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 #ifndef Elements
  30 #define Elements(x) (sizeof(x)/sizeof(*(x)))
  31 #endif
  32
  33 static void generate_ARB_draw_buffers_variables(exec_list *,
  34                                                 struct _mesa_glsl_parse_state *,
  35                                                 bool, _mesa_glsl_parser_targets);
  36
  37 static ir_variable *
  38 add_variable(const char *name, enum ir_variable_mode mode, int slot,
  39              const glsl_type *type, exec_list *instructions,
  40                      glsl_symbol_table *symtab)
  41 {
  42    ir_variable *var = new(symtab) ir_variable(type, name, mode);
  43
  44    switch (var->mode) {
  45    case ir_var_auto:
  46       var->read_only = true;
  47       break;
  48    case ir_var_in:
  49       var->shader_in = true;
  50       var->read_only = true;
  51       break;
  52    case ir_var_inout:
  53       var->shader_in = true;
  54       var->shader_out = true;
  55       break;
  56    case ir_var_out:
  57       var->shader_out = true;
  58       break;
  59    case ir_var_uniform:
  60       var->shader_in = true;
  61       var->read_only = true;
  62       break;
  63    default:
  64       assert(0);
  65       break;
  66    }
  67
  68    var->location = slot;
  69
  70    /* Once the variable is created an initialized, add it to the symbol table
  71     * and add the declaration to the IR stream.
  72     */
  73    instructions->push_tail(var);
  74
  75    symtab->add_variable(var->name, var);
  76    return var;
  77 }
  78
  79
  80 static void
  81 add_builtin_variable(const builtin_variable *proto, exec_list *instructions,
  82                      glsl_symbol_table *symtab)
  83 {
  84    /* Create a new variable declaration from the description supplied by
  85     * the caller.
  86     */
  87    const glsl_type *const type = symtab->get_type(proto->type);
  88
  89    assert(type != NULL);
  90
  91    add_variable(proto->name, proto->mode, proto->slot, type, instructions,
  92                 symtab);
  93 }
  94
  95 static void
  96 add_builtin_constant(exec_list *instructions,
  97                      struct _mesa_glsl_parse_state *state,
  98                      const char *name, int value)
  99 {
 100    ir_variable *const var = add_variable(name, ir_var_auto,
 101                                          -1, glsl_type::int_type,
 102                                          instructions, state->symbols);
 103    var->constant_value = new(var) ir_constant(value);
 104 }
 105
 106 static void
 107 generate_110_uniforms(exec_list *instructions,
 108                       struct _mesa_glsl_parse_state *state)
 109 {
 110    for (unsigned i = 0
 111            ; i < Elements(builtin_110_deprecated_uniforms)
 112            ; i++) {
 113       add_builtin_variable(& builtin_110_deprecated_uniforms[i],
 114                            instructions, state->symbols);
 115    }
 116
 117    add_builtin_constant(instructions, state, "gl_MaxLights",
 118                         state->Const.MaxLights);
 119    add_builtin_constant(instructions, state, "gl_MaxClipPlanes",
 120                         state->Const.MaxClipPlanes);
 121    add_builtin_constant(instructions, state, "gl_MaxTextureUnits",
 122                         state->Const.MaxTextureUnits);
 123    add_builtin_constant(instructions, state, "gl_MaxTextureCoords",
 124                         state->Const.MaxTextureCoords);
 125    add_builtin_constant(instructions, state, "gl_MaxVertexAttribs",
 126                         state->Const.MaxVertexAttribs);
 127    add_builtin_constant(instructions, state, "gl_MaxVertexUniformComponents",
 128                         state->Const.MaxVertexUniformComponents);
 129    add_builtin_constant(instructions, state, "gl_MaxVaryingFloats",
 130                         state->Const.MaxVaryingFloats);
 131    add_builtin_constant(instructions, state, "gl_MaxVertexTextureImageUnits",
 132                         state->Const.MaxVertexTextureImageUnits);
 133    add_builtin_constant(instructions, state, "gl_MaxCombinedTextureImageUnits",
 134                         state->Const.MaxCombinedTextureImageUnits);
 135    add_builtin_constant(instructions, state, "gl_MaxTextureImageUnits",
 136                         state->Const.MaxTextureImageUnits);
 137    add_builtin_constant(instructions, state, "gl_MaxFragmentUniformComponents",
 138                         state->Const.MaxFragmentUniformComponents);
 139
 140    const glsl_type *const mat4_array_type =
 141       glsl_type::get_array_instance(glsl_type::mat4_type,
 142                                     state->Const.MaxTextureCoords);
 143
 144    add_variable("gl_TextureMatrix", ir_var_uniform, -1, mat4_array_type,
 145                 instructions, state->symbols);
 146
 147    /* FINISHME: Add support for gl_DepthRangeParameters */
 148    /* FINISHME: Add support for gl_ClipPlane[] */
 149    /* FINISHME: Add support for gl_PointParameters */
 150
 151    /* FINISHME: Add support for gl_MaterialParameters
 152     * FINISHME: (glFrontMaterial, glBackMaterial)
 153     */
 154
 155    /* FINISHME: The size of this array is implementation dependent based on the
 156     * FINISHME: value of GL_MAX_TEXTURE_LIGHTS.  GL_MAX_TEXTURE_LIGHTS must be
 157     * FINISHME: at least 8, so hard-code 8 for now.
 158     */
 159    const glsl_type *const light_source_array_type =
 160       glsl_type::get_array_instance(state->symbols->get_type("gl_LightSourceParameters"), 8);
 161
 162    add_variable("gl_LightSource", ir_var_uniform, -1, light_source_array_type,
 163                 instructions, state->symbols);
 164
 165    /* FINISHME: Add support for gl_LightModel */
 166    /* FINISHME: Add support for gl_FrontLightProduct[], gl_BackLightProduct[] */
 167    /* FINISHME: Add support for gl_TextureEnvColor[] */
 168    /* FINISHME: Add support for gl_ObjectPlane*[], gl_EyePlane*[] */
 169    /* FINISHME: Add support for gl_Fog */
 170 }
 171
 172 static void
 173 generate_110_vs_variables(exec_list *instructions,
 174                           struct _mesa_glsl_parse_state *state)
 175 {
 176    for (unsigned i = 0; i < Elements(builtin_core_vs_variables); i++) {
 177       add_builtin_variable(& builtin_core_vs_variables[i],
 178                            instructions, state->symbols);
 179    }
 180
 181    for (unsigned i = 0
 182            ; i < Elements(builtin_110_deprecated_vs_variables)
 183            ; i++) {
 184       add_builtin_variable(& builtin_110_deprecated_vs_variables[i],
 185                            instructions, state->symbols);
 186    }
 187    generate_110_uniforms(instructions, state);
 188
 189    /* From page 54 (page 60 of the PDF) of the GLSL 1.20 spec:
 190     *
 191     *     "As with all arrays, indices used to subscript gl_TexCoord must
 192     *     either be an integral constant expressions, or this array must be
 193     *     re-declared by the shader with a size. The size can be at most
 194     *     gl_MaxTextureCoords. Using indexes close to 0 may aid the
 195     *     implementation in preserving varying resources."
 196     */
 197    const glsl_type *const vec4_array_type =
 198       glsl_type::get_array_instance(glsl_type::vec4_type, 0);
 199
 200    add_variable("gl_TexCoord", ir_var_out, VERT_RESULT_TEX0, vec4_array_type,
 201                 instructions, state->symbols);
 202
 203    generate_ARB_draw_buffers_variables(instructions, state, false,
 204                                        vertex_shader);
 205 }
 206
 207
 208 static void
 209 generate_120_vs_variables(exec_list *instructions,
 210                           struct _mesa_glsl_parse_state *state)
 211 {
 212    /* GLSL version 1.20 did not add any built-in variables in the vertex
 213     * shader.
 214     */
 215    generate_110_vs_variables(instructions, state);
 216 }
 217
 218
 219 static void
 220 generate_130_vs_variables(exec_list *instructions,
 221                           struct _mesa_glsl_parse_state *state)
 222 {
 223    generate_120_vs_variables(instructions, state);
 224
 225    for (unsigned i = 0; i < Elements(builtin_130_vs_variables); i++) {
 226       add_builtin_variable(& builtin_130_vs_variables[i],
 227                            instructions, state->symbols);
 228    }
 229
 230    /* FINISHME: The size of this array is implementation dependent based on
 231     * FINISHME: the value of GL_MAX_CLIP_DISTANCES.
 232     */
 233    const glsl_type *const clip_distance_array_type =
 234       glsl_type::get_array_instance(glsl_type::float_type, 8);
 235
 236    /* FINISHME: gl_ClipDistance needs a real location assigned. */
 237    add_variable("gl_ClipDistance", ir_var_out, -1, clip_distance_array_type,
 238                 instructions, state->symbols);
 239
 240 }
 241
 242
 243 static void
 244 initialize_vs_variables(exec_list *instructions,
 245                         struct _mesa_glsl_parse_state *state)
 246 {
 247
 248    switch (state->language_version) {
 249    case 110:
 250       generate_110_vs_variables(instructions, state);
 251       break;
 252    case 120:
 253       generate_120_vs_variables(instructions, state);
 254       break;
 255    case 130:
 256       generate_130_vs_variables(instructions, state);
 257       break;
 258    }
 259 }
 260
 261 static void
 262 generate_110_fs_variables(exec_list *instructions,
 263                           struct _mesa_glsl_parse_state *state)
 264 {
 265    for (unsigned i = 0; i < Elements(builtin_core_fs_variables); i++) {
 266       add_builtin_variable(& builtin_core_fs_variables[i],
 267                            instructions, state->symbols);
 268    }
 269
 270    for (unsigned i = 0
 271            ; i < Elements(builtin_110_deprecated_fs_variables)
 272            ; i++) {
 273       add_builtin_variable(& builtin_110_deprecated_fs_variables[i],
 274                            instructions, state->symbols);
 275    }
 276    generate_110_uniforms(instructions, state);
 277
 278    /* From page 54 (page 60 of the PDF) of the GLSL 1.20 spec:
 279     *
 280     *     "As with all arrays, indices used to subscript gl_TexCoord must
 281     *     either be an integral constant expressions, or this array must be
 282     *     re-declared by the shader with a size. The size can be at most
 283     *     gl_MaxTextureCoords. Using indexes close to 0 may aid the
 284     *     implementation in preserving varying resources."
 285     */
 286    const glsl_type *const vec4_array_type =
 287       glsl_type::get_array_instance(glsl_type::vec4_type, 0);
 288
 289    add_variable("gl_TexCoord", ir_var_in, FRAG_ATTRIB_TEX0, vec4_array_type,
 290                 instructions, state->symbols);
 291
 292    generate_ARB_draw_buffers_variables(instructions, state, false,
 293                                        fragment_shader);
 294 }
 295
 296
 297 static void
 298 generate_ARB_draw_buffers_variables(exec_list *instructions,
 299                                     struct _mesa_glsl_parse_state *state,
 300                                     bool warn, _mesa_glsl_parser_targets target)
 301 {
 302    /* gl_MaxDrawBuffers is available in all shader stages.
 303     */
 304    ir_variable *const mdb =
 305       add_variable("gl_MaxDrawBuffers", ir_var_auto, -1,
 306                    glsl_type::int_type, instructions, state->symbols);
 307
 308    if (warn)
 309       mdb->warn_extension = "GL_ARB_draw_buffers";
 310
 311    mdb->constant_value = new(mdb)
 312       ir_constant(int(state->Const.MaxDrawBuffers));
 313
 314
 315    /* gl_FragData is only available in the fragment shader.
 316     */
 317    if (target == fragment_shader) {
 318       const glsl_type *const vec4_array_type =
 319          glsl_type::get_array_instance(glsl_type::vec4_type,
 320                                        state->Const.MaxDrawBuffers);
 321
 322       ir_variable *const fd =
 323          add_variable("gl_FragData", ir_var_out, FRAG_RESULT_DATA0,
 324                       vec4_array_type, instructions, state->symbols);
 325
 326       if (warn)
 327          fd->warn_extension = "GL_ARB_draw_buffers";
 328    }
 329 }
 330
 331
 332 static void
 333 generate_120_fs_variables(exec_list *instructions,
 334                           struct _mesa_glsl_parse_state *state)
 335 {
 336    generate_110_fs_variables(instructions, state);
 337
 338    for (unsigned i = 0
 339            ; i < Elements(builtin_120_fs_variables)
 340            ; i++) {
 341       add_builtin_variable(& builtin_120_fs_variables[i],
 342                            instructions, state->symbols);
 343    }
 344 }
 345
 346 static void
 347 generate_130_fs_variables(exec_list *instructions,
 348                           struct _mesa_glsl_parse_state *state)
 349 {
 350    generate_120_fs_variables(instructions, state);
 351
 352    /* FINISHME: The size of this array is implementation dependent based on
 353     * FINISHME: the value of GL_MAX_CLIP_DISTANCES.
 354     */
 355    const glsl_type *const clip_distance_array_type =
 356       glsl_type::get_array_instance(glsl_type::float_type, 8);
 357
 358    /* FINISHME: gl_ClipDistance needs a real location assigned. */
 359    add_variable("gl_ClipDistance", ir_var_in, -1, clip_distance_array_type,
 360                 instructions, state->symbols);
 361 }
 362
 363 static void
 364 initialize_fs_variables(exec_list *instructions,
 365                         struct _mesa_glsl_parse_state *state)
 366 {
 367
 368    switch (state->language_version) {
 369    case 110:
 370       generate_110_fs_variables(instructions, state);
 371       break;
 372    case 120:
 373       generate_120_fs_variables(instructions, state);
 374       break;
 375    case 130:
 376       generate_130_fs_variables(instructions, state);
 377       break;
 378    }
 379 }
 380
 381 void
 382 _mesa_glsl_initialize_variables(exec_list *instructions,
 383                                 struct _mesa_glsl_parse_state *state)
 384 {
 385    switch (state->target) {
 386    case vertex_shader:
 387       initialize_vs_variables(instructions, state);
 388       break;
 389    case geometry_shader:
 390       break;
 391    case fragment_shader:
 392       initialize_fs_variables(instructions, state);
 393       break;
 394    case ir_shader:
 395       fprintf(stderr, "ir reader has no builtin variables");
 396       exit(1);
 397       break;
 398    }
 399 }