src/mesa/shader/program.c

   1 /*
   2  * Mesa 3-D graphics library
   3  * Version:  6.5.3
   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 program.c
  27  * Vertex and fragment program support functions.
  28  * \author Brian Paul
  29  */
  30
  31
  32 #include "main/glheader.h"
  33 #include "main/context.h"
  34 #include "main/hash.h"
  35 #include "program.h"
  36 #include "prog_cache.h"
  37 #include "prog_parameter.h"
  38 #include "prog_instruction.h"
  39
  40
  41 /**
  42  * A pointer to this dummy program is put into the hash table when
  43  * glGenPrograms is called.
  44  */
  45 struct gl_program _mesa_DummyProgram;
  46
  47
  48 /**
  49  * Init context's vertex/fragment program state
  50  */
  51 void
  52 _mesa_init_program(GLcontext *ctx)
  53 {
  54    GLuint i;
  55
  56    /*
  57     * If this assertion fails, we need to increase the field
  58     * size for register indexes.
  59     */
  60    ASSERT(ctx->Const.VertexProgram.MaxUniformComponents / 4
  61           <= (1 << INST_INDEX_BITS));
  62    ASSERT(ctx->Const.FragmentProgram.MaxUniformComponents / 4
  63           <= (1 << INST_INDEX_BITS));
  64
  65    ctx->Program.ErrorPos = -1;
  66    ctx->Program.ErrorString = _mesa_strdup("");
  67
  68 #if FEATURE_NV_vertex_program || FEATURE_ARB_vertex_program
  69    ctx->VertexProgram.Enabled = GL_FALSE;
  70 #if FEATURE_es2_glsl
  71    ctx->VertexProgram.PointSizeEnabled = GL_TRUE;
  72 #else
  73    ctx->VertexProgram.PointSizeEnabled = GL_FALSE;
  74 #endif
  75    ctx->VertexProgram.TwoSideEnabled = GL_FALSE;
  76    _mesa_reference_vertprog(ctx, &ctx->VertexProgram.Current,
  77                             ctx->Shared->DefaultVertexProgram);
  78    assert(ctx->VertexProgram.Current);
  79    for (i = 0; i < MAX_NV_VERTEX_PROGRAM_PARAMS / 4; i++) {
  80       ctx->VertexProgram.TrackMatrix[i] = GL_NONE;
  81       ctx->VertexProgram.TrackMatrixTransform[i] = GL_IDENTITY_NV;
  82    }
  83    ctx->VertexProgram.Cache = _mesa_new_program_cache();
  84 #endif
  85
  86 #if FEATURE_NV_fragment_program || FEATURE_ARB_fragment_program
  87    ctx->FragmentProgram.Enabled = GL_FALSE;
  88    _mesa_reference_fragprog(ctx, &ctx->FragmentProgram.Current,
  89                             ctx->Shared->DefaultFragmentProgram);
  90    assert(ctx->FragmentProgram.Current);
  91    ctx->FragmentProgram.Cache = _mesa_new_program_cache();
  92 #endif
  93
  94
  95    /* XXX probably move this stuff */
  96 #if FEATURE_ATI_fragment_shader
  97    ctx->ATIFragmentShader.Enabled = GL_FALSE;
  98    ctx->ATIFragmentShader.Current = ctx->Shared->DefaultFragmentShader;
  99    assert(ctx->ATIFragmentShader.Current);
 100    ctx->ATIFragmentShader.Current->RefCount++;
 101 #endif
 102 }
 103
 104
 105 /**
 106  * Free a context's vertex/fragment program state
 107  */
 108 void
 109 _mesa_free_program_data(GLcontext *ctx)
 110 {
 111 #if FEATURE_NV_vertex_program || FEATURE_ARB_vertex_program
 112    _mesa_reference_vertprog(ctx, &ctx->VertexProgram.Current, NULL);
 113    _mesa_delete_program_cache(ctx, ctx->VertexProgram.Cache);
 114 #endif
 115 #if FEATURE_NV_fragment_program || FEATURE_ARB_fragment_program
 116    _mesa_reference_fragprog(ctx, &ctx->FragmentProgram.Current, NULL);
 117    _mesa_delete_program_cache(ctx, ctx->FragmentProgram.Cache);
 118 #endif
 119    /* XXX probably move this stuff */
 120 #if FEATURE_ATI_fragment_shader
 121    if (ctx->ATIFragmentShader.Current) {
 122       ctx->ATIFragmentShader.Current->RefCount--;
 123       if (ctx->ATIFragmentShader.Current->RefCount <= 0) {
 124          _mesa_free(ctx->ATIFragmentShader.Current);
 125       }
 126    }
 127 #endif
 128    _mesa_free((void *) ctx->Program.ErrorString);
 129 }
 130
 131
 132 /**
 133  * Update the default program objects in the given context to reference those
 134  * specified in the shared state and release those referencing the old
 135  * shared state.
 136  */
 137 void
 138 _mesa_update_default_objects_program(GLcontext *ctx)
 139 {
 140 #if FEATURE_NV_vertex_program || FEATURE_ARB_vertex_program
 141    _mesa_reference_vertprog(ctx, &ctx->VertexProgram.Current,
 142                             (struct gl_vertex_program *)
 143                             ctx->Shared->DefaultVertexProgram);
 144    assert(ctx->VertexProgram.Current);
 145 #endif
 146
 147 #if FEATURE_NV_fragment_program || FEATURE_ARB_fragment_program
 148    _mesa_reference_fragprog(ctx, &ctx->FragmentProgram.Current,
 149                             (struct gl_fragment_program *)
 150                             ctx->Shared->DefaultFragmentProgram);
 151    assert(ctx->FragmentProgram.Current);
 152 #endif
 153
 154    /* XXX probably move this stuff */
 155 #if FEATURE_ATI_fragment_shader
 156    if (ctx->ATIFragmentShader.Current) {
 157       ctx->ATIFragmentShader.Current->RefCount--;
 158       if (ctx->ATIFragmentShader.Current->RefCount <= 0) {
 159          _mesa_free(ctx->ATIFragmentShader.Current);
 160       }
 161    }
 162    ctx->ATIFragmentShader.Current = (struct ati_fragment_shader *) ctx->Shared->DefaultFragmentShader;
 163    assert(ctx->ATIFragmentShader.Current);
 164    ctx->ATIFragmentShader.Current->RefCount++;
 165 #endif
 166 }
 167
 168
 169 /**
 170  * Set the vertex/fragment program error state (position and error string).
 171  * This is generally called from within the parsers.
 172  */
 173 void
 174 _mesa_set_program_error(GLcontext *ctx, GLint pos, const char *string)
 175 {
 176    ctx->Program.ErrorPos = pos;
 177    _mesa_free((void *) ctx->Program.ErrorString);
 178    if (!string)
 179       string = "";
 180    ctx->Program.ErrorString = _mesa_strdup(string);
 181 }
 182
 183
 184 /**
 185  * Find the line number and column for 'pos' within 'string'.
 186  * Return a copy of the line which contains 'pos'.  Free the line with
 187  * _mesa_free().
 188  * \param string  the program string
 189  * \param pos     the position within the string
 190  * \param line    returns the line number corresponding to 'pos'.
 191  * \param col     returns the column number corresponding to 'pos'.
 192  * \return copy of the line containing 'pos'.
 193  */
 194 const GLubyte *
 195 _mesa_find_line_column(const GLubyte *string, const GLubyte *pos,
 196                        GLint *line, GLint *col)
 197 {
 198    const GLubyte *lineStart = string;
 199    const GLubyte *p = string;
 200    GLubyte *s;
 201    int len;
 202
 203    *line = 1;
 204
 205    while (p != pos) {
 206       if (*p == (GLubyte) '\n') {
 207          (*line)++;
 208          lineStart = p + 1;
 209       }
 210       p++;
 211    }
 212
 213    *col = (pos - lineStart) + 1;
 214
 215    /* return copy of this line */
 216    while (*p != 0 && *p != '\n')
 217       p++;
 218    len = p - lineStart;
 219    s = (GLubyte *) _mesa_malloc(len + 1);
 220    _mesa_memcpy(s, lineStart, len);
 221    s[len] = 0;
 222
 223    return s;
 224 }
 225
 226
 227 /**
 228  * Initialize a new vertex/fragment program object.
 229  */
 230 static struct gl_program *
 231 _mesa_init_program_struct( GLcontext *ctx, struct gl_program *prog,
 232                            GLenum target, GLuint id)
 233 {
 234    (void) ctx;
 235    if (prog) {
 236       GLuint i;
 237       _mesa_bzero(prog, sizeof(*prog));
 238       prog->Id = id;
 239       prog->Target = target;
 240       prog->Resident = GL_TRUE;
 241       prog->RefCount = 1;
 242       prog->Format = GL_PROGRAM_FORMAT_ASCII_ARB;
 243
 244       /* default mapping from samplers to texture units */
 245       for (i = 0; i < MAX_SAMPLERS; i++)
 246          prog->SamplerUnits[i] = i;
 247    }
 248
 249    return prog;
 250 }
 251
 252
 253 /**
 254  * Initialize a new fragment program object.
 255  */
 256 struct gl_program *
 257 _mesa_init_fragment_program( GLcontext *ctx, struct gl_fragment_program *prog,
 258                              GLenum target, GLuint id)
 259 {
 260    if (prog)
 261       return _mesa_init_program_struct( ctx, &prog->Base, target, id );
 262    else
 263       return NULL;
 264 }
 265
 266
 267 /**
 268  * Initialize a new vertex program object.
 269  */
 270 struct gl_program *
 271 _mesa_init_vertex_program( GLcontext *ctx, struct gl_vertex_program *prog,
 272                            GLenum target, GLuint id)
 273 {
 274    if (prog)
 275       return _mesa_init_program_struct( ctx, &prog->Base, target, id );
 276    else
 277       return NULL;
 278 }
 279
 280
 281 /**
 282  * Allocate and initialize a new fragment/vertex program object but
 283  * don't put it into the program hash table.  Called via
 284  * ctx->Driver.NewProgram.  May be overridden (ie. replaced) by a
 285  * device driver function to implement OO deriviation with additional
 286  * types not understood by this function.
 287  *
 288  * \param ctx  context
 289  * \param id   program id/number
 290  * \param target  program target/type
 291  * \return  pointer to new program object
 292  */
 293 struct gl_program *
 294 _mesa_new_program(GLcontext *ctx, GLenum target, GLuint id)
 295 {
 296    struct gl_program *prog;
 297    switch (target) {
 298    case GL_VERTEX_PROGRAM_ARB: /* == GL_VERTEX_PROGRAM_NV */
 299       prog = _mesa_init_vertex_program(ctx, CALLOC_STRUCT(gl_vertex_program),
 300                                        target, id );
 301       break;
 302    case GL_FRAGMENT_PROGRAM_NV:
 303    case GL_FRAGMENT_PROGRAM_ARB:
 304       prog =_mesa_init_fragment_program(ctx,
 305                                          CALLOC_STRUCT(gl_fragment_program),
 306                                          target, id );
 307       break;
 308    default:
 309       _mesa_problem(ctx, "bad target in _mesa_new_program");
 310       prog = NULL;
 311    }
 312    return prog;
 313 }
 314
 315
 316 /**
 317  * Delete a program and remove it from the hash table, ignoring the
 318  * reference count.
 319  * Called via ctx->Driver.DeleteProgram.  May be wrapped (OO deriviation)
 320  * by a device driver function.
 321  */
 322 void
 323 _mesa_delete_program(GLcontext *ctx, struct gl_program *prog)
 324 {
 325    (void) ctx;
 326    ASSERT(prog);
 327    ASSERT(prog->RefCount==0);
 328
 329    if (prog == &_mesa_DummyProgram)
 330       return;
 331
 332    if (prog->String)
 333       _mesa_free(prog->String);
 334
 335    _mesa_free_instructions(prog->Instructions, prog->NumInstructions);
 336
 337    if (prog->Parameters) {
 338       _mesa_free_parameter_list(prog->Parameters);
 339    }
 340    if (prog->Varying) {
 341       _mesa_free_parameter_list(prog->Varying);
 342    }
 343    if (prog->Attributes) {
 344       _mesa_free_parameter_list(prog->Attributes);
 345    }
 346
 347    /* XXX this is a little ugly */
 348    if (prog->Target == GL_VERTEX_PROGRAM_ARB) {
 349       struct gl_vertex_program *vprog = (struct gl_vertex_program *) prog;
 350       if (vprog->TnlData)
 351          _mesa_free(vprog->TnlData);
 352    }
 353
 354    _mesa_free(prog);
 355 }
 356
 357
 358 /**
 359  * Return the gl_program object for a given ID.
 360  * Basically just a wrapper for _mesa_HashLookup() to avoid a lot of
 361  * casts elsewhere.
 362  */
 363 struct gl_program *
 364 _mesa_lookup_program(GLcontext *ctx, GLuint id)
 365 {
 366    if (id)
 367       return (struct gl_program *) _mesa_HashLookup(ctx->Shared->Programs, id);
 368    else
 369       return NULL;
 370 }
 371
 372
 373 /**
 374  * Reference counting for vertex/fragment programs
 375  */
 376 void
 377 _mesa_reference_program(GLcontext *ctx,
 378                         struct gl_program **ptr,
 379                         struct gl_program *prog)
 380 {
 381    assert(ptr);
 382    if (*ptr && prog) {
 383       /* sanity check */
 384       if ((*ptr)->Target == GL_VERTEX_PROGRAM_ARB)
 385          ASSERT(prog->Target == GL_VERTEX_PROGRAM_ARB);
 386       else if ((*ptr)->Target == GL_FRAGMENT_PROGRAM_ARB)
 387          ASSERT(prog->Target == GL_FRAGMENT_PROGRAM_ARB ||
 388                 prog->Target == GL_FRAGMENT_PROGRAM_NV);
 389    }
 390    if (*ptr == prog) {
 391       return;  /* no change */
 392    }
 393    if (*ptr) {
 394       GLboolean deleteFlag;
 395
 396       /*_glthread_LOCK_MUTEX((*ptr)->Mutex);*/
 397 #if 0
 398       printf("Program %p ID=%u Target=%s  Refcount-- to %d\n",
 399              *ptr, (*ptr)->Id,
 400              ((*ptr)->Target == GL_VERTEX_PROGRAM_ARB ? "VP" : "FP"),
 401              (*ptr)->RefCount - 1);
 402 #endif
 403       ASSERT((*ptr)->RefCount > 0);
 404       (*ptr)->RefCount--;
 405
 406       deleteFlag = ((*ptr)->RefCount == 0);
 407       /*_glthread_UNLOCK_MUTEX((*ptr)->Mutex);*/
 408
 409       if (deleteFlag) {
 410          ASSERT(ctx);
 411          ctx->Driver.DeleteProgram(ctx, *ptr);
 412       }
 413
 414       *ptr = NULL;
 415    }
 416
 417    assert(!*ptr);
 418    if (prog) {
 419       /*_glthread_LOCK_MUTEX(prog->Mutex);*/
 420       prog->RefCount++;
 421 #if 0
 422       printf("Program %p ID=%u Target=%s  Refcount++ to %d\n",
 423              prog, prog->Id,
 424              (prog->Target == GL_VERTEX_PROGRAM_ARB ? "VP" : "FP"),
 425              prog->RefCount);
 426 #endif
 427       /*_glthread_UNLOCK_MUTEX(prog->Mutex);*/
 428    }
 429
 430    *ptr = prog;
 431 }
 432
 433
 434 /**
 435  * Return a copy of a program.
 436  * XXX Problem here if the program object is actually OO-derivation
 437  * made by a device driver.
 438  */
 439 struct gl_program *
 440 _mesa_clone_program(GLcontext *ctx, const struct gl_program *prog)
 441 {
 442    struct gl_program *clone;
 443
 444    clone = ctx->Driver.NewProgram(ctx, prog->Target, prog->Id);
 445    if (!clone)
 446       return NULL;
 447
 448    assert(clone->Target == prog->Target);
 449    assert(clone->RefCount == 1);
 450
 451    clone->String = (GLubyte *) _mesa_strdup((char *) prog->String);
 452    clone->Format = prog->Format;
 453    clone->Instructions = _mesa_alloc_instructions(prog->NumInstructions);
 454    if (!clone->Instructions) {
 455       _mesa_reference_program(ctx, &clone, NULL);
 456       return NULL;
 457    }
 458    _mesa_copy_instructions(clone->Instructions, prog->Instructions,
 459                            prog->NumInstructions);
 460    clone->InputsRead = prog->InputsRead;
 461    clone->OutputsWritten = prog->OutputsWritten;
 462    clone->SamplersUsed = prog->SamplersUsed;
 463    clone->ShadowSamplers = prog->ShadowSamplers;
 464    memcpy(clone->TexturesUsed, prog->TexturesUsed, sizeof(prog->TexturesUsed));
 465
 466    if (prog->Parameters)
 467       clone->Parameters = _mesa_clone_parameter_list(prog->Parameters);
 468    memcpy(clone->LocalParams, prog->LocalParams, sizeof(clone->LocalParams));
 469    if (prog->Varying)
 470       clone->Varying = _mesa_clone_parameter_list(prog->Varying);
 471    if (prog->Attributes)
 472       clone->Attributes = _mesa_clone_parameter_list(prog->Attributes);
 473    memcpy(clone->LocalParams, prog->LocalParams, sizeof(clone->LocalParams));
 474    clone->NumInstructions = prog->NumInstructions;
 475    clone->NumTemporaries = prog->NumTemporaries;
 476    clone->NumParameters = prog->NumParameters;
 477    clone->NumAttributes = prog->NumAttributes;
 478    clone->NumAddressRegs = prog->NumAddressRegs;
 479    clone->NumNativeInstructions = prog->NumNativeInstructions;
 480    clone->NumNativeTemporaries = prog->NumNativeTemporaries;
 481    clone->NumNativeParameters = prog->NumNativeParameters;
 482    clone->NumNativeAttributes = prog->NumNativeAttributes;
 483    clone->NumNativeAddressRegs = prog->NumNativeAddressRegs;
 484    clone->NumAluInstructions = prog->NumAluInstructions;
 485    clone->NumTexInstructions = prog->NumTexInstructions;
 486    clone->NumTexIndirections = prog->NumTexIndirections;
 487    clone->NumNativeAluInstructions = prog->NumNativeAluInstructions;
 488    clone->NumNativeTexInstructions = prog->NumNativeTexInstructions;
 489    clone->NumNativeTexIndirections = prog->NumNativeTexIndirections;
 490
 491    switch (prog->Target) {
 492    case GL_VERTEX_PROGRAM_ARB:
 493       {
 494          const struct gl_vertex_program *vp
 495             = (const struct gl_vertex_program *) prog;
 496          struct gl_vertex_program *vpc = (struct gl_vertex_program *) clone;
 497          vpc->IsPositionInvariant = vp->IsPositionInvariant;
 498       }
 499       break;
 500    case GL_FRAGMENT_PROGRAM_ARB:
 501       {
 502          const struct gl_fragment_program *fp
 503             = (const struct gl_fragment_program *) prog;
 504          struct gl_fragment_program *fpc = (struct gl_fragment_program *) clone;
 505          fpc->FogOption = fp->FogOption;
 506          fpc->UsesKill = fp->UsesKill;
 507       }
 508       break;
 509    default:
 510       _mesa_problem(NULL, "Unexpected target in _mesa_clone_program");
 511    }
 512
 513    return clone;
 514 }
 515
 516
 517 /**
 518  * Insert 'count' NOP instructions at 'start' in the given program.
 519  * Adjust branch targets accordingly.
 520  */
 521 GLboolean
 522 _mesa_insert_instructions(struct gl_program *prog, GLuint start, GLuint count)
 523 {
 524    const GLuint origLen = prog->NumInstructions;
 525    const GLuint newLen = origLen + count;
 526    struct prog_instruction *newInst;
 527    GLuint i;
 528
 529    /* adjust branches */
 530    for (i = 0; i < prog->NumInstructions; i++) {
 531       struct prog_instruction *inst = prog->Instructions + i;
 532       if (inst->BranchTarget > 0) {
 533          if ((GLuint)inst->BranchTarget >= start) {
 534             inst->BranchTarget += count;
 535          }
 536       }
 537    }
 538
 539    /* Alloc storage for new instructions */
 540    newInst = _mesa_alloc_instructions(newLen);
 541    if (!newInst) {
 542       return GL_FALSE;
 543    }
 544
 545    /* Copy 'start' instructions into new instruction buffer */
 546    _mesa_copy_instructions(newInst, prog->Instructions, start);
 547
 548    /* init the new instructions */
 549    _mesa_init_instructions(newInst + start, count);
 550
 551    /* Copy the remaining/tail instructions to new inst buffer */
 552    _mesa_copy_instructions(newInst + start + count,
 553                            prog->Instructions + start,
 554                            origLen - start);
 555
 556    /* free old instructions */
 557    _mesa_free_instructions(prog->Instructions, origLen);
 558
 559    /* install new instructions */
 560    prog->Instructions = newInst;
 561    prog->NumInstructions = newLen;
 562
 563    return GL_TRUE;
 564 }
 565
 566 /**
 567  * Delete 'count' instructions at 'start' in the given program.
 568  * Adjust branch targets accordingly.
 569  */
 570 GLboolean
 571 _mesa_delete_instructions(struct gl_program *prog, GLuint start, GLuint count)
 572 {
 573    const GLuint origLen = prog->NumInstructions;
 574    const GLuint newLen = origLen - count;
 575    struct prog_instruction *newInst;
 576    GLuint i;
 577
 578    /* adjust branches */
 579    for (i = 0; i < prog->NumInstructions; i++) {
 580       struct prog_instruction *inst = prog->Instructions + i;
 581       if (inst->BranchTarget > 0) {
 582          if (inst->BranchTarget > start) {
 583             inst->BranchTarget -= count;
 584          }
 585       }
 586    }
 587
 588    /* Alloc storage for new instructions */
 589    newInst = _mesa_alloc_instructions(newLen);
 590    if (!newInst) {
 591       return GL_FALSE;
 592    }
 593
 594    /* Copy 'start' instructions into new instruction buffer */
 595    _mesa_copy_instructions(newInst, prog->Instructions, start);
 596
 597    /* Copy the remaining/tail instructions to new inst buffer */
 598    _mesa_copy_instructions(newInst + start,
 599                            prog->Instructions + start + count,
 600                            newLen - start);
 601
 602    /* free old instructions */
 603    _mesa_free_instructions(prog->Instructions, origLen);
 604
 605    /* install new instructions */
 606    prog->Instructions = newInst;
 607    prog->NumInstructions = newLen;
 608
 609    return GL_TRUE;
 610 }
 611
 612
 613 /**
 614  * Search instructions for registers that match (oldFile, oldIndex),
 615  * replacing them with (newFile, newIndex).
 616  */
 617 static void
 618 replace_registers(struct prog_instruction *inst, GLuint numInst,
 619                   GLuint oldFile, GLuint oldIndex,
 620                   GLuint newFile, GLuint newIndex)
 621 {
 622    GLuint i, j;
 623    for (i = 0; i < numInst; i++) {
 624       /* src regs */
 625       for (j = 0; j < _mesa_num_inst_src_regs(inst->Opcode); j++) {
 626          if (inst[i].SrcReg[j].File == oldFile &&
 627              inst[i].SrcReg[j].Index == oldIndex) {
 628             inst[i].SrcReg[j].File = newFile;
 629             inst[i].SrcReg[j].Index = newIndex;
 630          }
 631       }
 632       /* dst reg */
 633       if (inst[i].DstReg.File == oldFile && inst[i].DstReg.Index == oldIndex) {
 634          inst[i].DstReg.File = newFile;
 635          inst[i].DstReg.Index = newIndex;
 636       }
 637    }
 638 }
 639
 640
 641 /**
 642  * Search instructions for references to program parameters.  When found,
 643  * increment the parameter index by 'offset'.
 644  * Used when combining programs.
 645  */
 646 static void
 647 adjust_param_indexes(struct prog_instruction *inst, GLuint numInst,
 648                      GLuint offset)
 649 {
 650    GLuint i, j;
 651    for (i = 0; i < numInst; i++) {
 652       for (j = 0; j < _mesa_num_inst_src_regs(inst->Opcode); j++) {
 653          GLuint f = inst[i].SrcReg[j].File;
 654          if (f == PROGRAM_CONSTANT ||
 655              f == PROGRAM_UNIFORM ||
 656              f == PROGRAM_STATE_VAR) {
 657             inst[i].SrcReg[j].Index += offset;
 658          }
 659       }
 660    }
 661 }
 662
 663
 664 /**
 665  * Combine two programs into one.  Fix instructions so the outputs of
 666  * the first program go to the inputs of the second program.
 667  */
 668 struct gl_program *
 669 _mesa_combine_programs(GLcontext *ctx,
 670                        const struct gl_program *progA,
 671                        const struct gl_program *progB)
 672 {
 673    struct prog_instruction *newInst;
 674    struct gl_program *newProg;
 675    const GLuint lenA = progA->NumInstructions - 1; /* omit END instr */
 676    const GLuint lenB = progB->NumInstructions;
 677    const GLuint numParamsA = _mesa_num_parameters(progA->Parameters);
 678    const GLuint newLength = lenA + lenB;
 679    GLbitfield inputsB;
 680    GLuint i;
 681
 682    ASSERT(progA->Target == progB->Target);
 683
 684    newInst = _mesa_alloc_instructions(newLength);
 685    if (!newInst)
 686       return GL_FALSE;
 687
 688    _mesa_copy_instructions(newInst, progA->Instructions, lenA);
 689    _mesa_copy_instructions(newInst + lenA, progB->Instructions, lenB);
 690
 691    /* adjust branch / instruction addresses for B's instructions */
 692    for (i = 0; i < lenB; i++) {
 693       newInst[lenA + i].BranchTarget += lenA;
 694    }
 695
 696    newProg = ctx->Driver.NewProgram(ctx, progA->Target, 0);
 697    newProg->Instructions = newInst;
 698    newProg->NumInstructions = newLength;
 699
 700    if (newProg->Target == GL_FRAGMENT_PROGRAM_ARB) {
 701       struct gl_fragment_program *fprogA, *fprogB, *newFprog;
 702       GLbitfield progB_inputsRead = progB->InputsRead;
 703       GLint progB_colorFile, progB_colorIndex;
 704
 705       fprogA = (struct gl_fragment_program *) progA;
 706       fprogB = (struct gl_fragment_program *) progB;
 707       newFprog = (struct gl_fragment_program *) newProg;
 708
 709       newFprog->UsesKill = fprogA->UsesKill || fprogB->UsesKill;
 710
 711       /* We'll do a search and replace for instances
 712        * of progB_colorFile/progB_colorIndex below...
 713        */
 714       progB_colorFile = PROGRAM_INPUT;
 715       progB_colorIndex = FRAG_ATTRIB_COL0;
 716
 717       /*
 718        * The fragment program may get color from a state var rather than
 719        * a fragment input (vertex output) if it's constant.
 720        * See the texenvprogram.c code.
 721        * So, search the program's parameter list now to see if the program
 722        * gets color from a state var instead of a conventional fragment
 723        * input register.
 724        */
 725       for (i = 0; i < progB->Parameters->NumParameters; i++) {
 726          struct gl_program_parameter *p = &progB->Parameters->Parameters[i];
 727          if (p->Type == PROGRAM_STATE_VAR &&
 728              p->StateIndexes[0] == STATE_INTERNAL &&
 729              p->StateIndexes[1] == STATE_CURRENT_ATTRIB &&
 730              p->StateIndexes[2] == VERT_ATTRIB_COLOR0) {
 731             progB_inputsRead |= FRAG_BIT_COL0;
 732             progB_colorFile = PROGRAM_STATE_VAR;
 733             progB_colorIndex = i;
 734             break;
 735          }
 736       }
 737
 738       /* Connect color outputs of fprogA to color inputs of fprogB, via a
 739        * new temporary register.
 740        */
 741       if ((progA->OutputsWritten & (1 << FRAG_RESULT_COLOR)) &&
 742           (progB_inputsRead & FRAG_BIT_COL0)) {
 743          GLint tempReg = _mesa_find_free_register(newProg, PROGRAM_TEMPORARY);
 744          if (tempReg < 0) {
 745             _mesa_problem(ctx, "No free temp regs found in "
 746                           "_mesa_combine_programs(), using 31");
 747             tempReg = 31;
 748          }
 749          /* replace writes to result.color[0] with tempReg */
 750          replace_registers(newInst, lenA,
 751                            PROGRAM_OUTPUT, FRAG_RESULT_COLOR,
 752                            PROGRAM_TEMPORARY, tempReg);
 753          /* replace reads from the input color with tempReg */
 754          replace_registers(newInst + lenA, lenB,
 755                            progB_colorFile, progB_colorIndex, /* search for */
 756                            PROGRAM_TEMPORARY, tempReg  /* replace with */ );
 757       }
 758
 759       /* compute combined program's InputsRead */
 760       inputsB = progB_inputsRead;
 761       if (progA->OutputsWritten & (1 << FRAG_RESULT_COLOR)) {
 762          inputsB &= ~(1 << FRAG_ATTRIB_COL0);
 763       }
 764       newProg->InputsRead = progA->InputsRead | inputsB;
 765       newProg->OutputsWritten = progB->OutputsWritten;
 766       newProg->SamplersUsed = progA->SamplersUsed | progB->SamplersUsed;
 767    }
 768    else {
 769       /* vertex program */
 770       assert(0);      /* XXX todo */
 771    }
 772
 773    /*
 774     * Merge parameters (uniforms, constants, etc)
 775     */
 776    newProg->Parameters = _mesa_combine_parameter_lists(progA->Parameters,
 777                                                        progB->Parameters);
 778
 779    adjust_param_indexes(newInst + lenA, lenB, numParamsA);
 780
 781
 782    return newProg;
 783 }
 784
 785
 786
 787
 788 /**
 789  * Scan the given program to find a free register of the given type.
 790  * \param regFile - PROGRAM_INPUT, PROGRAM_OUTPUT or PROGRAM_TEMPORARY
 791  */
 792 GLint
 793 _mesa_find_free_register(const struct gl_program *prog, GLuint regFile)
 794 {
 795    GLboolean used[MAX_PROGRAM_TEMPS];
 796    GLuint i, k;
 797
 798    assert(regFile == PROGRAM_INPUT ||
 799           regFile == PROGRAM_OUTPUT ||
 800           regFile == PROGRAM_TEMPORARY);
 801
 802    _mesa_memset(used, 0, sizeof(used));
 803
 804    for (i = 0; i < prog->NumInstructions; i++) {
 805       const struct prog_instruction *inst = prog->Instructions + i;
 806       const GLuint n = _mesa_num_inst_src_regs(inst->Opcode);
 807
 808       for (k = 0; k < n; k++) {
 809          if (inst->SrcReg[k].File == regFile) {
 810             used[inst->SrcReg[k].Index] = GL_TRUE;
 811          }
 812       }
 813    }
 814
 815    for (i = 0; i < MAX_PROGRAM_TEMPS; i++) {
 816       if (!used[i])
 817          return i;
 818    }
 819
 820    return -1;
 821 }