src/glsl/ir_variable.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 "builtin_variables.h"
  28
  29 static void generate_ARB_draw_buffers_variables(exec_list *,
  30                                                 struct _mesa_glsl_parse_state *,
  31                                                 bool, _mesa_glsl_parser_targets);
  32
  33 static ir_variable *
  34 add_variable(const char *name, enum ir_variable_mode mode, int slot,
  35              const glsl_type *type, exec_list *instructions,
  36                      glsl_symbol_table *symtab)
  37 {
  38    ir_variable *var = new(symtab) ir_variable(type, name, mode);
  39
  40    switch (var->mode) {
  41    case ir_var_auto:
  42    case ir_var_in:
  43    case ir_var_uniform:
  44       var->read_only = true;
  45       break;
  46    case ir_var_inout:
  47    case ir_var_out:
  48       break;
  49    default:
  50       assert(0);
  51       break;
  52    }
  53
  54    var->location = slot;
  55
  56    /* Once the variable is created an initialized, add it to the symbol table
  57     * and add the declaration to the IR stream.
  58     */
  59    instructions->push_tail(var);
  60
  61    symtab->add_variable(var->name, var);
  62    return var;
  63 }
  64
  65 static ir_variable *
  66 add_uniform(exec_list *instructions,
  67             struct _mesa_glsl_parse_state *state,
  68             const char *name, const glsl_type *type)
  69 {
  70    return add_variable(name, ir_var_uniform, -1, type, instructions,
  71                        state->symbols);
  72 }
  73
  74 static void
  75 add_builtin_variable(const builtin_variable *proto, exec_list *instructions,
  76                      glsl_symbol_table *symtab)
  77 {
  78    /* Create a new variable declaration from the description supplied by
  79     * the caller.
  80     */
  81    const glsl_type *const type = symtab->get_type(proto->type);
  82
  83    assert(type != NULL);
  84
  85    add_variable(proto->name, proto->mode, proto->slot, type, instructions,
  86                 symtab);
  87 }
  88
  89 static void
  90 add_builtin_constant(exec_list *instructions,
  91                      struct _mesa_glsl_parse_state *state,
  92                      const char *name, int value)
  93 {
  94    ir_variable *const var = add_variable(name, ir_var_auto,
  95                                          -1, glsl_type::int_type,
  96                                          instructions, state->symbols);
  97    var->constant_value = new(var) ir_constant(value);
  98 }
  99
 100 /* Several constants in GLSL ES have different names than normal desktop GLSL.
 101  * Therefore, this function should only be called on the ES path.
 102  */
 103 static void
 104 generate_100ES_uniforms(exec_list *instructions,
 105                      struct _mesa_glsl_parse_state *state)
 106 {
 107    add_builtin_constant(instructions, state, "gl_MaxVertexAttribs",
 108                         state->Const.MaxVertexAttribs);
 109    add_builtin_constant(instructions, state, "gl_MaxVertexUniformVectors",
 110                         state->Const.MaxVertexUniformComponents);
 111    add_builtin_constant(instructions, state, "gl_MaxVaryingVectors",
 112                         state->Const.MaxVaryingFloats / 4);
 113    add_builtin_constant(instructions, state, "gl_MaxVertexTextureImageUnits",
 114                         state->Const.MaxVertexTextureImageUnits);
 115    add_builtin_constant(instructions, state, "gl_MaxCombinedTextureImageUnits",
 116                         state->Const.MaxCombinedTextureImageUnits);
 117    add_builtin_constant(instructions, state, "gl_MaxTextureImageUnits",
 118                         state->Const.MaxTextureImageUnits);
 119    add_builtin_constant(instructions, state, "gl_MaxFragmentUniformVectors",
 120                         state->Const.MaxFragmentUniformComponents);
 121
 122    add_uniform(instructions, state, "gl_DepthRange",
 123                state->symbols->get_type("gl_DepthRangeParameters"));
 124 }
 125
 126 static void
 127 generate_110_uniforms(exec_list *instructions,
 128                       struct _mesa_glsl_parse_state *state)
 129 {
 130    for (unsigned i = 0
 131            ; i < Elements(builtin_110_deprecated_uniforms)
 132            ; i++) {
 133       add_builtin_variable(& builtin_110_deprecated_uniforms[i],
 134                            instructions, state->symbols);
 135    }
 136
 137    add_builtin_constant(instructions, state, "gl_MaxLights",
 138                         state->Const.MaxLights);
 139    add_builtin_constant(instructions, state, "gl_MaxClipPlanes",
 140                         state->Const.MaxClipPlanes);
 141    add_builtin_constant(instructions, state, "gl_MaxTextureUnits",
 142                         state->Const.MaxTextureUnits);
 143    add_builtin_constant(instructions, state, "gl_MaxTextureCoords",
 144                         state->Const.MaxTextureCoords);
 145    add_builtin_constant(instructions, state, "gl_MaxVertexAttribs",
 146                         state->Const.MaxVertexAttribs);
 147    add_builtin_constant(instructions, state, "gl_MaxVertexUniformComponents",
 148                         state->Const.MaxVertexUniformComponents);
 149    add_builtin_constant(instructions, state, "gl_MaxVaryingFloats",
 150                         state->Const.MaxVaryingFloats);
 151    add_builtin_constant(instructions, state, "gl_MaxVertexTextureImageUnits",
 152                         state->Const.MaxVertexTextureImageUnits);
 153    add_builtin_constant(instructions, state, "gl_MaxCombinedTextureImageUnits",
 154                         state->Const.MaxCombinedTextureImageUnits);
 155    add_builtin_constant(instructions, state, "gl_MaxTextureImageUnits",
 156                         state->Const.MaxTextureImageUnits);
 157    add_builtin_constant(instructions, state, "gl_MaxFragmentUniformComponents",
 158                         state->Const.MaxFragmentUniformComponents);
 159
 160    const glsl_type *const mat4_array_type =
 161       glsl_type::get_array_instance(glsl_type::mat4_type,
 162                                     state->Const.MaxTextureCoords);
 163
 164    add_uniform(instructions, state, "gl_TextureMatrix", mat4_array_type);
 165
 166    add_uniform(instructions, state, "gl_DepthRange",
 167                 state->symbols->get_type("gl_DepthRangeParameters"));
 168
 169    add_uniform(instructions, state, "gl_ClipPlane",
 170                glsl_type::get_array_instance(glsl_type::vec4_type,
 171                                              state->Const.MaxClipPlanes));
 172    add_uniform(instructions, state, "gl_Point",
 173                state->symbols->get_type("gl_PointParameters"));
 174
 175    const glsl_type *const material_parameters_type =
 176       state->symbols->get_type("gl_MaterialParameters");
 177    add_uniform(instructions, state, "gl_FrontMaterial", material_parameters_type);
 178    add_uniform(instructions, state, "gl_BackMaterial", material_parameters_type);
 179
 180    const glsl_type *const light_source_array_type =
 181       glsl_type::get_array_instance(state->symbols->get_type("gl_LightSourceParameters"), state->Const.MaxLights);
 182
 183    add_uniform(instructions, state, "gl_LightSource", light_source_array_type);
 184
 185    const glsl_type *const light_model_products_type =
 186       state->symbols->get_type("gl_LightModelProducts");
 187    add_uniform(instructions, state, "gl_FrontLightModelProduct",
 188                light_model_products_type);
 189    add_uniform(instructions, state, "gl_BackLightModelProduct",
 190                light_model_products_type);
 191
 192    const glsl_type *const light_products_type =
 193       glsl_type::get_array_instance(state->symbols->get_type("gl_LightProducts"),
 194                                     state->Const.MaxLights);
 195    add_uniform(instructions, state, "gl_FrontLightProduct", light_products_type);
 196    add_uniform(instructions, state, "gl_BackLightProduct", light_products_type);
 197
 198    add_uniform(instructions, state, "gl_TextureEnvColor",
 199                glsl_type::get_array_instance(glsl_type::vec4_type,
 200                                              state->Const.MaxTextureUnits));
 201
 202    const glsl_type *const texcoords_vec4 =
 203       glsl_type::get_array_instance(glsl_type::vec4_type,
 204                                     state->Const.MaxTextureCoords);
 205    add_uniform(instructions, state, "gl_EyePlaneS", texcoords_vec4);
 206    add_uniform(instructions, state, "gl_EyePlaneT", texcoords_vec4);
 207    add_uniform(instructions, state, "gl_EyePlaneR", texcoords_vec4);
 208    add_uniform(instructions, state, "gl_EyePlaneQ", texcoords_vec4);
 209    add_uniform(instructions, state, "gl_ObjectPlaneS", texcoords_vec4);
 210    add_uniform(instructions, state, "gl_ObjectPlaneT", texcoords_vec4);
 211    add_uniform(instructions, state, "gl_ObjectPlaneR", texcoords_vec4);
 212    add_uniform(instructions, state, "gl_ObjectPlaneQ", texcoords_vec4);
 213
 214    add_uniform(instructions, state, "gl_Fog",
 215                state->symbols->get_type("gl_FogParameters"));
 216 }
 217
 218 /* This function should only be called for ES, not desktop GL. */
 219 static void
 220 generate_100ES_vs_variables(exec_list *instructions,
 221                           struct _mesa_glsl_parse_state *state)
 222 {
 223    for (unsigned i = 0; i < Elements(builtin_core_vs_variables); i++) {
 224       add_builtin_variable(& builtin_core_vs_variables[i],
 225                            instructions, state->symbols);
 226    }
 227
 228    generate_100ES_uniforms(instructions, state);
 229
 230    generate_ARB_draw_buffers_variables(instructions, state, false,
 231                                        vertex_shader);
 232 }
 233
 234
 235 static void
 236 generate_110_vs_variables(exec_list *instructions,
 237                           struct _mesa_glsl_parse_state *state)
 238 {
 239    for (unsigned i = 0; i < Elements(builtin_core_vs_variables); i++) {
 240       add_builtin_variable(& builtin_core_vs_variables[i],
 241                            instructions, state->symbols);
 242    }
 243
 244    for (unsigned i = 0
 245            ; i < Elements(builtin_110_deprecated_vs_variables)
 246            ; i++) {
 247       add_builtin_variable(& builtin_110_deprecated_vs_variables[i],
 248                            instructions, state->symbols);
 249    }
 250    generate_110_uniforms(instructions, state);
 251
 252    /* From page 54 (page 60 of the PDF) of the GLSL 1.20 spec:
 253     *
 254     *     "As with all arrays, indices used to subscript gl_TexCoord must
 255     *     either be an integral constant expressions, or this array must be
 256     *     re-declared by the shader with a size. The size can be at most
 257     *     gl_MaxTextureCoords. Using indexes close to 0 may aid the
 258     *     implementation in preserving varying resources."
 259     */
 260    const glsl_type *const vec4_array_type =
 261       glsl_type::get_array_instance(glsl_type::vec4_type, 0);
 262
 263    add_variable("gl_TexCoord", ir_var_out, VERT_RESULT_TEX0, vec4_array_type,
 264                 instructions, state->symbols);
 265
 266    generate_ARB_draw_buffers_variables(instructions, state, false,
 267                                        vertex_shader);
 268 }
 269
 270
 271 static void
 272 generate_120_vs_variables(exec_list *instructions,
 273                           struct _mesa_glsl_parse_state *state)
 274 {
 275    /* GLSL version 1.20 did not add any built-in variables in the vertex
 276     * shader.
 277     */
 278    generate_110_vs_variables(instructions, state);
 279 }
 280
 281
 282 static void
 283 generate_130_vs_variables(exec_list *instructions,
 284                           struct _mesa_glsl_parse_state *state)
 285 {
 286    generate_120_vs_variables(instructions, state);
 287
 288    for (unsigned i = 0; i < Elements(builtin_130_vs_variables); i++) {
 289       add_builtin_variable(& builtin_130_vs_variables[i],
 290                            instructions, state->symbols);
 291    }
 292
 293    const glsl_type *const clip_distance_array_type =
 294       glsl_type::get_array_instance(glsl_type::float_type,
 295                                     state->Const.MaxClipPlanes);
 296
 297    /* FINISHME: gl_ClipDistance needs a real location assigned. */
 298    add_variable("gl_ClipDistance", ir_var_out, -1, clip_distance_array_type,
 299                 instructions, state->symbols);
 300
 301 }
 302
 303
 304 static void
 305 initialize_vs_variables(exec_list *instructions,
 306                         struct _mesa_glsl_parse_state *state)
 307 {
 308
 309    switch (state->language_version) {
 310    case 100:
 311       generate_100ES_vs_variables(instructions, state);
 312       break;
 313    case 110:
 314       generate_110_vs_variables(instructions, state);
 315       break;
 316    case 120:
 317       generate_120_vs_variables(instructions, state);
 318       break;
 319    case 130:
 320       generate_130_vs_variables(instructions, state);
 321       break;
 322    }
 323 }
 324
 325 /* This function should only be called for ES, not desktop GL. */
 326 static void
 327 generate_100ES_fs_variables(exec_list *instructions,
 328                           struct _mesa_glsl_parse_state *state)
 329 {
 330    for (unsigned i = 0; i < Elements(builtin_core_fs_variables); i++) {
 331       add_builtin_variable(& builtin_core_fs_variables[i],
 332                            instructions, state->symbols);
 333    }
 334
 335    for (unsigned i = 0; i < Elements(builtin_100ES_fs_variables); i++) {
 336       add_builtin_variable(& builtin_100ES_fs_variables[i],
 337                            instructions, state->symbols);
 338    }
 339
 340    generate_100ES_uniforms(instructions, state);
 341
 342    generate_ARB_draw_buffers_variables(instructions, state, false,
 343                                        fragment_shader);
 344 }
 345
 346 static void
 347 generate_110_fs_variables(exec_list *instructions,
 348                           struct _mesa_glsl_parse_state *state)
 349 {
 350    for (unsigned i = 0; i < Elements(builtin_core_fs_variables); i++) {
 351       add_builtin_variable(& builtin_core_fs_variables[i],
 352                            instructions, state->symbols);
 353    }
 354
 355    for (unsigned i = 0; i < Elements(builtin_110_fs_variables); i++) {
 356       add_builtin_variable(& builtin_110_fs_variables[i],
 357                            instructions, state->symbols);
 358    }
 359
 360    for (unsigned i = 0
 361            ; i < Elements(builtin_110_deprecated_fs_variables)
 362            ; i++) {
 363       add_builtin_variable(& builtin_110_deprecated_fs_variables[i],
 364                            instructions, state->symbols);
 365    }
 366    generate_110_uniforms(instructions, state);
 367
 368    /* From page 54 (page 60 of the PDF) of the GLSL 1.20 spec:
 369     *
 370     *     "As with all arrays, indices used to subscript gl_TexCoord must
 371     *     either be an integral constant expressions, or this array must be
 372     *     re-declared by the shader with a size. The size can be at most
 373     *     gl_MaxTextureCoords. Using indexes close to 0 may aid the
 374     *     implementation in preserving varying resources."
 375     */
 376    const glsl_type *const vec4_array_type =
 377       glsl_type::get_array_instance(glsl_type::vec4_type, 0);
 378
 379    add_variable("gl_TexCoord", ir_var_in, FRAG_ATTRIB_TEX0, vec4_array_type,
 380                 instructions, state->symbols);
 381
 382    generate_ARB_draw_buffers_variables(instructions, state, false,
 383                                        fragment_shader);
 384 }
 385
 386
 387 static void
 388 generate_ARB_draw_buffers_variables(exec_list *instructions,
 389                                     struct _mesa_glsl_parse_state *state,
 390                                     bool warn, _mesa_glsl_parser_targets target)
 391 {
 392    /* gl_MaxDrawBuffers is available in all shader stages.
 393     */
 394    ir_variable *const mdb =
 395       add_variable("gl_MaxDrawBuffers", ir_var_auto, -1,
 396                    glsl_type::int_type, instructions, state->symbols);
 397
 398    if (warn)
 399       mdb->warn_extension = "GL_ARB_draw_buffers";
 400
 401    mdb->constant_value = new(mdb)
 402       ir_constant(int(state->Const.MaxDrawBuffers));
 403
 404
 405    /* gl_FragData is only available in the fragment shader.
 406     */
 407    if (target == fragment_shader) {
 408       const glsl_type *const vec4_array_type =
 409          glsl_type::get_array_instance(glsl_type::vec4_type,
 410                                        state->Const.MaxDrawBuffers);
 411
 412       ir_variable *const fd =
 413          add_variable("gl_FragData", ir_var_out, FRAG_RESULT_DATA0,
 414                       vec4_array_type, instructions, state->symbols);
 415
 416       if (warn)
 417          fd->warn_extension = "GL_ARB_draw_buffers";
 418    }
 419 }
 420
 421
 422 static void
 423 generate_120_fs_variables(exec_list *instructions,
 424                           struct _mesa_glsl_parse_state *state)
 425 {
 426    generate_110_fs_variables(instructions, state);
 427
 428    for (unsigned i = 0
 429            ; i < Elements(builtin_120_fs_variables)
 430            ; i++) {
 431       add_builtin_variable(& builtin_120_fs_variables[i],
 432                            instructions, state->symbols);
 433    }
 434 }
 435
 436 static void
 437 generate_130_fs_variables(exec_list *instructions,
 438                           struct _mesa_glsl_parse_state *state)
 439 {
 440    generate_120_fs_variables(instructions, state);
 441
 442    const glsl_type *const clip_distance_array_type =
 443       glsl_type::get_array_instance(glsl_type::float_type,
 444                                     state->Const.MaxClipPlanes);
 445
 446    /* FINISHME: gl_ClipDistance needs a real location assigned. */
 447    add_variable("gl_ClipDistance", ir_var_in, -1, clip_distance_array_type,
 448                 instructions, state->symbols);
 449 }
 450
 451 static void
 452 initialize_fs_variables(exec_list *instructions,
 453                         struct _mesa_glsl_parse_state *state)
 454 {
 455
 456    switch (state->language_version) {
 457    case 100:
 458       generate_100ES_fs_variables(instructions, state);
 459       break;
 460    case 110:
 461       generate_110_fs_variables(instructions, state);
 462       break;
 463    case 120:
 464       generate_120_fs_variables(instructions, state);
 465       break;
 466    case 130:
 467       generate_130_fs_variables(instructions, state);
 468       break;
 469    }
 470 }
 471
 472 void
 473 _mesa_glsl_initialize_variables(exec_list *instructions,
 474                                 struct _mesa_glsl_parse_state *state)
 475 {
 476    switch (state->target) {
 477    case vertex_shader:
 478       initialize_vs_variables(instructions, state);
 479       break;
 480    case geometry_shader:
 481       break;
 482    case fragment_shader:
 483       initialize_fs_variables(instructions, state);
 484       break;
 485    case ir_shader:
 486       fprintf(stderr, "ir reader has no builtin variables");
 487       exit(1);
 488       break;
 489    }
 490 }