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_SCREEN_BIT_MESA | /* XXX should check the extension */
 329                    EGL_VG_COLORSPACE_LINEAR_BIT |
 330                    EGL_VG_ALPHA_FORMAT_PRE_BIT |
 331                    EGL_MULTISAMPLE_RESOLVE_BOX_BIT |
 332                    EGL_SWAP_BEHAVIOR_PRESERVED_BIT;
 333             break;
 334          case EGL_RENDERABLE_TYPE:
 335          case EGL_CONFORMANT:
 336             mask = EGL_OPENGL_ES_BIT |
 337                    EGL_OPENVG_BIT |
 338                    EGL_OPENGL_ES2_BIT |
 339                    EGL_OPENGL_BIT;
 340             break;
 341          default:
 342             assert(0);
 343             break;
 344          }
 345          if (val & ~mask)
 346             valid = EGL_FALSE;
 347          break;
 348       case ATTRIB_TYPE_PLATFORM:
 349          /* unable to check platform-dependent attributes here */
 350          break;
 351       case ATTRIB_TYPE_PSEUDO:
 352          /* pseudo attributes should not be set */
 353          if (val != 0)
 354             valid = EGL_FALSE;
 355          break;
 356       default:
 357          assert(0);
 358          break;
 359       }
 360
 361       if (!valid && for_matching) {
 362          /* accept EGL_DONT_CARE as a valid value */
 363          if (val == EGL_DONT_CARE)
 364             valid = EGL_TRUE;
 365          if (_eglValidationTable[i].criterion == ATTRIB_CRITERION_SPECIAL)
 366             valid = EGL_TRUE;
 367       }
 368       if (!valid)
 369          break;
 370    }
 371
 372    /* any invalid attribute value should have been catched */
 373    if (!valid || for_matching)
 374       return valid;
 375
 376    /* now check for conflicting attribute values */
 377
 378    switch (GET_CONFIG_ATTRIB(conf, EGL_COLOR_BUFFER_TYPE)) {
 379    case EGL_RGB_BUFFER:
 380       if (luminance_size)
 381          valid = EGL_FALSE;
 382       if (red_size + green_size + blue_size + alpha_size != buffer_size)
 383          valid = EGL_FALSE;
 384       break;
 385    case EGL_LUMINANCE_BUFFER:
 386       if (red_size || green_size || blue_size)
 387          valid = EGL_FALSE;
 388       if (luminance_size + alpha_size != buffer_size)
 389          valid = EGL_FALSE;
 390       break;
 391    }
 392
 393    val = GET_CONFIG_ATTRIB(conf, EGL_SAMPLE_BUFFERS);
 394    if (!val && GET_CONFIG_ATTRIB(conf, EGL_SAMPLES))
 395       valid = EGL_FALSE;
 396
 397    val = GET_CONFIG_ATTRIB(conf, EGL_SURFACE_TYPE);
 398    if (!(val & EGL_WINDOW_BIT)) {
 399       if (GET_CONFIG_ATTRIB(conf, EGL_NATIVE_VISUAL_ID) != 0 ||
 400           GET_CONFIG_ATTRIB(conf, EGL_NATIVE_VISUAL_TYPE) != EGL_NONE)
 401          valid = EGL_FALSE;
 402    }
 403    if (!(val & EGL_PBUFFER_BIT)) {
 404       if (GET_CONFIG_ATTRIB(conf, EGL_BIND_TO_TEXTURE_RGB) ||
 405           GET_CONFIG_ATTRIB(conf, EGL_BIND_TO_TEXTURE_RGBA))
 406          valid = EGL_FALSE;
 407    }
 408
 409    return valid;
 410 }
 411
 412
 413 /**
 414  * Return true if a config matches the criteria.  This and
 415  * _eglParseConfigAttribList together implement the algorithm
 416  * described in "Selection of EGLConfigs".
 417  *
 418  * Note that attributes that are special (currently, only
 419  * EGL_MATCH_NATIVE_PIXMAP) are ignored.
 420  */
 421 EGLBoolean
 422 _eglMatchConfig(const _EGLConfig *conf, const _EGLConfig *criteria)
 423 {
 424    EGLint attr, val, i;
 425    EGLBoolean matched = EGL_TRUE;
 426
 427    for (i = 0; i < ARRAY_SIZE(_eglValidationTable); i++) {
 428       EGLint cmp;
 429       if (_eglValidationTable[i].criterion == ATTRIB_CRITERION_IGNORE)
 430          continue;
 431
 432       attr = _eglValidationTable[i].attr;
 433       cmp = GET_CONFIG_ATTRIB(criteria, attr);
 434       if (cmp == EGL_DONT_CARE)
 435          continue;
 436
 437       val = GET_CONFIG_ATTRIB(conf, attr);
 438       switch (_eglValidationTable[i].criterion) {
 439       case ATTRIB_CRITERION_EXACT:
 440          if (val != cmp)
 441             matched = EGL_FALSE;
 442          break;
 443       case ATTRIB_CRITERION_ATLEAST:
 444          if (val < cmp)
 445             matched = EGL_FALSE;
 446          break;
 447       case ATTRIB_CRITERION_MASK:
 448          if ((val & cmp) != cmp)
 449             matched = EGL_FALSE;
 450          break;
 451       case ATTRIB_CRITERION_SPECIAL:
 452          /* ignored here */
 453          break;
 454       default:
 455          assert(0);
 456          break;
 457       }
 458
 459       if (!matched)
 460          break;
 461    }
 462
 463    return matched;
 464 }
 465
 466
 467 /**
 468  * Initialize a criteria config from the given attribute list.
 469  * Return EGL_FALSE if any of the attribute is invalid.
 470  */
 471 EGLBoolean
 472 _eglParseConfigAttribList(_EGLConfig *conf, const EGLint *attrib_list)
 473 {
 474    EGLint attr, val, i;
 475    EGLint config_id = 0, level = 0;
 476    EGLBoolean has_native_visual_type = EGL_FALSE;
 477    EGLBoolean has_transparent_color = EGL_FALSE;
 478
 479    /* reset to default values */
 480    for (i = 0; i < ARRAY_SIZE(_eglValidationTable); i++) {
 481       attr = _eglValidationTable[i].attr;
 482       val = _eglValidationTable[i].default_value;
 483       SET_CONFIG_ATTRIB(conf, attr, val);
 484    }
 485
 486    /* parse the list */
 487    for (i = 0; attrib_list && attrib_list[i] != EGL_NONE; i += 2) {
 488       EGLint idx;
 489
 490       attr = attrib_list[i];
 491       val = attrib_list[i + 1];
 492
 493       idx = _eglIndexConfig(conf, attr);
 494       if (idx < 0)
 495          return EGL_FALSE;
 496       conf->Storage[idx] = val;
 497
 498       /* rememeber some attributes for post-processing */
 499       switch (attr) {
 500       case EGL_CONFIG_ID:
 501          config_id = val;
 502          break;
 503       case EGL_LEVEL:
 504          level = val;
 505          break;
 506       case EGL_NATIVE_VISUAL_TYPE:
 507          has_native_visual_type = EGL_TRUE;
 508          break;
 509       case EGL_TRANSPARENT_RED_VALUE:
 510       case EGL_TRANSPARENT_GREEN_VALUE:
 511       case EGL_TRANSPARENT_BLUE_VALUE:
 512          has_transparent_color = EGL_TRUE;
 513          break;
 514       default:
 515          break;
 516       }
 517    }
 518
 519    if (!_eglValidateConfig(conf, EGL_TRUE))
 520       return EGL_FALSE;
 521
 522    /* the spec says that EGL_LEVEL cannot be EGL_DONT_CARE */
 523    if (level == EGL_DONT_CARE)
 524       return EGL_FALSE;
 525
 526    /* ignore other attributes when EGL_CONFIG_ID is given */
 527    if (config_id > 0) {
 528       _eglResetConfigKeys(conf, EGL_DONT_CARE);
 529       SET_CONFIG_ATTRIB(conf, EGL_CONFIG_ID, config_id);
 530    }
 531    else {
 532       if (has_native_visual_type) {
 533          val = GET_CONFIG_ATTRIB(conf, EGL_SURFACE_TYPE);
 534          if (!(val & EGL_WINDOW_BIT))
 535             SET_CONFIG_ATTRIB(conf, EGL_NATIVE_VISUAL_TYPE, EGL_DONT_CARE);
 536       }
 537
 538       if (has_transparent_color) {
 539          val = GET_CONFIG_ATTRIB(conf, EGL_TRANSPARENT_TYPE);
 540          if (val == EGL_NONE) {
 541             SET_CONFIG_ATTRIB(conf, EGL_TRANSPARENT_RED_VALUE,
 542                               EGL_DONT_CARE);
 543             SET_CONFIG_ATTRIB(conf, EGL_TRANSPARENT_GREEN_VALUE,
 544                               EGL_DONT_CARE);
 545             SET_CONFIG_ATTRIB(conf, EGL_TRANSPARENT_BLUE_VALUE,
 546                               EGL_DONT_CARE);
 547          }
 548       }
 549    }
 550
 551    return EGL_TRUE;
 552 }
 553
 554
 555 /**
 556  * Decide the ordering of conf1 and conf2, under the given criteria.
 557  * When compare_id is true, this implements the algorithm described
 558  * in "Sorting of EGLConfigs".  When compare_id is false,
 559  * EGL_CONFIG_ID is not compared.
 560  *
 561  * It returns a negative integer if conf1 is considered to come
 562  * before conf2;  a positive integer if conf2 is considered to come
 563  * before conf1;  zero if the ordering cannot be decided.
 564  *
 565  * Note that EGL_NATIVE_VISUAL_TYPE is platform-dependent and is
 566  * ignored here.
 567  */
 568 EGLint
 569 _eglCompareConfigs(const _EGLConfig *conf1, const _EGLConfig *conf2,
 570                    const _EGLConfig *criteria, EGLBoolean compare_id)
 571 {
 572    const EGLint compare_attribs[] = {
 573       EGL_BUFFER_SIZE,
 574       EGL_SAMPLE_BUFFERS,
 575       EGL_SAMPLES,
 576       EGL_DEPTH_SIZE,
 577       EGL_STENCIL_SIZE,
 578       EGL_ALPHA_MASK_SIZE,
 579    };
 580    EGLint val1, val2;
 581    EGLBoolean rgb_buffer;
 582    EGLint i;
 583
 584    if (conf1 == conf2)
 585       return 0;
 586
 587    /* the enum values have the desired ordering */
 588    assert(EGL_NONE < EGL_SLOW_CONFIG);
 589    assert(EGL_SLOW_CONFIG < EGL_NON_CONFORMANT_CONFIG);
 590    val1 = GET_CONFIG_ATTRIB(conf1, EGL_CONFIG_CAVEAT);
 591    val2 = GET_CONFIG_ATTRIB(conf2, EGL_CONFIG_CAVEAT);
 592    if (val1 != val2)
 593       return (val1 - val2);
 594
 595    /* the enum values have the desired ordering */
 596    assert(EGL_RGB_BUFFER < EGL_LUMINANCE_BUFFER);
 597    val1 = GET_CONFIG_ATTRIB(conf1, EGL_COLOR_BUFFER_TYPE);
 598    val2 = GET_CONFIG_ATTRIB(conf2, EGL_COLOR_BUFFER_TYPE);
 599    if (val1 != val2)
 600       return (val1 - val2);
 601    rgb_buffer = (val1 == EGL_RGB_BUFFER);
 602
 603    if (criteria) {
 604       val1 = val2 = 0;
 605       if (rgb_buffer) {
 606          if (GET_CONFIG_ATTRIB(criteria, EGL_RED_SIZE) > 0) {
 607             val1 += GET_CONFIG_ATTRIB(conf1, EGL_RED_SIZE);
 608             val2 += GET_CONFIG_ATTRIB(conf2, EGL_RED_SIZE);
 609          }
 610          if (GET_CONFIG_ATTRIB(criteria, EGL_GREEN_SIZE) > 0) {
 611             val1 += GET_CONFIG_ATTRIB(conf1, EGL_GREEN_SIZE);
 612             val2 += GET_CONFIG_ATTRIB(conf2, EGL_GREEN_SIZE);
 613          }
 614          if (GET_CONFIG_ATTRIB(criteria, EGL_BLUE_SIZE) > 0) {
 615             val1 += GET_CONFIG_ATTRIB(conf1, EGL_BLUE_SIZE);
 616             val2 += GET_CONFIG_ATTRIB(conf2, EGL_BLUE_SIZE);
 617          }
 618       }
 619       else {
 620          if (GET_CONFIG_ATTRIB(criteria, EGL_LUMINANCE_SIZE) > 0) {
 621             val1 += GET_CONFIG_ATTRIB(conf1, EGL_LUMINANCE_SIZE);
 622             val2 += GET_CONFIG_ATTRIB(conf2, EGL_LUMINANCE_SIZE);
 623          }
 624       }
 625       if (GET_CONFIG_ATTRIB(criteria, EGL_ALPHA_SIZE) > 0) {
 626          val1 += GET_CONFIG_ATTRIB(conf1, EGL_ALPHA_SIZE);
 627          val2 += GET_CONFIG_ATTRIB(conf2, EGL_ALPHA_SIZE);
 628       }
 629    }
 630    else {
 631       /* assume the default criteria, which gives no specific ordering */
 632       val1 = val2 = 0;
 633    }
 634
 635    /* for color bits, larger one is preferred */
 636    if (val1 != val2)
 637       return (val2 - val1);
 638
 639    for (i = 0; i < ARRAY_SIZE(compare_attribs); i++) {
 640       val1 = GET_CONFIG_ATTRIB(conf1, compare_attribs[i]);
 641       val2 = GET_CONFIG_ATTRIB(conf2, compare_attribs[i]);
 642       if (val1 != val2)
 643          return (val1 - val2);
 644    }
 645
 646    /* EGL_NATIVE_VISUAL_TYPE cannot be compared here */
 647
 648    if (compare_id) {
 649       val1 = GET_CONFIG_ATTRIB(conf1, EGL_CONFIG_ID);
 650       val2 = GET_CONFIG_ATTRIB(conf2, EGL_CONFIG_ID);
 651       assert(val1 != val2);
 652    }
 653    else {
 654       val1 = val2 = 0;
 655    }
 656
 657    return (val1 - val2);
 658 }
 659
 660
 661 static INLINE
 662 void _eglSwapConfigs(const _EGLConfig **conf1, const _EGLConfig **conf2)
 663 {
 664    const _EGLConfig *tmp = *conf1;
 665    *conf1 = *conf2;
 666    *conf2 = tmp;
 667 }
 668
 669
 670 /**
 671  * Quick sort an array of configs.  This differs from the standard
 672  * qsort() in that the compare function accepts an additional
 673  * argument.
 674  */
 675 void
 676 _eglSortConfigs(const _EGLConfig **configs, EGLint count,
 677                 EGLint (*compare)(const _EGLConfig *, const _EGLConfig *,
 678                                   void *),
 679                 void *priv_data)
 680 {
 681    const EGLint pivot = 0;
 682    EGLint i, j;
 683
 684    if (count <= 1)
 685       return;
 686
 687    _eglSwapConfigs(&configs[pivot], &configs[count / 2]);
 688    i = 1;
 689    j = count - 1;
 690    do {
 691       while (i < count && compare(configs[i], configs[pivot], priv_data) < 0)
 692          i++;
 693       while (compare(configs[j], configs[pivot], priv_data) > 0)
 694          j--;
 695       if (i < j) {
 696          _eglSwapConfigs(&configs[i], &configs[j]);
 697          i++;
 698          j--;
 699       }
 700       else if (i == j) {
 701          i++;
 702          j--;
 703          break;
 704       }
 705    } while (i <= j);
 706    _eglSwapConfigs(&configs[pivot], &configs[j]);
 707
 708    _eglSortConfigs(configs, j, compare, priv_data);
 709    _eglSortConfigs(configs + i, count - i, compare, priv_data);
 710 }
 711
 712
 713 static int
 714 _eglFallbackCompare(const _EGLConfig *conf1, const _EGLConfig *conf2,
 715                    void *priv_data)
 716 {
 717    const _EGLConfig *criteria = (const _EGLConfig *) priv_data;
 718    return _eglCompareConfigs(conf1, conf2, criteria, EGL_TRUE);
 719 }
 720
 721
 722 /**
 723  * Typical fallback routine for eglChooseConfig
 724  */
 725 EGLBoolean
 726 _eglChooseConfig(_EGLDriver *drv, _EGLDisplay *disp, const EGLint *attrib_list,
 727                  EGLConfig *configs, EGLint config_size, EGLint *num_configs)
 728 {
 729    _EGLConfig **configList, criteria;
 730    EGLint i, count;
 731
 732    if (!num_configs)
 733       return _eglError(EGL_BAD_PARAMETER, "eglChooseConfigs");
 734
 735    _eglInitConfig(&criteria, disp, 0);
 736    if (!_eglParseConfigAttribList(&criteria, attrib_list))
 737       return _eglError(EGL_BAD_ATTRIBUTE, "eglChooseConfig");
 738
 739    /* allocate array of config pointers */
 740    configList = (_EGLConfig **)
 741       malloc(disp->NumConfigs * sizeof(_EGLConfig *));
 742    if (!configList)
 743       return _eglError(EGL_BAD_ALLOC, "eglChooseConfig(out of memory)");
 744
 745    /* perform selection of configs */
 746    count = 0;
 747    for (i = 0; i < disp->NumConfigs; i++) {
 748       if (_eglMatchConfig(disp->Configs[i], &criteria))
 749          configList[count++] = disp->Configs[i];
 750    }
 751
 752    /* perform sorting of configs */
 753    if (configs && count) {
 754       _eglSortConfigs((const _EGLConfig **) configList, count,
 755                       _eglFallbackCompare, (void *) &criteria);
 756       count = MIN2(count, config_size);
 757       for (i = 0; i < count; i++)
 758          configs[i] = _eglGetConfigHandle(configList[i]);
 759    }
 760
 761    free(configList);
 762
 763    *num_configs = count;
 764
 765    return EGL_TRUE;
 766 }
 767
 768
 769 static INLINE EGLBoolean
 770 _eglIsConfigAttribValid(_EGLConfig *conf, EGLint attr)
 771 {
 772    if (_eglIndexConfig(conf, attr) < 0)
 773       return EGL_FALSE;
 774
 775    /* there are some holes in the range */
 776    switch (attr) {
 777    case 0x3030 /* a gap before EGL_SAMPLES */:
 778    case EGL_NONE:
 779 #ifdef EGL_VERSION_1_4
 780    case EGL_MATCH_NATIVE_PIXMAP:
 781 #endif
 782       return EGL_FALSE;
 783    default:
 784       break;
 785    }
 786
 787    return EGL_TRUE;
 788 }
 789
 790
 791 /**
 792  * Fallback for eglGetConfigAttrib.
 793  */
 794 EGLBoolean
 795 _eglGetConfigAttrib(_EGLDriver *drv, _EGLDisplay *dpy, _EGLConfig *conf,
 796                     EGLint attribute, EGLint *value)
 797 {
 798    if (!_eglIsConfigAttribValid(conf, attribute))
 799       return _eglError(EGL_BAD_ATTRIBUTE, "eglGetConfigAttrib");
 800    if (!value)
 801       return _eglError(EGL_BAD_PARAMETER, "eglGetConfigAttrib");
 802
 803    *value = GET_CONFIG_ATTRIB(conf, attribute);
 804    return EGL_TRUE;
 805 }
 806
 807
 808 /**
 809  * Fallback for eglGetConfigs.
 810  */
 811 EGLBoolean
 812 _eglGetConfigs(_EGLDriver *drv, _EGLDisplay *disp, EGLConfig *configs,
 813                EGLint config_size, EGLint *num_config)
 814 {
 815    if (!num_config)
 816       return _eglError(EGL_BAD_PARAMETER, "eglGetConfigs");
 817
 818    if (configs) {
 819       EGLint i;
 820       *num_config = MIN2(disp->NumConfigs, config_size);
 821       for (i = 0; i < *num_config; i++)
 822          configs[i] = _eglGetConfigHandle(disp->Configs[i]);
 823    }
 824    else {
 825       /* just return total number of supported configs */
 826       *num_config = disp->NumConfigs;
 827    }
 828
 829    return EGL_TRUE;
 830 }