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, ARRAY_SIZE(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].matrix_layout = GLSL_MATRIX_LAYOUT_INHERITED;
 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
 482    ir_state_slot *slots =
 483       uni->allocate_state_slots(array_count * statevar->num_elements);
 484
 485    for (unsigned a = 0; a < array_count; a++) {
 486       for (unsigned j = 0; j < statevar->num_elements; j++) {
 487          const struct gl_builtin_uniform_element *element =
 488             &statevar->elements[j];
 489
 490          memcpy(slots->tokens, element->tokens, sizeof(element->tokens));
 491          if (type->is_array()) {
 492             if (strcmp(name, "gl_CurrentAttribVertMESA") == 0 ||
 493                 strcmp(name, "gl_CurrentAttribFragMESA") == 0) {
 494                slots->tokens[2] = a;
 495             } else {
 496                slots->tokens[1] = a;
 497             }
 498          }
 499
 500          slots->swizzle = element->swizzle;
 501          slots++;
 502       }
 503    }
 504
 505    return uni;
 506 }
 507
 508
 509 ir_variable *
 510 builtin_variable_generator::add_const(const char *name, int value)
 511 {
 512    ir_variable *const var = add_variable(name, glsl_type::int_type,
 513                                          ir_var_auto, -1);
 514    var->constant_value = new(var) ir_constant(value);
 515    var->constant_initializer = new(var) ir_constant(value);
 516    var->data.has_initializer = true;
 517    return var;
 518 }
 519
 520
 521 ir_variable *
 522 builtin_variable_generator::add_const_ivec3(const char *name, int x, int y,
 523                                             int z)
 524 {
 525    ir_variable *const var = add_variable(name, glsl_type::ivec3_type,
 526                                          ir_var_auto, -1);
 527    ir_constant_data data;
 528    memset(&data, 0, sizeof(data));
 529    data.i[0] = x;
 530    data.i[1] = y;
 531    data.i[2] = z;
 532    var->constant_value = new(var) ir_constant(glsl_type::ivec3_type, &data);
 533    var->constant_initializer =
 534       new(var) ir_constant(glsl_type::ivec3_type, &data);
 535    var->data.has_initializer = true;
 536    return var;
 537 }
 538
 539
 540 void
 541 builtin_variable_generator::generate_constants()
 542 {
 543    add_const("gl_MaxVertexAttribs", state->Const.MaxVertexAttribs);
 544    add_const("gl_MaxVertexTextureImageUnits",
 545              state->Const.MaxVertexTextureImageUnits);
 546    add_const("gl_MaxCombinedTextureImageUnits",
 547              state->Const.MaxCombinedTextureImageUnits);
 548    add_const("gl_MaxTextureImageUnits", state->Const.MaxTextureImageUnits);
 549    add_const("gl_MaxDrawBuffers", state->Const.MaxDrawBuffers);
 550
 551    /* Max uniforms/varyings: GLSL ES counts these in units of vectors; desktop
 552     * GL counts them in units of "components" or "floats".
 553     */
 554    if (state->es_shader) {
 555       add_const("gl_MaxVertexUniformVectors",
 556                 state->Const.MaxVertexUniformComponents / 4);
 557       add_const("gl_MaxFragmentUniformVectors",
 558                 state->Const.MaxFragmentUniformComponents / 4);
 559
 560       /* In GLSL ES 3.00, gl_MaxVaryingVectors was split out to separate
 561        * vertex and fragment shader constants.
 562        */
 563       if (state->is_version(0, 300)) {
 564          add_const("gl_MaxVertexOutputVectors",
 565                    state->ctx->Const.Program[MESA_SHADER_VERTEX].MaxOutputComponents / 4);
 566          add_const("gl_MaxFragmentInputVectors",
 567                    state->ctx->Const.Program[MESA_SHADER_FRAGMENT].MaxInputComponents / 4);
 568       } else {
 569          add_const("gl_MaxVaryingVectors",
 570                    state->ctx->Const.MaxVarying);
 571       }
 572    } else {
 573       add_const("gl_MaxVertexUniformComponents",
 574                 state->Const.MaxVertexUniformComponents);
 575
 576       /* Note: gl_MaxVaryingFloats was deprecated in GLSL 1.30+, but not
 577        * removed
 578        */
 579       add_const("gl_MaxVaryingFloats", state->ctx->Const.MaxVarying * 4);
 580
 581       add_const("gl_MaxFragmentUniformComponents",
 582                 state->Const.MaxFragmentUniformComponents);
 583    }
 584
 585    /* Texel offsets were introduced in ARB_shading_language_420pack (which
 586     * requires desktop GLSL version 130), and adopted into desktop GLSL
 587     * version 4.20 and GLSL ES version 3.00.
 588     */
 589    if ((state->is_version(130, 0) &&
 590         state->ARB_shading_language_420pack_enable) ||
 591       state->is_version(420, 300)) {
 592       add_const("gl_MinProgramTexelOffset",
 593                 state->Const.MinProgramTexelOffset);
 594       add_const("gl_MaxProgramTexelOffset",
 595                 state->Const.MaxProgramTexelOffset);
 596    }
 597
 598    if (state->is_version(130, 0)) {
 599       add_const("gl_MaxClipDistances", state->Const.MaxClipPlanes);
 600       add_const("gl_MaxVaryingComponents", state->ctx->Const.MaxVarying * 4);
 601    }
 602
 603    if (state->is_version(150, 0)) {
 604       add_const("gl_MaxVertexOutputComponents",
 605                 state->Const.MaxVertexOutputComponents);
 606       add_const("gl_MaxGeometryInputComponents",
 607                 state->Const.MaxGeometryInputComponents);
 608       add_const("gl_MaxGeometryOutputComponents",
 609                 state->Const.MaxGeometryOutputComponents);
 610       add_const("gl_MaxFragmentInputComponents",
 611                 state->Const.MaxFragmentInputComponents);
 612       add_const("gl_MaxGeometryTextureImageUnits",
 613                 state->Const.MaxGeometryTextureImageUnits);
 614       add_const("gl_MaxGeometryOutputVertices",
 615                 state->Const.MaxGeometryOutputVertices);
 616       add_const("gl_MaxGeometryTotalOutputComponents",
 617                 state->Const.MaxGeometryTotalOutputComponents);
 618       add_const("gl_MaxGeometryUniformComponents",
 619                 state->Const.MaxGeometryUniformComponents);
 620
 621       /* Note: the GLSL 1.50-4.40 specs require
 622        * gl_MaxGeometryVaryingComponents to be present, and to be at least 64.
 623        * But they do not define what it means (and there does not appear to be
 624        * any corresponding constant in the GL specs).  However,
 625        * ARB_geometry_shader4 defines MAX_GEOMETRY_VARYING_COMPONENTS_ARB to
 626        * be the maximum number of components available for use as geometry
 627        * outputs.  So we assume this is a synonym for
 628        * gl_MaxGeometryOutputComponents.
 629        */
 630       add_const("gl_MaxGeometryVaryingComponents",
 631                 state->Const.MaxGeometryOutputComponents);
 632    }
 633
 634    if (compatibility) {
 635       /* Note: gl_MaxLights stopped being listed as an explicit constant in
 636        * GLSL 1.30, however it continues to be referred to (as a minimum size
 637        * for compatibility-mode uniforms) all the way up through GLSL 4.30, so
 638        * this seems like it was probably an oversight.
 639        */
 640       add_const("gl_MaxLights", state->Const.MaxLights);
 641
 642       add_const("gl_MaxClipPlanes", state->Const.MaxClipPlanes);
 643
 644       /* Note: gl_MaxTextureUnits wasn't made compatibility-only until GLSL
 645        * 1.50, however this seems like it was probably an oversight.
 646        */
 647       add_const("gl_MaxTextureUnits", state->Const.MaxTextureUnits);
 648
 649       /* Note: gl_MaxTextureCoords was left out of GLSL 1.40, but it was
 650        * re-introduced in GLSL 1.50, so this seems like it was probably an
 651        * oversight.
 652        */
 653       add_const("gl_MaxTextureCoords", state->Const.MaxTextureCoords);
 654    }
 655
 656    if (state->has_atomic_counters()) {
 657       add_const("gl_MaxVertexAtomicCounters",
 658                 state->Const.MaxVertexAtomicCounters);
 659       add_const("gl_MaxFragmentAtomicCounters",
 660                 state->Const.MaxFragmentAtomicCounters);
 661       add_const("gl_MaxCombinedAtomicCounters",
 662                 state->Const.MaxCombinedAtomicCounters);
 663       add_const("gl_MaxAtomicCounterBindings",
 664                 state->Const.MaxAtomicBufferBindings);
 665
 666       /* When Mesa adds support for GL_OES_geometry_shader and
 667        * GL_OES_tessellation_shader, this will need to change.
 668        */
 669       if (!state->es_shader) {
 670          add_const("gl_MaxGeometryAtomicCounters",
 671                    state->Const.MaxGeometryAtomicCounters);
 672          add_const("gl_MaxTessControlAtomicCounters", 0);
 673          add_const("gl_MaxTessEvaluationAtomicCounters", 0);
 674       }
 675    }
 676
 677    if (state->is_version(420, 310)) {
 678       add_const("gl_MaxVertexAtomicCounterBuffers",
 679                 state->Const.MaxVertexAtomicCounterBuffers);
 680       add_const("gl_MaxFragmentAtomicCounterBuffers",
 681                 state->Const.MaxFragmentAtomicCounterBuffers);
 682       add_const("gl_MaxCombinedAtomicCounterBuffers",
 683                 state->Const.MaxCombinedAtomicCounterBuffers);
 684       add_const("gl_MaxAtomicCounterBufferSize",
 685                 state->Const.MaxAtomicCounterBufferSize);
 686
 687       /* When Mesa adds support for GL_OES_geometry_shader and
 688        * GL_OES_tessellation_shader, this will need to change.
 689        */
 690       if (!state->es_shader) {
 691          add_const("gl_MaxGeometryAtomicCounterBuffers",
 692                    state->Const.MaxGeometryAtomicCounterBuffers);
 693          add_const("gl_MaxTessControlAtomicCounterBuffers", 0);
 694          add_const("gl_MaxTessEvaluationAtomicCounterBuffers", 0);
 695       }
 696    }
 697
 698    if (state->is_version(430, 0) || state->ARB_compute_shader_enable) {
 699       add_const("gl_MaxComputeAtomicCounterBuffers", MAX_COMPUTE_ATOMIC_COUNTER_BUFFERS);
 700       add_const("gl_MaxComputeAtomicCounters", MAX_COMPUTE_ATOMIC_COUNTERS);
 701       add_const("gl_MaxComputeImageUniforms", MAX_COMPUTE_IMAGE_UNIFORMS);
 702       add_const("gl_MaxComputeTextureImageUnits", MAX_COMPUTE_TEXTURE_IMAGE_UNITS);
 703       add_const("gl_MaxComputeUniformComponents", MAX_COMPUTE_UNIFORM_COMPONENTS);
 704
 705       add_const_ivec3("gl_MaxComputeWorkGroupCount",
 706                       state->Const.MaxComputeWorkGroupCount[0],
 707                       state->Const.MaxComputeWorkGroupCount[1],
 708                       state->Const.MaxComputeWorkGroupCount[2]);
 709       add_const_ivec3("gl_MaxComputeWorkGroupSize",
 710                       state->Const.MaxComputeWorkGroupSize[0],
 711                       state->Const.MaxComputeWorkGroupSize[1],
 712                       state->Const.MaxComputeWorkGroupSize[2]);
 713
 714       /* From the GLSL 4.40 spec, section 7.1 (Built-In Language Variables):
 715        *
 716        *     The built-in constant gl_WorkGroupSize is a compute-shader
 717        *     constant containing the local work-group size of the shader.  The
 718        *     size of the work group in the X, Y, and Z dimensions is stored in
 719        *     the x, y, and z components.  The constants values in
 720        *     gl_WorkGroupSize will match those specified in the required
 721        *     local_size_x, local_size_y, and local_size_z layout qualifiers
 722        *     for the current shader.  This is a constant so that it can be
 723        *     used to size arrays of memory that can be shared within the local
 724        *     work group.  It is a compile-time error to use gl_WorkGroupSize
 725        *     in a shader that does not declare a fixed local group size, or
 726        *     before that shader has declared a fixed local group size, using
 727        *     local_size_x, local_size_y, and local_size_z.
 728        *
 729        * To prevent the shader from trying to refer to gl_WorkGroupSize before
 730        * the layout declaration, we don't define it here.  Intead we define it
 731        * in ast_cs_input_layout::hir().
 732        */
 733    }
 734
 735    if (state->is_version(420, 0) ||
 736        state->ARB_shader_image_load_store_enable) {
 737       add_const("gl_MaxImageUnits",
 738                 state->Const.MaxImageUnits);
 739       add_const("gl_MaxCombinedImageUnitsAndFragmentOutputs",
 740                 state->Const.MaxCombinedImageUnitsAndFragmentOutputs);
 741       add_const("gl_MaxImageSamples",
 742                 state->Const.MaxImageSamples);
 743       add_const("gl_MaxVertexImageUniforms",
 744                 state->Const.MaxVertexImageUniforms);
 745       add_const("gl_MaxTessControlImageUniforms", 0);
 746       add_const("gl_MaxTessEvaluationImageUniforms", 0);
 747       add_const("gl_MaxGeometryImageUniforms",
 748                 state->Const.MaxGeometryImageUniforms);
 749       add_const("gl_MaxFragmentImageUniforms",
 750                 state->Const.MaxFragmentImageUniforms);
 751       add_const("gl_MaxCombinedImageUniforms",
 752                 state->Const.MaxCombinedImageUniforms);
 753    }
 754
 755    if (state->is_version(410, 0) ||
 756        state->ARB_viewport_array_enable)
 757       add_const("gl_MaxViewports", state->Const.MaxViewports);
 758 }
 759
 760
 761 /**
 762  * Generate uniform variables (which exist in all types of shaders).
 763  */
 764 void
 765 builtin_variable_generator::generate_uniforms()
 766 {
 767    if (state->is_version(400, 0) || state->ARB_sample_shading_enable)
 768       add_uniform(int_t, "gl_NumSamples");
 769    add_uniform(type("gl_DepthRangeParameters"), "gl_DepthRange");
 770    add_uniform(array(vec4_t, VERT_ATTRIB_MAX), "gl_CurrentAttribVertMESA");
 771    add_uniform(array(vec4_t, VARYING_SLOT_MAX), "gl_CurrentAttribFragMESA");
 772
 773    if (compatibility) {
 774       add_uniform(mat4_t, "gl_ModelViewMatrix");
 775       add_uniform(mat4_t, "gl_ProjectionMatrix");
 776       add_uniform(mat4_t, "gl_ModelViewProjectionMatrix");
 777       add_uniform(mat3_t, "gl_NormalMatrix");
 778       add_uniform(mat4_t, "gl_ModelViewMatrixInverse");
 779       add_uniform(mat4_t, "gl_ProjectionMatrixInverse");
 780       add_uniform(mat4_t, "gl_ModelViewProjectionMatrixInverse");
 781       add_uniform(mat4_t, "gl_ModelViewMatrixTranspose");
 782       add_uniform(mat4_t, "gl_ProjectionMatrixTranspose");
 783       add_uniform(mat4_t, "gl_ModelViewProjectionMatrixTranspose");
 784       add_uniform(mat4_t, "gl_ModelViewMatrixInverseTranspose");
 785       add_uniform(mat4_t, "gl_ProjectionMatrixInverseTranspose");
 786       add_uniform(mat4_t, "gl_ModelViewProjectionMatrixInverseTranspose");
 787       add_uniform(float_t, "gl_NormalScale");
 788       add_uniform(type("gl_LightModelParameters"), "gl_LightModel");
 789       add_uniform(vec4_t, "gl_FogParamsOptimizedMESA");
 790
 791       const glsl_type *const mat4_array_type =
 792          array(mat4_t, state->Const.MaxTextureCoords);
 793       add_uniform(mat4_array_type, "gl_TextureMatrix");
 794       add_uniform(mat4_array_type, "gl_TextureMatrixInverse");
 795       add_uniform(mat4_array_type, "gl_TextureMatrixTranspose");
 796       add_uniform(mat4_array_type, "gl_TextureMatrixInverseTranspose");
 797
 798       add_uniform(array(vec4_t, state->Const.MaxClipPlanes), "gl_ClipPlane");
 799       add_uniform(type("gl_PointParameters"), "gl_Point");
 800
 801       const glsl_type *const material_parameters_type =
 802          type("gl_MaterialParameters");
 803       add_uniform(material_parameters_type, "gl_FrontMaterial");
 804       add_uniform(material_parameters_type, "gl_BackMaterial");
 805
 806       add_uniform(array(type("gl_LightSourceParameters"),
 807                         state->Const.MaxLights),
 808                   "gl_LightSource");
 809
 810       const glsl_type *const light_model_products_type =
 811          type("gl_LightModelProducts");
 812       add_uniform(light_model_products_type, "gl_FrontLightModelProduct");
 813       add_uniform(light_model_products_type, "gl_BackLightModelProduct");
 814
 815       const glsl_type *const light_products_type =
 816          array(type("gl_LightProducts"), state->Const.MaxLights);
 817       add_uniform(light_products_type, "gl_FrontLightProduct");
 818       add_uniform(light_products_type, "gl_BackLightProduct");
 819
 820       add_uniform(array(vec4_t, state->Const.MaxTextureUnits),
 821                   "gl_TextureEnvColor");
 822
 823       const glsl_type *const texcoords_vec4 =
 824          array(vec4_t, state->Const.MaxTextureCoords);
 825       add_uniform(texcoords_vec4, "gl_EyePlaneS");
 826       add_uniform(texcoords_vec4, "gl_EyePlaneT");
 827       add_uniform(texcoords_vec4, "gl_EyePlaneR");
 828       add_uniform(texcoords_vec4, "gl_EyePlaneQ");
 829       add_uniform(texcoords_vec4, "gl_ObjectPlaneS");
 830       add_uniform(texcoords_vec4, "gl_ObjectPlaneT");
 831       add_uniform(texcoords_vec4, "gl_ObjectPlaneR");
 832       add_uniform(texcoords_vec4, "gl_ObjectPlaneQ");
 833
 834       add_uniform(type("gl_FogParameters"), "gl_Fog");
 835    }
 836 }
 837
 838
 839 /**
 840  * Generate variables which only exist in vertex shaders.
 841  */
 842 void
 843 builtin_variable_generator::generate_vs_special_vars()
 844 {
 845    if (state->is_version(130, 300))
 846       add_system_value(SYSTEM_VALUE_VERTEX_ID, int_t, "gl_VertexID");
 847    if (state->ARB_draw_instanced_enable)
 848       add_system_value(SYSTEM_VALUE_INSTANCE_ID, int_t, "gl_InstanceIDARB");
 849    if (state->ARB_draw_instanced_enable || state->is_version(140, 300))
 850       add_system_value(SYSTEM_VALUE_INSTANCE_ID, int_t, "gl_InstanceID");
 851    if (state->AMD_vertex_shader_layer_enable)
 852       add_output(VARYING_SLOT_LAYER, int_t, "gl_Layer");
 853    if (state->AMD_vertex_shader_viewport_index_enable)
 854       add_output(VARYING_SLOT_VIEWPORT, int_t, "gl_ViewportIndex");
 855    if (compatibility) {
 856       add_input(VERT_ATTRIB_POS, vec4_t, "gl_Vertex");
 857       add_input(VERT_ATTRIB_NORMAL, vec3_t, "gl_Normal");
 858       add_input(VERT_ATTRIB_COLOR0, vec4_t, "gl_Color");
 859       add_input(VERT_ATTRIB_COLOR1, vec4_t, "gl_SecondaryColor");
 860       add_input(VERT_ATTRIB_TEX0, vec4_t, "gl_MultiTexCoord0");
 861       add_input(VERT_ATTRIB_TEX1, vec4_t, "gl_MultiTexCoord1");
 862       add_input(VERT_ATTRIB_TEX2, vec4_t, "gl_MultiTexCoord2");
 863       add_input(VERT_ATTRIB_TEX3, vec4_t, "gl_MultiTexCoord3");
 864       add_input(VERT_ATTRIB_TEX4, vec4_t, "gl_MultiTexCoord4");
 865       add_input(VERT_ATTRIB_TEX5, vec4_t, "gl_MultiTexCoord5");
 866       add_input(VERT_ATTRIB_TEX6, vec4_t, "gl_MultiTexCoord6");
 867       add_input(VERT_ATTRIB_TEX7, vec4_t, "gl_MultiTexCoord7");
 868       add_input(VERT_ATTRIB_FOG, float_t, "gl_FogCoord");
 869    }
 870 }
 871
 872
 873 /**
 874  * Generate variables which only exist in geometry shaders.
 875  */
 876 void
 877 builtin_variable_generator::generate_gs_special_vars()
 878 {
 879    add_output(VARYING_SLOT_LAYER, int_t, "gl_Layer");
 880    if (state->is_version(410, 0) || state->ARB_viewport_array_enable)
 881       add_output(VARYING_SLOT_VIEWPORT, int_t, "gl_ViewportIndex");
 882    if (state->is_version(400, 0) || state->ARB_gpu_shader5_enable)
 883       add_system_value(SYSTEM_VALUE_INVOCATION_ID, int_t, "gl_InvocationID");
 884
 885    /* Although gl_PrimitiveID appears in tessellation control and tessellation
 886     * evaluation shaders, it has a different function there than it has in
 887     * geometry shaders, so we treat it (and its counterpart gl_PrimitiveIDIn)
 888     * as special geometry shader variables.
 889     *
 890     * Note that although the general convention of suffixing geometry shader
 891     * input varyings with "In" was not adopted into GLSL 1.50, it is used in
 892     * the specific case of gl_PrimitiveIDIn.  So we don't need to treat
 893     * gl_PrimitiveIDIn as an {ARB,EXT}_geometry_shader4-only variable.
 894     */
 895    ir_variable *var;
 896    var = add_input(VARYING_SLOT_PRIMITIVE_ID, int_t, "gl_PrimitiveIDIn");
 897    var->data.interpolation = INTERP_QUALIFIER_FLAT;
 898    var = add_output(VARYING_SLOT_PRIMITIVE_ID, int_t, "gl_PrimitiveID");
 899    var->data.interpolation = INTERP_QUALIFIER_FLAT;
 900 }
 901
 902
 903 /**
 904  * Generate variables which only exist in fragment shaders.
 905  */
 906 void
 907 builtin_variable_generator::generate_fs_special_vars()
 908 {
 909    add_input(VARYING_SLOT_POS, vec4_t, "gl_FragCoord");
 910    add_input(VARYING_SLOT_FACE, bool_t, "gl_FrontFacing");
 911    if (state->is_version(120, 100))
 912       add_input(VARYING_SLOT_PNTC, vec2_t, "gl_PointCoord");
 913
 914    if (state->is_version(150, 0)) {
 915       ir_variable *var =
 916          add_input(VARYING_SLOT_PRIMITIVE_ID, int_t, "gl_PrimitiveID");
 917       var->data.interpolation = INTERP_QUALIFIER_FLAT;
 918    }
 919
 920    /* gl_FragColor and gl_FragData were deprecated starting in desktop GLSL
 921     * 1.30, and were relegated to the compatibility profile in GLSL 4.20.
 922     * They were removed from GLSL ES 3.00.
 923     */
 924    if (compatibility || !state->is_version(420, 300)) {
 925       add_output(FRAG_RESULT_COLOR, vec4_t, "gl_FragColor");
 926       add_output(FRAG_RESULT_DATA0,
 927                  array(vec4_t, state->Const.MaxDrawBuffers), "gl_FragData");
 928    }
 929
 930    /* gl_FragDepth has always been in desktop GLSL, but did not appear in GLSL
 931     * ES 1.00.
 932     */
 933    if (state->is_version(110, 300))
 934       add_output(FRAG_RESULT_DEPTH, float_t, "gl_FragDepth");
 935
 936    if (state->ARB_shader_stencil_export_enable) {
 937       ir_variable *const var =
 938          add_output(FRAG_RESULT_STENCIL, int_t, "gl_FragStencilRefARB");
 939       if (state->ARB_shader_stencil_export_warn)
 940          var->enable_extension_warning("GL_ARB_shader_stencil_export");
 941    }
 942
 943    if (state->AMD_shader_stencil_export_enable) {
 944       ir_variable *const var =
 945          add_output(FRAG_RESULT_STENCIL, int_t, "gl_FragStencilRefAMD");
 946       if (state->AMD_shader_stencil_export_warn)
 947          var->enable_extension_warning("GL_AMD_shader_stencil_export");
 948    }
 949
 950    if (state->is_version(400, 0) || state->ARB_sample_shading_enable) {
 951       add_system_value(SYSTEM_VALUE_SAMPLE_ID, int_t, "gl_SampleID");
 952       add_system_value(SYSTEM_VALUE_SAMPLE_POS, vec2_t, "gl_SamplePosition");
 953       /* From the ARB_sample_shading specification:
 954        *    "The number of elements in the array is ceil(<s>/32), where
 955        *    <s> is the maximum number of color samples supported by the
 956        *    implementation."
 957        * Since no drivers expose more than 32x MSAA, we can simply set
 958        * the array size to 1 rather than computing it.
 959        */
 960       add_output(FRAG_RESULT_SAMPLE_MASK, array(int_t, 1), "gl_SampleMask");
 961    }
 962
 963    if (state->is_version(400, 0) || state->ARB_gpu_shader5_enable) {
 964       add_system_value(SYSTEM_VALUE_SAMPLE_MASK_IN, array(int_t, 1), "gl_SampleMaskIn");
 965    }
 966
 967    if (state->is_version(430, 0) || state->ARB_fragment_layer_viewport_enable) {
 968       add_input(VARYING_SLOT_LAYER, int_t, "gl_Layer");
 969       add_input(VARYING_SLOT_VIEWPORT, int_t, "gl_ViewportIndex");
 970    }
 971 }
 972
 973
 974 /**
 975  * Generate variables which only exist in compute shaders.
 976  */
 977 void
 978 builtin_variable_generator::generate_cs_special_vars()
 979 {
 980    /* TODO: finish this. */
 981 }
 982
 983
 984 /**
 985  * Add a single "varying" variable.  The variable's type and direction (input
 986  * or output) are adjusted as appropriate for the type of shader being
 987  * compiled.  For geometry shaders using {ARB,EXT}_geometry_shader4,
 988  * name_as_gs_input is used for the input (to avoid ambiguity).
 989  */
 990 void
 991 builtin_variable_generator::add_varying(int slot, const glsl_type *type,
 992                                         const char *name,
 993                                         const char *name_as_gs_input)
 994 {
 995    switch (state->stage) {
 996    case MESA_SHADER_GEOMETRY:
 997       this->per_vertex_in.add_field(slot, type, name);
 998       /* FALLTHROUGH */
 999    case MESA_SHADER_VERTEX:
1000       this->per_vertex_out.add_field(slot, type, name);
1001       break;
1002    case MESA_SHADER_FRAGMENT:
1003       add_input(slot, type, name);
1004       break;
1005    case MESA_SHADER_COMPUTE:
1006       /* Compute shaders don't have varyings. */
1007       break;
1008    }
1009 }
1010
1011
1012 /**
1013  * Generate variables that are used to communicate data from one shader stage
1014  * to the next ("varyings").
1015  */
1016 void
1017 builtin_variable_generator::generate_varyings()
1018 {
1019 #define ADD_VARYING(loc, type, name) \
1020    add_varying(loc, type, name, name "In")
1021
1022    /* gl_Position and gl_PointSize are not visible from fragment shaders. */
1023    if (state->stage != MESA_SHADER_FRAGMENT) {
1024       ADD_VARYING(VARYING_SLOT_POS, vec4_t, "gl_Position");
1025       ADD_VARYING(VARYING_SLOT_PSIZ, float_t, "gl_PointSize");
1026    }
1027
1028    if (state->is_version(130, 0)) {
1029        ADD_VARYING(VARYING_SLOT_CLIP_DIST0, array(float_t, 0),
1030                    "gl_ClipDistance");
1031    }
1032
1033    if (compatibility) {
1034       ADD_VARYING(VARYING_SLOT_TEX0, array(vec4_t, 0), "gl_TexCoord");
1035       ADD_VARYING(VARYING_SLOT_FOGC, float_t, "gl_FogFragCoord");
1036       if (state->stage == MESA_SHADER_FRAGMENT) {
1037          ADD_VARYING(VARYING_SLOT_COL0, vec4_t, "gl_Color");
1038          ADD_VARYING(VARYING_SLOT_COL1, vec4_t, "gl_SecondaryColor");
1039       } else {
1040          ADD_VARYING(VARYING_SLOT_CLIP_VERTEX, vec4_t, "gl_ClipVertex");
1041          ADD_VARYING(VARYING_SLOT_COL0, vec4_t, "gl_FrontColor");
1042          ADD_VARYING(VARYING_SLOT_BFC0, vec4_t, "gl_BackColor");
1043          ADD_VARYING(VARYING_SLOT_COL1, vec4_t, "gl_FrontSecondaryColor");
1044          ADD_VARYING(VARYING_SLOT_BFC1, vec4_t, "gl_BackSecondaryColor");
1045       }
1046    }
1047
1048    if (state->stage == MESA_SHADER_GEOMETRY) {
1049       const glsl_type *per_vertex_in_type =
1050          this->per_vertex_in.construct_interface_instance();
1051       add_variable("gl_in", array(per_vertex_in_type, 0),
1052                    ir_var_shader_in, -1);
1053    }
1054    if (state->stage == MESA_SHADER_VERTEX || state->stage == MESA_SHADER_GEOMETRY) {
1055       const glsl_type *per_vertex_out_type =
1056          this->per_vertex_out.construct_interface_instance();
1057       const glsl_struct_field *fields = per_vertex_out_type->fields.structure;
1058       for (unsigned i = 0; i < per_vertex_out_type->length; i++) {
1059          ir_variable *var =
1060             add_variable(fields[i].name, fields[i].type, ir_var_shader_out,
1061                          fields[i].location);
1062          var->data.interpolation = fields[i].interpolation;
1063          var->data.centroid = fields[i].centroid;
1064          var->data.sample = fields[i].sample;
1065          var->init_interface_type(per_vertex_out_type);
1066       }
1067    }
1068 }
1069
1070
1071 }; /* Anonymous namespace */
1072
1073
1074 void
1075 _mesa_glsl_initialize_variables(exec_list *instructions,
1076                                 struct _mesa_glsl_parse_state *state)
1077 {
1078    builtin_variable_generator gen(instructions, state);
1079
1080    gen.generate_constants();
1081    gen.generate_uniforms();
1082
1083    gen.generate_varyings();
1084
1085    switch (state->stage) {
1086    case MESA_SHADER_VERTEX:
1087       gen.generate_vs_special_vars();
1088       break;
1089    case MESA_SHADER_GEOMETRY:
1090       gen.generate_gs_special_vars();
1091       break;
1092    case MESA_SHADER_FRAGMENT:
1093       gen.generate_fs_special_vars();
1094       break;
1095    case MESA_SHADER_COMPUTE:
1096       gen.generate_cs_special_vars();
1097       break;
1098    }
1099 }