workbench/libs/mesa/src/egl/main/eglconfig.c

   1 /**************************************************************************
   2  *
   3  * Copyright 2008 Tungsten Graphics, Inc., Cedar Park, Texas.
   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 "eglconfig.h"
  40 #include "egldisplay.h"
  41 #include "eglcurrent.h"
  42 #include "egllog.h"
  43
  44
  45 #define MIN2(A, B)  (((A) < (B)) ? (A) : (B))
  46
  47
  48 /**
  49  * Init the given _EGLconfig to default values.
  50  * \param id  the configuration's ID.
  51  *
  52  * Note that id must be positive for the config to be valid.
  53  * It is also recommended that when there are N configs, their
  54  * IDs are from 1 to N respectively.
  55  */
  56 void
  57 _eglInitConfig(_EGLConfig *conf, _EGLDisplay *dpy, EGLint id)
  58 {
  59    memset(conf, 0, sizeof(*conf));
  60
  61    conf->Display = dpy;
  62
  63    /* some attributes take non-zero default values */
  64    conf->ConfigID = id;
  65    conf->ConfigCaveat = EGL_NONE;
  66    conf->TransparentType = EGL_NONE;
  67    conf->NativeVisualType = EGL_NONE;
  68    conf->ColorBufferType = EGL_RGB_BUFFER;
  69 }
  70
  71
  72 /**
  73  * Link a config to its display and return the handle of the link.
  74  * The handle can be passed to client directly.
  75  *
  76  * Note that we just save the ptr to the config (we don't copy the config).
  77  */
  78 PUBLIC EGLConfig
  79 _eglLinkConfig(_EGLConfig *conf)
  80 {
  81    _EGLDisplay *dpy = conf->Display;
  82
  83    /* sanity check */
  84    assert(dpy && conf->ConfigID > 0);
  85
  86    if (!dpy->Configs) {
  87       dpy->Configs = _eglCreateArray("Config", 16);
  88       if (!dpy->Configs)
  89          return (EGLConfig) NULL;
  90    }
  91
  92    _eglAppendArray(dpy->Configs, (void *) conf);
  93
  94    return (EGLConfig) conf;
  95 }
  96
  97
  98 /**
  99  * Lookup a handle to find the linked config.
 100  * Return NULL if the handle has no corresponding linked config.
 101  */
 102 _EGLConfig *
 103 _eglLookupConfig(EGLConfig config, _EGLDisplay *dpy)
 104 {
 105    _EGLConfig *conf;
 106
 107    if (!dpy)
 108       return NULL;
 109
 110    conf = (_EGLConfig *) _eglFindArray(dpy->Configs, (void *) config);
 111    if (conf)
 112       assert(conf->Display == dpy);
 113
 114    return conf;
 115 }
 116
 117
 118 enum {
 119    /* types */
 120    ATTRIB_TYPE_INTEGER,
 121    ATTRIB_TYPE_BOOLEAN,
 122    ATTRIB_TYPE_BITMASK,
 123    ATTRIB_TYPE_ENUM,
 124    ATTRIB_TYPE_PSEUDO, /* non-queryable */
 125    ATTRIB_TYPE_PLATFORM, /* platform-dependent */
 126    /* criteria */
 127    ATTRIB_CRITERION_EXACT,
 128    ATTRIB_CRITERION_ATLEAST,
 129    ATTRIB_CRITERION_MASK,
 130    ATTRIB_CRITERION_SPECIAL,
 131    ATTRIB_CRITERION_IGNORE
 132 };
 133
 134
 135 /* EGL spec Table 3.1 and 3.4 */
 136 static const struct {
 137    EGLint attr;
 138    EGLint type;
 139    EGLint criterion;
 140    EGLint default_value;
 141 } _eglValidationTable[] =
 142 {
 143    /* core */
 144    { EGL_BUFFER_SIZE,               ATTRIB_TYPE_INTEGER,
 145                                     ATTRIB_CRITERION_ATLEAST,
 146                                     0 },
 147    { EGL_RED_SIZE,                  ATTRIB_TYPE_INTEGER,
 148                                     ATTRIB_CRITERION_ATLEAST,
 149                                     0 },
 150    { EGL_GREEN_SIZE,                ATTRIB_TYPE_INTEGER,
 151                                     ATTRIB_CRITERION_ATLEAST,
 152                                     0 },
 153    { EGL_BLUE_SIZE,                 ATTRIB_TYPE_INTEGER,
 154                                     ATTRIB_CRITERION_ATLEAST,
 155                                     0 },
 156    { EGL_LUMINANCE_SIZE,            ATTRIB_TYPE_INTEGER,
 157                                     ATTRIB_CRITERION_ATLEAST,
 158                                     0 },
 159    { EGL_ALPHA_SIZE,                ATTRIB_TYPE_INTEGER,
 160                                     ATTRIB_CRITERION_ATLEAST,
 161                                     0 },
 162    { EGL_ALPHA_MASK_SIZE,           ATTRIB_TYPE_INTEGER,
 163                                     ATTRIB_CRITERION_ATLEAST,
 164                                     0 },
 165    { EGL_BIND_TO_TEXTURE_RGB,       ATTRIB_TYPE_BOOLEAN,
 166                                     ATTRIB_CRITERION_EXACT,
 167                                     EGL_DONT_CARE },
 168    { EGL_BIND_TO_TEXTURE_RGBA,      ATTRIB_TYPE_BOOLEAN,
 169                                     ATTRIB_CRITERION_EXACT,
 170                                     EGL_DONT_CARE },
 171    { EGL_COLOR_BUFFER_TYPE,         ATTRIB_TYPE_ENUM,
 172                                     ATTRIB_CRITERION_EXACT,
 173                                     EGL_RGB_BUFFER },
 174    { EGL_CONFIG_CAVEAT,             ATTRIB_TYPE_ENUM,
 175                                     ATTRIB_CRITERION_EXACT,
 176                                     EGL_DONT_CARE },
 177    { EGL_CONFIG_ID,                 ATTRIB_TYPE_INTEGER,
 178                                     ATTRIB_CRITERION_EXACT,
 179                                     EGL_DONT_CARE },
 180    { EGL_CONFORMANT,                ATTRIB_TYPE_BITMASK,
 181                                     ATTRIB_CRITERION_MASK,
 182                                     0 },
 183    { EGL_DEPTH_SIZE,                ATTRIB_TYPE_INTEGER,
 184                                     ATTRIB_CRITERION_ATLEAST,
 185                                     0 },
 186    { EGL_LEVEL,                     ATTRIB_TYPE_PLATFORM,
 187                                     ATTRIB_CRITERION_EXACT,
 188                                     0 },
 189    { EGL_MAX_PBUFFER_WIDTH,         ATTRIB_TYPE_INTEGER,
 190                                     ATTRIB_CRITERION_IGNORE,
 191                                     0 },
 192    { EGL_MAX_PBUFFER_HEIGHT,        ATTRIB_TYPE_INTEGER,
 193                                     ATTRIB_CRITERION_IGNORE,
 194                                     0 },
 195    { EGL_MAX_PBUFFER_PIXELS,        ATTRIB_TYPE_INTEGER,
 196                                     ATTRIB_CRITERION_IGNORE,
 197                                     0 },
 198    { EGL_MAX_SWAP_INTERVAL,         ATTRIB_TYPE_INTEGER,
 199                                     ATTRIB_CRITERION_EXACT,
 200                                     EGL_DONT_CARE },
 201    { EGL_MIN_SWAP_INTERVAL,         ATTRIB_TYPE_INTEGER,
 202                                     ATTRIB_CRITERION_EXACT,
 203                                     EGL_DONT_CARE },
 204    { EGL_NATIVE_RENDERABLE,         ATTRIB_TYPE_BOOLEAN,
 205                                     ATTRIB_CRITERION_EXACT,
 206                                     EGL_DONT_CARE },
 207    { EGL_NATIVE_VISUAL_ID,          ATTRIB_TYPE_PLATFORM,
 208                                     ATTRIB_CRITERION_IGNORE,
 209                                     0 },
 210    { EGL_NATIVE_VISUAL_TYPE,        ATTRIB_TYPE_PLATFORM,
 211                                     ATTRIB_CRITERION_EXACT,
 212                                     EGL_DONT_CARE },
 213    { EGL_RENDERABLE_TYPE,           ATTRIB_TYPE_BITMASK,
 214                                     ATTRIB_CRITERION_MASK,
 215                                     EGL_OPENGL_ES_BIT },
 216    { EGL_SAMPLE_BUFFERS,            ATTRIB_TYPE_INTEGER,
 217                                     ATTRIB_CRITERION_ATLEAST,
 218                                     0 },
 219    { EGL_SAMPLES,                   ATTRIB_TYPE_INTEGER,
 220                                     ATTRIB_CRITERION_ATLEAST,
 221                                     0 },
 222    { EGL_STENCIL_SIZE,              ATTRIB_TYPE_INTEGER,
 223                                     ATTRIB_CRITERION_ATLEAST,
 224                                     0 },
 225    { EGL_SURFACE_TYPE,              ATTRIB_TYPE_BITMASK,
 226                                     ATTRIB_CRITERION_MASK,
 227                                     EGL_WINDOW_BIT },
 228    { EGL_TRANSPARENT_TYPE,          ATTRIB_TYPE_ENUM,
 229                                     ATTRIB_CRITERION_EXACT,
 230                                     EGL_NONE },
 231    { EGL_TRANSPARENT_RED_VALUE,     ATTRIB_TYPE_INTEGER,
 232                                     ATTRIB_CRITERION_EXACT,
 233                                     EGL_DONT_CARE },
 234    { EGL_TRANSPARENT_GREEN_VALUE,   ATTRIB_TYPE_INTEGER,
 235                                     ATTRIB_CRITERION_EXACT,
 236                                     EGL_DONT_CARE },
 237    { EGL_TRANSPARENT_BLUE_VALUE,    ATTRIB_TYPE_INTEGER,
 238                                     ATTRIB_CRITERION_EXACT,
 239                                     EGL_DONT_CARE },
 240    { EGL_MATCH_NATIVE_PIXMAP,       ATTRIB_TYPE_PSEUDO,
 241                                     ATTRIB_CRITERION_SPECIAL,
 242                                     EGL_NONE },
 243    /* extensions */
 244    { EGL_Y_INVERTED_NOK,            ATTRIB_TYPE_BOOLEAN,
 245                                     ATTRIB_CRITERION_EXACT,
 246                                     EGL_DONT_CARE }
 247 };
 248
 249
 250 /**
 251  * Return true if a config is valid.  When for_matching is true,
 252  * EGL_DONT_CARE is accepted as a valid attribute value, and checks
 253  * for conflicting attribute values are skipped.
 254  *
 255  * Note that some attributes are platform-dependent and are not
 256  * checked.
 257  */
 258 EGLBoolean
 259 _eglValidateConfig(const _EGLConfig *conf, EGLBoolean for_matching)
 260 {
 261    EGLint i, attr, val;
 262    EGLBoolean valid = EGL_TRUE;
 263
 264    /* check attributes by their types */
 265    for (i = 0; i < ARRAY_SIZE(_eglValidationTable); i++) {
 266       EGLint mask = 0;
 267
 268       attr = _eglValidationTable[i].attr;
 269       val = _eglGetConfigKey(conf, attr);
 270
 271       switch (_eglValidationTable[i].type) {
 272       case ATTRIB_TYPE_INTEGER:
 273          switch (attr) {
 274          case EGL_CONFIG_ID:
 275             /* config id must be positive */
 276             if (val <= 0)
 277                valid = EGL_FALSE;
 278             break;
 279          case EGL_SAMPLE_BUFFERS:
 280             /* there can be at most 1 sample buffer */
 281             if (val > 1 || val < 0)
 282                valid = EGL_FALSE;
 283             break;
 284          default:
 285             if (val < 0)
 286                valid = EGL_FALSE;
 287             break;
 288          }
 289          break;
 290       case ATTRIB_TYPE_BOOLEAN:
 291          if (val != EGL_TRUE && val != EGL_FALSE)
 292             valid = EGL_FALSE;
 293          break;
 294       case ATTRIB_TYPE_ENUM:
 295          switch (attr) {
 296          case EGL_CONFIG_CAVEAT:
 297             if (val != EGL_NONE && val != EGL_SLOW_CONFIG &&
 298                 val != EGL_NON_CONFORMANT_CONFIG)
 299                valid = EGL_FALSE;
 300             break;
 301          case EGL_TRANSPARENT_TYPE:
 302             if (val != EGL_NONE && val != EGL_TRANSPARENT_RGB)
 303                valid = EGL_FALSE;
 304             break;
 305          case EGL_COLOR_BUFFER_TYPE:
 306             if (val != EGL_RGB_BUFFER && val != EGL_LUMINANCE_BUFFER)
 307                valid = EGL_FALSE;
 308             break;
 309          default:
 310             assert(0);
 311             break;
 312          }
 313          break;
 314       case ATTRIB_TYPE_BITMASK:
 315          switch (attr) {
 316          case EGL_SURFACE_TYPE:
 317             mask = EGL_PBUFFER_BIT |
 318                    EGL_PIXMAP_BIT |
 319                    EGL_WINDOW_BIT |
 320                    EGL_VG_COLORSPACE_LINEAR_BIT |
 321                    EGL_VG_ALPHA_FORMAT_PRE_BIT |
 322                    EGL_MULTISAMPLE_RESOLVE_BOX_BIT |
 323                    EGL_SWAP_BEHAVIOR_PRESERVED_BIT;
 324 #ifdef EGL_MESA_screen_surface
 325             if (conf->Display->Extensions.MESA_screen_surface)
 326                mask |= EGL_SCREEN_BIT_MESA;
 327 #endif
 328             break;
 329          case EGL_RENDERABLE_TYPE:
 330          case EGL_CONFORMANT:
 331             mask = EGL_OPENGL_ES_BIT |
 332                    EGL_OPENVG_BIT |
 333                    EGL_OPENGL_ES2_BIT |
 334                    EGL_OPENGL_BIT;
 335             break;
 336          default:
 337             assert(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    /* the spec says that EGL_LEVEL cannot be EGL_DONT_CARE */
 532    if (conf->Level == EGL_DONT_CARE)
 533       return EGL_FALSE;
 534
 535    /* ignore other attributes when EGL_CONFIG_ID is given */
 536    if (conf->ConfigID != EGL_DONT_CARE) {
 537       for (i = 0; i < ARRAY_SIZE(_eglValidationTable); i++) {
 538          attr = _eglValidationTable[i].attr;
 539          if (attr != EGL_CONFIG_ID)
 540             _eglSetConfigKey(conf, attr, EGL_DONT_CARE);
 541       }
 542    }
 543    else {
 544       if (!(conf->SurfaceType & EGL_WINDOW_BIT))
 545          conf->NativeVisualType = EGL_DONT_CARE;
 546
 547       if (conf->TransparentType == EGL_NONE) {
 548          conf->TransparentRedValue = EGL_DONT_CARE;
 549          conf->TransparentGreenValue = EGL_DONT_CARE;
 550          conf->TransparentBlueValue = EGL_DONT_CARE;
 551       }
 552    }
 553
 554    return EGL_TRUE;
 555 }
 556
 557
 558 /**
 559  * Decide the ordering of conf1 and conf2, under the given criteria.
 560  * When compare_id is true, this implements the algorithm described
 561  * in "Sorting of EGLConfigs".  When compare_id is false,
 562  * EGL_CONFIG_ID is not compared.
 563  *
 564  * It returns a negative integer if conf1 is considered to come
 565  * before conf2;  a positive integer if conf2 is considered to come
 566  * before conf1;  zero if the ordering cannot be decided.
 567  *
 568  * Note that EGL_NATIVE_VISUAL_TYPE is platform-dependent and is
 569  * ignored here.
 570  */
 571 EGLint
 572 _eglCompareConfigs(const _EGLConfig *conf1, const _EGLConfig *conf2,
 573                    const _EGLConfig *criteria, EGLBoolean compare_id)
 574 {
 575    const EGLint compare_attribs[] = {
 576       EGL_BUFFER_SIZE,
 577       EGL_SAMPLE_BUFFERS,
 578       EGL_SAMPLES,
 579       EGL_DEPTH_SIZE,
 580       EGL_STENCIL_SIZE,
 581       EGL_ALPHA_MASK_SIZE,
 582    };
 583    EGLint val1, val2;
 584    EGLint i;
 585
 586    if (conf1 == conf2)
 587       return 0;
 588
 589    /* the enum values have the desired ordering */
 590    assert(EGL_NONE < EGL_SLOW_CONFIG);
 591    assert(EGL_SLOW_CONFIG < EGL_NON_CONFORMANT_CONFIG);
 592    val1 = conf1->ConfigCaveat - conf2->ConfigCaveat;
 593    if (val1)
 594       return val1;
 595
 596    /* the enum values have the desired ordering */
 597    assert(EGL_RGB_BUFFER < EGL_LUMINANCE_BUFFER);
 598    val1 = conf1->ColorBufferType - conf2->ColorBufferType;
 599    if (val1)
 600       return val1;
 601
 602    if (criteria) {
 603       val1 = val2 = 0;
 604       if (conf1->ColorBufferType == EGL_RGB_BUFFER) {
 605          if (criteria->RedSize > 0) {
 606             val1 += conf1->RedSize;
 607             val2 += conf2->RedSize;
 608          }
 609          if (criteria->GreenSize > 0) {
 610             val1 += conf1->GreenSize;
 611             val2 += conf2->GreenSize;
 612          }
 613          if (criteria->BlueSize > 0) {
 614             val1 += conf1->BlueSize;
 615             val2 += conf2->BlueSize;
 616          }
 617       }
 618       else {
 619          if (criteria->LuminanceSize > 0) {
 620             val1 += conf1->LuminanceSize;
 621             val2 += conf2->LuminanceSize;
 622          }
 623       }
 624       if (criteria->AlphaSize > 0) {
 625          val1 += conf1->AlphaSize;
 626          val2 += conf2->AlphaSize;
 627       }
 628    }
 629    else {
 630       /* assume the default criteria, which gives no specific ordering */
 631       val1 = val2 = 0;
 632    }
 633
 634    /* for color bits, larger one is preferred */
 635    if (val1 != val2)
 636       return (val2 - val1);
 637
 638    for (i = 0; i < ARRAY_SIZE(compare_attribs); i++) {
 639       val1 = _eglGetConfigKey(conf1, compare_attribs[i]);
 640       val2 = _eglGetConfigKey(conf2, compare_attribs[i]);
 641       if (val1 != val2)
 642          return (val1 - val2);
 643    }
 644
 645    /* EGL_NATIVE_VISUAL_TYPE cannot be compared here */
 646
 647    return (compare_id) ? (conf1->ConfigID - conf2->ConfigID) : 0;
 648 }
 649
 650
 651 static INLINE
 652 void _eglSwapConfigs(const _EGLConfig **conf1, const _EGLConfig **conf2)
 653 {
 654    const _EGLConfig *tmp = *conf1;
 655    *conf1 = *conf2;
 656    *conf2 = tmp;
 657 }
 658
 659
 660 /**
 661  * Quick sort an array of configs.  This differs from the standard
 662  * qsort() in that the compare function accepts an additional
 663  * argument.
 664  */
 665 void
 666 _eglSortConfigs(const _EGLConfig **configs, EGLint count,
 667                 EGLint (*compare)(const _EGLConfig *, const _EGLConfig *,
 668                                   void *),
 669                 void *priv_data)
 670 {
 671    const EGLint pivot = 0;
 672    EGLint i, j;
 673
 674    if (count <= 1)
 675       return;
 676
 677    _eglSwapConfigs(&configs[pivot], &configs[count / 2]);
 678    i = 1;
 679    j = count - 1;
 680    do {
 681       while (i < count && compare(configs[i], configs[pivot], priv_data) < 0)
 682          i++;
 683       while (compare(configs[j], configs[pivot], priv_data) > 0)
 684          j--;
 685       if (i < j) {
 686          _eglSwapConfigs(&configs[i], &configs[j]);
 687          i++;
 688          j--;
 689       }
 690       else if (i == j) {
 691          i++;
 692          j--;
 693          break;
 694       }
 695    } while (i <= j);
 696    _eglSwapConfigs(&configs[pivot], &configs[j]);
 697
 698    _eglSortConfigs(configs, j, compare, priv_data);
 699    _eglSortConfigs(configs + i, count - i, compare, priv_data);
 700 }
 701
 702
 703 static EGLint
 704 _eglFallbackCompare(const _EGLConfig *conf1, const _EGLConfig *conf2,
 705                    void *priv_data)
 706 {
 707    const _EGLConfig *criteria = (const _EGLConfig *) priv_data;
 708    return _eglCompareConfigs(conf1, conf2, criteria, EGL_TRUE);
 709 }
 710
 711
 712 /**
 713  * Typical fallback routine for eglChooseConfig
 714  */
 715 EGLBoolean
 716 _eglChooseConfig(_EGLDriver *drv, _EGLDisplay *disp, const EGLint *attrib_list,
 717                  EGLConfig *configs, EGLint config_size, EGLint *num_configs)
 718 {
 719    _EGLConfig **configList, criteria;
 720    EGLint i, count;
 721
 722    if (!num_configs)
 723       return _eglError(EGL_BAD_PARAMETER, "eglChooseConfigs");
 724
 725    if (!_eglParseConfigAttribList(&criteria, disp, attrib_list))
 726       return _eglError(EGL_BAD_ATTRIBUTE, "eglChooseConfig");
 727
 728    /* get the number of matched configs */
 729    count = _eglFilterArray(disp->Configs, NULL, 0,
 730          (_EGLArrayForEach) _eglMatchConfig, (void *) &criteria);
 731    if (!count) {
 732       *num_configs = count;
 733       return EGL_TRUE;
 734    }
 735
 736    configList = malloc(sizeof(*configList) * count);
 737    if (!configList)
 738       return _eglError(EGL_BAD_ALLOC, "eglChooseConfig(out of memory)");
 739
 740    /* get the matched configs */
 741    _eglFilterArray(disp->Configs, (void **) configList, count,
 742          (_EGLArrayForEach) _eglMatchConfig, (void *) &criteria);
 743
 744    /* perform sorting of configs */
 745    if (configs && count) {
 746       _eglSortConfigs((const _EGLConfig **) configList, count,
 747                       _eglFallbackCompare, (void *) &criteria);
 748       count = MIN2(count, config_size);
 749       for (i = 0; i < count; i++)
 750          configs[i] = _eglGetConfigHandle(configList[i]);
 751    }
 752
 753    free(configList);
 754
 755    *num_configs = count;
 756
 757    return EGL_TRUE;
 758 }
 759
 760
 761 /**
 762  * Fallback for eglGetConfigAttrib.
 763  */
 764 EGLBoolean
 765 _eglGetConfigAttrib(_EGLDriver *drv, _EGLDisplay *dpy, _EGLConfig *conf,
 766                     EGLint attribute, EGLint *value)
 767 {
 768    if (!_eglIsConfigAttribValid(conf, attribute))
 769       return _eglError(EGL_BAD_ATTRIBUTE, "eglGetConfigAttrib");
 770
 771    /* nonqueryable attributes */
 772    switch (attribute) {
 773    case EGL_MATCH_NATIVE_PIXMAP:
 774       return _eglError(EGL_BAD_ATTRIBUTE, "eglGetConfigAttrib");
 775       break;
 776    default:
 777       break;
 778    }
 779
 780    if (!value)
 781       return _eglError(EGL_BAD_PARAMETER, "eglGetConfigAttrib");
 782
 783    *value = _eglGetConfigKey(conf, attribute);
 784    return EGL_TRUE;
 785 }
 786
 787
 788 static EGLBoolean
 789 _eglFlattenConfig(void *elem, void *buffer)
 790 {
 791    _EGLConfig *conf = (_EGLConfig *) elem;
 792    EGLConfig *handle = (EGLConfig *) buffer;
 793    *handle = _eglGetConfigHandle(conf);
 794    return EGL_TRUE;
 795 }
 796
 797 /**
 798  * Fallback for eglGetConfigs.
 799  */
 800 EGLBoolean
 801 _eglGetConfigs(_EGLDriver *drv, _EGLDisplay *disp, EGLConfig *configs,
 802                EGLint config_size, EGLint *num_config)
 803 {
 804    if (!num_config)
 805       return _eglError(EGL_BAD_PARAMETER, "eglGetConfigs");
 806
 807    *num_config = _eglFlattenArray(disp->Configs, (void *) configs,
 808          sizeof(configs[0]), config_size, _eglFlattenConfig);
 809
 810    return EGL_TRUE;
 811 }