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 /**
  52  * Given an extension name, lookup up the corresponding member of struct
  53  * gl_extensions and return that member's index.  If the name is
  54  * not found in the \c _mesa_extension_table, return -1.
  55  *
  56  * \param name Name of extension.
  57  * \return Index of member in struct gl_extensions.
  58  */
  59 static int
  60 name_to_index(const char* name)
  61 {
  62    unsigned i;
  63
  64    if (name == 0)
  65       return -1;
  66
  67    for (i = 0; i < MESA_EXTENSION_COUNT; ++i) {
  68       if (strcmp(name, _mesa_extension_table[i].name) == 0)
  69          return i;
  70    }
  71
  72    return -1;
  73 }
  74
  75 /**
  76  * Overrides extensions in \c ctx based on the values in
  77  * _mesa_extension_override_enables and _mesa_extension_override_disables.
  78  */
  79 void
  80 _mesa_override_extensions(struct gl_context *ctx)
  81 {
  82    unsigned i;
  83    const GLboolean *enables =
  84       (GLboolean*) &_mesa_extension_override_enables;
  85    const GLboolean *disables =
  86       (GLboolean*) &_mesa_extension_override_disables;
  87    GLboolean *ctx_ext = (GLboolean*)&ctx->Extensions;
  88
  89    for (i = 0; i < MESA_EXTENSION_COUNT; ++i) {
  90       size_t offset = _mesa_extension_table[i].offset;
  91
  92       assert(!enables[offset] || !disables[offset]);
  93       if (enables[offset]) {
  94          ctx_ext[offset] = 1;
  95       } else if (disables[offset]) {
  96          ctx_ext[offset] = 0;
  97       }
  98    }
  99 }
 100
 101
 102 /**
 103  * Enable all extensions suitable for a software-only renderer.
 104  * This is a convenience function used by the XMesa, OSMesa, GGI drivers, etc.
 105  */
 106 void
 107 _mesa_enable_sw_extensions(struct gl_context *ctx)
 108 {
 109    ctx->Extensions.ARB_depth_clamp = GL_TRUE;
 110    ctx->Extensions.ARB_depth_texture = GL_TRUE;
 111    ctx->Extensions.ARB_draw_elements_base_vertex = GL_TRUE;
 112    ctx->Extensions.ARB_draw_instanced = GL_TRUE;
 113    ctx->Extensions.ARB_explicit_attrib_location = GL_TRUE;
 114    ctx->Extensions.ARB_fragment_coord_conventions = GL_TRUE;
 115    ctx->Extensions.ARB_fragment_program = GL_TRUE;
 116    ctx->Extensions.ARB_fragment_program_shadow = GL_TRUE;
 117    ctx->Extensions.ARB_fragment_shader = GL_TRUE;
 118    ctx->Extensions.ARB_framebuffer_object = GL_TRUE;
 119    ctx->Extensions.ARB_half_float_vertex = GL_TRUE;
 120    ctx->Extensions.ARB_map_buffer_range = GL_TRUE;
 121    ctx->Extensions.ARB_occlusion_query = GL_TRUE;
 122    ctx->Extensions.ARB_occlusion_query2 = GL_TRUE;
 123    ctx->Extensions.ARB_point_sprite = GL_TRUE;
 124    ctx->Extensions.ARB_shadow = GL_TRUE;
 125    ctx->Extensions.ARB_texture_border_clamp = GL_TRUE;
 126    ctx->Extensions.ARB_texture_compression_bptc = GL_TRUE;
 127    ctx->Extensions.ARB_texture_cube_map = GL_TRUE;
 128    ctx->Extensions.ARB_texture_env_combine = GL_TRUE;
 129    ctx->Extensions.ARB_texture_env_crossbar = GL_TRUE;
 130    ctx->Extensions.ARB_texture_env_dot3 = GL_TRUE;
 131    ctx->Extensions.ARB_texture_filter_anisotropic = GL_TRUE;
 132 #ifdef TEXTURE_FLOAT_ENABLED
 133    ctx->Extensions.ARB_texture_float = GL_TRUE;
 134 #endif
 135    ctx->Extensions.ARB_texture_mirror_clamp_to_edge = GL_TRUE;
 136    ctx->Extensions.ARB_texture_non_power_of_two = GL_TRUE;
 137    ctx->Extensions.ARB_texture_rg = GL_TRUE;
 138    ctx->Extensions.ARB_texture_compression_rgtc = GL_TRUE;
 139    ctx->Extensions.ARB_vertex_program = GL_TRUE;
 140    ctx->Extensions.ARB_vertex_shader = GL_TRUE;
 141    ctx->Extensions.ARB_sync = GL_TRUE;
 142    ctx->Extensions.APPLE_object_purgeable = GL_TRUE;
 143    ctx->Extensions.ATI_fragment_shader = GL_TRUE;
 144    ctx->Extensions.ATI_texture_compression_3dc = GL_TRUE;
 145    ctx->Extensions.ATI_texture_env_combine3 = GL_TRUE;
 146    ctx->Extensions.ATI_texture_mirror_once = GL_TRUE;
 147    ctx->Extensions.ATI_separate_stencil = GL_TRUE;
 148    ctx->Extensions.EXT_blend_color = GL_TRUE;
 149    ctx->Extensions.EXT_blend_equation_separate = GL_TRUE;
 150    ctx->Extensions.EXT_blend_func_separate = GL_TRUE;
 151    ctx->Extensions.EXT_blend_minmax = GL_TRUE;
 152    ctx->Extensions.EXT_depth_bounds_test = GL_TRUE;
 153    ctx->Extensions.EXT_draw_buffers2 = GL_TRUE;
 154    ctx->Extensions.EXT_pixel_buffer_object = GL_TRUE;
 155    ctx->Extensions.EXT_point_parameters = GL_TRUE;
 156    ctx->Extensions.EXT_provoking_vertex = GL_TRUE;
 157    ctx->Extensions.EXT_stencil_two_side = GL_TRUE;
 158    ctx->Extensions.EXT_texture_array = GL_TRUE;
 159    ctx->Extensions.EXT_texture_compression_latc = GL_TRUE;
 160    ctx->Extensions.EXT_texture_env_dot3 = GL_TRUE;
 161    ctx->Extensions.EXT_texture_filter_anisotropic = GL_TRUE;
 162    ctx->Extensions.EXT_texture_mirror_clamp = GL_TRUE;
 163    ctx->Extensions.EXT_texture_shared_exponent = GL_TRUE;
 164    ctx->Extensions.EXT_texture_sRGB = GL_TRUE;
 165    ctx->Extensions.EXT_texture_sRGB_decode = GL_TRUE;
 166    ctx->Extensions.EXT_texture_swizzle = GL_TRUE;
 167    /*ctx->Extensions.EXT_transform_feedback = GL_TRUE;*/
 168    ctx->Extensions.EXT_vertex_array_bgra = GL_TRUE;
 169    ctx->Extensions.MESA_pack_invert = GL_TRUE;
 170    ctx->Extensions.MESA_ycbcr_texture = GL_TRUE;
 171    ctx->Extensions.NV_conditional_render = GL_TRUE;
 172    ctx->Extensions.NV_point_sprite = GL_TRUE;
 173    ctx->Extensions.NV_texture_env_combine4 = GL_TRUE;
 174    ctx->Extensions.NV_texture_rectangle = GL_TRUE;
 175    ctx->Extensions.EXT_gpu_program_parameters = GL_TRUE;
 176    ctx->Extensions.OES_standard_derivatives = GL_TRUE;
 177    ctx->Extensions.TDFX_texture_compression_FXT1 = GL_TRUE;
 178    ctx->Extensions.ANGLE_texture_compression_dxt = GL_TRUE;
 179    ctx->Extensions.EXT_texture_compression_s3tc = GL_TRUE;
 180 }
 181
 182 /**
 183  * Either enable or disable the named extension.
 184  * \return offset of extensions withint `ext' or 0 if extension is not known
 185  */
 186 static size_t
 187 set_extension(struct gl_extensions *ext, int i, GLboolean state)
 188 {
 189    size_t offset;
 190
 191    offset = i < 0 ? 0 : _mesa_extension_table[i].offset;
 192    if (offset != 0 && (offset != o(dummy_true) || state != GL_FALSE)) {
 193       ((GLboolean *) ext)[offset] = state;
 194    }
 195
 196    return offset;
 197 }
 198
 199 /**
 200  * The unrecognized extensions from \c MESA_EXTENSION_OVERRIDE.
 201  * Returns \c NULL if empty.
 202  */
 203 static const char *
 204 get_extension_override( struct gl_context *ctx )
 205 {
 206    if (extra_extensions)
 207       _mesa_problem(ctx, "Trying to enable unknown extensions: %s",
 208                     extra_extensions);
 209
 210    return extra_extensions;
 211 }
 212
 213
 214 /**
 215  * \brief Free extra_extensions string
 216  *
 217  * These strings are allocated early during the first context creation by
 218  * _mesa_one_time_init_extension_overrides.
 219  */
 220 static void
 221 free_unknown_extensions_strings(void)
 222 {
 223    free(extra_extensions);
 224 }
 225
 226
 227 /**
 228  * \brief Initialize extension override tables based on \c MESA_EXTENSION_OVERRIDE
 229  *
 230  * This should be called one time early during first context initialization.
 231
 232  * \c MESA_EXTENSION_OVERRIDE is a space-separated list of extensions to
 233  * enable or disable. The list is processed thus:
 234  *    - Enable recognized extension names that are prefixed with '+'.
 235  *    - Disable recognized extension names that are prefixed with '-'.
 236  *    - Enable recognized extension names that are not prefixed.
 237  *    - Collect unrecognized extension names in a new string.
 238  */
 239 void
 240 _mesa_one_time_init_extension_overrides(void)
 241 {
 242    const char *env_const = getenv("MESA_EXTENSION_OVERRIDE");
 243    char *env;
 244    char *ext;
 245    int len;
 246    size_t offset;
 247
 248    memset(&_mesa_extension_override_enables, 0, sizeof(struct gl_extensions));
 249    memset(&_mesa_extension_override_disables, 0, sizeof(struct gl_extensions));
 250
 251    if (env_const == NULL) {
 252       return;
 253    }
 254
 255    /* extra_exts: List of unrecognized extensions. */
 256    extra_extensions = calloc(ALIGN(strlen(env_const) + 2, 4), sizeof(char));
 257
 258    /* Copy env_const because strtok() is destructive. */
 259    env = strdup(env_const);
 260
 261    if (env == NULL ||
 262        extra_extensions == NULL) {
 263       free(env);
 264       free(extra_extensions);
 265       return;
 266    }
 267
 268    for (ext = strtok(env, " "); ext != NULL; ext = strtok(NULL, " ")) {
 269       int enable;
 270       int i;
 271       bool recognized;
 272       switch (ext[0]) {
 273       case '+':
 274          enable = 1;
 275          ++ext;
 276          break;
 277       case '-':
 278          enable = 0;
 279          ++ext;
 280          break;
 281       default:
 282          enable = 1;
 283          break;
 284       }
 285
 286       i = name_to_index(ext);
 287       offset = set_extension(&_mesa_extension_override_enables, i, enable);
 288       offset = set_extension(&_mesa_extension_override_disables, i, !enable);
 289       if (offset != 0)
 290          recognized = true;
 291       else
 292          recognized = false;
 293
 294       if (!recognized && enable) {
 295          strcat(extra_extensions, ext);
 296          strcat(extra_extensions, " ");
 297       }
 298    }
 299
 300    free(env);
 301
 302    /* Remove trailing space, and free if unused. */
 303    len = strlen(extra_extensions);
 304    if (len == 0) {
 305       free(extra_extensions);
 306    } else if (extra_extensions[len - 1] == ' ') {
 307       extra_extensions[len - 1] = '\0';
 308       atexit(free_unknown_extensions_strings);
 309    }
 310 }
 311
 312
 313 /**
 314  * \brief Initialize extension tables and enable default extensions.
 315  *
 316  * This should be called during context initialization.
 317  * Note: Sets gl_extensions.dummy_true to true.
 318  */
 319 void
 320 _mesa_init_extensions(struct gl_extensions *extensions)
 321 {
 322    GLboolean *base = (GLboolean *) extensions;
 323    GLboolean *sentinel = base + o(extension_sentinel);
 324    GLboolean *i;
 325
 326    /* First, turn all extensions off. */
 327    for (i = base; i != sentinel; ++i)
 328       *i = GL_FALSE;
 329
 330    /* Then, selectively turn default extensions on. */
 331    extensions->dummy_true = GL_TRUE;
 332 }
 333
 334
 335 typedef unsigned short extension_index;
 336
 337
 338 /**
 339  * Given an extension enum, return whether or not the extension is supported
 340  * dependent on the following factors:
 341  * There's driver support and the OpenGL/ES version is at least that
 342  * specified in the _mesa_extension_table.
 343  */
 344 static inline bool
 345 _mesa_extension_supported(const struct gl_context *ctx, extension_index i)
 346 {
 347    const bool *base = (bool *) &ctx->Extensions;
 348    const struct mesa_extension *ext = _mesa_extension_table + i;
 349
 350    return (ctx->Version >= ext->version[ctx->API]) && base[ext->offset];
 351 }
 352
 353
 354 /**
 355  * Construct the GL_EXTENSIONS string.  Called the first time that
 356  * glGetString(GL_EXTENSIONS) is called.
 357  */
 358 GLubyte*
 359 _mesa_make_extension_string(struct gl_context *ctx)
 360 {
 361    /* The extension string. */
 362    char *exts = 0;
 363    /* Length of extension string. */
 364    size_t length = 0;
 365    /* Number of extensions */
 366    unsigned count;
 367    /* Indices of the extensions sorted by year */
 368    extension_index extension_indices[MESA_EXTENSION_COUNT];
 369    /* String of extra extensions. */
 370    const char *extra_extensions = get_extension_override(ctx);
 371    unsigned k;
 372    unsigned j;
 373    unsigned maxYear = ~0;
 374
 375    /* Check if the MESA_EXTENSION_MAX_YEAR env var is set */
 376    {
 377       const char *env = getenv("MESA_EXTENSION_MAX_YEAR");
 378       if (env) {
 379          maxYear = atoi(env);
 380          _mesa_debug(ctx, "Note: limiting GL extensions to %u or earlier\n",
 381                      maxYear);
 382       }
 383    }
 384
 385    /* Compute length of the extension string. */
 386    count = 0;
 387    for (k = 0; k < MESA_EXTENSION_COUNT; ++k) {
 388       const struct mesa_extension *i = _mesa_extension_table + k;
 389
 390       if (i->year <= maxYear &&
 391           _mesa_extension_supported(ctx, k)) {
 392          length += strlen(i->name) + 1; /* +1 for space */
 393          extension_indices[count++] = k;
 394       }
 395    }
 396    if (extra_extensions != NULL)
 397       length += 1 + strlen(extra_extensions); /* +1 for space */
 398
 399    exts = calloc(ALIGN(length + 1, 4), sizeof(char));
 400    if (exts == NULL) {
 401       return NULL;
 402    }
 403
 404    /* Build the extension string.*/
 405    for (j = 0; j < count; ++j) {
 406       const struct mesa_extension *i = &_mesa_extension_table[extension_indices[j]];
 407       assert(_mesa_extension_supported(ctx, extension_indices[j]));
 408       strcat(exts, i->name);
 409       strcat(exts, " ");
 410    }
 411    if (extra_extensions != 0) {
 412       strcat(exts, extra_extensions);
 413    }
 414
 415    return (GLubyte *) exts;
 416 }
 417
 418 /**
 419  * Return number of enabled extensions.
 420  */
 421 GLuint
 422 _mesa_get_extension_count(struct gl_context *ctx)
 423 {
 424    unsigned k;
 425
 426    /* only count once */
 427    if (ctx->Extensions.Count != 0)
 428       return ctx->Extensions.Count;
 429
 430    for (k = 0; k < MESA_EXTENSION_COUNT; ++k) {
 431       if (_mesa_extension_supported(ctx, k))
 432          ctx->Extensions.Count++;
 433    }
 434    return ctx->Extensions.Count;
 435 }
 436
 437 /**
 438  * Return name of i-th enabled extension
 439  */
 440 const GLubyte *
 441 _mesa_get_enabled_extension(struct gl_context *ctx, GLuint index)
 442 {
 443    size_t n = 0;
 444    unsigned i;
 445
 446    for (i = 0; i < MESA_EXTENSION_COUNT; ++i) {
 447       if (_mesa_extension_supported(ctx, i)) {
 448          if (n == index)
 449             return (const GLubyte*) _mesa_extension_table[i].name;
 450          else
 451             ++n;
 452       }
 453    }
 454
 455    return NULL;
 456 }