src/mesa/main/extensions.c

   1 /*
   2  * Mesa 3-D graphics library
   3  *
   4  * Copyright (C) 1999-2008  Brian Paul   All Rights Reserved.
   5  * Copyright (C) 2009  VMware, Inc.  All Rights Reserved.
   6  *
   7  * Permission is hereby granted, free of charge, to any person obtaining a
   8  * copy of this software and associated documentation files (the "Software"),
   9  * to deal in the Software without restriction, including without limitation
  10  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  11  * and/or sell copies of the Software, and to permit persons to whom the
  12  * Software is furnished to do so, subject to the following conditions:
  13  *
  14  * The above copyright notice and this permission notice shall be included
  15  * in all copies or substantial portions of the Software.
  16  *
  17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  18  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  20  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
  21  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
  22  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
  23  * OTHER DEALINGS IN THE SOFTWARE.
  24  */
  25
  26
  27 /**
  28  * \file
  29  * \brief Extension handling
  30  */
  31
  32
  33 #include "glheader.h"
  34 #include "imports.h"
  35 #include "context.h"
  36 #include "extensions.h"
  37 #include "macros.h"
  38 #include "mtypes.h"
  39
  40 struct gl_extensions _mesa_extension_override_enables;
  41 struct gl_extensions _mesa_extension_override_disables;
  42 static char *extra_extensions = NULL;
  43
  44
  45 /**
  46  * Given a member \c x of struct gl_extensions, return offset of
  47  * \c x in bytes.
  48  */
  49 #define o(x) offsetof(struct gl_extensions, x)
  50
  51 static bool disabled_extensions[MESA_EXTENSION_COUNT];
  52
  53 /**
  54  * Given an extension name, lookup up the corresponding member of struct
  55  * gl_extensions and return that member's index.  If the name is
  56  * not found in the \c _mesa_extension_table, return -1.
  57  *
  58  * \param name Name of extension.
  59  * \return Index of member in struct gl_extensions.
  60  */
  61 static int
  62 name_to_index(const char* name)
  63 {
  64    unsigned i;
  65
  66    if (name == 0)
  67       return -1;
  68
  69    for (i = 0; i < MESA_EXTENSION_COUNT; ++i) {
  70       if (strcmp(name, _mesa_extension_table[i].name) == 0)
  71          return i;
  72    }
  73
  74    return -1;
  75 }
  76
  77 /**
  78  * Overrides extensions in \c ctx based on the values in
  79  * _mesa_extension_override_enables and _mesa_extension_override_disables.
  80  */
  81 static void
  82 override_extensions_in_context(struct gl_context *ctx)
  83 {
  84    unsigned i;
  85    const GLboolean *enables =
  86       (GLboolean*) &_mesa_extension_override_enables;
  87    const GLboolean *disables =
  88       (GLboolean*) &_mesa_extension_override_disables;
  89    GLboolean *ctx_ext = (GLboolean*)&ctx->Extensions;
  90
  91    for (i = 0; i < MESA_EXTENSION_COUNT; ++i) {
  92       size_t offset = _mesa_extension_table[i].offset;
  93
  94       assert(!enables[offset] || !disables[offset]);
  95       if (enables[offset]) {
  96          ctx_ext[offset] = 1;
  97       } else if (disables[offset]) {
  98          ctx_ext[offset] = 0;
  99       }
 100    }
 101 }
 102
 103
 104 /**
 105  * Enable all extensions suitable for a software-only renderer.
 106  * This is a convenience function used by the XMesa, OSMesa, GGI drivers, etc.
 107  */
 108 void
 109 _mesa_enable_sw_extensions(struct gl_context *ctx)
 110 {
 111    ctx->Extensions.ARB_depth_clamp = GL_TRUE;
 112    ctx->Extensions.ARB_depth_texture = GL_TRUE;
 113    ctx->Extensions.ARB_draw_elements_base_vertex = GL_TRUE;
 114    ctx->Extensions.ARB_draw_instanced = GL_TRUE;
 115    ctx->Extensions.ARB_explicit_attrib_location = GL_TRUE;
 116    ctx->Extensions.ARB_fragment_coord_conventions = GL_TRUE;
 117    ctx->Extensions.ARB_fragment_program = GL_TRUE;
 118    ctx->Extensions.ARB_fragment_program_shadow = GL_TRUE;
 119    ctx->Extensions.ARB_fragment_shader = GL_TRUE;
 120    ctx->Extensions.ARB_framebuffer_object = GL_TRUE;
 121    ctx->Extensions.ARB_half_float_vertex = GL_TRUE;
 122    ctx->Extensions.ARB_map_buffer_range = GL_TRUE;
 123    ctx->Extensions.ARB_occlusion_query = GL_TRUE;
 124    ctx->Extensions.ARB_occlusion_query2 = GL_TRUE;
 125    ctx->Extensions.ARB_point_sprite = GL_TRUE;
 126    ctx->Extensions.ARB_shadow = GL_TRUE;
 127    ctx->Extensions.ARB_texture_border_clamp = GL_TRUE;
 128    ctx->Extensions.ARB_texture_compression_bptc = GL_TRUE;
 129    ctx->Extensions.ARB_texture_cube_map = GL_TRUE;
 130    ctx->Extensions.ARB_texture_env_combine = GL_TRUE;
 131    ctx->Extensions.ARB_texture_env_crossbar = GL_TRUE;
 132    ctx->Extensions.ARB_texture_env_dot3 = GL_TRUE;
 133 #ifdef TEXTURE_FLOAT_ENABLED
 134    ctx->Extensions.ARB_texture_float = GL_TRUE;
 135 #endif
 136    ctx->Extensions.ARB_texture_mirror_clamp_to_edge = GL_TRUE;
 137    ctx->Extensions.ARB_texture_non_power_of_two = GL_TRUE;
 138    ctx->Extensions.ARB_texture_rg = GL_TRUE;
 139    ctx->Extensions.ARB_texture_compression_rgtc = GL_TRUE;
 140    ctx->Extensions.ARB_vertex_program = GL_TRUE;
 141    ctx->Extensions.ARB_vertex_shader = GL_TRUE;
 142    ctx->Extensions.ARB_sync = GL_TRUE;
 143    ctx->Extensions.APPLE_object_purgeable = GL_TRUE;
 144    ctx->Extensions.ATI_fragment_shader = GL_TRUE;
 145    ctx->Extensions.ATI_texture_compression_3dc = GL_TRUE;
 146    ctx->Extensions.ATI_texture_env_combine3 = GL_TRUE;
 147    ctx->Extensions.ATI_texture_mirror_once = GL_TRUE;
 148    ctx->Extensions.ATI_separate_stencil = GL_TRUE;
 149    ctx->Extensions.EXT_blend_color = GL_TRUE;
 150    ctx->Extensions.EXT_blend_equation_separate = GL_TRUE;
 151    ctx->Extensions.EXT_blend_func_separate = GL_TRUE;
 152    ctx->Extensions.EXT_blend_minmax = GL_TRUE;
 153    ctx->Extensions.EXT_depth_bounds_test = GL_TRUE;
 154    ctx->Extensions.EXT_draw_buffers2 = GL_TRUE;
 155    ctx->Extensions.EXT_pixel_buffer_object = GL_TRUE;
 156    ctx->Extensions.EXT_point_parameters = GL_TRUE;
 157    ctx->Extensions.EXT_provoking_vertex = GL_TRUE;
 158    ctx->Extensions.EXT_stencil_two_side = GL_TRUE;
 159    ctx->Extensions.EXT_texture_array = GL_TRUE;
 160    ctx->Extensions.EXT_texture_compression_latc = GL_TRUE;
 161    ctx->Extensions.EXT_texture_env_dot3 = GL_TRUE;
 162    ctx->Extensions.EXT_texture_filter_anisotropic = GL_TRUE;
 163    ctx->Extensions.EXT_texture_mirror_clamp = GL_TRUE;
 164    ctx->Extensions.EXT_texture_shared_exponent = GL_TRUE;
 165    ctx->Extensions.EXT_texture_sRGB = GL_TRUE;
 166    ctx->Extensions.EXT_texture_sRGB_decode = GL_TRUE;
 167    ctx->Extensions.EXT_texture_swizzle = GL_TRUE;
 168    /*ctx->Extensions.EXT_transform_feedback = GL_TRUE;*/
 169    ctx->Extensions.EXT_vertex_array_bgra = GL_TRUE;
 170    ctx->Extensions.MESA_pack_invert = GL_TRUE;
 171    ctx->Extensions.MESA_ycbcr_texture = GL_TRUE;
 172    ctx->Extensions.NV_conditional_render = GL_TRUE;
 173    ctx->Extensions.NV_point_sprite = GL_TRUE;
 174    ctx->Extensions.NV_texture_env_combine4 = GL_TRUE;
 175    ctx->Extensions.NV_texture_rectangle = GL_TRUE;
 176    ctx->Extensions.EXT_gpu_program_parameters = GL_TRUE;
 177    ctx->Extensions.OES_standard_derivatives = GL_TRUE;
 178    ctx->Extensions.TDFX_texture_compression_FXT1 = GL_TRUE;
 179    if (ctx->Mesa_DXTn) {
 180       ctx->Extensions.ANGLE_texture_compression_dxt = GL_TRUE;
 181       ctx->Extensions.EXT_texture_compression_s3tc = GL_TRUE;
 182    }
 183 }
 184
 185 /**
 186  * Either enable or disable the named extension.
 187  * \return offset of extensions withint `ext' or 0 if extension is not known
 188  */
 189 static size_t
 190 set_extension(struct gl_extensions *ext, int i, GLboolean state)
 191 {
 192    size_t offset;
 193
 194    offset = i < 0 ? 0 : _mesa_extension_table[i].offset;
 195    if (offset != 0 && (offset != o(dummy_true) || state != GL_FALSE)) {
 196       ((GLboolean *) ext)[offset] = state;
 197    }
 198
 199    return offset;
 200 }
 201
 202 /**
 203  * \brief Apply the \c MESA_EXTENSION_OVERRIDE environment variable.
 204  *
 205  * \c MESA_EXTENSION_OVERRIDE is a space-separated list of extensions to
 206  * enable or disable. The list is processed thus:
 207  *    - Enable recognized extension names that are prefixed with '+'.
 208  *    - Disable recognized extension names that are prefixed with '-'.
 209  *    - Enable recognized extension names that are not prefixed.
 210  *    - Collect unrecognized extension names in a new string.
 211  *
 212  * \c MESA_EXTENSION_OVERRIDE was previously parsed during
 213  * _mesa_one_time_init_extension_overrides. We just use the results of that
 214  * parsing in this function.
 215  *
 216  * \return Space-separated list of unrecognized extension names (which must
 217  *    be freed). Does not return \c NULL.
 218  */
 219 static char *
 220 get_extension_override( struct gl_context *ctx )
 221 {
 222    override_extensions_in_context(ctx);
 223
 224    if (extra_extensions == NULL) {
 225       return calloc(1, sizeof(char));
 226    } else {
 227       _mesa_problem(ctx, "Trying to enable unknown extensions: %s",
 228                     extra_extensions);
 229       return strdup(extra_extensions);
 230    }
 231 }
 232
 233
 234 /**
 235  * \brief Free extra_extensions string
 236  *
 237  * These strings are allocated early during the first context creation by
 238  * _mesa_one_time_init_extension_overrides.
 239  */
 240 static void
 241 free_unknown_extensions_strings(void)
 242 {
 243    free(extra_extensions);
 244 }
 245
 246
 247 /**
 248  * \brief Initialize extension override tables.
 249  *
 250  * This should be called one time early during first context initialization.
 251  */
 252 void
 253 _mesa_one_time_init_extension_overrides(void)
 254 {
 255    const char *env_const = getenv("MESA_EXTENSION_OVERRIDE");
 256    char *env;
 257    char *ext;
 258    int len;
 259    size_t offset;
 260
 261    atexit(free_unknown_extensions_strings);
 262
 263    memset(&_mesa_extension_override_enables, 0, sizeof(struct gl_extensions));
 264    memset(&_mesa_extension_override_disables, 0, sizeof(struct gl_extensions));
 265
 266    if (env_const == NULL) {
 267       return;
 268    }
 269
 270    /* extra_exts: List of unrecognized extensions. */
 271    extra_extensions = calloc(ALIGN(strlen(env_const) + 2, 4), sizeof(char));
 272
 273    /* Copy env_const because strtok() is destructive. */
 274    env = strdup(env_const);
 275
 276    if (env == NULL ||
 277        extra_extensions == NULL) {
 278       free(env);
 279       free(extra_extensions);
 280       return;
 281    }
 282
 283    for (ext = strtok(env, " "); ext != NULL; ext = strtok(NULL, " ")) {
 284       int enable;
 285       int i;
 286       bool recognized;
 287       switch (ext[0]) {
 288       case '+':
 289          enable = 1;
 290          ++ext;
 291          break;
 292       case '-':
 293          enable = 0;
 294          ++ext;
 295          break;
 296       default:
 297          enable = 1;
 298          break;
 299       }
 300
 301       i = name_to_index(ext);
 302       offset = set_extension(&_mesa_extension_override_enables, i, enable);
 303       if (offset != 0 && (offset != o(dummy_true) || enable != GL_FALSE)) {
 304          ((GLboolean *) &_mesa_extension_override_disables)[offset] = !enable;
 305          recognized = true;
 306       } else {
 307          recognized = false;
 308       }
 309
 310       if (i >= 0)
 311          disabled_extensions[i] = !enable;
 312
 313       if (!recognized && enable) {
 314          strcat(extra_extensions, ext);
 315          strcat(extra_extensions, " ");
 316       }
 317    }
 318
 319    free(env);
 320
 321    /* Remove trailing space, and free if unused. */
 322    len = strlen(extra_extensions);
 323    if (len == 0) {
 324       free(extra_extensions);
 325       extra_extensions = NULL;
 326    } else if (extra_extensions[len - 1] == ' ') {
 327       extra_extensions[len - 1] = '\0';
 328    }
 329 }
 330
 331
 332 /**
 333  * \brief Initialize extension tables and enable default extensions.
 334  *
 335  * This should be called during context initialization.
 336  * Note: Sets gl_extensions.dummy_true to true.
 337  */
 338 void
 339 _mesa_init_extensions(struct gl_extensions *extensions)
 340 {
 341    GLboolean *base = (GLboolean *) extensions;
 342    GLboolean *sentinel = base + o(extension_sentinel);
 343    GLboolean *i;
 344
 345    /* First, turn all extensions off. */
 346    for (i = base; i != sentinel; ++i)
 347       *i = GL_FALSE;
 348
 349    /* Then, selectively turn default extensions on. */
 350    extensions->dummy_true = GL_TRUE;
 351 }
 352
 353
 354 typedef unsigned short extension_index;
 355
 356
 357 /**
 358  * Given an extension enum, return whether or not the extension is supported
 359  * dependent on the following factors:
 360  * There's driver support and the OpenGL/ES version is at least that
 361  * specified in the _mesa_extension_table.
 362  */
 363 static inline bool
 364 _mesa_extension_supported(const struct gl_context *ctx, extension_index i)
 365 {
 366    const bool *base = (bool *) &ctx->Extensions;
 367    const struct mesa_extension *ext = _mesa_extension_table + i;
 368
 369    return !disabled_extensions[i] &&
 370           (ctx->Version >= ext->version[ctx->API]) && base[ext->offset];
 371 }
 372
 373 /**
 374  * Compare two entries of the extensions table.  Sorts first by year,
 375  * then by name.
 376  *
 377  * Arguments are indices into _mesa_extension_table.
 378  */
 379 static int
 380 extension_compare(const void *p1, const void *p2)
 381 {
 382    extension_index i1 = * (const extension_index *) p1;
 383    extension_index i2 = * (const extension_index *) p2;
 384    const struct mesa_extension *e1 = &_mesa_extension_table[i1];
 385    const struct mesa_extension *e2 = &_mesa_extension_table[i2];
 386    int res;
 387
 388    res = (int)e1->year - (int)e2->year;
 389
 390    if (res == 0) {
 391       res = strcmp(e1->name, e2->name);
 392    }
 393
 394    return res;
 395 }
 396
 397
 398 /**
 399  * Construct the GL_EXTENSIONS string.  Called the first time that
 400  * glGetString(GL_EXTENSIONS) is called.
 401  */
 402 GLubyte*
 403 _mesa_make_extension_string(struct gl_context *ctx)
 404 {
 405    /* The extension string. */
 406    char *exts = 0;
 407    /* Length of extension string. */
 408    size_t length = 0;
 409    /* Number of extensions */
 410    unsigned count;
 411    /* Indices of the extensions sorted by year */
 412    extension_index *extension_indices;
 413    /* String of extra extensions. */
 414    char *extra_extensions = get_extension_override(ctx);
 415    unsigned k;
 416    unsigned j;
 417    unsigned maxYear = ~0;
 418
 419    /* Check if the MESA_EXTENSION_MAX_YEAR env var is set */
 420    {
 421       const char *env = getenv("MESA_EXTENSION_MAX_YEAR");
 422       if (env) {
 423          maxYear = atoi(env);
 424          _mesa_debug(ctx, "Note: limiting GL extensions to %u or earlier\n",
 425                      maxYear);
 426       }
 427    }
 428
 429    /* Compute length of the extension string. */
 430    count = 0;
 431    for (k = 0; k < MESA_EXTENSION_COUNT; ++k) {
 432       const struct mesa_extension *i = _mesa_extension_table + k;
 433
 434       if (i->year <= maxYear &&
 435           _mesa_extension_supported(ctx, k)) {
 436          length += strlen(i->name) + 1; /* +1 for space */
 437          ++count;
 438       }
 439    }
 440    if (extra_extensions != NULL)
 441       length += 1 + strlen(extra_extensions); /* +1 for space */
 442
 443    exts = calloc(ALIGN(length + 1, 4), sizeof(char));
 444    if (exts == NULL) {
 445       free(extra_extensions);
 446       return NULL;
 447    }
 448
 449    extension_indices = malloc(count * sizeof(extension_index));
 450    if (extension_indices == NULL) {
 451       free(exts);
 452       free(extra_extensions);
 453       return NULL;
 454    }
 455
 456    /* Sort extensions in chronological order because certain old applications
 457     * (e.g., Quake3 demo) store the extension list in a static size buffer so
 458     * chronologically order ensure that the extensions that such applications
 459     * expect will fit into that buffer.
 460     */
 461    j = 0;
 462    for (k = 0; k < MESA_EXTENSION_COUNT; ++k) {
 463       if (_mesa_extension_table[k].year <= maxYear &&
 464          _mesa_extension_supported(ctx, k)) {
 465          extension_indices[j++] = k;
 466       }
 467    }
 468    assert(j == count);
 469    qsort(extension_indices, count,
 470          sizeof *extension_indices, extension_compare);
 471
 472    /* Build the extension string.*/
 473    for (j = 0; j < count; ++j) {
 474       const struct mesa_extension *i = &_mesa_extension_table[extension_indices[j]];
 475       assert(_mesa_extension_supported(ctx, extension_indices[j]));
 476       strcat(exts, i->name);
 477       strcat(exts, " ");
 478    }
 479    free(extension_indices);
 480    if (extra_extensions != 0) {
 481       strcat(exts, extra_extensions);
 482       free(extra_extensions);
 483    }
 484
 485    return (GLubyte *) exts;
 486 }
 487
 488 /**
 489  * Return number of enabled extensions.
 490  */
 491 GLuint
 492 _mesa_get_extension_count(struct gl_context *ctx)
 493 {
 494    unsigned k;
 495
 496    /* only count once */
 497    if (ctx->Extensions.Count != 0)
 498       return ctx->Extensions.Count;
 499
 500    for (k = 0; k < MESA_EXTENSION_COUNT; ++k) {
 501       if (_mesa_extension_supported(ctx, k))
 502          ctx->Extensions.Count++;
 503    }
 504    return ctx->Extensions.Count;
 505 }
 506
 507 /**
 508  * Return name of i-th enabled extension
 509  */
 510 const GLubyte *
 511 _mesa_get_enabled_extension(struct gl_context *ctx, GLuint index)
 512 {
 513    size_t n = 0;
 514    unsigned i;
 515
 516    for (i = 0; i < MESA_EXTENSION_COUNT; ++i) {
 517       if (_mesa_extension_supported(ctx, i)) {
 518          if (n == index)
 519             return (const GLubyte*) _mesa_extension_table[i].name;
 520          else
 521             ++n;
 522       }
 523    }
 524
 525    return NULL;
 526 }