src/egl/main/eglconfig.c

   1 /**************************************************************************
   2  *
   3  * Copyright 2008 VMware, Inc.
   4  * Copyright 2009-2010 Chia-I Wu <olvaffe@gmail.com>
   5  * Copyright 2010-2011 LunarG, Inc.
   6  * All Rights Reserved.
   7  *
   8  * Permission is hereby granted, free of charge, to any person obtaining a
   9  * copy of this software and associated documentation files (the
  10  * "Software"), to deal in the Software without restriction, including
  11  * without limitation the rights to use, copy, modify, merge, publish,
  12  * distribute, sub license, and/or sell copies of the Software, and to
  13  * permit persons to whom the Software is furnished to do so, subject to
  14  * the following conditions:
  15  *
  16  * The above copyright notice and this permission notice (including the
  17  * next paragraph) shall be included in all copies or substantial portions
  18  * of the Software.
  19  *
  20  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  21  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  22  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  23  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  24  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  25  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  26  * DEALINGS IN THE SOFTWARE.
  27  *
  28  **************************************************************************/
  29
  30
  31 /**
  32  * EGL Configuration (pixel format) functions.
  33  */
  34
  35
  36 #include <stdlib.h>
  37 #include <string.h>
  38 #include <assert.h>
  39 #include "c99_compat.h"
  40 #include "util/macros.h"
  41
  42 #include "eglconfig.h"
  43 #include "egldisplay.h"
  44 #include "eglcurrent.h"
  45 #include "egllog.h"
  46
  47
  48
  49
  50 /**
  51  * Init the given _EGLconfig to default values.
  52  * \param id  the configuration's ID.
  53  *
  54  * Note that id must be positive for the config to be valid.
  55  * It is also recommended that when there are N configs, their
  56  * IDs are from 1 to N respectively.
  57  */
  58 void
  59 _eglInitConfig(_EGLConfig *conf, _EGLDisplay *disp, EGLint id)
  60 {
  61    memset(conf, 0, sizeof(*conf));
  62
  63    conf->Display = disp;
  64
  65    /* some attributes take non-zero default values */
  66    conf->ConfigID = id;
  67    conf->ConfigCaveat = EGL_NONE;
  68    conf->TransparentType = EGL_NONE;
  69    conf->NativeVisualType = EGL_NONE;
  70    conf->ColorBufferType = EGL_RGB_BUFFER;
  71    conf->ComponentType = EGL_COLOR_COMPONENT_TYPE_FIXED_EXT;
  72 }
  73
  74
  75 /**
  76  * Link a config to its display and return the handle of the link.
  77  * The handle can be passed to client directly.
  78  *
  79  * Note that we just save the ptr to the config (we don't copy the config).
  80  */
  81 EGLConfig
  82 _eglLinkConfig(_EGLConfig *conf)
  83 {
  84    _EGLDisplay *disp = conf->Display;
  85
  86    /* sanity check */
  87    assert(disp);
  88    assert(conf->ConfigID > 0);
  89
  90    if (!disp->Configs) {
  91       disp->Configs = _eglCreateArray("Config", 16);
  92       if (!disp->Configs)
  93          return (EGLConfig) NULL;
  94    }
  95
  96    _eglAppendArray(disp->Configs, (void *) conf);
  97
  98    return (EGLConfig) conf;
  99 }
 100
 101
 102 /**
 103  * Lookup a handle to find the linked config.
 104  * Return NULL if the handle has no corresponding linked config.
 105  */
 106 _EGLConfig *
 107 _eglLookupConfig(EGLConfig config, _EGLDisplay *disp)
 108 {
 109    _EGLConfig *conf;
 110
 111    if (!disp)
 112       return NULL;
 113
 114    conf = (_EGLConfig *) _eglFindArray(disp->Configs, (void *) config);
 115    if (conf)
 116       assert(conf->Display == disp);
 117
 118    return conf;
 119 }
 120
 121
 122 enum type {
 123    ATTRIB_TYPE_INTEGER,
 124    ATTRIB_TYPE_BOOLEAN,
 125    ATTRIB_TYPE_BITMASK,
 126    ATTRIB_TYPE_ENUM,
 127    ATTRIB_TYPE_PSEUDO, /* non-queryable */
 128    ATTRIB_TYPE_PLATFORM, /* platform-dependent */
 129 };
 130
 131 enum criterion {
 132    ATTRIB_CRITERION_EXACT,
 133    ATTRIB_CRITERION_ATLEAST,
 134    ATTRIB_CRITERION_MASK,
 135    ATTRIB_CRITERION_SPECIAL,
 136    ATTRIB_CRITERION_IGNORE
 137 };
 138
 139
 140 /* EGL spec Table 3.1 and 3.4 */
 141 static const struct {
 142    EGLint attr;
 143    enum type type;
 144    enum criterion criterion;
 145    EGLint default_value;
 146 } _eglValidationTable[] =
 147 {
 148    /* core */
 149    { EGL_BUFFER_SIZE,               ATTRIB_TYPE_INTEGER,
 150                                     ATTRIB_CRITERION_ATLEAST,
 151                                     0 },
 152    { EGL_RED_SIZE,                  ATTRIB_TYPE_INTEGER,
 153                                     ATTRIB_CRITERION_ATLEAST,
 154                                     0 },
 155    { EGL_GREEN_SIZE,                ATTRIB_TYPE_INTEGER,
 156                                     ATTRIB_CRITERION_ATLEAST,
 157                                     0 },
 158    { EGL_BLUE_SIZE,                 ATTRIB_TYPE_INTEGER,
 159                                     ATTRIB_CRITERION_ATLEAST,
 160                                     0 },
 161    { EGL_LUMINANCE_SIZE,            ATTRIB_TYPE_INTEGER,
 162                                     ATTRIB_CRITERION_ATLEAST,
 163                                     0 },
 164    { EGL_ALPHA_SIZE,                ATTRIB_TYPE_INTEGER,
 165                                     ATTRIB_CRITERION_ATLEAST,
 166                                     0 },
 167    { EGL_ALPHA_MASK_SIZE,           ATTRIB_TYPE_INTEGER,
 168                                     ATTRIB_CRITERION_ATLEAST,
 169                                     0 },
 170    { EGL_BIND_TO_TEXTURE_RGB,       ATTRIB_TYPE_BOOLEAN,
 171                                     ATTRIB_CRITERION_EXACT,
 172                                     EGL_DONT_CARE },
 173    { EGL_BIND_TO_TEXTURE_RGBA,      ATTRIB_TYPE_BOOLEAN,
 174                                     ATTRIB_CRITERION_EXACT,
 175                                     EGL_DONT_CARE },
 176    { EGL_COLOR_BUFFER_TYPE,         ATTRIB_TYPE_ENUM,
 177                                     ATTRIB_CRITERION_EXACT,
 178                                     EGL_RGB_BUFFER },
 179    { EGL_CONFIG_CAVEAT,             ATTRIB_TYPE_ENUM,
 180                                     ATTRIB_CRITERION_EXACT,
 181                                     EGL_DONT_CARE },
 182    { EGL_CONFIG_ID,                 ATTRIB_TYPE_INTEGER,
 183                                     ATTRIB_CRITERION_EXACT,
 184                                     EGL_DONT_CARE },
 185    { EGL_CONFORMANT,                ATTRIB_TYPE_BITMASK,
 186                                     ATTRIB_CRITERION_MASK,
 187                                     0 },
 188    { EGL_DEPTH_SIZE,                ATTRIB_TYPE_INTEGER,
 189                                     ATTRIB_CRITERION_ATLEAST,
 190                                     0 },
 191    { EGL_LEVEL,                     ATTRIB_TYPE_PLATFORM,
 192                                     ATTRIB_CRITERION_EXACT,
 193                                     0 },
 194    { EGL_MAX_PBUFFER_WIDTH,         ATTRIB_TYPE_INTEGER,
 195                                     ATTRIB_CRITERION_IGNORE,
 196                                     0 },
 197    { EGL_MAX_PBUFFER_HEIGHT,        ATTRIB_TYPE_INTEGER,
 198                                     ATTRIB_CRITERION_IGNORE,
 199                                     0 },
 200    { EGL_MAX_PBUFFER_PIXELS,        ATTRIB_TYPE_INTEGER,
 201                                     ATTRIB_CRITERION_IGNORE,
 202                                     0 },
 203    { EGL_MAX_SWAP_INTERVAL,         ATTRIB_TYPE_INTEGER,
 204                                     ATTRIB_CRITERION_EXACT,
 205                                     EGL_DONT_CARE },
 206    { EGL_MIN_SWAP_INTERVAL,         ATTRIB_TYPE_INTEGER,
 207                                     ATTRIB_CRITERION_EXACT,
 208                                     EGL_DONT_CARE },
 209    { EGL_NATIVE_RENDERABLE,         ATTRIB_TYPE_BOOLEAN,
 210                                     ATTRIB_CRITERION_EXACT,
 211                                     EGL_DONT_CARE },
 212    { EGL_NATIVE_VISUAL_ID,          ATTRIB_TYPE_PLATFORM,
 213                                     ATTRIB_CRITERION_IGNORE,
 214                                     0 },
 215    { EGL_NATIVE_VISUAL_TYPE,        ATTRIB_TYPE_PLATFORM,
 216                                     ATTRIB_CRITERION_EXACT,
 217                                     EGL_DONT_CARE },
 218    { EGL_RENDERABLE_TYPE,           ATTRIB_TYPE_BITMASK,
 219                                     ATTRIB_CRITERION_MASK,
 220                                     EGL_OPENGL_ES_BIT },
 221    { EGL_SAMPLE_BUFFERS,            ATTRIB_TYPE_INTEGER,
 222                                     ATTRIB_CRITERION_ATLEAST,
 223                                     0 },
 224    { EGL_SAMPLES,                   ATTRIB_TYPE_INTEGER,
 225                                     ATTRIB_CRITERION_ATLEAST,
 226                                     0 },
 227    { EGL_STENCIL_SIZE,              ATTRIB_TYPE_INTEGER,
 228                                     ATTRIB_CRITERION_ATLEAST,
 229                                     0 },
 230    { EGL_SURFACE_TYPE,              ATTRIB_TYPE_BITMASK,
 231                                     ATTRIB_CRITERION_MASK,
 232                                     EGL_WINDOW_BIT },
 233    { EGL_TRANSPARENT_TYPE,          ATTRIB_TYPE_ENUM,
 234                                     ATTRIB_CRITERION_EXACT,
 235                                     EGL_NONE },
 236    { EGL_TRANSPARENT_RED_VALUE,     ATTRIB_TYPE_INTEGER,
 237                                     ATTRIB_CRITERION_EXACT,
 238                                     EGL_DONT_CARE },
 239    { EGL_TRANSPARENT_GREEN_VALUE,   ATTRIB_TYPE_INTEGER,
 240                                     ATTRIB_CRITERION_EXACT,
 241                                     EGL_DONT_CARE },
 242    { EGL_TRANSPARENT_BLUE_VALUE,    ATTRIB_TYPE_INTEGER,
 243                                     ATTRIB_CRITERION_EXACT,
 244                                     EGL_DONT_CARE },
 245    { EGL_MATCH_NATIVE_PIXMAP,       ATTRIB_TYPE_PSEUDO,
 246                                     ATTRIB_CRITERION_SPECIAL,
 247                                     EGL_NONE },
 248    /* extensions */
 249    { EGL_Y_INVERTED_NOK,            ATTRIB_TYPE_BOOLEAN,
 250                                     ATTRIB_CRITERION_EXACT,
 251                                     EGL_DONT_CARE },
 252    { EGL_FRAMEBUFFER_TARGET_ANDROID, ATTRIB_TYPE_BOOLEAN,
 253                                     ATTRIB_CRITERION_EXACT,
 254                                     EGL_DONT_CARE },
 255    { EGL_RECORDABLE_ANDROID,        ATTRIB_TYPE_BOOLEAN,
 256                                     ATTRIB_CRITERION_EXACT,
 257                                     EGL_DONT_CARE },
 258    { EGL_COLOR_COMPONENT_TYPE_EXT,  ATTRIB_TYPE_ENUM,
 259                                     ATTRIB_CRITERION_EXACT,
 260                                     EGL_COLOR_COMPONENT_TYPE_FIXED_EXT },
 261 };
 262
 263
 264 /**
 265  * Return true if a config is valid.  When for_matching is true,
 266  * EGL_DONT_CARE is accepted as a valid attribute value, and checks
 267  * for conflicting attribute values are skipped.
 268  *
 269  * Note that some attributes are platform-dependent and are not
 270  * checked.
 271  */
 272 EGLBoolean
 273 _eglValidateConfig(const _EGLConfig *conf, EGLBoolean for_matching)
 274 {
 275    _EGLDisplay *disp = conf->Display;
 276    EGLint i, attr, val;
 277    EGLBoolean valid = EGL_TRUE;
 278
 279    /* check attributes by their types */
 280    for (i = 0; i < ARRAY_SIZE(_eglValidationTable); i++) {
 281       EGLint mask;
 282
 283       attr = _eglValidationTable[i].attr;
 284       val = _eglGetConfigKey(conf, attr);
 285
 286       switch (_eglValidationTable[i].type) {
 287       case ATTRIB_TYPE_INTEGER:
 288          switch (attr) {
 289          case EGL_CONFIG_ID:
 290             /* config id must be positive */
 291             if (val <= 0)
 292                valid = EGL_FALSE;
 293             break;
 294          case EGL_SAMPLE_BUFFERS:
 295             /* there can be at most 1 sample buffer */
 296             if (val > 1 || val < 0)
 297                valid = EGL_FALSE;
 298             break;
 299          default:
 300             if (val < 0)
 301                valid = EGL_FALSE;
 302             break;
 303          }
 304          break;
 305       case ATTRIB_TYPE_BOOLEAN:
 306          if (val != EGL_TRUE && val != EGL_FALSE)
 307             valid = EGL_FALSE;
 308          break;
 309       case ATTRIB_TYPE_ENUM:
 310          switch (attr) {
 311          case EGL_CONFIG_CAVEAT:
 312             if (val != EGL_NONE && val != EGL_SLOW_CONFIG &&
 313                 val != EGL_NON_CONFORMANT_CONFIG)
 314                valid = EGL_FALSE;
 315             break;
 316          case EGL_TRANSPARENT_TYPE:
 317             if (val != EGL_NONE && val != EGL_TRANSPARENT_RGB)
 318                valid = EGL_FALSE;
 319             break;
 320          case EGL_COLOR_BUFFER_TYPE:
 321             if (val != EGL_RGB_BUFFER && val != EGL_LUMINANCE_BUFFER)
 322                valid = EGL_FALSE;
 323             break;
 324          case EGL_COLOR_COMPONENT_TYPE_EXT:
 325             if (val != EGL_COLOR_COMPONENT_TYPE_FIXED_EXT &&
 326                 val != EGL_COLOR_COMPONENT_TYPE_FLOAT_EXT)
 327                valid = EGL_FALSE;
 328             break;
 329          default:
 330             unreachable("check _eglValidationTable[]");
 331             break;
 332          }
 333          break;
 334       case ATTRIB_TYPE_BITMASK:
 335          switch (attr) {
 336          case EGL_SURFACE_TYPE:
 337             mask = EGL_PBUFFER_BIT |
 338                    EGL_PIXMAP_BIT |
 339                    EGL_WINDOW_BIT |
 340                    EGL_VG_COLORSPACE_LINEAR_BIT |
 341                    EGL_VG_ALPHA_FORMAT_PRE_BIT |
 342                    EGL_MULTISAMPLE_RESOLVE_BOX_BIT |
 343                    EGL_SWAP_BEHAVIOR_PRESERVED_BIT;
 344             if (disp->Extensions.KHR_mutable_render_buffer)
 345                mask |= EGL_MUTABLE_RENDER_BUFFER_BIT_KHR;
 346             break;
 347          case EGL_RENDERABLE_TYPE:
 348          case EGL_CONFORMANT:
 349             mask = EGL_OPENGL_ES_BIT |
 350                    EGL_OPENVG_BIT |
 351                    EGL_OPENGL_ES2_BIT |
 352                    EGL_OPENGL_ES3_BIT_KHR |
 353                    EGL_OPENGL_BIT;
 354             break;
 355          default:
 356             unreachable("check _eglValidationTable[]");
 357             mask = 0;
 358             break;
 359          }
 360          if (val & ~mask)
 361             valid = EGL_FALSE;
 362          break;
 363       case ATTRIB_TYPE_PLATFORM:
 364          /* unable to check platform-dependent attributes here */
 365          break;
 366       case ATTRIB_TYPE_PSEUDO:
 367          /* pseudo attributes should not be set */
 368          if (val != 0)
 369             valid = EGL_FALSE;
 370          break;
 371       }
 372
 373       if (!valid && for_matching) {
 374          /* accept EGL_DONT_CARE as a valid value */
 375          if (val == EGL_DONT_CARE)
 376             valid = EGL_TRUE;
 377          if (_eglValidationTable[i].criterion == ATTRIB_CRITERION_SPECIAL)
 378             valid = EGL_TRUE;
 379       }
 380       if (!valid) {
 381          _eglLog(_EGL_DEBUG,
 382                "attribute 0x%04x has an invalid value 0x%x", attr, val);
 383          break;
 384       }
 385    }
 386
 387    /* any invalid attribute value should have been catched */
 388    if (!valid || for_matching)
 389       return valid;
 390
 391    /* now check for conflicting attribute values */
 392
 393    switch (conf->ColorBufferType) {
 394    case EGL_RGB_BUFFER:
 395       if (conf->LuminanceSize)
 396          valid = EGL_FALSE;
 397       if (conf->RedSize + conf->GreenSize +
 398             conf->BlueSize + conf->AlphaSize != conf->BufferSize)
 399          valid = EGL_FALSE;
 400       break;
 401    case EGL_LUMINANCE_BUFFER:
 402       if (conf->RedSize || conf->GreenSize || conf->BlueSize)
 403          valid = EGL_FALSE;
 404       if (conf->LuminanceSize + conf->AlphaSize != conf->BufferSize)
 405          valid = EGL_FALSE;
 406       break;
 407    }
 408    if (!valid) {
 409       _eglLog(_EGL_DEBUG, "conflicting color buffer type and channel sizes");
 410       return EGL_FALSE;
 411    }
 412
 413    if (!conf->SampleBuffers && conf->Samples)
 414       valid = EGL_FALSE;
 415    if (!valid) {
 416       _eglLog(_EGL_DEBUG, "conflicting samples and sample buffers");
 417       return EGL_FALSE;
 418    }
 419
 420    if (!(conf->SurfaceType & EGL_WINDOW_BIT)) {
 421       if (conf->NativeVisualID != 0 || conf->NativeVisualType != EGL_NONE)
 422          valid = EGL_FALSE;
 423    }
 424    if (!(conf->SurfaceType & EGL_PBUFFER_BIT)) {
 425       if (conf->BindToTextureRGB || conf->BindToTextureRGBA)
 426          valid = EGL_FALSE;
 427    }
 428    if (!valid) {
 429       _eglLog(_EGL_DEBUG, "conflicting surface type and native visual/texture binding");
 430       return EGL_FALSE;
 431    }
 432
 433    return valid;
 434 }
 435
 436
 437 /**
 438  * Return true if a config matches the criteria.  This and
 439  * _eglParseConfigAttribList together implement the algorithm
 440  * described in "Selection of EGLConfigs".
 441  *
 442  * Note that attributes that are special (currently, only
 443  * EGL_MATCH_NATIVE_PIXMAP) are ignored.
 444  */
 445 EGLBoolean
 446 _eglMatchConfig(const _EGLConfig *conf, const _EGLConfig *criteria)
 447 {
 448    EGLint attr, val, i;
 449    EGLBoolean matched = EGL_TRUE;
 450
 451    for (i = 0; i < ARRAY_SIZE(_eglValidationTable); i++) {
 452       EGLint cmp;
 453       if (_eglValidationTable[i].criterion == ATTRIB_CRITERION_IGNORE)
 454          continue;
 455
 456       attr = _eglValidationTable[i].attr;
 457       cmp = _eglGetConfigKey(criteria, attr);
 458       if (cmp == EGL_DONT_CARE)
 459          continue;
 460
 461       val = _eglGetConfigKey(conf, attr);
 462       switch (_eglValidationTable[i].criterion) {
 463       case ATTRIB_CRITERION_EXACT:
 464          if (val != cmp)
 465             matched = EGL_FALSE;
 466          break;
 467       case ATTRIB_CRITERION_ATLEAST:
 468          if (val < cmp)
 469             matched = EGL_FALSE;
 470          break;
 471       case ATTRIB_CRITERION_MASK:
 472          if ((val & cmp) != cmp)
 473             matched = EGL_FALSE;
 474          break;
 475       case ATTRIB_CRITERION_SPECIAL:
 476          /* ignored here */
 477          break;
 478       case ATTRIB_CRITERION_IGNORE:
 479          unreachable("already handled above");
 480          break;
 481       }
 482
 483       if (!matched) {
 484 #ifndef DEBUG
 485          /* only print the common errors when DEBUG is not defined */
 486          if (attr != EGL_RENDERABLE_TYPE)
 487             break;
 488 #endif
 489          _eglLog(_EGL_DEBUG,
 490                "the value (0x%x) of attribute 0x%04x did not meet the criteria (0x%x)",
 491                val, attr, cmp);
 492          break;
 493       }
 494    }
 495
 496    return matched;
 497 }
 498
 499 static inline EGLBoolean
 500 _eglIsConfigAttribValid(_EGLConfig *conf, EGLint attr)
 501 {
 502    if (_eglOffsetOfConfig(attr) < 0)
 503       return EGL_FALSE;
 504
 505    switch (attr) {
 506    case EGL_Y_INVERTED_NOK:
 507       return conf->Display->Extensions.NOK_texture_from_pixmap;
 508    case EGL_FRAMEBUFFER_TARGET_ANDROID:
 509       return conf->Display->Extensions.ANDROID_framebuffer_target;
 510    case EGL_RECORDABLE_ANDROID:
 511       return conf->Display->Extensions.ANDROID_recordable;
 512    default:
 513       break;
 514    }
 515
 516    return EGL_TRUE;
 517 }
 518
 519 /**
 520  * Initialize a criteria config from the given attribute list.
 521  * Return EGL_FALSE if any of the attribute is invalid.
 522  */
 523 EGLBoolean
 524 _eglParseConfigAttribList(_EGLConfig *conf, _EGLDisplay *disp,
 525                           const EGLint *attrib_list)
 526 {
 527    EGLint attr, val, i;
 528
 529    _eglInitConfig(conf, disp, EGL_DONT_CARE);
 530
 531    /* reset to default values */
 532    for (i = 0; i < ARRAY_SIZE(_eglValidationTable); i++) {
 533       attr = _eglValidationTable[i].attr;
 534       val = _eglValidationTable[i].default_value;
 535       _eglSetConfigKey(conf, attr, val);
 536    }
 537
 538    /* parse the list */
 539    for (i = 0; attrib_list && attrib_list[i] != EGL_NONE; i += 2) {
 540       attr = attrib_list[i];
 541       val = attrib_list[i + 1];
 542
 543       if (!_eglIsConfigAttribValid(conf, attr))
 544          return EGL_FALSE;
 545
 546       _eglSetConfigKey(conf, attr, val);
 547    }
 548
 549    if (!_eglValidateConfig(conf, EGL_TRUE))
 550       return EGL_FALSE;
 551
 552    /* EGL_LEVEL and EGL_MATCH_NATIVE_PIXMAP cannot be EGL_DONT_CARE */
 553    if (conf->Level == EGL_DONT_CARE ||
 554        conf->MatchNativePixmap == EGL_DONT_CARE)
 555       return EGL_FALSE;
 556
 557    /* ignore other attributes when EGL_CONFIG_ID is given */
 558    if (conf->ConfigID != EGL_DONT_CARE) {
 559       for (i = 0; i < ARRAY_SIZE(_eglValidationTable); i++) {
 560          attr = _eglValidationTable[i].attr;
 561          if (attr != EGL_CONFIG_ID)
 562             _eglSetConfigKey(conf, attr, EGL_DONT_CARE);
 563       }
 564    }
 565    else {
 566       if (!(conf->SurfaceType & EGL_WINDOW_BIT))
 567          conf->NativeVisualType = EGL_DONT_CARE;
 568
 569       if (conf->TransparentType == EGL_NONE) {
 570          conf->TransparentRedValue = EGL_DONT_CARE;
 571          conf->TransparentGreenValue = EGL_DONT_CARE;
 572          conf->TransparentBlueValue = EGL_DONT_CARE;
 573       }
 574    }
 575
 576    return EGL_TRUE;
 577 }
 578
 579
 580 /**
 581  * Decide the ordering of conf1 and conf2, under the given criteria.
 582  * When compare_id is true, this implements the algorithm described
 583  * in "Sorting of EGLConfigs".  When compare_id is false,
 584  * EGL_CONFIG_ID is not compared.
 585  *
 586  * It returns a negative integer if conf1 is considered to come
 587  * before conf2;  a positive integer if conf2 is considered to come
 588  * before conf1;  zero if the ordering cannot be decided.
 589  *
 590  * Note that EGL_NATIVE_VISUAL_TYPE is platform-dependent and is
 591  * ignored here.
 592  */
 593 EGLint
 594 _eglCompareConfigs(const _EGLConfig *conf1, const _EGLConfig *conf2,
 595                    const _EGLConfig *criteria, EGLBoolean compare_id)
 596 {
 597    const EGLint compare_attribs[] = {
 598       EGL_BUFFER_SIZE,
 599       EGL_SAMPLE_BUFFERS,
 600       EGL_SAMPLES,
 601       EGL_DEPTH_SIZE,
 602       EGL_STENCIL_SIZE,
 603       EGL_ALPHA_MASK_SIZE,
 604    };
 605    EGLint val1, val2;
 606    EGLint i;
 607
 608    if (conf1 == conf2)
 609       return 0;
 610
 611    /* the enum values have the desired ordering */
 612    STATIC_ASSERT(EGL_NONE < EGL_SLOW_CONFIG);
 613    STATIC_ASSERT(EGL_SLOW_CONFIG < EGL_NON_CONFORMANT_CONFIG);
 614    val1 = conf1->ConfigCaveat - conf2->ConfigCaveat;
 615    if (val1)
 616       return val1;
 617
 618    /* the enum values have the desired ordering */
 619    STATIC_ASSERT(EGL_RGB_BUFFER < EGL_LUMINANCE_BUFFER);
 620    val1 = conf1->ColorBufferType - conf2->ColorBufferType;
 621    if (val1)
 622       return val1;
 623
 624    if (criteria) {
 625       val1 = val2 = 0;
 626       if (conf1->ColorBufferType == EGL_RGB_BUFFER) {
 627          if (criteria->RedSize > 0) {
 628             val1 += conf1->RedSize;
 629             val2 += conf2->RedSize;
 630          }
 631          if (criteria->GreenSize > 0) {
 632             val1 += conf1->GreenSize;
 633             val2 += conf2->GreenSize;
 634          }
 635          if (criteria->BlueSize > 0) {
 636             val1 += conf1->BlueSize;
 637             val2 += conf2->BlueSize;
 638          }
 639       }
 640       else {
 641          if (criteria->LuminanceSize > 0) {
 642             val1 += conf1->LuminanceSize;
 643             val2 += conf2->LuminanceSize;
 644          }
 645       }
 646       if (criteria->AlphaSize > 0) {
 647          val1 += conf1->AlphaSize;
 648          val2 += conf2->AlphaSize;
 649       }
 650    }
 651    else {
 652       /* assume the default criteria, which gives no specific ordering */
 653       val1 = val2 = 0;
 654    }
 655
 656    /* for color bits, larger one is preferred */
 657    if (val1 != val2)
 658       return (val2 - val1);
 659
 660    for (i = 0; i < ARRAY_SIZE(compare_attribs); i++) {
 661       val1 = _eglGetConfigKey(conf1, compare_attribs[i]);
 662       val2 = _eglGetConfigKey(conf2, compare_attribs[i]);
 663       if (val1 != val2)
 664          return (val1 - val2);
 665    }
 666
 667    /* EGL_NATIVE_VISUAL_TYPE cannot be compared here */
 668
 669    return (compare_id) ? (conf1->ConfigID - conf2->ConfigID) : 0;
 670 }
 671
 672
 673 static inline
 674 void _eglSwapConfigs(const _EGLConfig **conf1, const _EGLConfig **conf2)
 675 {
 676    const _EGLConfig *tmp = *conf1;
 677    *conf1 = *conf2;
 678    *conf2 = tmp;
 679 }
 680
 681
 682 /**
 683  * Quick sort an array of configs.  This differs from the standard
 684  * qsort() in that the compare function accepts an additional
 685  * argument.
 686  */
 687 static void
 688 _eglSortConfigs(const _EGLConfig **configs, EGLint count,
 689                 EGLint (*compare)(const _EGLConfig *, const _EGLConfig *,
 690                                   void *),
 691                 void *priv_data)
 692 {
 693    const EGLint pivot = 0;
 694    EGLint i, j;
 695
 696    if (count <= 1)
 697       return;
 698
 699    _eglSwapConfigs(&configs[pivot], &configs[count / 2]);
 700    i = 1;
 701    j = count - 1;
 702    do {
 703       while (i < count && compare(configs[i], configs[pivot], priv_data) < 0)
 704          i++;
 705       while (compare(configs[j], configs[pivot], priv_data) > 0)
 706          j--;
 707       if (i < j) {
 708          _eglSwapConfigs(&configs[i], &configs[j]);
 709          i++;
 710          j--;
 711       }
 712       else if (i == j) {
 713          i++;
 714          j--;
 715          break;
 716       }
 717    } while (i <= j);
 718    _eglSwapConfigs(&configs[pivot], &configs[j]);
 719
 720    _eglSortConfigs(configs, j, compare, priv_data);
 721    _eglSortConfigs(configs + i, count - i, compare, priv_data);
 722 }
 723
 724
 725 /**
 726  * A helper function for implementing eglChooseConfig.  See _eglFilterArray and
 727  * _eglSortConfigs for the meanings of match and compare.
 728  */
 729 EGLBoolean
 730 _eglFilterConfigArray(_EGLArray *array, EGLConfig *configs,
 731                       EGLint config_size, EGLint *num_configs,
 732                       EGLBoolean (*match)(const _EGLConfig *, void *),
 733                       EGLint (*compare)(const _EGLConfig *, const _EGLConfig *,
 734                                         void *),
 735                       void *priv_data)
 736 {
 737    _EGLConfig **configList;
 738    EGLint i, count;
 739
 740    /* get the number of matched configs */
 741    count = _eglFilterArray(array, NULL, 0,
 742          (_EGLArrayForEach) match, priv_data);
 743    if (!count) {
 744       *num_configs = count;
 745       return EGL_TRUE;
 746    }
 747
 748    configList = malloc(sizeof(*configList) * count);
 749    if (!configList)
 750       return _eglError(EGL_BAD_ALLOC, "eglChooseConfig(out of memory)");
 751
 752    /* get the matched configs */
 753    _eglFilterArray(array, (void **) configList, count,
 754          (_EGLArrayForEach) match, priv_data);
 755
 756    /* perform sorting of configs */
 757    if (configs && count) {
 758       _eglSortConfigs((const _EGLConfig **) configList, count,
 759                       compare, priv_data);
 760       count = MIN2(count, config_size);
 761       for (i = 0; i < count; i++)
 762          configs[i] = _eglGetConfigHandle(configList[i]);
 763    }
 764
 765    free(configList);
 766
 767    *num_configs = count;
 768
 769    return EGL_TRUE;
 770 }
 771
 772
 773 static EGLBoolean
 774 _eglFallbackMatch(const _EGLConfig *conf, void *priv_data)
 775 {
 776    return _eglMatchConfig(conf, (const _EGLConfig *) priv_data);
 777 }
 778
 779
 780 static EGLint
 781 _eglFallbackCompare(const _EGLConfig *conf1, const _EGLConfig *conf2,
 782                     void *priv_data)
 783 {
 784    return _eglCompareConfigs(conf1, conf2,
 785          (const _EGLConfig *) priv_data, EGL_TRUE);
 786 }
 787
 788
 789 /**
 790  * Typical fallback routine for eglChooseConfig
 791  */
 792 EGLBoolean
 793 _eglChooseConfig(_EGLDisplay *disp, const EGLint *attrib_list,
 794                  EGLConfig *configs, EGLint config_size, EGLint *num_configs)
 795 {
 796    _EGLConfig criteria;
 797
 798    if (!_eglParseConfigAttribList(&criteria, disp, attrib_list))
 799       return _eglError(EGL_BAD_ATTRIBUTE, "eglChooseConfig");
 800
 801    return _eglFilterConfigArray(disp->Configs,
 802          configs, config_size, num_configs,
 803          _eglFallbackMatch, _eglFallbackCompare,
 804          (void *) &criteria);
 805 }
 806
 807
 808 /**
 809  * Fallback for eglGetConfigAttrib.
 810  */
 811 EGLBoolean
 812 _eglGetConfigAttrib(_EGLDisplay *disp, _EGLConfig *conf,
 813                     EGLint attribute, EGLint *value)
 814 {
 815    if (!_eglIsConfigAttribValid(conf, attribute))
 816       return _eglError(EGL_BAD_ATTRIBUTE, "eglGetConfigAttrib");
 817
 818    /* nonqueryable attributes */
 819    switch (attribute) {
 820    case EGL_MATCH_NATIVE_PIXMAP:
 821       return _eglError(EGL_BAD_ATTRIBUTE, "eglGetConfigAttrib");
 822       break;
 823    default:
 824       break;
 825    }
 826
 827    if (!value)
 828       return _eglError(EGL_BAD_PARAMETER, "eglGetConfigAttrib");
 829
 830    *value = _eglGetConfigKey(conf, attribute);
 831    return EGL_TRUE;
 832 }
 833
 834
 835 static EGLBoolean
 836 _eglFlattenConfig(void *elem, void *buffer)
 837 {
 838    _EGLConfig *conf = (_EGLConfig *) elem;
 839    EGLConfig *handle = (EGLConfig *) buffer;
 840    *handle = _eglGetConfigHandle(conf);
 841    return EGL_TRUE;
 842 }
 843
 844 /**
 845  * Fallback for eglGetConfigs.
 846  */
 847 EGLBoolean
 848 _eglGetConfigs(_EGLDisplay *disp, EGLConfig *configs,
 849                EGLint config_size, EGLint *num_config)
 850 {
 851    *num_config = _eglFlattenArray(disp->Configs, (void *) configs,
 852          sizeof(configs[0]), config_size, _eglFlattenConfig);
 853
 854    return EGL_TRUE;
 855 }