src/glsl/builtin_variables.cpp

   1 /*
   2  * Copyright © 2010 Intel Corporation
   3  *
   4  * Permission is hereby granted, free of charge, to any person obtaining a
   5  * copy of this software and associated documentation files (the "Software"),
   6  * to deal in the Software without restriction, including without limitation
   7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   8  * and/or sell copies of the Software, and to permit persons to whom the
   9  * Software is furnished to do so, subject to the following conditions:
  10  *
  11  * The above copyright notice and this permission notice (including the next
  12  * paragraph) shall be included in all copies or substantial portions of the
  13  * Software.
  14  *
  15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  18  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  19  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  20  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  21  * DEALINGS IN THE SOFTWARE.
  22  */
  23
  24 #include "ir.h"
  25 #include "glsl_parser_extras.h"
  26 #include "glsl_symbol_table.h"
  27 #include "main/core.h"
  28 #include "main/uniforms.h"
  29 #include "program/prog_parameter.h"
  30 #include "program/prog_statevars.h"
  31 #include "program/prog_instruction.h"
  32
  33 static struct gl_builtin_uniform_element gl_NumSamples_elements[] = {
  34    {NULL, {STATE_NUM_SAMPLES, 0, 0}, SWIZZLE_XXXX}
  35 };
  36
  37 static struct gl_builtin_uniform_element gl_DepthRange_elements[] = {
  38    {"near", {STATE_DEPTH_RANGE, 0, 0}, SWIZZLE_XXXX},
  39    {"far", {STATE_DEPTH_RANGE, 0, 0}, SWIZZLE_YYYY},
  40    {"diff", {STATE_DEPTH_RANGE, 0, 0}, SWIZZLE_ZZZZ},
  41 };
  42
  43 static struct gl_builtin_uniform_element gl_ClipPlane_elements[] = {
  44    {NULL, {STATE_CLIPPLANE, 0, 0}, SWIZZLE_XYZW}
  45 };
  46
  47 static struct gl_builtin_uniform_element gl_Point_elements[] = {
  48    {"size", {STATE_POINT_SIZE}, SWIZZLE_XXXX},
  49    {"sizeMin", {STATE_POINT_SIZE}, SWIZZLE_YYYY},
  50    {"sizeMax", {STATE_POINT_SIZE}, SWIZZLE_ZZZZ},
  51    {"fadeThresholdSize", {STATE_POINT_SIZE}, SWIZZLE_WWWW},
  52    {"distanceConstantAttenuation", {STATE_POINT_ATTENUATION}, SWIZZLE_XXXX},
  53    {"distanceLinearAttenuation", {STATE_POINT_ATTENUATION}, SWIZZLE_YYYY},
  54    {"distanceQuadraticAttenuation", {STATE_POINT_ATTENUATION}, SWIZZLE_ZZZZ},
  55 };
  56
  57 static struct gl_builtin_uniform_element gl_FrontMaterial_elements[] = {
  58    {"emission", {STATE_MATERIAL, 0, STATE_EMISSION}, SWIZZLE_XYZW},
  59    {"ambient", {STATE_MATERIAL, 0, STATE_AMBIENT}, SWIZZLE_XYZW},
  60    {"diffuse", {STATE_MATERIAL, 0, STATE_DIFFUSE}, SWIZZLE_XYZW},
  61    {"specular", {STATE_MATERIAL, 0, STATE_SPECULAR}, SWIZZLE_XYZW},
  62    {"shininess", {STATE_MATERIAL, 0, STATE_SHININESS}, SWIZZLE_XXXX},
  63 };
  64
  65 static struct gl_builtin_uniform_element gl_BackMaterial_elements[] = {
  66    {"emission", {STATE_MATERIAL, 1, STATE_EMISSION}, SWIZZLE_XYZW},
  67    {"ambient", {STATE_MATERIAL, 1, STATE_AMBIENT}, SWIZZLE_XYZW},
  68    {"diffuse", {STATE_MATERIAL, 1, STATE_DIFFUSE}, SWIZZLE_XYZW},
  69    {"specular", {STATE_MATERIAL, 1, STATE_SPECULAR}, SWIZZLE_XYZW},
  70    {"shininess", {STATE_MATERIAL, 1, STATE_SHININESS}, SWIZZLE_XXXX},
  71 };
  72
  73 static struct gl_builtin_uniform_element gl_LightSource_elements[] = {
  74    {"ambient", {STATE_LIGHT, 0, STATE_AMBIENT}, SWIZZLE_XYZW},
  75    {"diffuse", {STATE_LIGHT, 0, STATE_DIFFUSE}, SWIZZLE_XYZW},
  76    {"specular", {STATE_LIGHT, 0, STATE_SPECULAR}, SWIZZLE_XYZW},
  77    {"position", {STATE_LIGHT, 0, STATE_POSITION}, SWIZZLE_XYZW},
  78    {"halfVector", {STATE_LIGHT, 0, STATE_HALF_VECTOR}, SWIZZLE_XYZW},
  79    {"spotDirection", {STATE_LIGHT, 0, STATE_SPOT_DIRECTION},
  80     MAKE_SWIZZLE4(SWIZZLE_X,
  81                   SWIZZLE_Y,
  82                   SWIZZLE_Z,
  83                   SWIZZLE_Z)},
  84    {"spotCosCutoff", {STATE_LIGHT, 0, STATE_SPOT_DIRECTION}, SWIZZLE_WWWW},
  85    {"spotCutoff", {STATE_LIGHT, 0, STATE_SPOT_CUTOFF}, SWIZZLE_XXXX},
  86    {"spotExponent", {STATE_LIGHT, 0, STATE_ATTENUATION}, SWIZZLE_WWWW},
  87    {"constantAttenuation", {STATE_LIGHT, 0, STATE_ATTENUATION}, SWIZZLE_XXXX},
  88    {"linearAttenuation", {STATE_LIGHT, 0, STATE_ATTENUATION}, SWIZZLE_YYYY},
  89    {"quadraticAttenuation", {STATE_LIGHT, 0, STATE_ATTENUATION}, SWIZZLE_ZZZZ},
  90 };
  91
  92 static struct gl_builtin_uniform_element gl_LightModel_elements[] = {
  93    {"ambient", {STATE_LIGHTMODEL_AMBIENT, 0}, SWIZZLE_XYZW},
  94 };
  95
  96 static struct gl_builtin_uniform_element gl_FrontLightModelProduct_elements[] = {
  97    {"sceneColor", {STATE_LIGHTMODEL_SCENECOLOR, 0}, SWIZZLE_XYZW},
  98 };
  99
 100 static struct gl_builtin_uniform_element gl_BackLightModelProduct_elements[] = {
 101    {"sceneColor", {STATE_LIGHTMODEL_SCENECOLOR, 1}, SWIZZLE_XYZW},
 102 };
 103
 104 static struct gl_builtin_uniform_element gl_FrontLightProduct_elements[] = {
 105    {"ambient", {STATE_LIGHTPROD, 0, 0, STATE_AMBIENT}, SWIZZLE_XYZW},
 106    {"diffuse", {STATE_LIGHTPROD, 0, 0, STATE_DIFFUSE}, SWIZZLE_XYZW},
 107    {"specular", {STATE_LIGHTPROD, 0, 0, STATE_SPECULAR}, SWIZZLE_XYZW},
 108 };
 109
 110 static struct gl_builtin_uniform_element gl_BackLightProduct_elements[] = {
 111    {"ambient", {STATE_LIGHTPROD, 0, 1, STATE_AMBIENT}, SWIZZLE_XYZW},
 112    {"diffuse", {STATE_LIGHTPROD, 0, 1, STATE_DIFFUSE}, SWIZZLE_XYZW},
 113    {"specular", {STATE_LIGHTPROD, 0, 1, STATE_SPECULAR}, SWIZZLE_XYZW},
 114 };
 115
 116 static struct gl_builtin_uniform_element gl_TextureEnvColor_elements[] = {
 117    {NULL, {STATE_TEXENV_COLOR, 0}, SWIZZLE_XYZW},
 118 };
 119
 120 static struct gl_builtin_uniform_element gl_EyePlaneS_elements[] = {
 121    {NULL, {STATE_TEXGEN, 0, STATE_TEXGEN_EYE_S}, SWIZZLE_XYZW},
 122 };
 123
 124 static struct gl_builtin_uniform_element gl_EyePlaneT_elements[] = {
 125    {NULL, {STATE_TEXGEN, 0, STATE_TEXGEN_EYE_T}, SWIZZLE_XYZW},
 126 };
 127
 128 static struct gl_builtin_uniform_element gl_EyePlaneR_elements[] = {
 129    {NULL, {STATE_TEXGEN, 0, STATE_TEXGEN_EYE_R}, SWIZZLE_XYZW},
 130 };
 131
 132 static struct gl_builtin_uniform_element gl_EyePlaneQ_elements[] = {
 133    {NULL, {STATE_TEXGEN, 0, STATE_TEXGEN_EYE_Q}, SWIZZLE_XYZW},
 134 };
 135
 136 static struct gl_builtin_uniform_element gl_ObjectPlaneS_elements[] = {
 137    {NULL, {STATE_TEXGEN, 0, STATE_TEXGEN_OBJECT_S}, SWIZZLE_XYZW},
 138 };
 139
 140 static struct gl_builtin_uniform_element gl_ObjectPlaneT_elements[] = {
 141    {NULL, {STATE_TEXGEN, 0, STATE_TEXGEN_OBJECT_T}, SWIZZLE_XYZW},
 142 };
 143
 144 static struct gl_builtin_uniform_element gl_ObjectPlaneR_elements[] = {
 145    {NULL, {STATE_TEXGEN, 0, STATE_TEXGEN_OBJECT_R}, SWIZZLE_XYZW},
 146 };
 147
 148 static struct gl_builtin_uniform_element gl_ObjectPlaneQ_elements[] = {
 149    {NULL, {STATE_TEXGEN, 0, STATE_TEXGEN_OBJECT_Q}, SWIZZLE_XYZW},
 150 };
 151
 152 static struct gl_builtin_uniform_element gl_Fog_elements[] = {
 153    {"color", {STATE_FOG_COLOR}, SWIZZLE_XYZW},
 154    {"density", {STATE_FOG_PARAMS}, SWIZZLE_XXXX},
 155    {"start", {STATE_FOG_PARAMS}, SWIZZLE_YYYY},
 156    {"end", {STATE_FOG_PARAMS}, SWIZZLE_ZZZZ},
 157    {"scale", {STATE_FOG_PARAMS}, SWIZZLE_WWWW},
 158 };
 159
 160 static struct gl_builtin_uniform_element gl_NormalScale_elements[] = {
 161    {NULL, {STATE_NORMAL_SCALE}, SWIZZLE_XXXX},
 162 };
 163
 164 static struct gl_builtin_uniform_element gl_BumpRotMatrix0MESA_elements[] = {
 165    {NULL, {STATE_INTERNAL, STATE_ROT_MATRIX_0}, SWIZZLE_XYZW},
 166 };
 167
 168 static struct gl_builtin_uniform_element gl_BumpRotMatrix1MESA_elements[] = {
 169    {NULL, {STATE_INTERNAL, STATE_ROT_MATRIX_1}, SWIZZLE_XYZW},
 170 };
 171
 172 static struct gl_builtin_uniform_element gl_FogParamsOptimizedMESA_elements[] = {
 173    {NULL, {STATE_INTERNAL, STATE_FOG_PARAMS_OPTIMIZED}, SWIZZLE_XYZW},
 174 };
 175
 176 static struct gl_builtin_uniform_element gl_CurrentAttribVertMESA_elements[] = {
 177    {NULL, {STATE_INTERNAL, STATE_CURRENT_ATTRIB, 0}, SWIZZLE_XYZW},
 178 };
 179
 180 static struct gl_builtin_uniform_element gl_CurrentAttribFragMESA_elements[] = {
 181    {NULL, {STATE_INTERNAL, STATE_CURRENT_ATTRIB_MAYBE_VP_CLAMPED, 0}, SWIZZLE_XYZW},
 182 };
 183
 184 #define MATRIX(name, statevar, modifier)                                \
 185    static struct gl_builtin_uniform_element name ## _elements[] = {     \
 186       { NULL, { statevar, 0, 0, 0, modifier}, SWIZZLE_XYZW },           \
 187       { NULL, { statevar, 0, 1, 1, modifier}, SWIZZLE_XYZW },           \
 188       { NULL, { statevar, 0, 2, 2, modifier}, SWIZZLE_XYZW },           \
 189       { NULL, { statevar, 0, 3, 3, modifier}, SWIZZLE_XYZW },           \
 190    }
 191
 192 MATRIX(gl_ModelViewMatrix,
 193        STATE_MODELVIEW_MATRIX, STATE_MATRIX_TRANSPOSE);
 194 MATRIX(gl_ModelViewMatrixInverse,
 195        STATE_MODELVIEW_MATRIX, STATE_MATRIX_INVTRANS);
 196 MATRIX(gl_ModelViewMatrixTranspose,
 197        STATE_MODELVIEW_MATRIX, 0);
 198 MATRIX(gl_ModelViewMatrixInverseTranspose,
 199        STATE_MODELVIEW_MATRIX, STATE_MATRIX_INVERSE);
 200
 201 MATRIX(gl_ProjectionMatrix,
 202        STATE_PROJECTION_MATRIX, STATE_MATRIX_TRANSPOSE);
 203 MATRIX(gl_ProjectionMatrixInverse,
 204        STATE_PROJECTION_MATRIX, STATE_MATRIX_INVTRANS);
 205 MATRIX(gl_ProjectionMatrixTranspose,
 206        STATE_PROJECTION_MATRIX, 0);
 207 MATRIX(gl_ProjectionMatrixInverseTranspose,
 208        STATE_PROJECTION_MATRIX, STATE_MATRIX_INVERSE);
 209
 210 MATRIX(gl_ModelViewProjectionMatrix,
 211        STATE_MVP_MATRIX, STATE_MATRIX_TRANSPOSE);
 212 MATRIX(gl_ModelViewProjectionMatrixInverse,
 213        STATE_MVP_MATRIX, STATE_MATRIX_INVTRANS);
 214 MATRIX(gl_ModelViewProjectionMatrixTranspose,
 215        STATE_MVP_MATRIX, 0);
 216 MATRIX(gl_ModelViewProjectionMatrixInverseTranspose,
 217        STATE_MVP_MATRIX, STATE_MATRIX_INVERSE);
 218
 219 MATRIX(gl_TextureMatrix,
 220        STATE_TEXTURE_MATRIX, STATE_MATRIX_TRANSPOSE);
 221 MATRIX(gl_TextureMatrixInverse,
 222        STATE_TEXTURE_MATRIX, STATE_MATRIX_INVTRANS);
 223 MATRIX(gl_TextureMatrixTranspose,
 224        STATE_TEXTURE_MATRIX, 0);
 225 MATRIX(gl_TextureMatrixInverseTranspose,
 226        STATE_TEXTURE_MATRIX, STATE_MATRIX_INVERSE);
 227
 228 static struct gl_builtin_uniform_element gl_NormalMatrix_elements[] = {
 229    { NULL, { STATE_MODELVIEW_MATRIX, 0, 0, 0, STATE_MATRIX_INVERSE},
 230      MAKE_SWIZZLE4(SWIZZLE_X, SWIZZLE_Y, SWIZZLE_Z, SWIZZLE_Z) },
 231    { NULL, { STATE_MODELVIEW_MATRIX, 0, 1, 1, STATE_MATRIX_INVERSE},
 232      MAKE_SWIZZLE4(SWIZZLE_X, SWIZZLE_Y, SWIZZLE_Z, SWIZZLE_Z) },
 233    { NULL, { STATE_MODELVIEW_MATRIX, 0, 2, 2, STATE_MATRIX_INVERSE},
 234      MAKE_SWIZZLE4(SWIZZLE_X, SWIZZLE_Y, SWIZZLE_Z, SWIZZLE_Z) },
 235 };
 236
 237 #undef MATRIX
 238
 239 #define STATEVAR(name) {#name, name ## _elements, Elements(name ## _elements)}
 240
 241 static const struct gl_builtin_uniform_desc _mesa_builtin_uniform_desc[] = {
 242    STATEVAR(gl_NumSamples),
 243    STATEVAR(gl_DepthRange),
 244    STATEVAR(gl_ClipPlane),
 245    STATEVAR(gl_Point),
 246    STATEVAR(gl_FrontMaterial),
 247    STATEVAR(gl_BackMaterial),
 248    STATEVAR(gl_LightSource),
 249    STATEVAR(gl_LightModel),
 250    STATEVAR(gl_FrontLightModelProduct),
 251    STATEVAR(gl_BackLightModelProduct),
 252    STATEVAR(gl_FrontLightProduct),
 253    STATEVAR(gl_BackLightProduct),
 254    STATEVAR(gl_TextureEnvColor),
 255    STATEVAR(gl_EyePlaneS),
 256    STATEVAR(gl_EyePlaneT),
 257    STATEVAR(gl_EyePlaneR),
 258    STATEVAR(gl_EyePlaneQ),
 259    STATEVAR(gl_ObjectPlaneS),
 260    STATEVAR(gl_ObjectPlaneT),
 261    STATEVAR(gl_ObjectPlaneR),
 262    STATEVAR(gl_ObjectPlaneQ),
 263    STATEVAR(gl_Fog),
 264
 265    STATEVAR(gl_ModelViewMatrix),
 266    STATEVAR(gl_ModelViewMatrixInverse),
 267    STATEVAR(gl_ModelViewMatrixTranspose),
 268    STATEVAR(gl_ModelViewMatrixInverseTranspose),
 269
 270    STATEVAR(gl_ProjectionMatrix),
 271    STATEVAR(gl_ProjectionMatrixInverse),
 272    STATEVAR(gl_ProjectionMatrixTranspose),
 273    STATEVAR(gl_ProjectionMatrixInverseTranspose),
 274
 275    STATEVAR(gl_ModelViewProjectionMatrix),
 276    STATEVAR(gl_ModelViewProjectionMatrixInverse),
 277    STATEVAR(gl_ModelViewProjectionMatrixTranspose),
 278    STATEVAR(gl_ModelViewProjectionMatrixInverseTranspose),
 279
 280    STATEVAR(gl_TextureMatrix),
 281    STATEVAR(gl_TextureMatrixInverse),
 282    STATEVAR(gl_TextureMatrixTranspose),
 283    STATEVAR(gl_TextureMatrixInverseTranspose),
 284
 285    STATEVAR(gl_NormalMatrix),
 286    STATEVAR(gl_NormalScale),
 287
 288    STATEVAR(gl_BumpRotMatrix0MESA),
 289    STATEVAR(gl_BumpRotMatrix1MESA),
 290    STATEVAR(gl_FogParamsOptimizedMESA),
 291    STATEVAR(gl_CurrentAttribVertMESA),
 292    STATEVAR(gl_CurrentAttribFragMESA),
 293
 294    {NULL, NULL, 0}
 295 };
 296
 297
 298 namespace {
 299
 300 /**
 301  * Data structure that accumulates fields for the gl_PerVertex interface
 302  * block.
 303  */
 304 class per_vertex_accumulator
 305 {
 306 public:
 307    per_vertex_accumulator();
 308    void add_field(int slot, const glsl_type *type, const char *name);
 309    const glsl_type *construct_interface_instance() const;
 310
 311 private:
 312    glsl_struct_field fields[10];
 313    unsigned num_fields;
 314 };
 315
 316
 317 per_vertex_accumulator::per_vertex_accumulator()
 318    : fields(),
 319      num_fields(0)
 320 {
 321 }
 322
 323
 324 void
 325 per_vertex_accumulator::add_field(int slot, const glsl_type *type,
 326                                   const char *name)
 327 {
 328    assert(this->num_fields < ARRAY_SIZE(this->fields));
 329    this->fields[this->num_fields].type = type;
 330    this->fields[this->num_fields].name = name;
 331    this->fields[this->num_fields].row_major = false;
 332    this->fields[this->num_fields].location = slot;
 333    this->fields[this->num_fields].interpolation = INTERP_QUALIFIER_NONE;
 334    this->fields[this->num_fields].centroid = 0;
 335    this->fields[this->num_fields].sample = 0;
 336    this->num_fields++;
 337 }
 338
 339
 340 const glsl_type *
 341 per_vertex_accumulator::construct_interface_instance() const
 342 {
 343    return glsl_type::get_interface_instance(this->fields, this->num_fields,
 344                                             GLSL_INTERFACE_PACKING_STD140,
 345                                             "gl_PerVertex");
 346 }
 347
 348
 349 class builtin_variable_generator
 350 {
 351 public:
 352    builtin_variable_generator(exec_list *instructions,
 353                               struct _mesa_glsl_parse_state *state);
 354    void generate_constants();
 355    void generate_uniforms();
 356    void generate_vs_special_vars();
 357    void generate_gs_special_vars();
 358    void generate_fs_special_vars();
 359    void generate_varyings();
 360
 361 private:
 362    const glsl_type *array(const glsl_type *base, unsigned elements)
 363    {
 364       return glsl_type::get_array_instance(base, elements);
 365    }
 366
 367    const glsl_type *type(const char *name)
 368    {
 369       return symtab->get_type(name);
 370    }
 371
 372    ir_variable *add_input(int slot, const glsl_type *type, const char *name)
 373    {
 374       return add_variable(name, type, ir_var_shader_in, slot);
 375    }
 376
 377    ir_variable *add_output(int slot, const glsl_type *type, const char *name)
 378    {
 379       return add_variable(name, type, ir_var_shader_out, slot);
 380    }
 381
 382    ir_variable *add_system_value(int slot, const glsl_type *type,
 383                                  const char *name)
 384    {
 385       return add_variable(name, type, ir_var_system_value, slot);
 386    }
 387
 388    ir_variable *add_variable(const char *name, const glsl_type *type,
 389                              enum ir_variable_mode mode, int slot);
 390    ir_variable *add_uniform(const glsl_type *type, const char *name);
 391    ir_variable *add_const(const char *name, int value);
 392    void add_varying(int slot, const glsl_type *type, const char *name,
 393                     const char *name_as_gs_input);
 394
 395    exec_list * const instructions;
 396    struct _mesa_glsl_parse_state * const state;
 397    glsl_symbol_table * const symtab;
 398
 399    /**
 400     * True if compatibility-profile-only variables should be included.  (In
 401     * desktop GL, these are always included when the GLSL version is 1.30 and
 402     * or below).
 403     */
 404    const bool compatibility;
 405
 406    const glsl_type * const bool_t;
 407    const glsl_type * const int_t;
 408    const glsl_type * const float_t;
 409    const glsl_type * const vec2_t;
 410    const glsl_type * const vec3_t;
 411    const glsl_type * const vec4_t;
 412    const glsl_type * const mat3_t;
 413    const glsl_type * const mat4_t;
 414
 415    per_vertex_accumulator per_vertex_in;
 416    per_vertex_accumulator per_vertex_out;
 417 };
 418
 419
 420 builtin_variable_generator::builtin_variable_generator(
 421    exec_list *instructions, struct _mesa_glsl_parse_state *state)
 422    : instructions(instructions), state(state), symtab(state->symbols),
 423      compatibility(!state->is_version(140, 100)),
 424      bool_t(glsl_type::bool_type), int_t(glsl_type::int_type),
 425      float_t(glsl_type::float_type), vec2_t(glsl_type::vec2_type),
 426      vec3_t(glsl_type::vec3_type), vec4_t(glsl_type::vec4_type),
 427      mat3_t(glsl_type::mat3_type), mat4_t(glsl_type::mat4_type)
 428 {
 429 }
 430
 431
 432 ir_variable *
 433 builtin_variable_generator::add_variable(const char *name,
 434                                          const glsl_type *type,
 435                                          enum ir_variable_mode mode, int slot)
 436 {
 437    ir_variable *var = new(symtab) ir_variable(type, name, mode);
 438    var->how_declared = ir_var_declared_implicitly;
 439
 440    switch (var->mode) {
 441    case ir_var_auto:
 442    case ir_var_shader_in:
 443    case ir_var_uniform:
 444    case ir_var_system_value:
 445       var->read_only = true;
 446       break;
 447    case ir_var_shader_out:
 448       break;
 449    default:
 450       /* The only variables that are added using this function should be
 451        * uniforms, shader inputs, and shader outputs, constants (which use
 452        * ir_var_auto), and system values.
 453        */
 454       assert(0);
 455       break;
 456    }
 457
 458    var->location = slot;
 459    var->explicit_location = (slot >= 0);
 460    var->explicit_index = 0;
 461
 462    /* Once the variable is created an initialized, add it to the symbol table
 463     * and add the declaration to the IR stream.
 464     */
 465    instructions->push_tail(var);
 466
 467    symtab->add_variable(var);
 468    return var;
 469 }
 470
 471
 472 ir_variable *
 473 builtin_variable_generator::add_uniform(const glsl_type *type,
 474                                         const char *name)
 475 {
 476    ir_variable *const uni = add_variable(name, type, ir_var_uniform, -1);
 477
 478    unsigned i;
 479    for (i = 0; _mesa_builtin_uniform_desc[i].name != NULL; i++) {
 480       if (strcmp(_mesa_builtin_uniform_desc[i].name, name) == 0) {
 481          break;
 482       }
 483    }
 484
 485    assert(_mesa_builtin_uniform_desc[i].name != NULL);
 486    const struct gl_builtin_uniform_desc* const statevar =
 487       &_mesa_builtin_uniform_desc[i];
 488
 489    const unsigned array_count = type->is_array() ? type->length : 1;
 490    uni->num_state_slots = array_count * statevar->num_elements;
 491
 492    ir_state_slot *slots =
 493       ralloc_array(uni, ir_state_slot, uni->num_state_slots);
 494
 495    uni->state_slots = slots;
 496
 497    for (unsigned a = 0; a < array_count; a++) {
 498       for (unsigned j = 0; j < statevar->num_elements; j++) {
 499          struct gl_builtin_uniform_element *element = &statevar->elements[j];
 500
 501          memcpy(slots->tokens, element->tokens, sizeof(element->tokens));
 502          if (type->is_array()) {
 503             if (strcmp(name, "gl_CurrentAttribVertMESA") == 0 ||
 504                 strcmp(name, "gl_CurrentAttribFragMESA") == 0) {
 505                slots->tokens[2] = a;
 506             } else {
 507                slots->tokens[1] = a;
 508             }
 509          }
 510
 511          slots->swizzle = element->swizzle;
 512          slots++;
 513       }
 514    }
 515
 516    return uni;
 517 }
 518
 519
 520 ir_variable *
 521 builtin_variable_generator::add_const(const char *name, int value)
 522 {
 523    ir_variable *const var = add_variable(name, glsl_type::int_type,
 524                                          ir_var_auto, -1);
 525    var->constant_value = new(var) ir_constant(value);
 526    var->constant_initializer = new(var) ir_constant(value);
 527    var->has_initializer = true;
 528    return var;
 529 }
 530
 531
 532 void
 533 builtin_variable_generator::generate_constants()
 534 {
 535    add_const("gl_MaxVertexAttribs", state->Const.MaxVertexAttribs);
 536    add_const("gl_MaxVertexTextureImageUnits",
 537              state->Const.MaxVertexTextureImageUnits);
 538    add_const("gl_MaxCombinedTextureImageUnits",
 539              state->Const.MaxCombinedTextureImageUnits);
 540    add_const("gl_MaxTextureImageUnits", state->Const.MaxTextureImageUnits);
 541    add_const("gl_MaxDrawBuffers", state->Const.MaxDrawBuffers);
 542
 543    /* Max uniforms/varyings: GLSL ES counts these in units of vectors; desktop
 544     * GL counts them in units of "components" or "floats".
 545     */
 546    if (state->es_shader) {
 547       add_const("gl_MaxVertexUniformVectors",
 548                 state->Const.MaxVertexUniformComponents / 4);
 549       add_const("gl_MaxFragmentUniformVectors",
 550                 state->Const.MaxFragmentUniformComponents / 4);
 551
 552       /* In GLSL ES 3.00, gl_MaxVaryingVectors was split out to separate
 553        * vertex and fragment shader constants.
 554        */
 555       if (state->is_version(0, 300)) {
 556          add_const("gl_MaxVertexOutputVectors",
 557                    state->ctx->Const.VertexProgram.MaxOutputComponents / 4);
 558          add_const("gl_MaxFragmentInputVectors",
 559                    state->ctx->Const.FragmentProgram.MaxInputComponents / 4);
 560       } else {
 561          add_const("gl_MaxVaryingVectors",
 562                    state->ctx->Const.MaxVarying);
 563       }
 564    } else {
 565       add_const("gl_MaxVertexUniformComponents",
 566                 state->Const.MaxVertexUniformComponents);
 567
 568       /* Note: gl_MaxVaryingFloats was deprecated in GLSL 1.30+, but not
 569        * removed
 570        */
 571       add_const("gl_MaxVaryingFloats", state->ctx->Const.MaxVarying * 4);
 572
 573       add_const("gl_MaxFragmentUniformComponents",
 574                 state->Const.MaxFragmentUniformComponents);
 575    }
 576
 577    /* Texel offsets were introduced in ARB_shading_language_420pack (which
 578     * requires desktop GLSL version 130), and adopted into desktop GLSL
 579     * version 4.20 and GLSL ES version 3.00.
 580     */
 581    if ((state->is_version(130, 0) &&
 582         state->ARB_shading_language_420pack_enable) ||
 583       state->is_version(420, 300)) {
 584       add_const("gl_MinProgramTexelOffset",
 585                 state->Const.MinProgramTexelOffset);
 586       add_const("gl_MaxProgramTexelOffset",
 587                 state->Const.MaxProgramTexelOffset);
 588    }
 589
 590    if (state->is_version(130, 0)) {
 591       add_const("gl_MaxClipDistances", state->Const.MaxClipPlanes);
 592       add_const("gl_MaxVaryingComponents", state->ctx->Const.MaxVarying * 4);
 593    }
 594
 595    if (state->is_version(150, 0)) {
 596       add_const("gl_MaxVertexOutputComponents",
 597                 state->Const.MaxVertexOutputComponents);
 598       add_const("gl_MaxGeometryInputComponents",
 599                 state->Const.MaxGeometryInputComponents);
 600       add_const("gl_MaxGeometryOutputComponents",
 601                 state->Const.MaxGeometryOutputComponents);
 602       add_const("gl_MaxFragmentInputComponents",
 603                 state->Const.MaxFragmentInputComponents);
 604       add_const("gl_MaxGeometryTextureImageUnits",
 605                 state->Const.MaxGeometryTextureImageUnits);
 606       add_const("gl_MaxGeometryOutputVertices",
 607                 state->Const.MaxGeometryOutputVertices);
 608       add_const("gl_MaxGeometryTotalOutputComponents",
 609                 state->Const.MaxGeometryTotalOutputComponents);
 610       add_const("gl_MaxGeometryUniformComponents",
 611                 state->Const.MaxGeometryUniformComponents);
 612
 613       /* Note: the GLSL 1.50-4.40 specs require
 614        * gl_MaxGeometryVaryingComponents to be present, and to be at least 64.
 615        * But they do not define what it means (and there does not appear to be
 616        * any corresponding constant in the GL specs).  However,
 617        * ARB_geometry_shader4 defines MAX_GEOMETRY_VARYING_COMPONENTS_ARB to
 618        * be the maximum number of components available for use as geometry
 619        * outputs.  So we assume this is a synonym for
 620        * gl_MaxGeometryOutputComponents.
 621        */
 622       add_const("gl_MaxGeometryVaryingComponents",
 623                 state->Const.MaxGeometryOutputComponents);
 624    }
 625
 626    if (compatibility) {
 627       /* Note: gl_MaxLights stopped being listed as an explicit constant in
 628        * GLSL 1.30, however it continues to be referred to (as a minimum size
 629        * for compatibility-mode uniforms) all the way up through GLSL 4.30, so
 630        * this seems like it was probably an oversight.
 631        */
 632       add_const("gl_MaxLights", state->Const.MaxLights);
 633
 634       add_const("gl_MaxClipPlanes", state->Const.MaxClipPlanes);
 635
 636       /* Note: gl_MaxTextureUnits wasn't made compatibility-only until GLSL
 637        * 1.50, however this seems like it was probably an oversight.
 638        */
 639       add_const("gl_MaxTextureUnits", state->Const.MaxTextureUnits);
 640
 641       /* Note: gl_MaxTextureCoords was left out of GLSL 1.40, but it was
 642        * re-introduced in GLSL 1.50, so this seems like it was probably an
 643        * oversight.
 644        */
 645       add_const("gl_MaxTextureCoords", state->Const.MaxTextureCoords);
 646    }
 647
 648    if (state->ARB_shader_atomic_counters_enable) {
 649       add_const("gl_MaxVertexAtomicCounters",
 650                 state->Const.MaxVertexAtomicCounters);
 651       add_const("gl_MaxGeometryAtomicCounters",
 652                 state->Const.MaxGeometryAtomicCounters);
 653       add_const("gl_MaxFragmentAtomicCounters",
 654                 state->Const.MaxFragmentAtomicCounters);
 655       add_const("gl_MaxCombinedAtomicCounters",
 656                 state->Const.MaxCombinedAtomicCounters);
 657       add_const("gl_MaxAtomicCounterBindings",
 658                 state->Const.MaxAtomicBufferBindings);
 659       add_const("gl_MaxTessControlAtomicCounters", 0);
 660       add_const("gl_MaxTessEvaluationAtomicCounters", 0);
 661    }
 662 }
 663
 664
 665 /**
 666  * Generate uniform variables (which exist in all types of shaders).
 667  */
 668 void
 669 builtin_variable_generator::generate_uniforms()
 670 {
 671    add_uniform(int_t, "gl_NumSamples");
 672    add_uniform(type("gl_DepthRangeParameters"), "gl_DepthRange");
 673    add_uniform(array(vec4_t, VERT_ATTRIB_MAX), "gl_CurrentAttribVertMESA");
 674    add_uniform(array(vec4_t, VARYING_SLOT_MAX), "gl_CurrentAttribFragMESA");
 675
 676    if (compatibility) {
 677       add_uniform(mat4_t, "gl_ModelViewMatrix");
 678       add_uniform(mat4_t, "gl_ProjectionMatrix");
 679       add_uniform(mat4_t, "gl_ModelViewProjectionMatrix");
 680       add_uniform(mat3_t, "gl_NormalMatrix");
 681       add_uniform(mat4_t, "gl_ModelViewMatrixInverse");
 682       add_uniform(mat4_t, "gl_ProjectionMatrixInverse");
 683       add_uniform(mat4_t, "gl_ModelViewProjectionMatrixInverse");
 684       add_uniform(mat4_t, "gl_ModelViewMatrixTranspose");
 685       add_uniform(mat4_t, "gl_ProjectionMatrixTranspose");
 686       add_uniform(mat4_t, "gl_ModelViewProjectionMatrixTranspose");
 687       add_uniform(mat4_t, "gl_ModelViewMatrixInverseTranspose");
 688       add_uniform(mat4_t, "gl_ProjectionMatrixInverseTranspose");
 689       add_uniform(mat4_t, "gl_ModelViewProjectionMatrixInverseTranspose");
 690       add_uniform(float_t, "gl_NormalScale");
 691       add_uniform(type("gl_LightModelParameters"), "gl_LightModel");
 692       add_uniform(vec2_t, "gl_BumpRotMatrix0MESA");
 693       add_uniform(vec2_t, "gl_BumpRotMatrix1MESA");
 694       add_uniform(vec4_t, "gl_FogParamsOptimizedMESA");
 695
 696       const glsl_type *const mat4_array_type =
 697          array(mat4_t, state->Const.MaxTextureCoords);
 698       add_uniform(mat4_array_type, "gl_TextureMatrix");
 699       add_uniform(mat4_array_type, "gl_TextureMatrixInverse");
 700       add_uniform(mat4_array_type, "gl_TextureMatrixTranspose");
 701       add_uniform(mat4_array_type, "gl_TextureMatrixInverseTranspose");
 702
 703       add_uniform(array(vec4_t, state->Const.MaxClipPlanes), "gl_ClipPlane");
 704       add_uniform(type("gl_PointParameters"), "gl_Point");
 705
 706       const glsl_type *const material_parameters_type =
 707          type("gl_MaterialParameters");
 708       add_uniform(material_parameters_type, "gl_FrontMaterial");
 709       add_uniform(material_parameters_type, "gl_BackMaterial");
 710
 711       add_uniform(array(type("gl_LightSourceParameters"),
 712                         state->Const.MaxLights),
 713                   "gl_LightSource");
 714
 715       const glsl_type *const light_model_products_type =
 716          type("gl_LightModelProducts");
 717       add_uniform(light_model_products_type, "gl_FrontLightModelProduct");
 718       add_uniform(light_model_products_type, "gl_BackLightModelProduct");
 719
 720       const glsl_type *const light_products_type =
 721          array(type("gl_LightProducts"), state->Const.MaxLights);
 722       add_uniform(light_products_type, "gl_FrontLightProduct");
 723       add_uniform(light_products_type, "gl_BackLightProduct");
 724
 725       add_uniform(array(vec4_t, state->Const.MaxTextureUnits),
 726                   "gl_TextureEnvColor");
 727
 728       const glsl_type *const texcoords_vec4 =
 729          array(vec4_t, state->Const.MaxTextureCoords);
 730       add_uniform(texcoords_vec4, "gl_EyePlaneS");
 731       add_uniform(texcoords_vec4, "gl_EyePlaneT");
 732       add_uniform(texcoords_vec4, "gl_EyePlaneR");
 733       add_uniform(texcoords_vec4, "gl_EyePlaneQ");
 734       add_uniform(texcoords_vec4, "gl_ObjectPlaneS");
 735       add_uniform(texcoords_vec4, "gl_ObjectPlaneT");
 736       add_uniform(texcoords_vec4, "gl_ObjectPlaneR");
 737       add_uniform(texcoords_vec4, "gl_ObjectPlaneQ");
 738
 739       add_uniform(type("gl_FogParameters"), "gl_Fog");
 740    }
 741 }
 742
 743
 744 /**
 745  * Generate variables which only exist in vertex shaders.
 746  */
 747 void
 748 builtin_variable_generator::generate_vs_special_vars()
 749 {
 750    if (state->is_version(130, 300))
 751       add_system_value(SYSTEM_VALUE_VERTEX_ID, int_t, "gl_VertexID");
 752    if (state->ARB_draw_instanced_enable)
 753       add_system_value(SYSTEM_VALUE_INSTANCE_ID, int_t, "gl_InstanceIDARB");
 754    if (state->ARB_draw_instanced_enable || state->is_version(140, 300))
 755       add_system_value(SYSTEM_VALUE_INSTANCE_ID, int_t, "gl_InstanceID");
 756    if (state->AMD_vertex_shader_layer_enable)
 757       add_output(VARYING_SLOT_LAYER, int_t, "gl_Layer");
 758    if (compatibility) {
 759       add_input(VERT_ATTRIB_POS, vec4_t, "gl_Vertex");
 760       add_input(VERT_ATTRIB_NORMAL, vec3_t, "gl_Normal");
 761       add_input(VERT_ATTRIB_COLOR0, vec4_t, "gl_Color");
 762       add_input(VERT_ATTRIB_COLOR1, vec4_t, "gl_SecondaryColor");
 763       add_input(VERT_ATTRIB_TEX0, vec4_t, "gl_MultiTexCoord0");
 764       add_input(VERT_ATTRIB_TEX1, vec4_t, "gl_MultiTexCoord1");
 765       add_input(VERT_ATTRIB_TEX2, vec4_t, "gl_MultiTexCoord2");
 766       add_input(VERT_ATTRIB_TEX3, vec4_t, "gl_MultiTexCoord3");
 767       add_input(VERT_ATTRIB_TEX4, vec4_t, "gl_MultiTexCoord4");
 768       add_input(VERT_ATTRIB_TEX5, vec4_t, "gl_MultiTexCoord5");
 769       add_input(VERT_ATTRIB_TEX6, vec4_t, "gl_MultiTexCoord6");
 770       add_input(VERT_ATTRIB_TEX7, vec4_t, "gl_MultiTexCoord7");
 771       add_input(VERT_ATTRIB_FOG, float_t, "gl_FogCoord");
 772    }
 773 }
 774
 775
 776 /**
 777  * Generate variables which only exist in geometry shaders.
 778  */
 779 void
 780 builtin_variable_generator::generate_gs_special_vars()
 781 {
 782    add_output(VARYING_SLOT_LAYER, int_t, "gl_Layer");
 783
 784    /* Although gl_PrimitiveID appears in tessellation control and tessellation
 785     * evaluation shaders, it has a different function there than it has in
 786     * geometry shaders, so we treat it (and its counterpart gl_PrimitiveIDIn)
 787     * as special geometry shader variables.
 788     *
 789     * Note that although the general convention of suffixing geometry shader
 790     * input varyings with "In" was not adopted into GLSL 1.50, it is used in
 791     * the specific case of gl_PrimitiveIDIn.  So we don't need to treat
 792     * gl_PrimitiveIDIn as an {ARB,EXT}_geometry_shader4-only variable.
 793     */
 794    ir_variable *var;
 795    var = add_input(VARYING_SLOT_PRIMITIVE_ID, int_t, "gl_PrimitiveIDIn");
 796    var->interpolation = INTERP_QUALIFIER_FLAT;
 797    var = add_output(VARYING_SLOT_PRIMITIVE_ID, int_t, "gl_PrimitiveID");
 798    var->interpolation = INTERP_QUALIFIER_FLAT;
 799 }
 800
 801
 802 /**
 803  * Generate variables which only exist in fragment shaders.
 804  */
 805 void
 806 builtin_variable_generator::generate_fs_special_vars()
 807 {
 808    add_input(VARYING_SLOT_POS, vec4_t, "gl_FragCoord");
 809    add_input(VARYING_SLOT_FACE, bool_t, "gl_FrontFacing");
 810    if (state->is_version(120, 100))
 811       add_input(VARYING_SLOT_PNTC, vec2_t, "gl_PointCoord");
 812
 813    if (state->is_version(150, 0)) {
 814       ir_variable *var =
 815          add_input(VARYING_SLOT_PRIMITIVE_ID, int_t, "gl_PrimitiveID");
 816       var->interpolation = INTERP_QUALIFIER_FLAT;
 817    }
 818
 819    /* gl_FragColor and gl_FragData were deprecated starting in desktop GLSL
 820     * 1.30, and were relegated to the compatibility profile in GLSL 4.20.
 821     * They were removed from GLSL ES 3.00.
 822     */
 823    if (compatibility || !state->is_version(420, 300)) {
 824       add_output(FRAG_RESULT_COLOR, vec4_t, "gl_FragColor");
 825       add_output(FRAG_RESULT_DATA0,
 826                  array(vec4_t, state->Const.MaxDrawBuffers), "gl_FragData");
 827    }
 828
 829    /* gl_FragDepth has always been in desktop GLSL, but did not appear in GLSL
 830     * ES 1.00.
 831     */
 832    if (state->is_version(110, 300))
 833       add_output(FRAG_RESULT_DEPTH, float_t, "gl_FragDepth");
 834
 835    if (state->ARB_shader_stencil_export_enable) {
 836       ir_variable *const var =
 837          add_output(FRAG_RESULT_STENCIL, int_t, "gl_FragStencilRefARB");
 838       if (state->ARB_shader_stencil_export_warn)
 839          var->warn_extension = "GL_ARB_shader_stencil_export";
 840    }
 841
 842    if (state->AMD_shader_stencil_export_enable) {
 843       ir_variable *const var =
 844          add_output(FRAG_RESULT_STENCIL, int_t, "gl_FragStencilRefAMD");
 845       if (state->AMD_shader_stencil_export_warn)
 846          var->warn_extension = "GL_AMD_shader_stencil_export";
 847    }
 848
 849    if (state->ARB_sample_shading_enable) {
 850       add_system_value(SYSTEM_VALUE_SAMPLE_ID, int_t, "gl_SampleID");
 851       add_system_value(SYSTEM_VALUE_SAMPLE_POS, vec2_t, "gl_SamplePosition");
 852       /* From the ARB_sample_shading specification:
 853        *    "The number of elements in the array is ceil(<s>/32), where
 854        *    <s> is the maximum number of color samples supported by the
 855        *    implementation."
 856        * Since no drivers expose more than 32x MSAA, we can simply set
 857        * the array size to 1 rather than computing it.
 858        */
 859       add_output(FRAG_RESULT_SAMPLE_MASK, array(int_t, 1), "gl_SampleMask");
 860    }
 861 }
 862
 863
 864 /**
 865  * Add a single "varying" variable.  The variable's type and direction (input
 866  * or output) are adjusted as appropriate for the type of shader being
 867  * compiled.  For geometry shaders using {ARB,EXT}_geometry_shader4,
 868  * name_as_gs_input is used for the input (to avoid ambiguity).
 869  */
 870 void
 871 builtin_variable_generator::add_varying(int slot, const glsl_type *type,
 872                                         const char *name,
 873                                         const char *name_as_gs_input)
 874 {
 875    switch (state->target) {
 876    case geometry_shader:
 877       this->per_vertex_in.add_field(slot, type, name);
 878       /* FALLTHROUGH */
 879    case vertex_shader:
 880       this->per_vertex_out.add_field(slot, type, name);
 881       break;
 882    case fragment_shader:
 883       add_input(slot, type, name);
 884       break;
 885    }
 886 }
 887
 888
 889 /**
 890  * Generate variables that are used to communicate data from one shader stage
 891  * to the next ("varyings").
 892  */
 893 void
 894 builtin_variable_generator::generate_varyings()
 895 {
 896 #define ADD_VARYING(loc, type, name) \
 897    add_varying(loc, type, name, name "In")
 898
 899    /* gl_Position and gl_PointSize are not visible from fragment shaders. */
 900    if (state->target != fragment_shader) {
 901       ADD_VARYING(VARYING_SLOT_POS, vec4_t, "gl_Position");
 902       ADD_VARYING(VARYING_SLOT_PSIZ, float_t, "gl_PointSize");
 903    }
 904
 905    if (state->is_version(130, 0)) {
 906        ADD_VARYING(VARYING_SLOT_CLIP_DIST0, array(float_t, 0),
 907                    "gl_ClipDistance");
 908    }
 909
 910    if (compatibility) {
 911       ADD_VARYING(VARYING_SLOT_TEX0, array(vec4_t, 0), "gl_TexCoord");
 912       ADD_VARYING(VARYING_SLOT_FOGC, float_t, "gl_FogFragCoord");
 913       if (state->target == fragment_shader) {
 914          ADD_VARYING(VARYING_SLOT_COL0, vec4_t, "gl_Color");
 915          ADD_VARYING(VARYING_SLOT_COL1, vec4_t, "gl_SecondaryColor");
 916       } else {
 917          ADD_VARYING(VARYING_SLOT_CLIP_VERTEX, vec4_t, "gl_ClipVertex");
 918          ADD_VARYING(VARYING_SLOT_COL0, vec4_t, "gl_FrontColor");
 919          ADD_VARYING(VARYING_SLOT_BFC0, vec4_t, "gl_BackColor");
 920          ADD_VARYING(VARYING_SLOT_COL1, vec4_t, "gl_FrontSecondaryColor");
 921          ADD_VARYING(VARYING_SLOT_BFC1, vec4_t, "gl_BackSecondaryColor");
 922       }
 923    }
 924
 925    if (state->target == geometry_shader) {
 926       const glsl_type *per_vertex_in_type =
 927          this->per_vertex_in.construct_interface_instance();
 928       add_variable("gl_in", array(per_vertex_in_type, 0),
 929                    ir_var_shader_in, -1);
 930    }
 931    if (state->target == vertex_shader || state->target == geometry_shader) {
 932       const glsl_type *per_vertex_out_type =
 933          this->per_vertex_out.construct_interface_instance();
 934       const glsl_struct_field *fields = per_vertex_out_type->fields.structure;
 935       for (unsigned i = 0; i < per_vertex_out_type->length; i++) {
 936          ir_variable *var =
 937             add_variable(fields[i].name, fields[i].type, ir_var_shader_out,
 938                          fields[i].location);
 939          var->interpolation = fields[i].interpolation;
 940          var->centroid = fields[i].centroid;
 941          var->sample = fields[i].sample;
 942          var->init_interface_type(per_vertex_out_type);
 943       }
 944    }
 945 }
 946
 947
 948 }; /* Anonymous namespace */
 949
 950
 951 void
 952 _mesa_glsl_initialize_variables(exec_list *instructions,
 953                                 struct _mesa_glsl_parse_state *state)
 954 {
 955    builtin_variable_generator gen(instructions, state);
 956
 957    gen.generate_constants();
 958    gen.generate_uniforms();
 959
 960    gen.generate_varyings();
 961
 962    switch (state->target) {
 963    case vertex_shader:
 964       gen.generate_vs_special_vars();
 965       break;
 966    case geometry_shader:
 967       gen.generate_gs_special_vars();
 968       break;
 969    case fragment_shader:
 970       gen.generate_fs_special_vars();
 971       break;
 972    }
 973 }