env program");
1217       return;
1218    }
1219    _mesa_copy_instructions(p.program->Base.Instructions, instBuffer,
1220                            p.program->Base.NumInstructions);
1221
1222    if (p.program->FogOption) {
1223       _mesa_append_fog_code(ctx, p.program);
1224       p.program->FogOption = GL_NONE;
1225    }
1226
1227
1228    /* Notify driver the fragment program has (actually) changed.
1229     */
1230    if (ctx->Driver.ProgramStringNotify) {
1231       ctx->Driver.ProgramStringNotify( ctx, GL_FRAGMENT_PROGRAM_ARB,
1232                                        &p.program->Base );
1233    }
1234
1235    if (DISASSEM) {
1236       _mesa_print_program(&p.program->Base);
1237       _mesa_printf("\n");
1238    }
1239 }
1240
1241
1242 /**
1243  * Return a fragment program which implements the current
1244  * fixed-function texture, fog and color-sum operations.
1245  */
1246 struct gl_fragment_program *
1247 _mesa_get_fixed_func_fragment_program(GLcontext *ctx)
1248 {
1249    struct gl_fragment_program *prog;
1250    struct state_key key;
1251
1252    make_state_key(ctx, &key);
1253
1254    prog = (struct gl_fragment_program *)
1255       _mesa_search_program_cache(ctx->FragmentProgram.Cache,
1256                                  &key, sizeof(key));
1257
1258    if (!prog) {
1259       prog = (struct gl_fragment_program *)
1260          ctx->Driver.NewProgram(ctx, GL_FRAGMENT_PROGRAM_ARB, 0);
1261
1262       create_new_program(ctx, &key, prog);
1263
1264       _mesa_program_cache_insert(ctx, ctx->FragmentProgram.Cache,
1265                                  &key, sizeof(key), &prog->Base);
1266    }
1267
1268    return prog;
1269 }
1270
1271
1272
1273 /**
1274  * If _MaintainTexEnvProgram is set we'll generate a fragment program that
1275  * implements the current texture env/combine mode.
1276  * This function generates that program and puts it into effect.
1277  */
1278 void
1279 _mesa_UpdateTexEnvProgram( GLcontext *ctx )
1280 {
1281    const struct gl_fragment_program *prev = ctx->FragmentProgram._Current;
1282
1283    ASSERT(ctx->FragmentProgram._MaintainTexEnvProgram);
1284
1285    /* If a conventional fragment program/shader isn't in effect... */
1286    if (!ctx->FragmentProgram._Enabled &&
1287        (!ctx->Shader.CurrentProgram ||
1288         !ctx->Shader.CurrentProgram->FragmentProgram) ) {
1289
1290       ctx->FragmentProgram._Current
1291          = ctx->FragmentProgram._TexEnvProgram
1292          = _mesa_get_fixed_func_fragment_program(ctx);
1293    }
1294
1295    /* Tell the driver about the change.  Could define a new target for
1296     * this?
1297     */
1298    if (ctx->FragmentProgram._Current != prev && ctx->Driver.BindProgram) {
1299       ctx->Driver.BindProgram(ctx, GL_FRAGMENT_PROGRAM_ARB,
1300                          (struct gl_program *) ctx->FragmentProgram._Current);
1301    }
1302 }