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