examples/gl_basic.c

   1 // Copyright 2012 - 2014 Intel Corporation
   2 //
   3 // All rights reserved.
   4 //
   5 // Redistribution and use in source and binary forms, with or without
   6 // modification, are permitted provided that the following conditions are met:
   7 //
   8 // - Redistributions of source code must retain the above copyright notice, this
   9 //   list of conditions and the following disclaimer.
  10 //
  11 // - Redistributions in binary form must reproduce the above copyright notice,
  12 //   this list of conditions and the following disclaimer in the documentation
  13 //   and/or other materials provided with the distribution.
  14 //
  15 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  16 // AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  17 // IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  18 // DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
  19 // FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  20 // DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
  21 // SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
  22 // CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  23 // OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  24 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  25
  26 /// @file
  27 /// @brief Do some basic OpenGL rendering using Waffle.
  28 ///
  29 /// This example does the following:
  30 ///     1. Dynamically choose the platform and OpenGL API according to
  31 ///        command line arguments.
  32 ///     2. Create a window and OpenGL context.
  33 ///     3. Fill the window with red, then green, then blue, sleeping between
  34 ///        each buffer swap.
  35
  36 #define _POSIX_C_SOURCE 199309L // glibc feature macro for nanosleep.
  37 #define WAFFLE_API_VERSION 0x0108
  38 #define WAFFLE_API_EXPERIMENTAL
  39
  40 #include <assert.h>
  41 #include <getopt.h>
  42 #include <stdarg.h>
  43 #include <stdbool.h>
  44 #include <stdio.h>
  45 #include <stdlib.h>
  46 #include <string.h>
  47 #if !defined(_WIN32)
  48 #include <time.h>
  49 #else
  50 #include <windows.h>
  51 #endif
  52
  53 #ifdef __APPLE__
  54 #    import <Foundation/NSAutoreleasePool.h>
  55 #    import <AppKit/NSApplication.h>
  56
  57 static void
  58 removeXcodeArgs(int *argc, char **argv);
  59 #endif
  60
  61 #include "waffle.h"
  62
  63 static const char *usage_message =
  64     "usage:\n"
  65     "    gl_basic --platform=android|cgl|gbm|glx|wayland|wgl|surfaceless_egl|x11_egl\n"
  66     "             --api=gl|gles1|gles2|gles3\n"
  67     "             [--version=MAJOR.MINOR]\n"
  68     "             [--profile=core|compat|none]\n"
  69     "             [--forward-compatible]\n"
  70     "             [--debug]\n"
  71     "             [--robust]\n"
  72     "             [--resize-window]\n"
  73     "             [--window-size=WIDTHxHEIGHT | --fullscreen]\n"
  74     "\n"
  75     "examples:\n"
  76     "    gl_basic --platform=glx --api=gl\n"
  77     "    gl_basic --platform=x11_egl --api=gl --version=3.2 --profile=core\n"
  78     "    gl_basic --platform=wayland --api=gles3\n"
  79     "\n"
  80     "description:\n"
  81     "    Create a window. Fill it with red, green, then blue.\n"
  82     "\n"
  83     "options:\n"
  84     "    --forward-compatible\n"
  85     "        Create a forward-compatible context.\n"
  86     "\n"
  87     "    --debug\n"
  88     "        Create a debug context.\n"
  89     "\n"
  90     "    --robust\n"
  91     "        Create a robust context.\n"
  92     "\n"
  93     "    --resize-window\n"
  94     "        Resize the window between each draw call.\n"
  95     "\n"
  96     "    --fullscreen\n"
  97     "        Create a fullscreen window.\n"
  98     ;
  99
 100 enum {
 101     OPT_PLATFORM = 1,
 102     OPT_API,
 103     OPT_VERSION,
 104     OPT_PROFILE,
 105     OPT_DEBUG,
 106     OPT_FORWARD_COMPATIBLE,
 107     OPT_ROBUST,
 108     OPT_RESIZE_WINDOW,
 109     OPT_WINDOW_SIZE,
 110     OPT_FULLSCREEN,
 111 };
 112
 113 static const struct option get_opts[] = {
 114     { .name = "platform",       .has_arg = required_argument,     .val = OPT_PLATFORM },
 115     { .name = "api",            .has_arg = required_argument,     .val = OPT_API },
 116     { .name = "version",        .has_arg = required_argument,     .val = OPT_VERSION },
 117     { .name = "profile",        .has_arg = required_argument,     .val = OPT_PROFILE },
 118     { .name = "debug",          .has_arg = no_argument,           .val = OPT_DEBUG },
 119     { .name = "forward-compatible", .has_arg = no_argument,       .val = OPT_FORWARD_COMPATIBLE },
 120     { .name = "robust",         .has_arg = no_argument,           .val = OPT_ROBUST },
 121     { .name = "resize-window",  .has_arg = no_argument,           .val = OPT_RESIZE_WINDOW },
 122     { .name = "window-size",    .has_arg = required_argument,     .val = OPT_WINDOW_SIZE },
 123     { .name = "fullscreen",     .has_arg = no_argument,           .val = OPT_FULLSCREEN },
 124     { 0 },
 125 };
 126
 127 #if defined(__GNUC__)
 128 #define NORETURN __attribute__((noreturn))
 129 #elif defined(_MSC_VER)
 130 #define NORETURN __declspec(noreturn)
 131 #else
 132 #define NORETURN
 133 #endif
 134
 135 #if defined(__GNUC__)
 136 #define PRINTFLIKE(f, a) __attribute__((__format__(__printf__, f, a)))
 137 #else
 138 #define PRINTFLIKE(f, a)
 139 #endif
 140
 141 static void NORETURN PRINTFLIKE(1, 2) error_printf(const char *fmt, ...)
 142 {
 143     va_list ap;
 144
 145     fflush(stdout);
 146
 147     va_start(ap, fmt);
 148     fprintf(stderr, "gl_basic: error: ");
 149     vfprintf(stderr, fmt, ap);
 150     fprintf(stderr, "\n");
 151     va_end(ap);
 152
 153     exit(EXIT_FAILURE);
 154 }
 155
 156 static void NORETURN PRINTFLIKE(1, 2) usage_error_printf(const char *fmt, ...)
 157 {
 158     fflush(stdout);
 159     fprintf(stderr, "gl_basic: usage error");
 160
 161     if (fmt) {
 162         va_list ap;
 163         va_start(ap, fmt);
 164         fprintf(stderr, ": ");
 165         vfprintf(stderr, fmt, ap);
 166         va_end(ap);
 167     }
 168
 169     fprintf(stderr, "\n");
 170     fprintf(stderr, "\n");
 171     fprintf(stderr, "%s", usage_message);
 172
 173     exit(EXIT_FAILURE);
 174 }
 175
 176 static void
 177 error_waffle(void)
 178 {
 179     const struct waffle_error_info *info = waffle_error_get_info();
 180     const char *code = waffle_error_to_string(info->code);
 181
 182     if (info->message_length > 0)
 183         error_printf("%s: %s", code, info->message);
 184     else
 185         error_printf("%s", code);
 186 }
 187
 188 static void
 189 error_get_gl_symbol(const char *name)
 190 {
 191     error_printf("failed to get function pointer for %s", name);
 192 }
 193
 194 typedef float GLclampf;
 195 typedef unsigned int GLbitfield;
 196 typedef unsigned int GLint;
 197 typedef int GLsizei;
 198 typedef unsigned int GLenum;
 199 typedef void GLvoid;
 200
 201 enum {
 202     // Copied from <GL/gl*.h>.
 203     GL_UNSIGNED_BYTE =    0x00001401,
 204     GL_RGBA =             0x00001908,
 205     GL_COLOR_BUFFER_BIT = 0x00004000,
 206
 207     GL_CONTEXT_FLAGS = 0x821e,
 208     GL_CONTEXT_FLAG_FORWARD_COMPATIBLE_BIT = 0x00000001,
 209     GL_CONTEXT_FLAG_DEBUG_BIT              = 0x00000002,
 210     GL_CONTEXT_FLAG_ROBUST_ACCESS_BIT      = 0x00000004 ,
 211 };
 212
 213 static int window_width = 320;
 214 static int window_height = 240;
 215
 216 #ifndef _WIN32
 217 #define APIENTRY
 218 #else
 219 #ifndef APIENTRY
 220 #define APIENTRY __stdcall
 221 #endif
 222 #endif
 223
 224 static void (APIENTRY *glClearColor)(GLclampf red, GLclampf green, GLclampf blue, GLclampf alpha);
 225 static void (APIENTRY *glClear)(GLbitfield mask);
 226 static GLenum (APIENTRY *glGetError)(void);
 227 static void (APIENTRY *glGetIntegerv)(GLenum pname, GLint *params);
 228 static void (APIENTRY *glReadPixels)(GLint x, GLint y, GLsizei width, GLsizei height,
 229                                      GLenum format, GLenum type, GLvoid* data);
 230 static void (APIENTRY *glViewport)(GLint x, GLint y, GLsizei width, GLsizei height);
 231
 232 /// @brief Command line options.
 233 struct options {
 234     /// @brief One of `WAFFLE_PLATFORM_*`.
 235     int platform;
 236
 237     /// @brief One of `WAFFLE_CONTEXT_OPENGL_*`.
 238     int context_api;
 239
 240     /// @brief One of `WAFFLE_CONTEXT_PROFILE_*` or `WAFFLE_NONE`.
 241     int context_profile;
 242
 243     int context_version;
 244
 245     bool context_forward_compatible;
 246     bool context_debug;
 247     bool context_robust;
 248
 249     bool resize_window;
 250
 251     bool fullscreen;
 252
 253     /// @brief One of `WAFFLE_DL_*`.
 254     int dl;
 255 };
 256
 257 struct enum_map {
 258     int i;
 259     const char *s;
 260 };
 261
 262 static const struct enum_map platform_map[] = {
 263     {WAFFLE_PLATFORM_ANDROID,   "android"       },
 264     {WAFFLE_PLATFORM_CGL,       "cgl",          },
 265     {WAFFLE_PLATFORM_GBM,       "gbm"           },
 266     {WAFFLE_PLATFORM_GLX,       "glx"           },
 267     {WAFFLE_PLATFORM_WAYLAND,   "wayland"       },
 268     {WAFFLE_PLATFORM_WGL,       "wgl"           },
 269     {WAFFLE_PLATFORM_SURFACELESS_EGL,   "surfaceless_egl"       },
 270     {WAFFLE_PLATFORM_X11_EGL,   "x11_egl"       },
 271     {0,                         0               },
 272 };
 273
 274 static const struct enum_map context_api_map[] = {
 275     {WAFFLE_CONTEXT_OPENGL,         "gl"        },
 276     {WAFFLE_CONTEXT_OPENGL_ES1,     "gles1"     },
 277     {WAFFLE_CONTEXT_OPENGL_ES2,     "gles2"     },
 278     {WAFFLE_CONTEXT_OPENGL_ES3,     "gles3"     },
 279     {0,                             0           },
 280 };
 281
 282 /// @brief Translate string to `enum waffle_enum`.
 283 ///
 284 /// @param self is a list of map items. The last item must be zero-filled.
 285 /// @param result is altered only if @a s if found.
 286 /// @return true if @a s was found in @a map.
 287 static bool
 288 enum_map_translate_str(
 289         const struct enum_map *self,
 290         const char *s,
 291         int *result)
 292 {
 293     for (const struct enum_map *i = self; i->i != 0; ++i) {
 294         if (!strncmp(s, i->s, strlen(i->s) + 1)) {
 295             *result = i->i;
 296             return true;
 297         }
 298     }
 299
 300     return false;
 301 }
 302
 303 /// @return true on success.
 304 static bool
 305 parse_args(int argc, char *argv[], struct options *opts)
 306 {
 307     bool ok;
 308     bool loop_get_opt = true;
 309     bool found_window_size = false;
 310
 311 #ifdef __APPLE__
 312     removeXcodeArgs(&argc, argv);
 313 #endif
 314
 315     // Set some context attrs to invalid values.
 316     opts->context_profile = -1;
 317     opts->context_version = -1;
 318
 319     while (loop_get_opt) {
 320         int opt = getopt_long(argc, argv, "", get_opts, NULL);
 321         switch (opt) {
 322             case -1:
 323                 loop_get_opt = false;
 324                 break;
 325             case '?':
 326                 goto error_unrecognized_arg;
 327             case OPT_PLATFORM:
 328                 ok = enum_map_translate_str(platform_map, optarg,
 329                                             &opts->platform);
 330                 if (!ok) {
 331                     usage_error_printf("'%s' is not a valid platform",
 332                                        optarg);
 333                 }
 334                 break;
 335             case OPT_API:
 336                 ok = enum_map_translate_str(context_api_map, optarg,
 337                                             &opts->context_api);
 338                 if (!ok) {
 339                     usage_error_printf("'%s' is not a valid API for an OpenGL "
 340                                        "context", optarg);
 341                 }
 342                 break;
 343             case OPT_VERSION: {
 344                 int major;
 345                 int minor;
 346                 int match_count;
 347
 348                 match_count = sscanf(optarg, "%d.%d", &major, &minor);
 349                 if (match_count != 2) {
 350                     usage_error_printf("'%s' is not a valid OpenGL version",
 351                                        optarg);
 352                 }
 353                 opts->context_version = 10 * major + minor;
 354                 break;
 355             }
 356             case OPT_PROFILE:
 357                 if (strcmp(optarg, "none") == 0) {
 358                     opts->context_profile = WAFFLE_NONE;
 359                 } else if (strcmp(optarg, "core") == 0) {
 360                     opts->context_profile = WAFFLE_CONTEXT_CORE_PROFILE;
 361                 } else if (strcmp(optarg, "compat") == 0) {
 362                     opts->context_profile = WAFFLE_CONTEXT_COMPATIBILITY_PROFILE;
 363                 } else {
 364                     usage_error_printf("'%s' is not a valid OpenGL profile",
 365                                        optarg);
 366                 }
 367                 break;
 368             case OPT_FORWARD_COMPATIBLE:
 369                 opts->context_forward_compatible = true;
 370                 break;
 371             case OPT_DEBUG:
 372                 opts->context_debug = true;
 373                 break;
 374             case OPT_ROBUST:
 375                 opts->context_robust = true;
 376                 break;
 377             case OPT_RESIZE_WINDOW:
 378                 opts->resize_window = true;
 379                 break;
 380             case OPT_WINDOW_SIZE: {
 381                 int match_count;
 382                 match_count = sscanf(optarg, "%dx%d", &window_width, &window_height);
 383                 if (match_count != 2) {
 384                     usage_error_printf("'%s' is not a valid window geometry",
 385                                        optarg);
 386                 }
 387                 found_window_size = true;
 388                 break;
 389             }
 390             case OPT_FULLSCREEN:
 391                 opts->fullscreen = true;
 392                 break;
 393             default:
 394                 abort();
 395                 loop_get_opt = false;
 396                 break;
 397         }
 398     }
 399
 400     if (optind < argc) {
 401         goto error_unrecognized_arg;
 402     }
 403
 404     if (!opts->platform) {
 405         usage_error_printf("--platform is required");
 406     }
 407
 408     if (!opts->context_api) {
 409         usage_error_printf("--api is required");
 410     }
 411
 412     if (opts->fullscreen && found_window_size) {
 413         usage_error_printf("--fullscreen and --window-size are mutually "
 414                            "exclusive options");
 415     }
 416
 417     // Set dl.
 418     switch (opts->context_api) {
 419         case WAFFLE_CONTEXT_OPENGL:     opts->dl = WAFFLE_DL_OPENGL;      break;
 420         case WAFFLE_CONTEXT_OPENGL_ES1: opts->dl = WAFFLE_DL_OPENGL_ES1;  break;
 421         case WAFFLE_CONTEXT_OPENGL_ES2: opts->dl = WAFFLE_DL_OPENGL_ES2;  break;
 422         case WAFFLE_CONTEXT_OPENGL_ES3: opts->dl = WAFFLE_DL_OPENGL_ES3;  break;
 423         default:
 424             abort();
 425             break;
 426     }
 427
 428     return true;
 429
 430 error_unrecognized_arg:
 431     usage_error_printf("unrecognized option '%s'", optarg);
 432 }
 433
 434 // The rules that dictate how to properly query a GL symbol are complex. The
 435 // rules depend on the OS, on the winsys API, and even on the particular driver
 436 // being used. The rules differ between EGL 1.4 and EGL 1.5; differ between
 437 // Linux, Windows, and Mac; and differ between Mesa and Mali.
 438 //
 439 // This function hides that complexity with a naive heuristic: try, then try
 440 // again.
 441 static void *
 442 get_gl_symbol(const struct options *opts, const char *name)
 443 {
 444     void *sym = NULL;
 445
 446     if (waffle_dl_can_open(opts->dl)) {
 447         sym = waffle_dl_sym(opts->dl, name);
 448     }
 449
 450     if (!sym) {
 451         sym = waffle_get_proc_address(name);
 452     }
 453
 454     return sym;
 455 }
 456
 457 static bool
 458 draw(struct waffle_window *window, bool resize)
 459 {
 460     bool ok;
 461     unsigned char *colors;
 462     int width = window_width;
 463     int height = window_height;
 464
 465 #if !defined(_WIN32)
 466     static const struct timespec sleep_time = {
 467          // 0.5 sec
 468         .tv_sec = 0,
 469         .tv_nsec = 500000000,
 470     };
 471 #endif
 472
 473     for (int i = 0; i < 3; ++i) {
 474         switch (i) {
 475             case 0: glClearColor(1, 0, 0, 1); break;
 476             case 1: glClearColor(0, 1, 0, 1); break;
 477             case 2: glClearColor(0, 0, 1, 1); break;
 478             case 3: abort(); break;
 479         }
 480
 481         if (resize) {
 482             width = (i + 2) * 40;
 483             height = width;
 484             waffle_window_resize(window, width, height);
 485             glViewport(0, 0, width, height);
 486         }
 487
 488         glClear(GL_COLOR_BUFFER_BIT);
 489
 490         colors = calloc(width * height * 4, sizeof(*colors));
 491         glReadPixels(0, 0,
 492                      width, height,
 493                      GL_RGBA, GL_UNSIGNED_BYTE,
 494                      colors);
 495         for (int j = 0; j < width * height * 4; j += 4) {
 496            if ((colors[j]   != (i == 0 ? 0xff : 0)) ||
 497                (colors[j+1] != (i == 1 ? 0xff : 0)) ||
 498                (colors[j+2] != (i == 2 ? 0xff : 0)) ||
 499                (colors[j+3] != 0xff)) {
 500               fprintf(stderr, "glReadPixels returned unexpected result\n");
 501               break;
 502            }
 503         }
 504         free(colors);
 505
 506         if (i == 0) {
 507             ok = waffle_window_show(window);
 508             if (!ok)
 509                 return false;
 510         }
 511
 512         ok = waffle_window_swap_buffers(window);
 513         if (!ok)
 514             return false;
 515
 516 #if !defined(_WIN32)
 517         nanosleep(&sleep_time, NULL);
 518 #else
 519         Sleep(500);
 520 #endif
 521     }
 522
 523     return true;
 524 }
 525
 526 #ifdef __APPLE__
 527
 528 static NSAutoreleasePool *pool;
 529
 530 static void
 531 cocoa_init(void)
 532 {
 533     // From the NSApplication Class Reference:
 534     //     [...] if you do need to use Cocoa classes within the main()
 535     //     function itself (other than to load nib files or to instantiate
 536     //     NSApplication), you should create an autorelease pool before using
 537     //     the classes and then release the pool when you’re done.
 538     pool = [[NSAutoreleasePool alloc] init];
 539
 540     // From the NSApplication Class Reference:
 541     //     The sharedApplication class method initializes the display
 542     //     environment and connects your program to the window server and the
 543     //     display server.
 544     //
 545     // It also creates the singleton NSApp if it does not yet exist.
 546     [NSApplication sharedApplication];
 547 }
 548
 549 static void
 550 cocoa_finish(void)
 551 {
 552     [pool drain];
 553 }
 554
 555 static void
 556 removeArg(int index, int *argc, char **argv)
 557 {
 558     --*argc;
 559     for (; index < *argc; ++index)
 560         argv[index] = argv[index + 1];
 561 }
 562
 563 static void
 564 removeXcodeArgs(int *argc, char **argv)
 565 {
 566     // Xcode sometimes adds additional arguments.
 567     for (int i = 1; i < *argc; )
 568     {
 569         if (strcmp(argv[i], "-NSDocumentRevisionsDebugMode") == 0 ||
 570             strcmp(argv[i], "-ApplePersistenceIgnoreState" ) == 0)
 571         {
 572             removeArg(i, argc, argv);
 573             removeArg(i, argc, argv);
 574         } else
 575             ++i;
 576     }
 577 }
 578
 579 #endif // __APPLE__
 580
 581 #ifdef __native_client__
 582 #include "ppapi_simple/ps_main.h"
 583 //
 584 // We need to rename main() for native client
 585 // because ppapi_simple already defines main().
 586 //
 587 int basic_test_main(int argc, char **argv);
 588 PPAPI_SIMPLE_REGISTER_MAIN(basic_test_main)
 589 int
 590 basic_test_main(int argc, char **argv)
 591 #else
 592 int
 593 main(int argc, char **argv)
 594 #endif
 595 {
 596     bool ok;
 597     int i;
 598
 599     struct options opts = {0};
 600
 601     int32_t init_attrib_list[3];
 602     int32_t config_attrib_list[64];
 603     intptr_t window_attrib_list[5];
 604
 605     struct waffle_display *dpy;
 606     struct waffle_config *config;
 607     struct waffle_context *ctx;
 608     struct waffle_window *window;
 609
 610     GLint context_flags = 0;
 611
 612     #ifdef __APPLE__
 613         cocoa_init();
 614     #endif
 615
 616     #ifdef __native_client__
 617         // Fixed arguments for native client.
 618         opts.context_api = WAFFLE_CONTEXT_OPENGL_ES2;
 619         opts.platform = WAFFLE_PLATFORM_NACL;
 620         opts.dl = WAFFLE_DL_OPENGL_ES2;
 621         opts.context_profile = WAFFLE_NONE;
 622         opts.context_version = -1;
 623     #else
 624     ok = parse_args(argc, argv, &opts);
 625     if (!ok)
 626         exit(EXIT_FAILURE);
 627     #endif
 628
 629     i = 0;
 630     init_attrib_list[i++] = WAFFLE_PLATFORM;
 631     init_attrib_list[i++] = opts.platform;
 632     init_attrib_list[i++] = WAFFLE_NONE;
 633
 634     ok = waffle_init(init_attrib_list);
 635     if (!ok)
 636         error_waffle();
 637
 638     dpy = waffle_display_connect(NULL);
 639     if (!dpy)
 640         error_waffle();
 641
 642     if (!waffle_display_supports_context_api(dpy, opts.context_api)) {
 643         error_printf("Display does not support %s",
 644                      waffle_enum_to_string(opts.context_api));
 645     }
 646
 647     glClear = get_gl_symbol(&opts, "glClear");
 648     if (!glClear)
 649         error_get_gl_symbol("glClear");
 650
 651     glClearColor = get_gl_symbol(&opts, "glClearColor");
 652     if (!glClearColor)
 653         error_get_gl_symbol("glClearColor");
 654
 655     glGetError = get_gl_symbol(&opts, "glGetError");
 656     if (!glGetError)
 657         error_get_gl_symbol("glGetError");
 658
 659     glGetIntegerv = get_gl_symbol(&opts, "glGetIntegerv");
 660     if (!glGetIntegerv)
 661         error_get_gl_symbol("glGetIntegerv");
 662
 663     glReadPixels = get_gl_symbol(&opts, "glReadPixels");
 664     if (!glReadPixels)
 665         error_get_gl_symbol("glReadPixels");
 666
 667     glViewport = get_gl_symbol(&opts, "glViewport");
 668     if (!glViewport)
 669         error_get_gl_symbol("glViewport");
 670
 671     i = 0;
 672     config_attrib_list[i++] = WAFFLE_CONTEXT_API;
 673     config_attrib_list[i++] = opts.context_api;
 674
 675     if (opts.context_profile != -1) {
 676         config_attrib_list[i++] = WAFFLE_CONTEXT_PROFILE;
 677         config_attrib_list[i++] = opts.context_profile;
 678     }
 679
 680     if (opts.context_version != -1) {
 681         config_attrib_list[i++] = WAFFLE_CONTEXT_MAJOR_VERSION;
 682         config_attrib_list[i++] = opts.context_version / 10;
 683         config_attrib_list[i++] = WAFFLE_CONTEXT_MINOR_VERSION;
 684         config_attrib_list[i++] = opts.context_version % 10;
 685     }
 686
 687     if (opts.context_forward_compatible) {
 688         config_attrib_list[i++] = WAFFLE_CONTEXT_FORWARD_COMPATIBLE;
 689         config_attrib_list[i++] = true;
 690     }
 691
 692     if (opts.context_debug) {
 693         config_attrib_list[i++] = WAFFLE_CONTEXT_DEBUG;
 694         config_attrib_list[i++] = true;
 695     }
 696
 697     if (opts.context_robust) {
 698         config_attrib_list[i++] = WAFFLE_CONTEXT_ROBUST_ACCESS,
 699         config_attrib_list[i++] = true;
 700     }
 701
 702     config_attrib_list[i++] = WAFFLE_RED_SIZE;
 703     config_attrib_list[i++] = 8;
 704     config_attrib_list[i++] = WAFFLE_GREEN_SIZE;
 705     config_attrib_list[i++] = 8;
 706     config_attrib_list[i++] = WAFFLE_BLUE_SIZE;
 707     config_attrib_list[i++] = 8;
 708     config_attrib_list[i++] = WAFFLE_ALPHA_SIZE;
 709     config_attrib_list[i++] = 8;
 710     config_attrib_list[i++] = WAFFLE_DOUBLE_BUFFERED;
 711     config_attrib_list[i++] = true;
 712     config_attrib_list[i++] = 0;
 713
 714     config = waffle_config_choose(dpy, config_attrib_list);
 715     if (!config)
 716         error_waffle();
 717
 718     ctx = waffle_context_create(config, NULL);
 719     if (!ctx)
 720         error_waffle();
 721
 722
 723     i = 0;
 724     if (opts.fullscreen) {
 725         window_attrib_list[i++] = WAFFLE_WINDOW_FULLSCREEN;
 726         window_attrib_list[i++] = true;
 727         window_attrib_list[i++] = 0;
 728     } else {
 729         window_attrib_list[i++] = WAFFLE_WINDOW_WIDTH;
 730         window_attrib_list[i++] = window_width;
 731         window_attrib_list[i++] = WAFFLE_WINDOW_HEIGHT;
 732         window_attrib_list[i++] = window_height;
 733         window_attrib_list[i++] = 0;
 734     }
 735
 736     window = waffle_window_create2(config, window_attrib_list);
 737     if (!window)
 738         error_waffle();
 739
 740     ok = waffle_make_current(dpy, window, ctx);
 741     if (!ok)
 742         error_waffle();
 743
 744     if (opts.context_forward_compatible || opts.context_debug) {
 745         glGetIntegerv(GL_CONTEXT_FLAGS, &context_flags);
 746     }
 747
 748     if (glGetError())
 749         error_printf("glGetIntegerv(GL_CONTEXT_FLAGS) failed");
 750
 751     if (opts.context_forward_compatible
 752         && !(context_flags & GL_CONTEXT_FLAG_FORWARD_COMPATIBLE_BIT)) {
 753         error_printf("context is not forward-compatible");
 754     }
 755
 756     if (opts.context_debug
 757         && !(context_flags & GL_CONTEXT_FLAG_DEBUG_BIT)) {
 758         error_printf("context is not a debug context");
 759     }
 760
 761     // Don't verify if the context is robust because that pollutes this simple
 762     // example program with hairy GL logic. The method of verifying if
 763     // a context is robust varies on the combination of context profile,
 764     // context version, and supported extensions.
 765
 766     ok = draw(window, opts.resize_window);
 767     if (!ok)
 768         error_waffle();
 769
 770     ok = waffle_make_current(dpy, NULL, NULL);
 771     if (!ok)
 772         error_waffle();
 773
 774     ok = waffle_window_destroy(window);
 775     if (!ok)
 776         error_waffle();
 777
 778     ok = waffle_context_destroy(ctx);
 779     if (!ok)
 780         error_waffle();
 781
 782     ok = waffle_config_destroy(config);
 783     if (!ok)
 784         error_waffle();
 785
 786     ok = waffle_display_disconnect(dpy);
 787     if (!ok)
 788         error_waffle();
 789
 790     ok = waffle_teardown();
 791     if (!ok)
 792         error_waffle();
 793
 794     #ifdef __APPLE__
 795         cocoa_finish();
 796     #endif
 797
 798     printf("gl_basic: run was successful\n");
 799     return EXIT_SUCCESS;
 800 }