src/mesa/shader/slang/slang_link.c

   1 /*
   2  * Mesa 3-D graphics library
   3  * Version:  7.2
   4  *
   5  * Copyright (C) 2008  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 slang_link.c
  27  * GLSL linker
  28  * \author Brian Paul
  29  */
  30
  31 #include "main/imports.h"
  32 #include "main/context.h"
  33 #include "main/hash.h"
  34 #include "main/macros.h"
  35 #include "shader/program.h"
  36 #include "shader/prog_instruction.h"
  37 #include "shader/prog_parameter.h"
  38 #include "shader/prog_print.h"
  39 #include "shader/prog_statevars.h"
  40 #include "shader/prog_uniform.h"
  41 #include "shader/shader_api.h"
  42 #include "slang_link.h"
  43
  44
  45 /** cast wrapper */
  46 static struct gl_vertex_program *
  47 vertex_program(struct gl_program *prog)
  48 {
  49    assert(prog->Target == GL_VERTEX_PROGRAM_ARB);
  50    return (struct gl_vertex_program *) prog;
  51 }
  52
  53
  54 /** cast wrapper */
  55 static struct gl_fragment_program *
  56 fragment_program(struct gl_program *prog)
  57 {
  58    assert(prog->Target == GL_FRAGMENT_PROGRAM_ARB);
  59    return (struct gl_fragment_program *) prog;
  60 }
  61
  62
  63 /**
  64  * Record a linking error.
  65  */
  66 static void
  67 link_error(struct gl_shader_program *shProg, const char *msg)
  68 {
  69    if (shProg->InfoLog) {
  70       _mesa_free(shProg->InfoLog);
  71    }
  72    shProg->InfoLog = _mesa_strdup(msg);
  73    shProg->LinkStatus = GL_FALSE;
  74 }
  75
  76
  77
  78 /**
  79  * Linking varying vars involves rearranging varying vars so that the
  80  * vertex program's output varyings matches the order of the fragment
  81  * program's input varyings.
  82  */
  83 static GLboolean
  84 link_varying_vars(struct gl_shader_program *shProg, struct gl_program *prog)
  85 {
  86    GLuint *map, i, firstVarying, newFile;
  87
  88    map = (GLuint *) malloc(prog->Varying->NumParameters * sizeof(GLuint));
  89    if (!map)
  90       return GL_FALSE;
  91
  92    for (i = 0; i < prog->Varying->NumParameters; i++) {
  93       /* see if this varying is in the linked varying list */
  94       const struct gl_program_parameter *var = prog->Varying->Parameters + i;
  95       GLint j = _mesa_lookup_parameter_index(shProg->Varying, -1, var->Name);
  96       if (j >= 0) {
  97          /* already in list, check size */
  98          if (var->Size != shProg->Varying->Parameters[j].Size) {
  99             /* error */
 100             link_error(shProg, "mismatched varying variable types");
 101             return GL_FALSE;
 102          }
 103       }
 104       else {
 105          /* not already in linked list */
 106          j = _mesa_add_varying(shProg->Varying, var->Name, var->Size);
 107       }
 108
 109       /* map varying[i] to varying[j].
 110        * Note: the loop here takes care of arrays or large (sz>4) vars.
 111        */
 112       {
 113          GLint sz = var->Size;
 114          while (sz > 0) {
 115             /*printf("Link varying from %d to %d\n", i, j);*/
 116             map[i++] = j++;
 117             sz -= 4;
 118          }
 119          i--; /* go back one */
 120       }
 121    }
 122
 123
 124    /* Varying variables are treated like other vertex program outputs
 125     * (and like other fragment program inputs).  The position of the
 126     * first varying differs for vertex/fragment programs...
 127     * Also, replace File=PROGRAM_VARYING with File=PROGRAM_INPUT/OUTPUT.
 128     */
 129    if (prog->Target == GL_VERTEX_PROGRAM_ARB) {
 130       firstVarying = VERT_RESULT_VAR0;
 131       newFile = PROGRAM_OUTPUT;
 132    }
 133    else {
 134       assert(prog->Target == GL_FRAGMENT_PROGRAM_ARB);
 135       firstVarying = FRAG_ATTRIB_VAR0;
 136       newFile = PROGRAM_INPUT;
 137    }
 138
 139    /* OK, now scan the program/shader instructions looking for varying vars,
 140     * replacing the old index with the new index.
 141     */
 142    for (i = 0; i < prog->NumInstructions; i++) {
 143       struct prog_instruction *inst = prog->Instructions + i;
 144       GLuint j;
 145
 146       if (inst->DstReg.File == PROGRAM_VARYING) {
 147          inst->DstReg.File = newFile;
 148          inst->DstReg.Index = map[ inst->DstReg.Index ] + firstVarying;
 149       }
 150
 151       for (j = 0; j < 3; j++) {
 152          if (inst->SrcReg[j].File == PROGRAM_VARYING) {
 153             inst->SrcReg[j].File = newFile;
 154             inst->SrcReg[j].Index = map[ inst->SrcReg[j].Index ] + firstVarying;
 155          }
 156       }
 157    }
 158
 159    free(map);
 160
 161    /* these will get recomputed before linking is completed */
 162    prog->InputsRead = 0x0;
 163    prog->OutputsWritten = 0x0;
 164
 165    return GL_TRUE;
 166 }
 167
 168
 169 /**
 170  * Build the shProg->Uniforms list.
 171  * This is basically a list/index of all uniforms found in either/both of
 172  * the vertex and fragment shaders.
 173  */
 174 static void
 175 link_uniform_vars(struct gl_shader_program *shProg,
 176                   struct gl_program *prog,
 177                   GLuint *numSamplers)
 178 {
 179    GLuint samplerMap[MAX_SAMPLERS];
 180    GLuint i;
 181
 182    for (i = 0; i < prog->Parameters->NumParameters; i++) {
 183       const struct gl_program_parameter *p = prog->Parameters->Parameters + i;
 184
 185       /*
 186        * XXX FIX NEEDED HERE
 187        * We should also be adding a uniform if p->Type == PROGRAM_STATE_VAR.
 188        * For example, modelview matrix, light pos, etc.
 189        * Also, we need to update the state-var name-generator code to
 190        * generate GLSL-style names, like "gl_LightSource[0].position".
 191        * Furthermore, we'll need to fix the state-var's size/datatype info.
 192        */
 193
 194       if ((p->Type == PROGRAM_UNIFORM && p->Used) ||
 195           p->Type == PROGRAM_SAMPLER) {
 196          struct gl_uniform *uniform =
 197             _mesa_append_uniform(shProg->Uniforms, p->Name, prog->Target, i);
 198          if (uniform)
 199             uniform->Initialized = p->Initialized;
 200       }
 201
 202       if (p->Type == PROGRAM_SAMPLER) {
 203          /* Allocate a new sampler index */
 204          GLuint sampNum = *numSamplers;
 205          GLuint oldSampNum = (GLuint) prog->Parameters->ParameterValues[i][0];
 206          assert(oldSampNum < MAX_SAMPLERS);
 207          samplerMap[oldSampNum] = sampNum;
 208          (*numSamplers)++;
 209       }
 210    }
 211
 212
 213    /* OK, now scan the program/shader instructions looking for sampler vars,
 214     * replacing the old index with the new index.
 215     */
 216    prog->SamplersUsed = 0x0;
 217    for (i = 0; i < prog->NumInstructions; i++) {
 218       struct prog_instruction *inst = prog->Instructions + i;
 219       if (_mesa_is_tex_instruction(inst->Opcode)) {
 220          /*
 221          printf("====== remap sampler from %d to %d\n",
 222                 inst->Sampler, map[ inst->Sampler ]);
 223          */
 224          /* here, texUnit is really samplerUnit */
 225          assert(inst->TexSrcUnit < MAX_SAMPLERS);
 226          inst->TexSrcUnit = samplerMap[inst->TexSrcUnit];
 227          prog->SamplerTargets[inst->TexSrcUnit] = inst->TexSrcTarget;
 228          prog->SamplersUsed |= (1 << inst->TexSrcUnit);
 229       }
 230    }
 231
 232 }
 233
 234
 235 /**
 236  * Resolve binding of generic vertex attributes.
 237  * For example, if the vertex shader declared "attribute vec4 foobar" we'll
 238  * allocate a generic vertex attribute for "foobar" and plug that value into
 239  * the vertex program instructions.
 240  * But if the user called glBindAttributeLocation(), those bindings will
 241  * have priority.
 242  */
 243 static GLboolean
 244 _slang_resolve_attributes(struct gl_shader_program *shProg,
 245                           const struct gl_program *origProg,
 246                           struct gl_program *linkedProg)
 247 {
 248    GLint attribMap[MAX_VERTEX_ATTRIBS];
 249    GLuint i, j;
 250    GLbitfield usedAttributes;
 251
 252    assert(origProg != linkedProg);
 253    assert(origProg->Target == GL_VERTEX_PROGRAM_ARB);
 254    assert(linkedProg->Target == GL_VERTEX_PROGRAM_ARB);
 255
 256    if (!shProg->Attributes)
 257       shProg->Attributes = _mesa_new_parameter_list();
 258
 259    if (linkedProg->Attributes) {
 260       _mesa_free_parameter_list(linkedProg->Attributes);
 261    }
 262    linkedProg->Attributes = _mesa_new_parameter_list();
 263
 264
 265    /* Build a bitmask indicating which attribute indexes have been
 266     * explicitly bound by the user with glBindAttributeLocation().
 267     */
 268    usedAttributes = 0x0;
 269    for (i = 0; i < shProg->Attributes->NumParameters; i++) {
 270       GLint attr = shProg->Attributes->Parameters[i].StateIndexes[0];
 271       usedAttributes |= (1 << attr);
 272    }
 273
 274    /* initialize the generic attribute map entries to -1 */
 275    for (i = 0; i < MAX_VERTEX_ATTRIBS; i++) {
 276       attribMap[i] = -1;
 277    }
 278
 279    /*
 280     * Scan program for generic attribute references
 281     */
 282    for (i = 0; i < linkedProg->NumInstructions; i++) {
 283       struct prog_instruction *inst = linkedProg->Instructions + i;
 284       for (j = 0; j < 3; j++) {
 285          if (inst->SrcReg[j].File == PROGRAM_INPUT &&
 286              inst->SrcReg[j].Index >= VERT_ATTRIB_GENERIC0) {
 287             /*
 288              * OK, we've found a generic vertex attribute reference.
 289              */
 290             const GLint k = inst->SrcReg[j].Index - VERT_ATTRIB_GENERIC0;
 291
 292             GLint attr = attribMap[k];
 293
 294             if (attr < 0) {
 295                /* Need to figure out attribute mapping now.
 296                 */
 297                const char *name = origProg->Attributes->Parameters[k].Name;
 298                const GLint size = origProg->Attributes->Parameters[k].Size;
 299                const GLenum type =origProg->Attributes->Parameters[k].DataType;
 300                GLint index;
 301
 302                /* See if there's a user-defined attribute binding for
 303                 * this name.
 304                 */
 305                index = _mesa_lookup_parameter_index(shProg->Attributes,
 306                                                     -1, name);
 307                if (index >= 0) {
 308                   /* Found a user-defined binding */
 309                   attr = shProg->Attributes->Parameters[index].StateIndexes[0];
 310                }
 311                else {
 312                   /* No user-defined binding, choose our own attribute number.
 313                    * Start at 1 since generic attribute 0 always aliases
 314                    * glVertex/position.
 315                    */
 316                   for (attr = 1; attr < MAX_VERTEX_ATTRIBS; attr++) {
 317                      if (((1 << attr) & usedAttributes) == 0)
 318                         break;
 319                   }
 320                   if (attr == MAX_VERTEX_ATTRIBS) {
 321                      link_error(shProg, "Too many vertex attributes");
 322                      return GL_FALSE;
 323                   }
 324
 325                   /* mark this attribute as used */
 326                   usedAttributes |= (1 << attr);
 327                }
 328
 329                attribMap[k] = attr;
 330
 331                /* Save the final name->attrib binding so it can be queried
 332                 * with glGetAttributeLocation().
 333                 */
 334                _mesa_add_attribute(linkedProg->Attributes, name,
 335                                    size, type, attr);
 336             }
 337
 338             assert(attr >= 0);
 339
 340             /* update the instruction's src reg */
 341             inst->SrcReg[j].Index = VERT_ATTRIB_GENERIC0 + attr;
 342          }
 343       }
 344    }
 345
 346    return GL_TRUE;
 347 }
 348
 349
 350 /**
 351  * Scan program instructions to update the program's NumTemporaries field.
 352  * Note: this implemenation relies on the code generator allocating
 353  * temps in increasing order (0, 1, 2, ... ).
 354  */
 355 static void
 356 _slang_count_temporaries(struct gl_program *prog)
 357 {
 358    GLuint i, j;
 359    GLint maxIndex = -1;
 360
 361    for (i = 0; i < prog->NumInstructions; i++) {
 362       const struct prog_instruction *inst = prog->Instructions + i;
 363       const GLuint numSrc = _mesa_num_inst_src_regs(inst->Opcode);
 364       for (j = 0; j < numSrc; j++) {
 365          if (inst->SrcReg[j].File == PROGRAM_TEMPORARY) {
 366             if (maxIndex < inst->SrcReg[j].Index)
 367                maxIndex = inst->SrcReg[j].Index;
 368          }
 369          if (inst->DstReg.File == PROGRAM_TEMPORARY) {
 370             if (maxIndex < (GLint) inst->DstReg.Index)
 371                maxIndex = inst->DstReg.Index;
 372          }
 373       }
 374    }
 375
 376    prog->NumTemporaries = (GLuint) (maxIndex + 1);
 377 }
 378
 379
 380 /**
 381  * Scan program instructions to update the program's InputsRead and
 382  * OutputsWritten fields.
 383  */
 384 static void
 385 _slang_update_inputs_outputs(struct gl_program *prog)
 386 {
 387    GLuint i, j;
 388    GLuint maxAddrReg = 0;
 389
 390    prog->InputsRead = 0x0;
 391    prog->OutputsWritten = 0x0;
 392
 393    for (i = 0; i < prog->NumInstructions; i++) {
 394       const struct prog_instruction *inst = prog->Instructions + i;
 395       const GLuint numSrc = _mesa_num_inst_src_regs(inst->Opcode);
 396       for (j = 0; j < numSrc; j++) {
 397          if (inst->SrcReg[j].File == PROGRAM_INPUT) {
 398             prog->InputsRead |= 1 << inst->SrcReg[j].Index;
 399             if (prog->Target == GL_FRAGMENT_PROGRAM_ARB &&
 400                 inst->SrcReg[j].Index == FRAG_ATTRIB_FOGC) {
 401                /* The fragment shader FOGC input is used for fog,
 402                 * front-facing and sprite/point coord.
 403                 */
 404                struct gl_fragment_program *fp = fragment_program(prog);
 405                const GLint swz = GET_SWZ(inst->SrcReg[j].Swizzle, 0);
 406                if (swz == SWIZZLE_X)
 407                   fp->UsesFogFragCoord = GL_TRUE;
 408                else if (swz == SWIZZLE_Y)
 409                   fp->UsesFrontFacing = GL_TRUE;
 410                else if (swz == SWIZZLE_Z || swz == SWIZZLE_W)
 411                   fp->UsesPointCoord = GL_TRUE;
 412             }
 413          }
 414          else if (inst->SrcReg[j].File == PROGRAM_ADDRESS) {
 415             maxAddrReg = MAX2(maxAddrReg, (GLuint) (inst->SrcReg[j].Index + 1));
 416          }
 417       }
 418       if (inst->DstReg.File == PROGRAM_OUTPUT) {
 419          prog->OutputsWritten |= 1 << inst->DstReg.Index;
 420       }
 421       else if (inst->DstReg.File == PROGRAM_ADDRESS) {
 422          maxAddrReg = MAX2(maxAddrReg, inst->DstReg.Index + 1);
 423       }
 424    }
 425    prog->NumAddressRegs = maxAddrReg;
 426 }
 427
 428
 429 /**
 430  * Shader linker.  Currently:
 431  *
 432  * 1. The last attached vertex shader and fragment shader are linked.
 433  * 2. Varying vars in the two shaders are combined so their locations
 434  *    agree between the vertex and fragment stages.  They're treated as
 435  *    vertex program output attribs and as fragment program input attribs.
 436  * 3. The vertex and fragment programs are cloned and modified to update
 437  *    src/dst register references so they use the new, linked varying
 438  *    storage locations.
 439  */
 440 void
 441 _slang_link(GLcontext *ctx,
 442             GLhandleARB programObj,
 443             struct gl_shader_program *shProg)
 444 {
 445    const struct gl_vertex_program *vertProg;
 446    const struct gl_fragment_program *fragProg;
 447    GLuint numSamplers = 0;
 448    GLuint i;
 449
 450    _mesa_clear_shader_program_data(ctx, shProg);
 451
 452    /* check that all programs compiled successfully */
 453    for (i = 0; i < shProg->NumShaders; i++) {
 454       if (!shProg->Shaders[i]->CompileStatus) {
 455          link_error(shProg, "linking with uncompiled shader\n");
 456          return;
 457       }
 458    }
 459
 460    shProg->Uniforms = _mesa_new_uniform_list();
 461    shProg->Varying = _mesa_new_parameter_list();
 462
 463    /**
 464     * Find attached vertex, fragment shaders defining main()
 465     */
 466    vertProg = NULL;
 467    fragProg = NULL;
 468    for (i = 0; i < shProg->NumShaders; i++) {
 469       struct gl_shader *shader = shProg->Shaders[i];
 470       if (shader->Type == GL_VERTEX_SHADER) {
 471          if (shader->Main)
 472             vertProg = vertex_program(shader->Program);
 473       }
 474       else if (shader->Type == GL_FRAGMENT_SHADER) {
 475          if (shader->Main)
 476             fragProg = fragment_program(shader->Program);
 477       }
 478       else {
 479          _mesa_problem(ctx, "unexpected shader target in slang_link()");
 480       }
 481    }
 482
 483 #if FEATURE_es2_glsl
 484    /* must have both a vertex and fragment program for ES2 */
 485    if (!vertProg) {
 486       link_error(shProg, "missing vertex shader\n");
 487       return;
 488    }
 489    if (!fragProg) {
 490       link_error(shProg, "missing fragment shader\n");
 491       return;
 492    }
 493 #endif
 494
 495    /*
 496     * Make copies of the vertex/fragment programs now since we'll be
 497     * changing src/dst registers after merging the uniforms and varying vars.
 498     */
 499    _mesa_reference_vertprog(ctx, &shProg->VertexProgram, NULL);
 500    if (vertProg) {
 501       struct gl_vertex_program *linked_vprog =
 502          vertex_program(_mesa_clone_program(ctx, &vertProg->Base));
 503       shProg->VertexProgram = linked_vprog; /* refcount OK */
 504       ASSERT(shProg->VertexProgram->Base.RefCount == 1);
 505    }
 506
 507    _mesa_reference_fragprog(ctx, &shProg->FragmentProgram, NULL);
 508    if (fragProg) {
 509       struct gl_fragment_program *linked_fprog =
 510          fragment_program(_mesa_clone_program(ctx, &fragProg->Base));
 511       shProg->FragmentProgram = linked_fprog; /* refcount OK */
 512       ASSERT(shProg->FragmentProgram->Base.RefCount == 1);
 513    }
 514
 515    /* link varying vars */
 516    if (shProg->VertexProgram) {
 517       if (!link_varying_vars(shProg, &shProg->VertexProgram->Base))
 518          return;
 519    }
 520    if (shProg->FragmentProgram) {
 521       if (!link_varying_vars(shProg, &shProg->FragmentProgram->Base))
 522          return;
 523    }
 524
 525    /* link uniform vars */
 526    if (shProg->VertexProgram)
 527       link_uniform_vars(shProg, &shProg->VertexProgram->Base, &numSamplers);
 528    if (shProg->FragmentProgram)
 529       link_uniform_vars(shProg, &shProg->FragmentProgram->Base, &numSamplers);
 530
 531    /*_mesa_print_uniforms(shProg->Uniforms);*/
 532
 533    if (shProg->VertexProgram) {
 534       if (!_slang_resolve_attributes(shProg, &vertProg->Base,
 535                                      &shProg->VertexProgram->Base)) {
 536          return;
 537       }
 538    }
 539
 540    if (shProg->VertexProgram) {
 541       _slang_update_inputs_outputs(&shProg->VertexProgram->Base);
 542       _slang_count_temporaries(&shProg->VertexProgram->Base);
 543       if (!(shProg->VertexProgram->Base.OutputsWritten & (1 << VERT_RESULT_HPOS))) {
 544          /* the vertex program did not compute a vertex position */
 545          link_error(shProg,
 546                     "gl_Position was not written by vertex shader\n");
 547          return;
 548       }
 549    }
 550    if (shProg->FragmentProgram) {
 551       _slang_count_temporaries(&shProg->FragmentProgram->Base);
 552       _slang_update_inputs_outputs(&shProg->FragmentProgram->Base);
 553    }
 554
 555    /* Check that all the varying vars needed by the fragment shader are
 556     * actually produced by the vertex shader.
 557     */
 558    if (shProg->FragmentProgram) {
 559       const GLbitfield varyingRead
 560          = shProg->FragmentProgram->Base.InputsRead >> FRAG_ATTRIB_VAR0;
 561       const GLbitfield varyingWritten = shProg->VertexProgram ?
 562          shProg->VertexProgram->Base.OutputsWritten >> VERT_RESULT_VAR0 : 0x0;
 563       if ((varyingRead & varyingWritten) != varyingRead) {
 564          link_error(shProg,
 565           "Fragment program using varying vars not written by vertex shader\n");
 566          return;
 567       }
 568    }
 569
 570
 571    if (fragProg && shProg->FragmentProgram) {
 572       /* Compute initial program's TexturesUsed info */
 573       _mesa_update_shader_textures_used(&shProg->FragmentProgram->Base);
 574
 575       /* notify driver that a new fragment program has been compiled/linked */
 576       ctx->Driver.ProgramStringNotify(ctx, GL_FRAGMENT_PROGRAM_ARB,
 577                                       &shProg->FragmentProgram->Base);
 578       if (MESA_VERBOSE & VERBOSE_GLSL_DUMP) {
 579          printf("Mesa original fragment program:\n");
 580          _mesa_print_program(&fragProg->Base);
 581          _mesa_print_program_parameters(ctx, &fragProg->Base);
 582
 583          printf("Mesa post-link fragment program:\n");
 584          _mesa_print_program(&shProg->FragmentProgram->Base);
 585          _mesa_print_program_parameters(ctx, &shProg->FragmentProgram->Base);
 586       }
 587    }
 588
 589    if (vertProg && shProg->VertexProgram) {
 590       /* Compute initial program's TexturesUsed info */
 591       _mesa_update_shader_textures_used(&shProg->VertexProgram->Base);
 592
 593       /* notify driver that a new vertex program has been compiled/linked */
 594       ctx->Driver.ProgramStringNotify(ctx, GL_VERTEX_PROGRAM_ARB,
 595                                       &shProg->VertexProgram->Base);
 596       if (MESA_VERBOSE & VERBOSE_GLSL_DUMP) {
 597          printf("Mesa original vertex program:\n");
 598          _mesa_print_program(&vertProg->Base);
 599          _mesa_print_program_parameters(ctx, &vertProg->Base);
 600
 601          printf("Mesa post-link vertex program:\n");
 602          _mesa_print_program(&shProg->VertexProgram->Base);
 603          _mesa_print_program_parameters(ctx, &shProg->VertexProgram->Base);
 604       }
 605    }
 606
 607    shProg->LinkStatus = (shProg->VertexProgram || shProg->FragmentProgram);
 608 }
 609