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_statevars.h"
  30 #include "program/prog_instruction.h"
  31
  32 static const struct gl_builtin_uniform_element gl_NumSamples_elements[] = {
  33    {NULL, {STATE_NUM_SAMPLES, 0, 0}, SWIZZLE_XXXX}
  34 };
  35
  36 static const struct gl_builtin_uniform_element gl_DepthRange_elements[] = {
  37    {"near", {STATE_DEPTH_RANGE, 0, 0}, SWIZZLE_XXXX},
  38    {"far", {STATE_DEPTH_RANGE, 0, 0}, SWIZZLE_YYYY},
  39    {"diff", {STATE_DEPTH_RANGE, 0, 0}, SWIZZLE_ZZZZ},
  40 };
  41
  42 static const struct gl_builtin_uniform_element gl_ClipPlane_elements[] = {
  43    {NULL, {STATE_CLIPPLANE, 0, 0}, SWIZZLE_XYZW}
  44 };
  45
  46 static const struct gl_builtin_uniform_element gl_Point_elements[] = {
  47    {"size", {STATE_POINT_SIZE}, SWIZZLE_XXXX},
  48    {"sizeMin", {STATE_POINT_SIZE}, SWIZZLE_YYYY},
  49    {"sizeMax", {STATE_POINT_SIZE}, SWIZZLE_ZZZZ},
  50    {"fadeThresholdSize", {STATE_POINT_SIZE}, SWIZZLE_WWWW},
  51    {"distanceConstantAttenuation", {STATE_POINT_ATTENUATION}, SWIZZLE_XXXX},
  52    {"distanceLinearAttenuation", {STATE_POINT_ATTENUATION}, SWIZZLE_YYYY},
  53    {"distanceQuadraticAttenuation", {STATE_POINT_ATTENUATION}, SWIZZLE_ZZZZ},
  54 };
  55
  56 static const struct gl_builtin_uniform_element gl_FrontMaterial_elements[] = {
  57    {"emission", {STATE_MATERIAL, 0, STATE_EMISSION}, SWIZZLE_XYZW},
  58    {"ambient", {STATE_MATERIAL, 0, STATE_AMBIENT}, SWIZZLE_XYZW},
  59    {"diffuse", {STATE_MATERIAL, 0, STATE_DIFFUSE}, SWIZZLE_XYZW},
  60    {"specular", {STATE_MATERIAL, 0, STATE_SPECULAR}, SWIZZLE_XYZW},
  61    {"shininess", {STATE_MATERIAL, 0, STATE_SHININESS}, SWIZZLE_XXXX},
  62 };
  63
  64 static const struct gl_builtin_uniform_element gl_BackMaterial_elements[] = {
  65    {"emission", {STATE_MATERIAL, 1, STATE_EMISSION}, SWIZZLE_XYZW},
  66    {"ambient", {STATE_MATERIAL, 1, STATE_AMBIENT}, SWIZZLE_XYZW},
  67    {"diffuse", {STATE_MATERIAL, 1, STATE_DIFFUSE}, SWIZZLE_XYZW},
  68    {"specular", {STATE_MATERIAL, 1, STATE_SPECULAR}, SWIZZLE_XYZW},
  69    {"shininess", {STATE_MATERIAL, 1, STATE_SHININESS}, SWIZZLE_XXXX},
  70 };
  71
  72 static const struct gl_builtin_uniform_element gl_LightSource_elements[] = {
  73    {"ambient", {STATE_LIGHT, 0, STATE_AMBIENT}, SWIZZLE_XYZW},
  74    {"diffuse", {STATE_LIGHT, 0, STATE_DIFFUSE}, SWIZZLE_XYZW},
  75    {"specular", {STATE_LIGHT, 0, STATE_SPECULAR}, SWIZZLE_XYZW},
  76    {"position", {STATE_LIGHT, 0, STATE_POSITION}, SWIZZLE_XYZW},
  77    {"halfVector", {STATE_LIGHT, 0, STATE_HALF_VECTOR}, SWIZZLE_XYZW},
  78    {"spotDirection", {STATE_LIGHT, 0, STATE_SPOT_DIRECTION},
  79     MAKE_SWIZZLE4(SWIZZLE_X,
  80                   SWIZZLE_Y,
  81                   SWIZZLE_Z,
  82                   SWIZZLE_Z)},
  83    {"spotCosCutoff", {STATE_LIGHT, 0, STATE_SPOT_DIRECTION}, SWIZZLE_WWWW},
  84    {"spotCutoff", {STATE_LIGHT, 0, STATE_SPOT_CUTOFF}, SWIZZLE_XXXX},
  85    {"spotExponent", {STATE_LIGHT, 0, STATE_ATTENUATION}, SWIZZLE_WWWW},
  86    {"constantAttenuation", {STATE_LIGHT, 0, STATE_ATTENUATION}, SWIZZLE_XXXX},
  87    {"linearAttenuation", {STATE_LIGHT, 0, STATE_ATTENUATION}, SWIZZLE_YYYY},
  88    {"quadraticAttenuation", {STATE_LIGHT, 0, STATE_ATTENUATION}, SWIZZLE_ZZZZ},
  89 };
  90
  91 static const struct gl_builtin_uniform_element gl_LightModel_elements[] = {
  92    {"ambient", {STATE_LIGHTMODEL_AMBIENT, 0}, SWIZZLE_XYZW},
  93 };
  94
  95 static const struct gl_builtin_uniform_element gl_FrontLightModelProduct_elements[] = {
  96    {"sceneColor", {STATE_LIGHTMODEL_SCENECOLOR, 0}, SWIZZLE_XYZW},
  97 };
  98
  99 static const struct gl_builtin_uniform_element gl_BackLightModelProduct_elements[] = {
 100    {"sceneColor", {STATE_LIGHTMODEL_SCENECOLOR, 1}, SWIZZLE_XYZW},
 101 };
 102
 103 static const struct gl_builtin_uniform_element gl_FrontLightProduct_elements[] = {
 104    {"ambient", {STATE_LIGHTPROD, 0, 0, STATE_AMBIENT}, SWIZZLE_XYZW},
 105    {"diffuse", {STATE_LIGHTPROD, 0, 0, STATE_DIFFUSE}, SWIZZLE_XYZW},
 106    {"specular", {STATE_LIGHTPROD, 0, 0, STATE_SPECULAR}, SWIZZLE_XYZW},
 107 };
 108
 109 static const struct gl_builtin_uniform_element gl_BackLightProduct_elements[] = {
 110    {"ambient", {STATE_LIGHTPROD, 0, 1, STATE_AMBIENT}, SWIZZLE_XYZW},
 111    {"diffuse", {STATE_LIGHTPROD, 0, 1, STATE_DIFFUSE}, SWIZZLE_XYZW},
 112    {"specular", {STATE_LIGHTPROD, 0, 1, STATE_SPECULAR}, SWIZZLE_XYZW},
 113 };
 114
 115 static const struct gl_builtin_uniform_element gl_TextureEnvColor_elements[] = {
 116    {NULL, {STATE_TEXENV_COLOR, 0}, SWIZZLE_XYZW},
 117 };
 118
 119 static const struct gl_builtin_uniform_element gl_EyePlaneS_elements[] = {
 120    {NULL, {STATE_TEXGEN, 0, STATE_TEXGEN_EYE_S}, SWIZZLE_XYZW},
 121 };
 122
 123 static const struct gl_builtin_uniform_element gl_EyePlaneT_elements[] = {
 124    {NULL, {STATE_TEXGEN, 0, STATE_TEXGEN_EYE_T}, SWIZZLE_XYZW},
 125 };
 126
 127 static const struct gl_builtin_uniform_element gl_EyePlaneR_elements[] = {
 128    {NULL, {STATE_TEXGEN, 0, STATE_TEXGEN_EYE_R}, SWIZZLE_XYZW},
 129 };
 130
 131 static const struct gl_builtin_uniform_element gl_EyePlaneQ_elements[] = {
 132    {NULL, {STATE_TEXGEN, 0, STATE_TEXGEN_EYE_Q}, SWIZZLE_XYZW},
 133 };
 134
 135 static const struct gl_builtin_uniform_element gl_ObjectPlaneS_elements[] = {
 136    {NULL, {STATE_TEXGEN, 0, STATE_TEXGEN_OBJECT_S}, SWIZZLE_XYZW},
 137 };
 138
 139 static const struct gl_builtin_uniform_element gl_ObjectPlaneT_elements[] = {
 140    {NULL, {STATE_TEXGEN, 0, STATE_TEXGEN_OBJECT_T}, SWIZZLE_XYZW},
 141 };
 142
 143 static const struct gl_builtin_uniform_element gl_ObjectPlaneR_elements[] = {
 144    {NULL, {STATE_TEXGEN, 0, STATE_TEXGEN_OBJECT_R}, SWIZZLE_XYZW},
 145 };
 146
 147 static const struct gl_builtin_uniform_element gl_ObjectPlaneQ_elements[] = {
 148    {NULL, {STATE_TEXGEN, 0, STATE_TEXGEN_OBJECT_Q}, SWIZZLE_XYZW},
 149 };
 150
 151 static const struct gl_builtin_uniform_element gl_Fog_elements[] = {
 152    {"color", {STATE_FOG_COLOR}, SWIZZLE_XYZW},
 153    {"density", {STATE_FOG_PARAMS}, SWIZZLE_XXXX},
 154    {"start", {STATE_FOG_PARAMS}, SWIZZLE_YYYY},
 155    {"end", {STATE_FOG_PARAMS}, SWIZZLE_ZZZZ},
 156    {"scale", {STATE_FOG_PARAMS}, SWIZZLE_WWWW},
 157 };
 158
 159 static const struct gl_builtin_uniform_element gl_NormalScale_elements[] = {
 160    {NULL, {STATE_NORMAL_SCALE}, SWIZZLE_XXXX},
 161 };
 162
 163 static const struct gl_builtin_uniform_element gl_FogParamsOptimizedMESA_elements[] = {
 164    {NULL, {STATE_INTERNAL, STATE_FOG_PARAMS_OPTIMIZED}, SWIZZLE_XYZW},
 165 };
 166
 167 static const struct gl_builtin_uniform_element gl_CurrentAttribVertMESA_elements[] = {
 168    {NULL, {STATE_INTERNAL, STATE_CURRENT_ATTRIB, 0}, SWIZZLE_XYZW},
 169 };
 170
 171 static const struct gl_builtin_uniform_element gl_CurrentAttribFragMESA_elements[] = {
 172    {NULL, {STATE_INTERNAL, STATE_CURRENT_ATTRIB_MAYBE_VP_CLAMPED, 0}, SWIZZLE_XYZW},
 173 };
 174
 175 #define MATRIX(name, statevar, modifier)                                \
 176    static const struct gl_builtin_uniform_element name ## _elements[] = { \
 177       { NULL, { statevar, 0, 0, 0, modifier}, SWIZZLE_XYZW },           \
 178       { NULL, { statevar, 0, 1, 1, modifier}, SWIZZLE_XYZW },           \
 179       { NULL, { statevar, 0, 2, 2, modifier}, SWIZZLE_XYZW },           \
 180       { NULL, { statevar, 0, 3, 3, modifier}, SWIZZLE_XYZW },           \
 181    }
 182
 183 MATRIX(gl_ModelViewMatrix,
 184        STATE_MODELVIEW_MATRIX, STATE_MATRIX_TRANSPOSE);
 185 MATRIX(gl_ModelViewMatrixInverse,
 186        STATE_MODELVIEW_MATRIX, STATE_MATRIX_INVTRANS);
 187 MATRIX(gl_ModelViewMatrixTranspose,
 188        STATE_MODELVIEW_MATRIX, 0);
 189 MATRIX(gl_ModelViewMatrixInverseTranspose,
 190        STATE_MODELVIEW_MATRIX, STATE_MATRIX_INVERSE);
 191
 192 MATRIX(gl_ProjectionMatrix,
 193        STATE_PROJECTION_MATRIX, STATE_MATRIX_TRANSPOSE);
 194 MATRIX(gl_ProjectionMatrixInverse,
 195        STATE_PROJECTION_MATRIX, STATE_MATRIX_INVTRANS);
 196 MATRIX(gl_ProjectionMatrixTranspose,
 197        STATE_PROJECTION_MATRIX, 0);
 198 MATRIX(gl_ProjectionMatrixInverseTranspose,
 199        STATE_PROJECTION_MATRIX, STATE_MATRIX_INVERSE);
 200
 201 MATRIX(gl_ModelViewProjectionMatrix,
 202        STATE_MVP_MATRIX, STATE_MATRIX_TRANSPOSE);
 203 MATRIX(gl_ModelViewProjectionMatrixInverse,
 204        STATE_MVP_MATRIX, STATE_MATRIX_INVTRANS);
 205 MATRIX(gl_ModelViewProjectionMatrixTranspose,
 206        STATE_MVP_MATRIX, 0);
 207 MATRIX(gl_ModelViewProjectionMatrixInverseTranspose,
 208        STATE_MVP_MATRIX, STATE_MATRIX_INVERSE);
 209
 210 MATRIX(gl_TextureMatrix,
 211        STATE_TEXTURE_MATRIX, STATE_MATRIX_TRANSPOSE);
 212 MATRIX(gl_TextureMatrixInverse,
 213        STATE_TEXTURE_MATRIX, STATE_MATRIX_INVTRANS);
 214 MATRIX(gl_TextureMatrixTranspose,
 215        STATE_TEXTURE_MATRIX, 0);
 216 MATRIX(gl_TextureMatrixInverseTranspose,
 217        STATE_TEXTURE_MATRIX, STATE_MATRIX_INVERSE);
 218
 219 static const struct gl_builtin_uniform_element gl_NormalMatrix_elements[] = {
 220    { NULL, { STATE_MODELVIEW_MATRIX, 0, 0, 0, STATE_MATRIX_INVERSE},
 221      MAKE_SWIZZLE4(SWIZZLE_X, SWIZZLE_Y, SWIZZLE_Z, SWIZZLE_Z) },
 222    { NULL, { STATE_MODELVIEW_MATRIX, 0, 1, 1, STATE_MATRIX_INVERSE},
 223      MAKE_SWIZZLE4(SWIZZLE_X, SWIZZLE_Y, SWIZZLE_Z, SWIZZLE_Z) },
 224    { NULL, { STATE_MODELVIEW_MATRIX, 0, 2, 2, STATE_MATRIX_INVERSE},
 225      MAKE_SWIZZLE4(SWIZZLE_X, SWIZZLE_Y, SWIZZLE_Z, SWIZZLE_Z) },
 226 };
 227
 228 #undef MATRIX
 229
 230 #define STATEVAR(name) {#name, name ## _elements, Elements(name ## _elements)}
 231
 232 static const struct gl_builtin_uniform_desc _mesa_builtin_uniform_desc[] = {
 233    STATEVAR(gl_NumSamples),
 234    STATEVAR(gl_DepthRange),
 235    STATEVAR(gl_ClipPlane),
 236    STATEVAR(gl_Point),
 237    STATEVAR(gl_FrontMaterial),
 238    STATEVAR(gl_BackMaterial),
 239    STATEVAR(gl_LightSource),
 240    STATEVAR(gl_LightModel),
 241    STATEVAR(gl_FrontLightModelProduct),
 242    STATEVAR(gl_BackLightModelProduct),
 243    STATEVAR(gl_FrontLightProduct),
 244    STATEVAR(gl_BackLightProduct),
 245    STATEVAR(gl_TextureEnvColor),
 246    STATEVAR(gl_EyePlaneS),
 247    STATEVAR(gl_EyePlaneT),
 248    STATEVAR(gl_EyePlaneR),
 249    STATEVAR(gl_EyePlaneQ),
 250    STATEVAR(gl_ObjectPlaneS),
 251    STATEVAR(gl_ObjectPlaneT),
 252    STATEVAR(gl_ObjectPlaneR),
 253    STATEVAR(gl_ObjectPlaneQ),
 254    STATEVAR(gl_Fog),
 255
 256    STATEVAR(gl_ModelViewMatrix),
 257    STATEVAR(gl_ModelViewMatrixInverse),
 258    STATEVAR(gl_ModelViewMatrixTranspose),
 259    STATEVAR(gl_ModelViewMatrixInverseTranspose),
 260
 261    STATEVAR(gl_ProjectionMatrix),
 262    STATEVAR(gl_ProjectionMatrixInverse),
 263    STATEVAR(gl_ProjectionMatrixTranspose),
 264    STATEVAR(gl_ProjectionMatrixInverseTranspose),
 265
 266    STATEVAR(gl_ModelViewProjectionMatrix),
 267    STATEVAR(gl_ModelViewProjectionMatrixInverse),
 268    STATEVAR(gl_ModelViewProjectionMatrixTranspose),
 269    STATEVAR(gl_ModelViewProjectionMatrixInverseTranspose),
 270
 271    STATEVAR(gl_TextureMatrix),
 272    STATEVAR(gl_TextureMatrixInverse),
 273    STATEVAR(gl_TextureMatrixTranspose),
 274    STATEVAR(gl_TextureMatrixInverseTranspose),
 275
 276    STATEVAR(gl_NormalMatrix),
 277    STATEVAR(gl_NormalScale),
 278
 279    STATEVAR(gl_FogParamsOptimizedMESA),
 280    STATEVAR(gl_CurrentAttribVertMESA),
 281    STATEVAR(gl_CurrentAttribFragMESA),
 282
 283    {NULL, NULL, 0}
 284 };
 285
 286
 287 namespace {
 288
 289 /**
 290  * Data structure that accumulates fields for the gl_PerVertex interface
 291  * block.
 292  */
 293 class per_vertex_accumulator
 294 {
 295 public:
 296    per_vertex_accumulator();
 297    void add_field(int slot, const glsl_type *type, const char *name);
 298    const glsl_type *construct_interface_instance() const;
 299
 300 private:
 301    glsl_struct_field fields[10];
 302    unsigned num_fields;
 303 };
 304
 305
 306 per_vertex_accumulator::per_vertex_accumulator()
 307    : fields(),
 308      num_fields(0)
 309 {
 310 }
 311
 312
 313 void
 314 per_vertex_accumulator::add_field(int slot, const glsl_type *type,
 315                                   const char *name)
 316 {
 317    assert(this->num_fields < ARRAY_SIZE(this->fields));
 318    this->fields[this->num_fields].type = type;
 319    this->fields[this->num_fields].name = name;
 320    this->fields[this->num_fields].row_major = false;
 321    this->fields[this->num_fields].location = slot;
 322    this->fields[this->num_fields].interpolation = INTERP_QUALIFIER_NONE;
 323    this->fields[this->num_fields].centroid = 0;
 324    this->fields[this->num_fields].sample = 0;
 325    this->num_fields++;
 326 }
 327
 328
 329 const glsl_type *
 330 per_vertex_accumulator::construct_interface_instance() const
 331 {
 332    return glsl_type::get_interface_instance(this->fields, this->num_fields,
 333                                             GLSL_INTERFACE_PACKING_STD140,
 334                                             "gl_PerVertex");
 335 }
 336
 337
 338 class builtin_variable_generator
 339 {
 340 public:
 341    builtin_variable_generator(exec_list *instructions,
 342                               struct _mesa_glsl_parse_state *state);
 343    void generate_constants();
 344    void generate_uniforms();
 345    void generate_vs_special_vars();
 346    void generate_gs_special_vars();
 347    void generate_fs_special_vars();
 348    void generate_cs_special_vars();
 349    void generate_varyings();
 350
 351 private:
 352    const glsl_type *array(const glsl_type *base, unsigned elements)
 353    {
 354       return glsl_type::get_array_instance(base, elements);
 355    }
 356
 357    const glsl_type *type(const char *name)
 358    {
 359       return symtab->get_type(name);
 360    }
 361
 362    ir_variable *add_input(int slot, const glsl_type *type, const char *name)
 363    {
 364       return add_variable(name, type, ir_var_shader_in, slot);
 365    }
 366
 367    ir_variable *add_output(int slot, const glsl_type *type, const char *name)
 368    {
 369       return add_variable(name, type, ir_var_shader_out, slot);
 370    }
 371
 372    ir_variable *add_system_value(int slot, const glsl_type *type,
 373                                  const char *name)
 374    {
 375       return add_variable(name, type, ir_var_system_value, slot);
 376    }
 377
 378    ir_variable *add_variable(const char *name, const glsl_type *type,
 379                              enum ir_variable_mode mode, int slot);
 380    ir_variable *add_uniform(const glsl_type *type, const char *name);
 381    ir_variable *add_const(const char *name, int value);
 382    ir_variable *add_const_ivec3(const char *name, int x, int y, int z);
 383    void add_varying(int slot, const glsl_type *type, const char *name,
 384                     const char *name_as_gs_input);
 385
 386    exec_list * const instructions;
 387    struct _mesa_glsl_parse_state * const state;
 388    glsl_symbol_table * const symtab;
 389
 390    /**
 391     * True if compatibility-profile-only variables should be included.  (In
 392     * desktop GL, these are always included when the GLSL version is 1.30 and
 393     * or below).
 394     */
 395    const bool compatibility;
 396
 397    const glsl_type * const bool_t;
 398    const glsl_type * const int_t;
 399    const glsl_type * const float_t;
 400    const glsl_type * const vec2_t;
 401    const glsl_type * const vec3_t;
 402    const glsl_type * const vec4_t;
 403    const glsl_type * const mat3_t;
 404    const glsl_type * const mat4_t;
 405
 406    per_vertex_accumulator per_vertex_in;
 407    per_vertex_accumulator per_vertex_out;
 408 };
 409
 410
 411 builtin_variable_generator::builtin_variable_generator(
 412    exec_list *instructions, struct _mesa_glsl_parse_state *state)
 413    : instructions(instructions), state(state), symtab(state->symbols),
 414      compatibility(!state->is_version(140, 100)),
 415      bool_t(glsl_type::bool_type), int_t(glsl_type::int_type),
 416      float_t(glsl_type::float_type), vec2_t(glsl_type::vec2_type),
 417      vec3_t(glsl_type::vec3_type), vec4_t(glsl_type::vec4_type),
 418      mat3_t(glsl_type::mat3_type), mat4_t(glsl_type::mat4_type)
 419 {
 420 }
 421
 422
 423 ir_variable *
 424 builtin_variable_generator::add_variable(const char *name,
 425                                          const glsl_type *type,
 426                                          enum ir_variable_mode mode, int slot)
 427 {
 428    ir_variable *var = new(symtab) ir_variable(type, name, mode);
 429    var->data.how_declared = ir_var_declared_implicitly;
 430
 431    switch (var->data.mode) {
 432    case ir_var_auto:
 433    case ir_var_shader_in:
 434    case ir_var_uniform:
 435    case ir_var_system_value:
 436       var->data.read_only = true;
 437       break;
 438    case ir_var_shader_out:
 439       break;
 440    default:
 441       /* The only variables that are added using this function should be
 442        * uniforms, shader inputs, and shader outputs, constants (which use
 443        * ir_var_auto), and system values.
 444        */
 445       assert(0);
 446       break;
 447    }
 448
 449    var->data.location = slot;
 450    var->data.explicit_location = (slot >= 0);
 451    var->data.explicit_index = 0;
 452
 453    /* Once the variable is created an initialized, add it to the symbol table
 454     * and add the declaration to the IR stream.
 455     */
 456    instructions->push_tail(var);
 457
 458    symtab->add_variable(var);
 459    return var;
 460 }
 461
 462
 463 ir_variable *
 464 builtin_variable_generator::add_uniform(const glsl_type *type,
 465                                         const char *name)
 466 {
 467    ir_variable *const uni = add_variable(name, type, ir_var_uniform, -1);
 468
 469    unsigned i;
 470    for (i = 0; _mesa_builtin_uniform_desc[i].name != NULL; i++) {
 471       if (strcmp(_mesa_builtin_uniform_desc[i].name, name) == 0) {
 472          break;
 473       }
 474    }
 475
 476    assert(_mesa_builtin_uniform_desc[i].name != NULL);
 477    const struct gl_builtin_uniform_desc* const statevar =
 478       &_mesa_builtin_uniform_desc[i];
 479
 480    const unsigned array_count = type->is_array() ? type->length : 1;
 481    uni->num_state_slots = array_count * statevar->num_elements;
 482
 483    ir_state_slot *slots =
 484       ralloc_array(uni, ir_state_slot, uni->num_state_slots);
 485
 486    uni->state_slots = slots;
 487
 488    for (unsigned a = 0; a < array_count; a++) {
 489       for (unsigned j = 0; j < statevar->num_elements; j++) {
 490          const struct gl_builtin_uniform_element *element =
 491             &statevar->elements[j];
 492
 493          memcpy(slots->tokens, element->tokens, sizeof(element->tokens));
 494          if (type->is_array()) {
 495             if (strcmp(name, "gl_CurrentAttribVertMESA") == 0 ||
 496                 strcmp(name, "gl_CurrentAttribFragMESA") == 0) {
 497                slots->tokens[2] = a;
 498             } else {
 499                slots->tokens[1] = a;
 500             }
 501          }
 502
 503          slots->swizzle = element->swizzle;
 504          slots++;
 505       }
 506    }
 507
 508    return uni;
 509 }
 510
 511
 512 ir_variable *
 513 builtin_variable_generator::add_const(const char *name, int value)
 514 {
 515    ir_variable *const var = add_variable(name, glsl_type::int_type,
 516                                          ir_var_auto, -1);
 517    var->constant_value = new(var) ir_constant(value);
 518    var->constant_initializer = new(var) ir_constant(value);
 519    var->data.has_initializer = true;
 520    return var;
 521 }
 522
 523
 524 ir_variable *
 525 builtin_variable_generator::add_const_ivec3(const char *name, int x, int y,
 526                                             int z)
 527 {
 528    ir_variable *const var = add_variable(name, glsl_type::ivec3_type,
 529                                          ir_var_auto, -1);
 530    ir_constant_data data;
 531    memset(&data, 0, sizeof(data));
 532    data.i[0] = x;
 533    data.i[1] = y;
 534    data.i[2] = z;
 535    var->constant_value = new(var) ir_constant(glsl_type::ivec3_type, &data);
 536    var->constant_initializer =
 537       new(var) ir_constant(glsl_type::ivec3_type, &data);
 538    var->data.has_initializer = true;
 539    return var;
 540 }
 541
 542
 543 void
 544 builtin_variable_generator::generate_constants()
 545 {
 546    add_const("gl_MaxVertexAttribs", state->Const.MaxVertexAttribs);
 547    add_const("gl_MaxVertexTextureImageUnits",
 548              state->Const.MaxVertexTextureImageUnits);
 549    add_const("gl_MaxCombinedTextureImageUnits",
 550              state->Const.MaxCombinedTextureImageUnits);
 551    add_const("gl_MaxTextureImageUnits", state->Const.MaxTextureImageUnits);
 552    add_const("gl_MaxDrawBuffers", state->Const.MaxDrawBuffers);
 553
 554    /* Max uniforms/varyings: GLSL ES counts these in units of vectors; desktop
 555     * GL counts them in units of "components" or "floats".
 556     */
 557    if (state->es_shader) {
 558       add_const("gl_MaxVertexUniformVectors",
 559                 state->Const.MaxVertexUniformComponents / 4);
 560       add_const("gl_MaxFragmentUniformVectors",
 561                 state->Const.MaxFragmentUniformComponents / 4);
 562
 563       /* In GLSL ES 3.00, gl_MaxVaryingVectors was split out to separate
 564        * vertex and fragment shader constants.
 565        */
 566       if (state->is_version(0, 300)) {
 567          add_const("gl_MaxVertexOutputVectors",
 568                    state->ctx->Const.Program[MESA_SHADER_VERTEX].MaxOutputComponents / 4);
 569          add_const("gl_MaxFragmentInputVectors",
 570                    state->ctx->Const.Program[MESA_SHADER_FRAGMENT].MaxInputComponents / 4);
 571       } else {
 572          add_const("gl_MaxVaryingVectors",
 573                    state->ctx->Const.MaxVarying);
 574       }
 575    } else {
 576       add_const("gl_MaxVertexUniformComponents",
 577                 state->Const.MaxVertexUniformComponents);
 578
 579       /* Note: gl_MaxVaryingFloats was deprecated in GLSL 1.30+, but not
 580        * removed
 581        */
 582       add_const("gl_MaxVaryingFloats", state->ctx->Const.MaxVarying * 4);
 583
 584       add_const("gl_MaxFragmentUniformComponents",
 585                 state->Const.MaxFragmentUniformComponents);
 586    }
 587
 588    /* Texel offsets were introduced in ARB_shading_language_420pack (which
 589     * requires desktop GLSL version 130), and adopted into desktop GLSL
 590     * version 4.20 and GLSL ES version 3.00.
 591     */
 592    if ((state->is_version(130, 0) &&
 593         state->ARB_shading_language_420pack_enable) ||
 594       state->is_version(420, 300)) {
 595       add_const("gl_MinProgramTexelOffset",
 596                 state->Const.MinProgramTexelOffset);
 597       add_const("gl_MaxProgramTexelOffset",
 598                 state->Const.MaxProgramTexelOffset);
 599    }
 600
 601    if (state->is_version(130, 0)) {
 602       add_const("gl_MaxClipDistances", state->Const.MaxClipPlanes);
 603       add_const("gl_MaxVaryingComponents", state->ctx->Const.MaxVarying * 4);
 604    }
 605
 606    if (state->is_version(150, 0)) {
 607       add_const("gl_MaxVertexOutputComponents",
 608                 state->Const.MaxVertexOutputComponents);
 609       add_const("gl_MaxGeometryInputComponents",
 610                 state->Const.MaxGeometryInputComponents);
 611       add_const("gl_MaxGeometryOutputComponents",
 612                 state->Const.MaxGeometryOutputComponents);
 613       add_const("gl_MaxFragmentInputComponents",
 614                 state->Const.MaxFragmentInputComponents);
 615       add_const("gl_MaxGeometryTextureImageUnits",
 616                 state->Const.MaxGeometryTextureImageUnits);
 617       add_const("gl_MaxGeometryOutputVertices",
 618                 state->Const.MaxGeometryOutputVertices);
 619       add_const("gl_MaxGeometryTotalOutputComponents",
 620                 state->Const.MaxGeometryTotalOutputComponents);
 621       add_const("gl_MaxGeometryUniformComponents",
 622                 state->Const.MaxGeometryUniformComponents);
 623
 624       /* Note: the GLSL 1.50-4.40 specs require
 625        * gl_MaxGeometryVaryingComponents to be present, and to be at least 64.
 626        * But they do not define what it means (and there does not appear to be
 627        * any corresponding constant in the GL specs).  However,
 628        * ARB_geometry_shader4 defines MAX_GEOMETRY_VARYING_COMPONENTS_ARB to
 629        * be the maximum number of components available for use as geometry
 630        * outputs.  So we assume this is a synonym for
 631        * gl_MaxGeometryOutputComponents.
 632        */
 633       add_const("gl_MaxGeometryVaryingComponents",
 634                 state->Const.MaxGeometryOutputComponents);
 635    }
 636
 637    if (compatibility) {
 638       /* Note: gl_MaxLights stopped being listed as an explicit constant in
 639        * GLSL 1.30, however it continues to be referred to (as a minimum size
 640        * for compatibility-mode uniforms) all the way up through GLSL 4.30, so
 641        * this seems like it was probably an oversight.
 642        */
 643       add_const("gl_MaxLights", state->Const.MaxLights);
 644
 645       add_const("gl_MaxClipPlanes", state->Const.MaxClipPlanes);
 646
 647       /* Note: gl_MaxTextureUnits wasn't made compatibility-only until GLSL
 648        * 1.50, however this seems like it was probably an oversight.
 649        */
 650       add_const("gl_MaxTextureUnits", state->Const.MaxTextureUnits);
 651
 652       /* Note: gl_MaxTextureCoords was left out of GLSL 1.40, but it was
 653        * re-introduced in GLSL 1.50, so this seems like it was probably an
 654        * oversight.
 655        */
 656       add_const("gl_MaxTextureCoords", state->Const.MaxTextureCoords);
 657    }
 658
 659    if (state->ARB_shader_atomic_counters_enable) {
 660       add_const("gl_MaxVertexAtomicCounters",
 661                 state->Const.MaxVertexAtomicCounters);
 662       add_const("gl_MaxGeometryAtomicCounters",
 663                 state->Const.MaxGeometryAtomicCounters);
 664       add_const("gl_MaxFragmentAtomicCounters",
 665                 state->Const.MaxFragmentAtomicCounters);
 666       add_const("gl_MaxCombinedAtomicCounters",
 667                 state->Const.MaxCombinedAtomicCounters);
 668       add_const("gl_MaxAtomicCounterBindings",
 669                 state->Const.MaxAtomicBufferBindings);
 670       add_const("gl_MaxTessControlAtomicCounters", 0);
 671       add_const("gl_MaxTessEvaluationAtomicCounters", 0);
 672    }
 673
 674    if (state->is_version(430, 0) || state->ARB_compute_shader_enable) {
 675       add_const_ivec3("gl_MaxComputeWorkGroupCount",
 676                       state->Const.MaxComputeWorkGroupCount[0],
 677                       state->Const.MaxComputeWorkGroupCount[1],
 678                       state->Const.MaxComputeWorkGroupCount[2]);
 679       add_const_ivec3("gl_MaxComputeWorkGroupSize",
 680                       state->Const.MaxComputeWorkGroupSize[0],
 681                       state->Const.MaxComputeWorkGroupSize[1],
 682                       state->Const.MaxComputeWorkGroupSize[2]);
 683
 684       /* From the GLSL 4.40 spec, section 7.1 (Built-In Language Variables):
 685        *
 686        *     The built-in constant gl_WorkGroupSize is a compute-shader
 687        *     constant containing the local work-group size of the shader.  The
 688        *     size of the work group in the X, Y, and Z dimensions is stored in
 689        *     the x, y, and z components.  The constants values in
 690        *     gl_WorkGroupSize will match those specified in the required
 691        *     local_size_x, local_size_y, and local_size_z layout qualifiers
 692        *     for the current shader.  This is a constant so that it can be
 693        *     used to size arrays of memory that can be shared within the local
 694        *     work group.  It is a compile-time error to use gl_WorkGroupSize
 695        *     in a shader that does not declare a fixed local group size, or
 696        *     before that shader has declared a fixed local group size, using
 697        *     local_size_x, local_size_y, and local_size_z.
 698        *
 699        * To prevent the shader from trying to refer to gl_WorkGroupSize before
 700        * the layout declaration, we don't define it here.  Intead we define it
 701        * in ast_cs_input_layout::hir().
 702        */
 703    }
 704
 705    if (state->is_version(420, 0) ||
 706        state->ARB_shader_image_load_store_enable) {
 707       add_const("gl_MaxImageUnits",
 708                 state->Const.MaxImageUnits);
 709       add_const("gl_MaxCombinedImageUnitsAndFragmentOutputs",
 710                 state->Const.MaxCombinedImageUnitsAndFragmentOutputs);
 711       add_const("gl_MaxImageSamples",
 712                 state->Const.MaxImageSamples);
 713       add_const("gl_MaxVertexImageUniforms",
 714                 state->Const.MaxVertexImageUniforms);
 715       add_const("gl_MaxTessControlImageUniforms", 0);
 716       add_const("gl_MaxTessEvaluationImageUniforms", 0);
 717       add_const("gl_MaxGeometryImageUniforms",
 718                 state->Const.MaxGeometryImageUniforms);
 719       add_const("gl_MaxFragmentImageUniforms",
 720                 state->Const.MaxFragmentImageUniforms);
 721       add_const("gl_MaxCombinedImageUniforms",
 722                 state->Const.MaxCombinedImageUniforms);
 723    }
 724 }
 725
 726
 727 /**
 728  * Generate uniform variables (which exist in all types of shaders).
 729  */
 730 void
 731 builtin_variable_generator::generate_uniforms()
 732 {
 733    add_uniform(int_t, "gl_NumSamples");
 734    add_uniform(type("gl_DepthRangeParameters"), "gl_DepthRange");
 735    add_uniform(array(vec4_t, VERT_ATTRIB_MAX), "gl_CurrentAttribVertMESA");
 736    add_uniform(array(vec4_t, VARYING_SLOT_MAX), "gl_CurrentAttribFragMESA");
 737
 738    if (compatibility) {
 739       add_uniform(mat4_t, "gl_ModelViewMatrix");
 740       add_uniform(mat4_t, "gl_ProjectionMatrix");
 741       add_uniform(mat4_t, "gl_ModelViewProjectionMatrix");
 742       add_uniform(mat3_t, "gl_NormalMatrix");
 743       add_uniform(mat4_t, "gl_ModelViewMatrixInverse");
 744       add_uniform(mat4_t, "gl_ProjectionMatrixInverse");
 745       add_uniform(mat4_t, "gl_ModelViewProjectionMatrixInverse");
 746       add_uniform(mat4_t, "gl_ModelViewMatrixTranspose");
 747       add_uniform(mat4_t, "gl_ProjectionMatrixTranspose");
 748       add_uniform(mat4_t, "gl_ModelViewProjectionMatrixTranspose");
 749       add_uniform(mat4_t, "gl_ModelViewMatrixInverseTranspose");
 750       add_uniform(mat4_t, "gl_ProjectionMatrixInverseTranspose");
 751       add_uniform(mat4_t, "gl_ModelViewProjectionMatrixInverseTranspose");
 752       add_uniform(float_t, "gl_NormalScale");
 753       add_uniform(type("gl_LightModelParameters"), "gl_LightModel");
 754       add_uniform(vec4_t, "gl_FogParamsOptimizedMESA");
 755
 756       const glsl_type *const mat4_array_type =
 757          array(mat4_t, state->Const.MaxTextureCoords);
 758       add_uniform(mat4_array_type, "gl_TextureMatrix");
 759       add_uniform(mat4_array_type, "gl_TextureMatrixInverse");
 760       add_uniform(mat4_array_type, "gl_TextureMatrixTranspose");
 761       add_uniform(mat4_array_type, "gl_TextureMatrixInverseTranspose");
 762
 763       add_uniform(array(vec4_t, state->Const.MaxClipPlanes), "gl_ClipPlane");
 764       add_uniform(type("gl_PointParameters"), "gl_Point");
 765
 766       const glsl_type *const material_parameters_type =
 767          type("gl_MaterialParameters");
 768       add_uniform(material_parameters_type, "gl_FrontMaterial");
 769       add_uniform(material_parameters_type, "gl_BackMaterial");
 770
 771       add_uniform(array(type("gl_LightSourceParameters"),
 772                         state->Const.MaxLights),
 773                   "gl_LightSource");
 774
 775       const glsl_type *const light_model_products_type =
 776          type("gl_LightModelProducts");
 777       add_uniform(light_model_products_type, "gl_FrontLightModelProduct");
 778       add_uniform(light_model_products_type, "gl_BackLightModelProduct");
 779
 780       const glsl_type *const light_products_type =
 781          array(type("gl_LightProducts"), state->Const.MaxLights);
 782       add_uniform(light_products_type, "gl_FrontLightProduct");
 783       add_uniform(light_products_type, "gl_BackLightProduct");
 784
 785       add_uniform(array(vec4_t, state->Const.MaxTextureUnits),
 786                   "gl_TextureEnvColor");
 787
 788       const glsl_type *const texcoords_vec4 =
 789          array(vec4_t, state->Const.MaxTextureCoords);
 790       add_uniform(texcoords_vec4, "gl_EyePlaneS");
 791       add_uniform(texcoords_vec4, "gl_EyePlaneT");
 792       add_uniform(texcoords_vec4, "gl_EyePlaneR");
 793       add_uniform(texcoords_vec4, "gl_EyePlaneQ");
 794       add_uniform(texcoords_vec4, "gl_ObjectPlaneS");
 795       add_uniform(texcoords_vec4, "gl_ObjectPlaneT");
 796       add_uniform(texcoords_vec4, "gl_ObjectPlaneR");
 797       add_uniform(texcoords_vec4, "gl_ObjectPlaneQ");
 798
 799       add_uniform(type("gl_FogParameters"), "gl_Fog");
 800    }
 801 }
 802
 803
 804 /**
 805  * Generate variables which only exist in vertex shaders.
 806  */
 807 void
 808 builtin_variable_generator::generate_vs_special_vars()
 809 {
 810    if (state->is_version(130, 300))
 811       add_system_value(SYSTEM_VALUE_VERTEX_ID, int_t, "gl_VertexID");
 812    if (state->ARB_draw_instanced_enable)
 813       add_system_value(SYSTEM_VALUE_INSTANCE_ID, int_t, "gl_InstanceIDARB");
 814    if (state->ARB_draw_instanced_enable || state->is_version(140, 300))
 815       add_system_value(SYSTEM_VALUE_INSTANCE_ID, int_t, "gl_InstanceID");
 816    if (state->AMD_vertex_shader_layer_enable)
 817       add_output(VARYING_SLOT_LAYER, int_t, "gl_Layer");
 818    if (state->AMD_vertex_shader_viewport_index_enable)
 819       add_output(VARYING_SLOT_VIEWPORT, int_t, "gl_ViewportIndex");
 820    if (compatibility) {
 821       add_input(VERT_ATTRIB_POS, vec4_t, "gl_Vertex");
 822       add_input(VERT_ATTRIB_NORMAL, vec3_t, "gl_Normal");
 823       add_input(VERT_ATTRIB_COLOR0, vec4_t, "gl_Color");
 824       add_input(VERT_ATTRIB_COLOR1, vec4_t, "gl_SecondaryColor");
 825       add_input(VERT_ATTRIB_TEX0, vec4_t, "gl_MultiTexCoord0");
 826       add_input(VERT_ATTRIB_TEX1, vec4_t, "gl_MultiTexCoord1");
 827       add_input(VERT_ATTRIB_TEX2, vec4_t, "gl_MultiTexCoord2");
 828       add_input(VERT_ATTRIB_TEX3, vec4_t, "gl_MultiTexCoord3");
 829       add_input(VERT_ATTRIB_TEX4, vec4_t, "gl_MultiTexCoord4");
 830       add_input(VERT_ATTRIB_TEX5, vec4_t, "gl_MultiTexCoord5");
 831       add_input(VERT_ATTRIB_TEX6, vec4_t, "gl_MultiTexCoord6");
 832       add_input(VERT_ATTRIB_TEX7, vec4_t, "gl_MultiTexCoord7");
 833       add_input(VERT_ATTRIB_FOG, float_t, "gl_FogCoord");
 834    }
 835 }
 836
 837
 838 /**
 839  * Generate variables which only exist in geometry shaders.
 840  */
 841 void
 842 builtin_variable_generator::generate_gs_special_vars()
 843 {
 844    add_output(VARYING_SLOT_LAYER, int_t, "gl_Layer");
 845    if (state->ARB_viewport_array_enable)
 846       add_output(VARYING_SLOT_VIEWPORT, int_t, "gl_ViewportIndex");
 847    if (state->ARB_gpu_shader5_enable)
 848       add_system_value(SYSTEM_VALUE_INVOCATION_ID, int_t, "gl_InvocationID");
 849
 850    /* Although gl_PrimitiveID appears in tessellation control and tessellation
 851     * evaluation shaders, it has a different function there than it has in
 852     * geometry shaders, so we treat it (and its counterpart gl_PrimitiveIDIn)
 853     * as special geometry shader variables.
 854     *
 855     * Note that although the general convention of suffixing geometry shader
 856     * input varyings with "In" was not adopted into GLSL 1.50, it is used in
 857     * the specific case of gl_PrimitiveIDIn.  So we don't need to treat
 858     * gl_PrimitiveIDIn as an {ARB,EXT}_geometry_shader4-only variable.
 859     */
 860    ir_variable *var;
 861    var = add_input(VARYING_SLOT_PRIMITIVE_ID, int_t, "gl_PrimitiveIDIn");
 862    var->data.interpolation = INTERP_QUALIFIER_FLAT;
 863    var = add_output(VARYING_SLOT_PRIMITIVE_ID, int_t, "gl_PrimitiveID");
 864    var->data.interpolation = INTERP_QUALIFIER_FLAT;
 865 }
 866
 867
 868 /**
 869  * Generate variables which only exist in fragment shaders.
 870  */
 871 void
 872 builtin_variable_generator::generate_fs_special_vars()
 873 {
 874    add_input(VARYING_SLOT_POS, vec4_t, "gl_FragCoord");
 875    add_input(VARYING_SLOT_FACE, bool_t, "gl_FrontFacing");
 876    if (state->is_version(120, 100))
 877       add_input(VARYING_SLOT_PNTC, vec2_t, "gl_PointCoord");
 878
 879    if (state->is_version(150, 0)) {
 880       ir_variable *var =
 881          add_input(VARYING_SLOT_PRIMITIVE_ID, int_t, "gl_PrimitiveID");
 882       var->data.interpolation = INTERP_QUALIFIER_FLAT;
 883    }
 884
 885    /* gl_FragColor and gl_FragData were deprecated starting in desktop GLSL
 886     * 1.30, and were relegated to the compatibility profile in GLSL 4.20.
 887     * They were removed from GLSL ES 3.00.
 888     */
 889    if (compatibility || !state->is_version(420, 300)) {
 890       add_output(FRAG_RESULT_COLOR, vec4_t, "gl_FragColor");
 891       add_output(FRAG_RESULT_DATA0,
 892                  array(vec4_t, state->Const.MaxDrawBuffers), "gl_FragData");
 893    }
 894
 895    /* gl_FragDepth has always been in desktop GLSL, but did not appear in GLSL
 896     * ES 1.00.
 897     */
 898    if (state->is_version(110, 300))
 899       add_output(FRAG_RESULT_DEPTH, float_t, "gl_FragDepth");
 900
 901    if (state->ARB_shader_stencil_export_enable) {
 902       ir_variable *const var =
 903          add_output(FRAG_RESULT_STENCIL, int_t, "gl_FragStencilRefARB");
 904       if (state->ARB_shader_stencil_export_warn)
 905          var->warn_extension = "GL_ARB_shader_stencil_export";
 906    }
 907
 908    if (state->AMD_shader_stencil_export_enable) {
 909       ir_variable *const var =
 910          add_output(FRAG_RESULT_STENCIL, int_t, "gl_FragStencilRefAMD");
 911       if (state->AMD_shader_stencil_export_warn)
 912          var->warn_extension = "GL_AMD_shader_stencil_export";
 913    }
 914
 915    if (state->ARB_sample_shading_enable) {
 916       add_system_value(SYSTEM_VALUE_SAMPLE_ID, int_t, "gl_SampleID");
 917       add_system_value(SYSTEM_VALUE_SAMPLE_POS, vec2_t, "gl_SamplePosition");
 918       /* From the ARB_sample_shading specification:
 919        *    "The number of elements in the array is ceil(<s>/32), where
 920        *    <s> is the maximum number of color samples supported by the
 921        *    implementation."
 922        * Since no drivers expose more than 32x MSAA, we can simply set
 923        * the array size to 1 rather than computing it.
 924        */
 925       add_output(FRAG_RESULT_SAMPLE_MASK, array(int_t, 1), "gl_SampleMask");
 926    }
 927
 928    if (state->ARB_gpu_shader5_enable) {
 929       add_system_value(SYSTEM_VALUE_SAMPLE_MASK_IN, array(int_t, 1), "gl_SampleMaskIn");
 930    }
 931
 932    if (state->ARB_fragment_layer_viewport_enable) {
 933       add_input(VARYING_SLOT_LAYER, int_t, "gl_Layer");
 934       add_input(VARYING_SLOT_VIEWPORT, int_t, "gl_ViewportIndex");
 935    }
 936 }
 937
 938
 939 /**
 940  * Generate variables which only exist in compute shaders.
 941  */
 942 void
 943 builtin_variable_generator::generate_cs_special_vars()
 944 {
 945    /* TODO: finish this. */
 946 }
 947
 948
 949 /**
 950  * Add a single "varying" variable.  The variable's type and direction (input
 951  * or output) are adjusted as appropriate for the type of shader being
 952  * compiled.  For geometry shaders using {ARB,EXT}_geometry_shader4,
 953  * name_as_gs_input is used for the input (to avoid ambiguity).
 954  */
 955 void
 956 builtin_variable_generator::add_varying(int slot, const glsl_type *type,
 957                                         const char *name,
 958                                         const char *name_as_gs_input)
 959 {
 960    switch (state->stage) {
 961    case MESA_SHADER_GEOMETRY:
 962       this->per_vertex_in.add_field(slot, type, name);
 963       /* FALLTHROUGH */
 964    case MESA_SHADER_VERTEX:
 965       this->per_vertex_out.add_field(slot, type, name);
 966       break;
 967    case MESA_SHADER_FRAGMENT:
 968       add_input(slot, type, name);
 969       break;
 970    case MESA_SHADER_COMPUTE:
 971       /* Compute shaders don't have varyings. */
 972       break;
 973    }
 974 }
 975
 976
 977 /**
 978  * Generate variables that are used to communicate data from one shader stage
 979  * to the next ("varyings").
 980  */
 981 void
 982 builtin_variable_generator::generate_varyings()
 983 {
 984 #define ADD_VARYING(loc, type, name) \
 985    add_varying(loc, type, name, name "In")
 986
 987    /* gl_Position and gl_PointSize are not visible from fragment shaders. */
 988    if (state->stage != MESA_SHADER_FRAGMENT) {
 989       ADD_VARYING(VARYING_SLOT_POS, vec4_t, "gl_Position");
 990       ADD_VARYING(VARYING_SLOT_PSIZ, float_t, "gl_PointSize");
 991    }
 992
 993    if (state->is_version(130, 0)) {
 994        ADD_VARYING(VARYING_SLOT_CLIP_DIST0, array(float_t, 0),
 995                    "gl_ClipDistance");
 996    }
 997
 998    if (compatibility) {
 999       ADD_VARYING(VARYING_SLOT_TEX0, array(vec4_t, 0), "gl_TexCoord");
1000       ADD_VARYING(VARYING_SLOT_FOGC, float_t, "gl_FogFragCoord");
1001       if (state->stage == MESA_SHADER_FRAGMENT) {
1002          ADD_VARYING(VARYING_SLOT_COL0, vec4_t, "gl_Color");
1003          ADD_VARYING(VARYING_SLOT_COL1, vec4_t, "gl_SecondaryColor");
1004       } else {
1005          ADD_VARYING(VARYING_SLOT_CLIP_VERTEX, vec4_t, "gl_ClipVertex");
1006          ADD_VARYING(VARYING_SLOT_COL0, vec4_t, "gl_FrontColor");
1007          ADD_VARYING(VARYING_SLOT_BFC0, vec4_t, "gl_BackColor");
1008          ADD_VARYING(VARYING_SLOT_COL1, vec4_t, "gl_FrontSecondaryColor");
1009          ADD_VARYING(VARYING_SLOT_BFC1, vec4_t, "gl_BackSecondaryColor");
1010       }
1011    }
1012
1013    if (state->stage == MESA_SHADER_GEOMETRY) {
1014       const glsl_type *per_vertex_in_type =
1015          this->per_vertex_in.construct_interface_instance();
1016       add_variable("gl_in", array(per_vertex_in_type, 0),
1017                    ir_var_shader_in, -1);
1018    }
1019    if (state->stage == MESA_SHADER_VERTEX || state->stage == MESA_SHADER_GEOMETRY) {
1020       const glsl_type *per_vertex_out_type =
1021          this->per_vertex_out.construct_interface_instance();
1022       const glsl_struct_field *fields = per_vertex_out_type->fields.structure;
1023       for (unsigned i = 0; i < per_vertex_out_type->length; i++) {
1024          ir_variable *var =
1025             add_variable(fields[i].name, fields[i].type, ir_var_shader_out,
1026                          fields[i].location);
1027          var->data.interpolation = fields[i].interpolation;
1028          var->data.centroid = fields[i].centroid;
1029          var->data.sample = fields[i].sample;
1030          var->init_interface_type(per_vertex_out_type);
1031       }
1032    }
1033 }
1034
1035
1036 }; /* Anonymous namespace */
1037
1038
1039 void
1040 _mesa_glsl_initialize_variables(exec_list *instructions,
1041                                 struct _mesa_glsl_parse_state *state)
1042 {
1043    builtin_variable_generator gen(instructions, state);
1044
1045    gen.generate_constants();
1046    gen.generate_uniforms();
1047
1048    gen.generate_varyings();
1049
1050    switch (state->stage) {
1051    case MESA_SHADER_VERTEX:
1052       gen.generate_vs_special_vars();
1053       break;
1054    case MESA_SHADER_GEOMETRY:
1055       gen.generate_gs_special_vars();
1056       break;
1057    case MESA_SHADER_FRAGMENT:
1058       gen.generate_fs_special_vars();
1059       break;
1060    case MESA_SHADER_COMPUTE:
1061       gen.generate_cs_special_vars();
1062       break;
1063    }
1064 }