src/egl/main/eglconfig.c

   1 /**
   2  * EGL Configuration (pixel format) functions.
   3  */
   4
   5
   6 #include <stdlib.h>
   7 #include <string.h>
   8 #include <assert.h>
   9 #include "eglconfig.h"
  10 #include "egldisplay.h"
  11 #include "eglcurrent.h"
  12 #include "egllog.h"
  13
  14
  15 #define MIN2(A, B)  (((A) < (B)) ? (A) : (B))
  16 #define ARRAY_SIZE(a) (sizeof(a) / sizeof((a)[0]))
  17
  18
  19 /**
  20  * Init the given _EGLconfig to default values.
  21  * \param id  the configuration's ID.
  22  *
  23  * Note that id must be positive for the config to be valid.
  24  * It is also recommended that when there are N configs, their
  25  * IDs are from 1 to N respectively.
  26  */
  27 void
  28 _eglInitConfig(_EGLConfig *config, _EGLDisplay *dpy, EGLint id)
  29 {
  30    memset(config, 0, sizeof(*config));
  31
  32    config->Display = dpy;
  33
  34    /* some attributes take non-zero default values */
  35    SET_CONFIG_ATTRIB(config, EGL_CONFIG_ID,               id);
  36    SET_CONFIG_ATTRIB(config, EGL_CONFIG_CAVEAT,           EGL_NONE);
  37    SET_CONFIG_ATTRIB(config, EGL_TRANSPARENT_TYPE,        EGL_NONE);
  38    SET_CONFIG_ATTRIB(config, EGL_NATIVE_VISUAL_TYPE,      EGL_NONE);
  39 #ifdef EGL_VERSION_1_2
  40    SET_CONFIG_ATTRIB(config, EGL_COLOR_BUFFER_TYPE,       EGL_RGB_BUFFER);
  41 #endif /* EGL_VERSION_1_2 */
  42 }
  43
  44
  45 /**
  46  * Link a config to a display and return the handle of the link.
  47  * The handle can be passed to client directly.
  48  *
  49  * Note that we just save the ptr to the config (we don't copy the config).
  50  */
  51 EGLConfig
  52 _eglAddConfig(_EGLDisplay *dpy, _EGLConfig *conf)
  53 {
  54    _EGLConfig **configs;
  55
  56    /* sanity check */
  57    assert(GET_CONFIG_ATTRIB(conf, EGL_CONFIG_ID) > 0);
  58
  59    configs = dpy->Configs;
  60    if (dpy->NumConfigs >= dpy->MaxConfigs) {
  61       EGLint new_size = dpy->MaxConfigs + 16;
  62       assert(dpy->NumConfigs < new_size);
  63
  64       configs = realloc(dpy->Configs, new_size * sizeof(dpy->Configs[0]));
  65       if (!configs)
  66          return (EGLConfig) NULL;
  67
  68       dpy->Configs = configs;
  69       dpy->MaxConfigs = new_size;
  70    }
  71
  72    conf->Display = dpy;
  73    dpy->Configs[dpy->NumConfigs++] = conf;
  74
  75    return (EGLConfig) conf;
  76 }
  77
  78
  79 #ifndef _EGL_SKIP_HANDLE_CHECK
  80
  81
  82 EGLBoolean
  83 _eglCheckConfigHandle(EGLConfig config, _EGLDisplay *dpy)
  84 {
  85    EGLint num_configs = (dpy) ? dpy->NumConfigs : 0;
  86    EGLint i;
  87
  88    for (i = 0; i < num_configs; i++) {
  89       _EGLConfig *conf = dpy->Configs[i];
  90       if (conf == (_EGLConfig *) config) {
  91          assert(conf->Display == dpy);
  92          break;
  93       }
  94    }
  95    return (i < num_configs);
  96 }
  97
  98
  99 #endif /* _EGL_SKIP_HANDLE_CHECK */
 100
 101
 102 enum {
 103    /* types */
 104    ATTRIB_TYPE_INTEGER,
 105    ATTRIB_TYPE_BOOLEAN,
 106    ATTRIB_TYPE_BITMASK,
 107    ATTRIB_TYPE_ENUM,
 108    ATTRIB_TYPE_PSEUDO, /* non-queryable */
 109    ATTRIB_TYPE_PLATFORM, /* platform-dependent */
 110    /* criteria */
 111    ATTRIB_CRITERION_EXACT,
 112    ATTRIB_CRITERION_ATLEAST,
 113    ATTRIB_CRITERION_MASK,
 114    ATTRIB_CRITERION_SPECIAL,
 115    ATTRIB_CRITERION_IGNORE,
 116 };
 117
 118
 119 /* EGL spec Table 3.1 and 3.4 */
 120 static const struct {
 121    EGLint attr;
 122    EGLint type;
 123    EGLint criterion;
 124    EGLint default_value;
 125 } _eglValidationTable[] =
 126 {
 127    { EGL_BUFFER_SIZE,               ATTRIB_TYPE_INTEGER,
 128                                     ATTRIB_CRITERION_ATLEAST,
 129                                     0 },
 130    { EGL_RED_SIZE,                  ATTRIB_TYPE_INTEGER,
 131                                     ATTRIB_CRITERION_ATLEAST,
 132                                     0 },
 133    { EGL_GREEN_SIZE,                ATTRIB_TYPE_INTEGER,
 134                                     ATTRIB_CRITERION_ATLEAST,
 135                                     0 },
 136    { EGL_BLUE_SIZE,                 ATTRIB_TYPE_INTEGER,
 137                                     ATTRIB_CRITERION_ATLEAST,
 138                                     0 },
 139    { EGL_LUMINANCE_SIZE,            ATTRIB_TYPE_INTEGER,
 140                                     ATTRIB_CRITERION_ATLEAST,
 141                                     0 },
 142    { EGL_ALPHA_SIZE,                ATTRIB_TYPE_INTEGER,
 143                                     ATTRIB_CRITERION_ATLEAST,
 144                                     0 },
 145    { EGL_ALPHA_MASK_SIZE,           ATTRIB_TYPE_INTEGER,
 146                                     ATTRIB_CRITERION_ATLEAST,
 147                                     0 },
 148    { EGL_BIND_TO_TEXTURE_RGB,       ATTRIB_TYPE_BOOLEAN,
 149                                     ATTRIB_CRITERION_EXACT,
 150                                     EGL_DONT_CARE },
 151    { EGL_BIND_TO_TEXTURE_RGBA,      ATTRIB_TYPE_BOOLEAN,
 152                                     ATTRIB_CRITERION_EXACT,
 153                                     EGL_DONT_CARE },
 154    { EGL_COLOR_BUFFER_TYPE,         ATTRIB_TYPE_ENUM,
 155                                     ATTRIB_CRITERION_EXACT,
 156                                     EGL_RGB_BUFFER },
 157    { EGL_CONFIG_CAVEAT,             ATTRIB_TYPE_ENUM,
 158                                     ATTRIB_CRITERION_EXACT,
 159                                     EGL_DONT_CARE },
 160    { EGL_CONFIG_ID,                 ATTRIB_TYPE_INTEGER,
 161                                     ATTRIB_CRITERION_EXACT,
 162                                     EGL_DONT_CARE },
 163    { EGL_CONFORMANT,                ATTRIB_TYPE_BITMASK,
 164                                     ATTRIB_CRITERION_MASK,
 165                                     0 },
 166    { EGL_DEPTH_SIZE,                ATTRIB_TYPE_INTEGER,
 167                                     ATTRIB_CRITERION_ATLEAST,
 168                                     0 },
 169    { EGL_LEVEL,                     ATTRIB_TYPE_PLATFORM,
 170                                     ATTRIB_CRITERION_EXACT,
 171                                     0 },
 172    { EGL_MAX_PBUFFER_WIDTH,         ATTRIB_TYPE_INTEGER,
 173                                     ATTRIB_CRITERION_IGNORE,
 174                                     0 },
 175    { EGL_MAX_PBUFFER_HEIGHT,        ATTRIB_TYPE_INTEGER,
 176                                     ATTRIB_CRITERION_IGNORE,
 177                                     0 },
 178    { EGL_MAX_PBUFFER_PIXELS,        ATTRIB_TYPE_INTEGER,
 179                                     ATTRIB_CRITERION_IGNORE,
 180                                     0 },
 181    { EGL_MAX_SWAP_INTERVAL,         ATTRIB_TYPE_INTEGER,
 182                                     ATTRIB_CRITERION_EXACT,
 183                                     EGL_DONT_CARE },
 184    { EGL_MIN_SWAP_INTERVAL,         ATTRIB_TYPE_INTEGER,
 185                                     ATTRIB_CRITERION_EXACT,
 186                                     EGL_DONT_CARE },
 187    { EGL_NATIVE_RENDERABLE,         ATTRIB_TYPE_BOOLEAN,
 188                                     ATTRIB_CRITERION_EXACT,
 189                                     EGL_DONT_CARE },
 190    { EGL_NATIVE_VISUAL_ID,          ATTRIB_TYPE_PLATFORM,
 191                                     ATTRIB_CRITERION_IGNORE,
 192                                     0 },
 193    { EGL_NATIVE_VISUAL_TYPE,        ATTRIB_TYPE_PLATFORM,
 194                                     ATTRIB_CRITERION_EXACT,
 195                                     EGL_DONT_CARE },
 196    { EGL_RENDERABLE_TYPE,           ATTRIB_TYPE_BITMASK,
 197                                     ATTRIB_CRITERION_MASK,
 198                                     EGL_OPENGL_ES_BIT },
 199    { EGL_SAMPLE_BUFFERS,            ATTRIB_TYPE_INTEGER,
 200                                     ATTRIB_CRITERION_ATLEAST,
 201                                     0 },
 202    { EGL_SAMPLES,                   ATTRIB_TYPE_INTEGER,
 203                                     ATTRIB_CRITERION_ATLEAST,
 204                                     0 },
 205    { EGL_STENCIL_SIZE,              ATTRIB_TYPE_INTEGER,
 206                                     ATTRIB_CRITERION_ATLEAST,
 207                                     0 },
 208    { EGL_SURFACE_TYPE,              ATTRIB_TYPE_BITMASK,
 209                                     ATTRIB_CRITERION_MASK,
 210                                     EGL_WINDOW_BIT },
 211    { EGL_TRANSPARENT_TYPE,          ATTRIB_TYPE_ENUM,
 212                                     ATTRIB_CRITERION_EXACT,
 213                                     EGL_NONE },
 214    { EGL_TRANSPARENT_RED_VALUE,     ATTRIB_TYPE_INTEGER,
 215                                     ATTRIB_CRITERION_EXACT,
 216                                     EGL_DONT_CARE },
 217    { EGL_TRANSPARENT_GREEN_VALUE,   ATTRIB_TYPE_INTEGER,
 218                                     ATTRIB_CRITERION_EXACT,
 219                                     EGL_DONT_CARE },
 220    { EGL_TRANSPARENT_BLUE_VALUE,    ATTRIB_TYPE_INTEGER,
 221                                     ATTRIB_CRITERION_EXACT,
 222                                     EGL_DONT_CARE },
 223    /* these are not real attributes */
 224    { EGL_MATCH_NATIVE_PIXMAP,       ATTRIB_TYPE_PSEUDO,
 225                                     ATTRIB_CRITERION_SPECIAL,
 226                                     EGL_NONE },
 227    /* there is a gap before EGL_SAMPLES */
 228    { 0x3030,                        ATTRIB_TYPE_PSEUDO,
 229                                     ATTRIB_CRITERION_IGNORE,
 230                                     0 },
 231    { EGL_NONE,                      ATTRIB_TYPE_PSEUDO,
 232                                     ATTRIB_CRITERION_IGNORE,
 233                                     0 }
 234 };
 235
 236
 237 /**
 238  * Return true if a config is valid.  When for_matching is true,
 239  * EGL_DONT_CARE is accepted as a valid attribute value, and checks
 240  * for conflicting attribute values are skipped.
 241  *
 242  * Note that some attributes are platform-dependent and are not
 243  * checked.
 244  */
 245 EGLBoolean
 246 _eglValidateConfig(const _EGLConfig *conf, EGLBoolean for_matching)
 247 {
 248    EGLint i, attr, val;
 249    EGLBoolean valid = EGL_TRUE;
 250    EGLint red_size = 0, green_size = 0, blue_size = 0, luminance_size = 0;
 251    EGLint alpha_size = 0, buffer_size = 0;
 252
 253    /* all attributes should have been listed */
 254    assert(ARRAY_SIZE(_eglValidationTable) == _EGL_CONFIG_NUM_ATTRIBS);
 255
 256    /* check attributes by their types */
 257    for (i = 0; i < ARRAY_SIZE(_eglValidationTable); i++) {
 258       EGLint mask;
 259
 260       attr = _eglValidationTable[i].attr;
 261       val = GET_CONFIG_ATTRIB(conf, attr);
 262
 263       switch (_eglValidationTable[i].type) {
 264       case ATTRIB_TYPE_INTEGER:
 265          switch (attr) {
 266          case EGL_CONFIG_ID:
 267             /* config id must be positive */
 268             if (val <= 0)
 269                valid = EGL_FALSE;
 270             break;
 271          case EGL_SAMPLE_BUFFERS:
 272             /* there can be at most 1 sample buffer */
 273             if (val > 1)
 274                valid = EGL_FALSE;
 275             break;
 276          case EGL_RED_SIZE:
 277             red_size = val;
 278             break;
 279          case EGL_GREEN_SIZE:
 280             green_size = val;
 281             break;
 282          case EGL_BLUE_SIZE:
 283             blue_size = val;
 284             break;
 285          case EGL_LUMINANCE_SIZE:
 286             luminance_size = val;
 287             break;
 288          case EGL_ALPHA_SIZE:
 289             alpha_size = val;
 290             break;
 291          case EGL_BUFFER_SIZE:
 292             buffer_size = val;
 293             break;
 294          }
 295          if (val < 0)
 296             valid = EGL_FALSE;
 297          break;
 298       case ATTRIB_TYPE_BOOLEAN:
 299          if (val != EGL_TRUE && val != EGL_FALSE)
 300             valid = EGL_FALSE;
 301          break;
 302       case ATTRIB_TYPE_ENUM:
 303          switch (attr) {
 304          case EGL_CONFIG_CAVEAT:
 305             if (val != EGL_NONE && val != EGL_SLOW_CONFIG &&
 306                 val != EGL_NON_CONFORMANT_CONFIG)
 307                valid = EGL_FALSE;
 308             break;
 309          case EGL_TRANSPARENT_TYPE:
 310             if (val != EGL_NONE && val != EGL_TRANSPARENT_RGB)
 311                valid = EGL_FALSE;
 312             break;
 313          case EGL_COLOR_BUFFER_TYPE:
 314             if (val != EGL_RGB_BUFFER && val != EGL_LUMINANCE_BUFFER)
 315                valid = EGL_FALSE;
 316             break;
 317          default:
 318             assert(0);
 319             break;
 320          }
 321          break;
 322       case ATTRIB_TYPE_BITMASK:
 323          switch (attr) {
 324          case EGL_SURFACE_TYPE:
 325             mask = EGL_PBUFFER_BIT |
 326                    EGL_PIXMAP_BIT |
 327                    EGL_WINDOW_BIT |
 328                    EGL_VG_COLORSPACE_LINEAR_BIT |
 329                    EGL_VG_ALPHA_FORMAT_PRE_BIT |
 330                    EGL_MULTISAMPLE_RESOLVE_BOX_BIT |
 331                    EGL_SWAP_BEHAVIOR_PRESERVED_BIT;
 332             if (conf->Display->Extensions.MESA_screen_surface)
 333                mask |= EGL_SCREEN_BIT_MESA;
 334             break;
 335          case EGL_RENDERABLE_TYPE:
 336          case EGL_CONFORMANT:
 337             mask = EGL_OPENGL_ES_BIT |
 338                    EGL_OPENVG_BIT |
 339                    EGL_OPENGL_ES2_BIT |
 340                    EGL_OPENGL_BIT;
 341             break;
 342          default:
 343             assert(0);
 344             break;
 345          }
 346          if (val & ~mask)
 347             valid = EGL_FALSE;
 348          break;
 349       case ATTRIB_TYPE_PLATFORM:
 350          /* unable to check platform-dependent attributes here */
 351          break;
 352       case ATTRIB_TYPE_PSEUDO:
 353          /* pseudo attributes should not be set */
 354          if (val != 0)
 355             valid = EGL_FALSE;
 356          break;
 357       default:
 358          assert(0);
 359          break;
 360       }
 361
 362       if (!valid && for_matching) {
 363          /* accept EGL_DONT_CARE as a valid value */
 364          if (val == EGL_DONT_CARE)
 365             valid = EGL_TRUE;
 366          if (_eglValidationTable[i].criterion == ATTRIB_CRITERION_SPECIAL)
 367             valid = EGL_TRUE;
 368       }
 369       if (!valid)
 370          break;
 371    }
 372
 373    /* any invalid attribute value should have been catched */
 374    if (!valid || for_matching)
 375       return valid;
 376
 377    /* now check for conflicting attribute values */
 378
 379    switch (GET_CONFIG_ATTRIB(conf, EGL_COLOR_BUFFER_TYPE)) {
 380    case EGL_RGB_BUFFER:
 381       if (luminance_size)
 382          valid = EGL_FALSE;
 383       if (red_size + green_size + blue_size + alpha_size != buffer_size)
 384          valid = EGL_FALSE;
 385       break;
 386    case EGL_LUMINANCE_BUFFER:
 387       if (red_size || green_size || blue_size)
 388          valid = EGL_FALSE;
 389       if (luminance_size + alpha_size != buffer_size)
 390          valid = EGL_FALSE;
 391       break;
 392    }
 393
 394    val = GET_CONFIG_ATTRIB(conf, EGL_SAMPLE_BUFFERS);
 395    if (!val && GET_CONFIG_ATTRIB(conf, EGL_SAMPLES))
 396       valid = EGL_FALSE;
 397
 398    val = GET_CONFIG_ATTRIB(conf, EGL_SURFACE_TYPE);
 399    if (!(val & EGL_WINDOW_BIT)) {
 400       if (GET_CONFIG_ATTRIB(conf, EGL_NATIVE_VISUAL_ID) != 0 ||
 401           GET_CONFIG_ATTRIB(conf, EGL_NATIVE_VISUAL_TYPE) != EGL_NONE)
 402          valid = EGL_FALSE;
 403    }
 404    if (!(val & EGL_PBUFFER_BIT)) {
 405       if (GET_CONFIG_ATTRIB(conf, EGL_BIND_TO_TEXTURE_RGB) ||
 406           GET_CONFIG_ATTRIB(conf, EGL_BIND_TO_TEXTURE_RGBA))
 407          valid = EGL_FALSE;
 408    }
 409
 410    return valid;
 411 }
 412
 413
 414 /**
 415  * Return true if a config matches the criteria.  This and
 416  * _eglParseConfigAttribList together implement the algorithm
 417  * described in "Selection of EGLConfigs".
 418  *
 419  * Note that attributes that are special (currently, only
 420  * EGL_MATCH_NATIVE_PIXMAP) are ignored.
 421  */
 422 EGLBoolean
 423 _eglMatchConfig(const _EGLConfig *conf, const _EGLConfig *criteria)
 424 {
 425    EGLint attr, val, i;
 426    EGLBoolean matched = EGL_TRUE;
 427
 428    for (i = 0; i < ARRAY_SIZE(_eglValidationTable); i++) {
 429       EGLint cmp;
 430       if (_eglValidationTable[i].criterion == ATTRIB_CRITERION_IGNORE)
 431          continue;
 432
 433       attr = _eglValidationTable[i].attr;
 434       cmp = GET_CONFIG_ATTRIB(criteria, attr);
 435       if (cmp == EGL_DONT_CARE)
 436          continue;
 437
 438       val = GET_CONFIG_ATTRIB(conf, attr);
 439       switch (_eglValidationTable[i].criterion) {
 440       case ATTRIB_CRITERION_EXACT:
 441          if (val != cmp)
 442             matched = EGL_FALSE;
 443          break;
 444       case ATTRIB_CRITERION_ATLEAST:
 445          if (val < cmp)
 446             matched = EGL_FALSE;
 447          break;
 448       case ATTRIB_CRITERION_MASK:
 449          if ((val & cmp) != cmp)
 450             matched = EGL_FALSE;
 451          break;
 452       case ATTRIB_CRITERION_SPECIAL:
 453          /* ignored here */
 454          break;
 455       default:
 456          assert(0);
 457          break;
 458       }
 459
 460       if (!matched)
 461          break;
 462    }
 463
 464    return matched;
 465 }
 466
 467
 468 /**
 469  * Initialize a criteria config from the given attribute list.
 470  * Return EGL_FALSE if any of the attribute is invalid.
 471  */
 472 EGLBoolean
 473 _eglParseConfigAttribList(_EGLConfig *conf, const EGLint *attrib_list)
 474 {
 475    EGLint attr, val, i;
 476    EGLint config_id = 0, level = 0;
 477    EGLBoolean has_native_visual_type = EGL_FALSE;
 478    EGLBoolean has_transparent_color = EGL_FALSE;
 479
 480    /* reset to default values */
 481    for (i = 0; i < ARRAY_SIZE(_eglValidationTable); i++) {
 482       attr = _eglValidationTable[i].attr;
 483       val = _eglValidationTable[i].default_value;
 484       SET_CONFIG_ATTRIB(conf, attr, val);
 485    }
 486
 487    /* parse the list */
 488    for (i = 0; attrib_list && attrib_list[i] != EGL_NONE; i += 2) {
 489       EGLint idx;
 490
 491       attr = attrib_list[i];
 492       val = attrib_list[i + 1];
 493
 494       idx = _eglIndexConfig(conf, attr);
 495       if (idx < 0)
 496          return EGL_FALSE;
 497       conf->Storage[idx] = val;
 498
 499       /* rememeber some attributes for post-processing */
 500       switch (attr) {
 501       case EGL_CONFIG_ID:
 502          config_id = val;
 503          break;
 504       case EGL_LEVEL:
 505          level = val;
 506          break;
 507       case EGL_NATIVE_VISUAL_TYPE:
 508          has_native_visual_type = EGL_TRUE;
 509          break;
 510       case EGL_TRANSPARENT_RED_VALUE:
 511       case EGL_TRANSPARENT_GREEN_VALUE:
 512       case EGL_TRANSPARENT_BLUE_VALUE:
 513          has_transparent_color = EGL_TRUE;
 514          break;
 515       default:
 516          break;
 517       }
 518    }
 519
 520    if (!_eglValidateConfig(conf, EGL_TRUE))
 521       return EGL_FALSE;
 522
 523    /* the spec says that EGL_LEVEL cannot be EGL_DONT_CARE */
 524    if (level == EGL_DONT_CARE)
 525       return EGL_FALSE;
 526
 527    /* ignore other attributes when EGL_CONFIG_ID is given */
 528    if (config_id > 0) {
 529       _eglResetConfigKeys(conf, EGL_DONT_CARE);
 530       SET_CONFIG_ATTRIB(conf, EGL_CONFIG_ID, config_id);
 531    }
 532    else {
 533       if (has_native_visual_type) {
 534          val = GET_CONFIG_ATTRIB(conf, EGL_SURFACE_TYPE);
 535          if (!(val & EGL_WINDOW_BIT))
 536             SET_CONFIG_ATTRIB(conf, EGL_NATIVE_VISUAL_TYPE, EGL_DONT_CARE);
 537       }
 538
 539       if (has_transparent_color) {
 540          val = GET_CONFIG_ATTRIB(conf, EGL_TRANSPARENT_TYPE);
 541          if (val == EGL_NONE) {
 542             SET_CONFIG_ATTRIB(conf, EGL_TRANSPARENT_RED_VALUE,
 543                               EGL_DONT_CARE);
 544             SET_CONFIG_ATTRIB(conf, EGL_TRANSPARENT_GREEN_VALUE,
 545                               EGL_DONT_CARE);
 546             SET_CONFIG_ATTRIB(conf, EGL_TRANSPARENT_BLUE_VALUE,
 547                               EGL_DONT_CARE);
 548          }
 549       }
 550    }
 551
 552    return EGL_TRUE;
 553 }
 554
 555
 556 /**
 557  * Decide the ordering of conf1 and conf2, under the given criteria.
 558  * When compare_id is true, this implements the algorithm described
 559  * in "Sorting of EGLConfigs".  When compare_id is false,
 560  * EGL_CONFIG_ID is not compared.
 561  *
 562  * It returns a negative integer if conf1 is considered to come
 563  * before conf2;  a positive integer if conf2 is considered to come
 564  * before conf1;  zero if the ordering cannot be decided.
 565  *
 566  * Note that EGL_NATIVE_VISUAL_TYPE is platform-dependent and is
 567  * ignored here.
 568  */
 569 EGLint
 570 _eglCompareConfigs(const _EGLConfig *conf1, const _EGLConfig *conf2,
 571                    const _EGLConfig *criteria, EGLBoolean compare_id)
 572 {
 573    const EGLint compare_attribs[] = {
 574       EGL_BUFFER_SIZE,
 575       EGL_SAMPLE_BUFFERS,
 576       EGL_SAMPLES,
 577       EGL_DEPTH_SIZE,
 578       EGL_STENCIL_SIZE,
 579       EGL_ALPHA_MASK_SIZE,
 580    };
 581    EGLint val1, val2;
 582    EGLBoolean rgb_buffer;
 583    EGLint i;
 584
 585    if (conf1 == conf2)
 586       return 0;
 587
 588    /* the enum values have the desired ordering */
 589    assert(EGL_NONE < EGL_SLOW_CONFIG);
 590    assert(EGL_SLOW_CONFIG < EGL_NON_CONFORMANT_CONFIG);
 591    val1 = GET_CONFIG_ATTRIB(conf1, EGL_CONFIG_CAVEAT);
 592    val2 = GET_CONFIG_ATTRIB(conf2, EGL_CONFIG_CAVEAT);
 593    if (val1 != val2)
 594       return (val1 - val2);
 595
 596    /* the enum values have the desired ordering */
 597    assert(EGL_RGB_BUFFER < EGL_LUMINANCE_BUFFER);
 598    val1 = GET_CONFIG_ATTRIB(conf1, EGL_COLOR_BUFFER_TYPE);
 599    val2 = GET_CONFIG_ATTRIB(conf2, EGL_COLOR_BUFFER_TYPE);
 600    if (val1 != val2)
 601       return (val1 - val2);
 602    rgb_buffer = (val1 == EGL_RGB_BUFFER);
 603
 604    if (criteria) {
 605       val1 = val2 = 0;
 606       if (rgb_buffer) {
 607          if (GET_CONFIG_ATTRIB(criteria, EGL_RED_SIZE) > 0) {
 608             val1 += GET_CONFIG_ATTRIB(conf1, EGL_RED_SIZE);
 609             val2 += GET_CONFIG_ATTRIB(conf2, EGL_RED_SIZE);
 610          }
 611          if (GET_CONFIG_ATTRIB(criteria, EGL_GREEN_SIZE) > 0) {
 612             val1 += GET_CONFIG_ATTRIB(conf1, EGL_GREEN_SIZE);
 613             val2 += GET_CONFIG_ATTRIB(conf2, EGL_GREEN_SIZE);
 614          }
 615          if (GET_CONFIG_ATTRIB(criteria, EGL_BLUE_SIZE) > 0) {
 616             val1 += GET_CONFIG_ATTRIB(conf1, EGL_BLUE_SIZE);
 617             val2 += GET_CONFIG_ATTRIB(conf2, EGL_BLUE_SIZE);
 618          }
 619       }
 620       else {
 621          if (GET_CONFIG_ATTRIB(criteria, EGL_LUMINANCE_SIZE) > 0) {
 622             val1 += GET_CONFIG_ATTRIB(conf1, EGL_LUMINANCE_SIZE);
 623             val2 += GET_CONFIG_ATTRIB(conf2, EGL_LUMINANCE_SIZE);
 624          }
 625       }
 626       if (GET_CONFIG_ATTRIB(criteria, EGL_ALPHA_SIZE) > 0) {
 627          val1 += GET_CONFIG_ATTRIB(conf1, EGL_ALPHA_SIZE);
 628          val2 += GET_CONFIG_ATTRIB(conf2, EGL_ALPHA_SIZE);
 629       }
 630    }
 631    else {
 632       /* assume the default criteria, which gives no specific ordering */
 633       val1 = val2 = 0;
 634    }
 635
 636    /* for color bits, larger one is preferred */
 637    if (val1 != val2)
 638       return (val2 - val1);
 639
 640    for (i = 0; i < ARRAY_SIZE(compare_attribs); i++) {
 641       val1 = GET_CONFIG_ATTRIB(conf1, compare_attribs[i]);
 642       val2 = GET_CONFIG_ATTRIB(conf2, compare_attribs[i]);
 643       if (val1 != val2)
 644          return (val1 - val2);
 645    }
 646
 647    /* EGL_NATIVE_VISUAL_TYPE cannot be compared here */
 648
 649    if (compare_id) {
 650       val1 = GET_CONFIG_ATTRIB(conf1, EGL_CONFIG_ID);
 651       val2 = GET_CONFIG_ATTRIB(conf2, EGL_CONFIG_ID);
 652       assert(val1 != val2);
 653    }
 654    else {
 655       val1 = val2 = 0;
 656    }
 657
 658    return (val1 - val2);
 659 }
 660
 661
 662 static INLINE
 663 void _eglSwapConfigs(const _EGLConfig **conf1, const _EGLConfig **conf2)
 664 {
 665    const _EGLConfig *tmp = *conf1;
 666    *conf1 = *conf2;
 667    *conf2 = tmp;
 668 }
 669
 670
 671 /**
 672  * Quick sort an array of configs.  This differs from the standard
 673  * qsort() in that the compare function accepts an additional
 674  * argument.
 675  */
 676 void
 677 _eglSortConfigs(const _EGLConfig **configs, EGLint count,
 678                 EGLint (*compare)(const _EGLConfig *, const _EGLConfig *,
 679                                   void *),
 680                 void *priv_data)
 681 {
 682    const EGLint pivot = 0;
 683    EGLint i, j;
 684
 685    if (count <= 1)
 686       return;
 687
 688    _eglSwapConfigs(&configs[pivot], &configs[count / 2]);
 689    i = 1;
 690    j = count - 1;
 691    do {
 692       while (i < count && compare(configs[i], configs[pivot], priv_data) < 0)
 693          i++;
 694       while (compare(configs[j], configs[pivot], priv_data) > 0)
 695          j--;
 696       if (i < j) {
 697          _eglSwapConfigs(&configs[i], &configs[j]);
 698          i++;
 699          j--;
 700       }
 701       else if (i == j) {
 702          i++;
 703          j--;
 704          break;
 705       }
 706    } while (i <= j);
 707    _eglSwapConfigs(&configs[pivot], &configs[j]);
 708
 709    _eglSortConfigs(configs, j, compare, priv_data);
 710    _eglSortConfigs(configs + i, count - i, compare, priv_data);
 711 }
 712
 713
 714 static int
 715 _eglFallbackCompare(const _EGLConfig *conf1, const _EGLConfig *conf2,
 716                    void *priv_data)
 717 {
 718    const _EGLConfig *criteria = (const _EGLConfig *) priv_data;
 719    return _eglCompareConfigs(conf1, conf2, criteria, EGL_TRUE);
 720 }
 721
 722
 723 /**
 724  * Typical fallback routine for eglChooseConfig
 725  */
 726 EGLBoolean
 727 _eglChooseConfig(_EGLDriver *drv, _EGLDisplay *disp, const EGLint *attrib_list,
 728                  EGLConfig *configs, EGLint config_size, EGLint *num_configs)
 729 {
 730    _EGLConfig **configList, criteria;
 731    EGLint i, count;
 732
 733    if (!num_configs)
 734       return _eglError(EGL_BAD_PARAMETER, "eglChooseConfigs");
 735
 736    _eglInitConfig(&criteria, disp, 0);
 737    if (!_eglParseConfigAttribList(&criteria, attrib_list))
 738       return _eglError(EGL_BAD_ATTRIBUTE, "eglChooseConfig");
 739
 740    /* allocate array of config pointers */
 741    configList = (_EGLConfig **)
 742       malloc(disp->NumConfigs * sizeof(_EGLConfig *));
 743    if (!configList)
 744       return _eglError(EGL_BAD_ALLOC, "eglChooseConfig(out of memory)");
 745
 746    /* perform selection of configs */
 747    count = 0;
 748    for (i = 0; i < disp->NumConfigs; i++) {
 749       if (_eglMatchConfig(disp->Configs[i], &criteria))
 750          configList[count++] = disp->Configs[i];
 751    }
 752
 753    /* perform sorting of configs */
 754    if (configs && count) {
 755       _eglSortConfigs((const _EGLConfig **) configList, count,
 756                       _eglFallbackCompare, (void *) &criteria);
 757       count = MIN2(count, config_size);
 758       for (i = 0; i < count; i++)
 759          configs[i] = _eglGetConfigHandle(configList[i]);
 760    }
 761
 762    free(configList);
 763
 764    *num_configs = count;
 765
 766    return EGL_TRUE;
 767 }
 768
 769
 770 static INLINE EGLBoolean
 771 _eglIsConfigAttribValid(_EGLConfig *conf, EGLint attr)
 772 {
 773    if (_eglIndexConfig(conf, attr) < 0)
 774       return EGL_FALSE;
 775
 776    /* there are some holes in the range */
 777    switch (attr) {
 778    case 0x3030 /* a gap before EGL_SAMPLES */:
 779    case EGL_NONE:
 780 #ifdef EGL_VERSION_1_4
 781    case EGL_MATCH_NATIVE_PIXMAP:
 782 #endif
 783       return EGL_FALSE;
 784    default:
 785       break;
 786    }
 787
 788    return EGL_TRUE;
 789 }
 790
 791
 792 /**
 793  * Fallback for eglGetConfigAttrib.
 794  */
 795 EGLBoolean
 796 _eglGetConfigAttrib(_EGLDriver *drv, _EGLDisplay *dpy, _EGLConfig *conf,
 797                     EGLint attribute, EGLint *value)
 798 {
 799    if (!_eglIsConfigAttribValid(conf, attribute))
 800       return _eglError(EGL_BAD_ATTRIBUTE, "eglGetConfigAttrib");
 801    if (!value)
 802       return _eglError(EGL_BAD_PARAMETER, "eglGetConfigAttrib");
 803
 804    *value = GET_CONFIG_ATTRIB(conf, attribute);
 805    return EGL_TRUE;
 806 }
 807
 808
 809 /**
 810  * Fallback for eglGetConfigs.
 811  */
 812 EGLBoolean
 813 _eglGetConfigs(_EGLDriver *drv, _EGLDisplay *disp, EGLConfig *configs,
 814                EGLint config_size, EGLint *num_config)
 815 {
 816    if (!num_config)
 817       return _eglError(EGL_BAD_PARAMETER, "eglGetConfigs");
 818
 819    if (configs) {
 820       EGLint i;
 821       *num_config = MIN2(disp->NumConfigs, config_size);
 822       for (i = 0; i < *num_config; i++)
 823          configs[i] = _eglGetConfigHandle(disp->Configs[i]);
 824    }
 825    else {
 826       /* just return total number of supported configs */
 827       *num_config = disp->NumConfigs;
 828    }
 829
 830    return EGL_TRUE;
 831 }