src/vg/vg.h

   1 /* Copyright (C) 2021-2022 Harry Godden (hgn) - All Rights Reserved */
   2
   3 /*
   4  * Memory model:
   5  *    [global (.data)] [temp-stack] [system-stack] [game-heap]
   6  *
   7  *    1. Program starts: .data memory is loaded
   8  *    2. System initialization:
   9  *       2a. the large heap buffer is allocated
  10  *       2b. each engine system is initialized in order, using some of the
  11  *           system stack
  12  *       2c. game systems are also put into here
  13  */
  14
  15
  16 #ifndef VG_HEADER_H
  17 #define VG_HEADER_H
  18
  19 #include "vg_platform.h"
  20 #include "vg_mem.h"
  21
  22 #ifndef _WIN32
  23 #include <execinfo.h>
  24 #endif
  25
  26
  27 #if defined(VG_SERVER) || defined(VG_TOOLS)
  28  #define VG_NON_CLIENT
  29 #endif
  30
  31 #ifndef VG_SERVER
  32 #include "../../dep/glad/glad.h"
  33
  34 #define GLFW_INCLUDE_GLCOREARB
  35
  36 #ifdef _WIN32
  37   #define GLFW_DLL
  38 #endif
  39
  40 #include "../../dep/glfw/glfw3.h"
  41 #endif
  42
  43 #include "vg_stdint.h"
  44
  45 void vg_register_exit( void( *funcptr )(void), const char *name );
  46
  47 #include "vg_m.h"
  48 #include "vg_io.h"
  49 #include "vg_log.h"
  50
  51 #ifdef VG_STEAM
  52 //#include "vg_steamworks.h"
  53 #include "vg_steam.h"
  54 #endif
  55
  56 #ifndef VG_NON_CLIENT
  57
  58 struct vg
  59 {
  60    /* Engine sync */
  61    GLFWwindow* window;
  62
  63    vg_mutex     mux_context;
  64    vg_semaphore sem_allow_exec,
  65                 sem_exec_finished,
  66                 sem_loader,
  67                 sem_fatal;
  68    int exec_context;
  69
  70    vg_mutex     mux_engine_status;
  71    enum engine_status
  72    {
  73       k_engine_status_none,
  74       k_engine_status_running,
  75       k_engine_status_crashed
  76    }
  77    engine_status;
  78    const char *str_const_engine_err;
  79    int          is_loaded;
  80
  81    /* Window information */
  82    int window_x,
  83        window_y,
  84        samples;
  85    float refresh_rate;
  86
  87    v2f mouse,
  88        mouse_wheel;
  89
  90    /* Runtime */
  91    double time,
  92           time_delta,
  93           frame_delta,
  94           time_real,
  95           time_real_last,
  96           time_rate,
  97           accumulator;
  98
  99    int fixed_iterations;
 100
 101    enum engine_stage
 102    {
 103       k_engine_stage_none,
 104       k_engine_stage_update,
 105       k_engine_stage_update_fixed,
 106       k_engine_stage_rendering,
 107       k_engine_stage_ui
 108    }
 109    engine_stage;
 110
 111    /* graphics */
 112    m4x4f pv;
 113
 114    /* Gamepad */
 115    GLFWgamepadstate  gamepad;
 116    int                        gamepad_ready;
 117    const char       *gamepad_name;
 118    int                        gamepad_id;
 119 }
 120 VG_STATIC vg = { .time_rate = 1.0 };
 121
 122 struct vg_thread_info
 123 {
 124    enum vg_thread_purpose
 125    {
 126       k_thread_purpose_nothing,
 127       k_thread_purpose_main,
 128       k_thread_purpose_loader
 129    }
 130    purpose;
 131
 132    int gl_context_level;
 133 };
 134
 135 static VG_THREAD_LOCAL struct vg_thread_info vg_thread_info;
 136
 137
 138 //#define VG_SYNC_DEBUG
 139
 140 #ifdef VG_SYNC_DEBUG
 141   #define VG_SYNC_LOG(STR,...) vg_info(STR,vg_thread_info.purpose,##__VA_ARGS__)
 142 #else
 143   #define VG_SYNC_LOG(...)
 144 #endif
 145
 146 VG_STATIC void vg_fatal_exit_loop( const char *error );
 147
 148 VG_STATIC void vg_ensure_engine_running(void)
 149 {
 150    /* Check if the engine is no longer running */
 151    vg_mutex_lock( &vg.mux_engine_status );
 152    if( vg.engine_status != k_engine_status_running )
 153    {
 154       VG_SYNC_LOG( "[%d] Engine is no longer running\n");
 155       vg_mutex_unlock( &vg.mux_engine_status );
 156
 157       /* Safe to disregard loader thread from this point on, elswhere */
 158       if( vg_thread_info.purpose == k_thread_purpose_loader )
 159       {
 160          vg_semaphore_post( &vg.sem_loader );
 161       }
 162
 163       VG_SYNC_LOG( "[%d] about to kill\n");
 164       vg_thread_exit();
 165    }
 166    vg_mutex_unlock( &vg.mux_engine_status );
 167 }
 168
 169 /*
 170  * Sync execution so that the OpenGL context is switched onto this thread.
 171  * Anything after this call will be in a valid context.
 172  */
 173 VG_STATIC void vg_acquire_thread_sync(void)
 174 {
 175    /* We dont want to do anything if this is the main thread */
 176    if( vg_thread_info.purpose == k_thread_purpose_main )
 177       return;
 178
 179    assert( vg_thread_info.purpose == k_thread_purpose_loader );
 180
 181    vg_ensure_engine_running();
 182
 183    /* Check if thread already has the context */
 184    if( vg_thread_info.gl_context_level )
 185    {
 186       vg_thread_info.gl_context_level ++;
 187       VG_SYNC_LOG( "[%d] We already have sync here\n" );
 188       return;
 189    }
 190
 191    vg_mutex_lock( &vg.mux_context );
 192    VG_SYNC_LOG( "[%d] Signal to sync.\n" );
 193    vg.exec_context = 1;
 194    vg_mutex_unlock( &vg.mux_context );
 195
 196    /* wait until told we can go */
 197    VG_SYNC_LOG( "[%d] Waiting to acuire sync.\n" );
 198    vg_semaphore_wait( &vg.sem_allow_exec );
 199    glfwMakeContextCurrent( vg.window );
 200
 201    /* context now valid to work in while we hold up main thread */
 202    VG_SYNC_LOG( "[%d] Context acquired.\n" );
 203    vg_thread_info.gl_context_level ++;
 204 }
 205
 206 /*
 207  * Signify that we are done with the OpenGL context in this thread.
 208  * Anything after this call will be in an undefined context.
 209  */
 210 VG_STATIC void vg_release_thread_sync(void)
 211 {
 212    if( vg_thread_info.purpose == k_thread_purpose_main )
 213       return;
 214
 215    assert( vg_thread_info.purpose == k_thread_purpose_loader );
 216
 217    /* signal that we are done */
 218    vg_thread_info.gl_context_level --;
 219
 220    if( !vg_thread_info.gl_context_level )
 221    {
 222       VG_SYNC_LOG( "[%d] Releasing context.\n" );
 223       glfwMakeContextCurrent( NULL );
 224       vg_semaphore_post( &vg.sem_exec_finished );
 225    }
 226 }
 227
 228 VG_STATIC void vg_run_synced_content(void)
 229 {
 230    assert( vg_thread_info.purpose == k_thread_purpose_main );
 231
 232    vg_mutex_lock( &vg.mux_context );
 233
 234    if( vg.exec_context != 0 )
 235    {
 236       VG_SYNC_LOG( "[%d] Allowing content (%d).\n", vg.exec_context );
 237
 238       /* allow operations to go */
 239       vg_thread_info.gl_context_level = 0;
 240       glfwMakeContextCurrent( NULL );
 241       vg_semaphore_post( &vg.sem_allow_exec );
 242
 243       /* wait for operations to complete */
 244       VG_SYNC_LOG( "[%d] Waiting for content (%d).\n", vg.exec_context );
 245       vg_semaphore_wait( &vg.sem_exec_finished );
 246
 247       /* check if we killed the engine */
 248       vg_ensure_engine_running();
 249
 250       /* re-engage main thread */
 251       VG_SYNC_LOG( "[%d] Re-engaging.\n" );
 252       vg.exec_context = 0;
 253       glfwMakeContextCurrent( vg.window );
 254       vg_thread_info.gl_context_level = 1;
 255    }
 256
 257    vg_mutex_unlock( &vg.mux_context );
 258 }
 259
 260 VG_STATIC void vg_opengl_sync_init(void)
 261 {
 262    vg_semaphore_init( &vg.sem_allow_exec, 0 );
 263    vg_semaphore_init( &vg.sem_exec_finished, 0 );
 264    vg_semaphore_init( &vg.sem_loader, 1 );
 265    vg_semaphore_init( &vg.sem_fatal, 1 );
 266    vg_mutex_init( &vg.mux_context );
 267
 268    vg_set_thread_name( "[vg] Main" );
 269    vg_thread_info.purpose = k_thread_purpose_main;
 270    vg_thread_info.gl_context_level = 1;
 271 }
 272
 273 VG_STATIC void vg_checkgl( const char *src_info );
 274 #define VG_STRINGIT( X ) #X
 275 #define VG_CHECK_GL_ERR() vg_checkgl( __FILE__ ":L" VG_STRINGIT(__LINE__) )
 276
 277 #include "vg_console.h"
 278 #include "vg_profiler.h"
 279 #include "vg_audio.h"
 280 #include "vg_shader.h"
 281 #include "vg_tex.h"
 282 #include "vg_input.h"
 283 #include "vg_ui.h"
 284 #include "vg_lines.h"
 285 #include "vg_loader.h"
 286 #include "vg_opt.h"
 287
 288 /* Diagnostic */
 289 VG_STATIC struct vg_profile vg_prof_update = {.name="update()"},
 290                             vg_prof_render = {.name="render()"};
 291
 292 #define VG_GAMELOOP
 293 VG_STATIC void vg_register(void) VG_GAMELOOP;
 294 VG_STATIC void vg_start(void) VG_GAMELOOP;
 295
 296 VG_STATIC void vg_update(int loaded) VG_GAMELOOP;
 297 VG_STATIC void vg_update_fixed(int loaded) VG_GAMELOOP;
 298 VG_STATIC void vg_update_post(int loaded) VG_GAMELOOP;
 299
 300 VG_STATIC void vg_framebuffer_resize(int w, int h) VG_GAMELOOP;
 301 VG_STATIC void vg_render(void) VG_GAMELOOP;
 302 VG_STATIC void vg_ui(void) VG_GAMELOOP;
 303
 304 VG_STATIC void vg_checkgl( const char *src_info )
 305 {
 306    int fail = 0;
 307
 308    GLenum err;
 309    while( (err = glGetError()) != GL_NO_ERROR )
 310    {
 311       vg_error( "(%s) OpenGL Error: #%d\n", src_info, err );
 312       fail = 1;
 313    }
 314
 315    if( fail )
 316       vg_fatal_exit_loop( "OpenGL Error" );
 317 }
 318
 319 void vg_mouse_callback( GLFWwindow* ptrW, double xpos, double ypos )
 320 {
 321    vg.mouse[0] = xpos;
 322    vg.mouse[1] = ypos;
 323 }
 324
 325 void vg_scroll_callback( GLFWwindow* ptrW, double xoffset, double yoffset )
 326 {
 327    vg.mouse_wheel[0] += xoffset;
 328    vg.mouse_wheel[1] += yoffset;
 329 }
 330
 331 void vg_framebuffer_resize_callback( GLFWwindow *ptrW, int w, int h )
 332 {
 333    if( !w || !h )
 334    {
 335       vg_warn( "Got a invalid framebuffer size: %dx%d... ignoring\n", w, h );
 336       return;
 337    }
 338
 339    vg.window_x = w;
 340    vg.window_y = h;
 341
 342    vg_framebuffer_resize(w,h);
 343 }
 344
 345 VG_STATIC void vg_bake_shaders(void)
 346 {
 347    vg_acquire_thread_sync();
 348
 349 #if 0
 350    vg_function_push( (struct vg_cmd)
 351    {
 352       .name = "shaders",
 353       .function = vg_shaders_live_recompile
 354    });
 355 #endif
 356
 357    vg_shaders_compile();
 358    vg_release_thread_sync();
 359 }
 360
 361 VG_STATIC void vg_preload(void);
 362 VG_STATIC void vg_load(void);
 363 VG_STATIC void vg_load_full(void)
 364 {
 365    vg_preload();
 366
 367    /* internal */
 368    vg_loader_highwater( vg_gamepad_init, NULL, NULL );
 369    vg_loader_highwater( vg_lines_init, NULL, NULL );
 370    vg_loader_highwater( vg_audio_init, vg_audio_free, NULL );
 371    vg_loader_highwater( vg_profiler_init, NULL, NULL );
 372
 373    /* client */
 374    vg_load();
 375
 376    vg_acquire_thread_sync();
 377    vg.is_loaded = 1;
 378    vg_release_thread_sync();
 379 }
 380
 381 VG_STATIC void vg_enter( int argc, char *argv[], const char *window_name )
 382 {
 383    char *arg;
 384    while( vg_argp( argc, argv ) )
 385    {
 386       if( (arg = vg_opt_arg( 'w' )) )
 387       {
 388          vg.window_x = atoi( arg );
 389       }
 390
 391       if( (arg = vg_opt_arg( 'h' )) )
 392       {
 393          vg.window_y = atoi( arg );
 394       }
 395
 396       if( (arg = vg_long_opt_arg( "samples" )) )
 397       {
 398          vg.samples = VG_MAX( 0, VG_MIN( 8, atoi( arg ) ) );
 399       }
 400    }
 401
 402    vg_log_init();
 403    vg_console_init();
 404
 405    glfwInit();
 406    glfwWindowHint( GLFW_CONTEXT_VERSION_MAJOR, 3 );
 407    glfwWindowHint( GLFW_CONTEXT_VERSION_MINOR, 3 );
 408    glfwWindowHint( GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE );
 409    //glfwWindowHint( GLFW_OPENGL_DEBUG_CONTEXT, GL_FALSE );
 410    glfwWindowHint( GLFW_CONTEXT_RELEASE_BEHAVIOR, GLFW_RELEASE_BEHAVIOR_FLUSH );
 411
 412    glfwWindowHint( GLFW_RESIZABLE, GLFW_FALSE );
 413    glfwWindowHint( GLFW_DOUBLEBUFFER, GLFW_TRUE );
 414
 415    glfwWindowHint( GLFW_SAMPLES, vg.samples );
 416
 417    GLFWmonitor *monitor_primary = glfwGetPrimaryMonitor();
 418
 419    const GLFWvidmode *mode = glfwGetVideoMode( monitor_primary );
 420    glfwWindowHint( GLFW_RED_BITS, mode->redBits );
 421    glfwWindowHint( GLFW_GREEN_BITS, mode->greenBits );
 422    glfwWindowHint( GLFW_BLUE_BITS, mode->blueBits );
 423
 424    glfwWindowHint( GLFW_REFRESH_RATE, mode->refreshRate );
 425
 426    if( !vg.window_x )
 427       vg.window_x = mode->width;
 428
 429    if( !vg.window_y )
 430       vg.window_y = mode->height;
 431
 432    vg.refresh_rate = mode->refreshRate;
 433
 434    if( (vg.window = glfwCreateWindow(  vg.window_x, vg.window_y,
 435                                        window_name, monitor_primary, NULL)) )
 436    {
 437       glfwGetFramebufferSize( vg.window, &vg.window_x, &vg.window_y );
 438       vg_success( "Window created (%dx%d)\n", vg.window_x, vg.window_y );
 439    }
 440    else
 441    {
 442       vg_error( "GLFW Failed to initialize\n" );
 443       return;
 444    }
 445
 446    /* We need 3.1.2 for correct VSync on windows */
 447    {
 448       int vmaj, vmin, vrev;
 449       glfwGetVersion( &vmaj, &vmin, &vrev );
 450
 451       if( vmaj < 3 ||
 452          (vmaj == 3 && vmin  < 1) ||
 453          (vmaj == 3 && vmin == 1 && vrev < 2 ) )
 454       {
 455          vg_error( "GLFW out of date (%d.%d.%d); (3.1.2 is required)\n",
 456                     vmaj, vmin, vrev );
 457
 458          glfwTerminate();
 459          return;
 460       }
 461
 462       vg_success( "GLFW Version %d.%d.%d\n", vmaj, vmin, vrev );
 463    }
 464
 465    glfwMakeContextCurrent( vg.window );
 466    glfwSwapInterval( 1 );
 467
 468    glfwSetWindowSizeLimits( vg.window, 800, 600, GLFW_DONT_CARE,GLFW_DONT_CARE);
 469    glfwSetFramebufferSizeCallback( vg.window, vg_framebuffer_resize_callback );
 470
 471    glfwSetCursorPosCallback( vg.window, vg_mouse_callback );
 472    glfwSetScrollCallback( vg.window, vg_scroll_callback );
 473
 474    glfwSetCharCallback( vg.window, console_proc_wchar );
 475    glfwSetKeyCallback( vg.window, console_proc_key );
 476    glfwSetInputMode( vg.window, GLFW_CURSOR, GLFW_CURSOR_HIDDEN );
 477
 478    if( !gladLoadGLLoader((GLADloadproc)glfwGetProcAddress) )
 479    {
 480       vg_error( "Glad Failed to initialize\n" );
 481       glfwTerminate();
 482       return;
 483    }
 484
 485    const unsigned char* glver = glGetString( GL_VERSION );
 486    vg_success( "Load setup complete, OpenGL version: %s\n", glver );
 487
 488    /* init systems
 489     * -----------------------------------------------------------------------*/
 490    ui_init_context();
 491    vg_loader_init();
 492
 493    vg_mutex_init( &vg.mux_engine_status );
 494    vg.engine_status = k_engine_status_running;
 495
 496    vg_opengl_sync_init();
 497    vg_loader_start();
 498
 499    vg.accumulator = 0.75f * (1.0f/60.0f);
 500
 501    int loaded = 0;
 502    while(1)
 503    {
 504       if( glfwWindowShouldClose( vg.window ) )
 505          break;
 506
 507       v2_copy( (v2f){ 0.0f, 0.0f }, vg.mouse_wheel );
 508       glfwPollEvents();
 509
 510       vg.time_real_last = vg.time_real;
 511       vg.time_real = glfwGetTime();
 512       vg.frame_delta = vg.time_real-vg.time_real_last;
 513
 514       /* scaled time */
 515       vg.time_delta = vg.frame_delta * vg.time_rate;
 516       vg.time += vg.time_delta;
 517
 518       if( vg.is_loaded )
 519       {
 520          if( !loaded )
 521          {
 522             vg_start();
 523             loaded = 1;
 524          }
 525       }
 526       else
 527       {
 528          vg_loader_render();
 529       }
 530
 531       /*
 532        * Game logic
 533        * -------------------------------------------------------
 534        */
 535       vg_profile_begin( &vg_prof_update );
 536       vg_update_inputs();
 537
 538       vg.engine_stage = k_engine_stage_update;
 539       vg_update( loaded );
 540
 541       /* Fixed update loop */
 542       vg.engine_stage = k_engine_stage_update_fixed;
 543       vg.accumulator += vg.time_delta;
 544
 545       vg.fixed_iterations = 0;
 546       while( vg.accumulator >= (VG_TIMESTEP_FIXED-0.00125) )
 547       {
 548          vg_update_fixed( loaded );
 549
 550          vg.accumulator -= VG_TIMESTEP_FIXED;
 551          vg.accumulator  = VG_MAX( 0.0, vg.accumulator );
 552
 553          vg.fixed_iterations ++;
 554          if( vg.fixed_iterations == 8 )
 555          {
 556             break;
 557          }
 558       }
 559
 560       /*
 561        * Rendering
 562        * ---------------------------------------------
 563        */
 564       vg.engine_stage = k_engine_stage_update;
 565       vg_update_post( loaded );
 566       vg_profile_end( &vg_prof_update );
 567
 568       vg_profile_begin( &vg_prof_render );
 569
 570       if( loaded )
 571       {
 572          /* render */
 573          vg.engine_stage = k_engine_stage_rendering;
 574          vg_render();
 575
 576          /* ui */
 577          vg.engine_stage = k_engine_stage_ui;
 578          {
 579             ui_begin( vg.window_x, vg.window_y );
 580             ui_set_mouse( vg.mouse[0], vg.mouse[1],
 581                            vg_get_button_state( "primary" ) );
 582
 583             vg_profile_drawn(
 584                   (struct vg_profile *[]){&vg_prof_update,&vg_prof_render}, 2,
 585                   (1.0f/(float)vg.refresh_rate)*1000.0f,
 586                   (ui_rect){ 4, 4, 250, 0 }, 0
 587             );
 588
 589             if( vg_profiler )
 590             {
 591
 592                char perf[128];
 593
 594                snprintf( perf, 127,
 595                      "x: %d y: %d\n"
 596                      "refresh: %.1f (%.1fms)\n"
 597                      "samples: %d\n"
 598                      "iterations: %d (acc: %.3fms%%)\n",
 599                      vg.window_x, vg.window_y,
 600                      vg.refresh_rate, (1.0f/vg.refresh_rate)*1000.0f,
 601                      vg.samples,
 602                      vg.fixed_iterations,
 603                      (vg.accumulator/VG_TIMESTEP_FIXED)*100.0f );
 604
 605                ui_text( (ui_rect){258, 4+24+12,0,0},perf, 1,0);
 606             }
 607
 608             audio_debug_ui( vg.pv );
 609             vg_ui();
 610             vg_console_draw();
 611
 612             ui_resolve();
 613             ui_draw( NULL );
 614          }
 615       }
 616
 617       vg_profile_end( &vg_prof_render );
 618
 619       glfwSwapBuffers( vg.window );
 620       vg_run_synced_content();
 621    }
 622
 623    vg_console_write_persistent();
 624
 625    vg_mutex_lock( &vg.mux_engine_status );
 626    vg.engine_status = k_engine_status_none;
 627    vg_mutex_unlock( &vg.mux_engine_status );
 628
 629    vg_loader_free();
 630
 631    vg_success( "If you see this it means everything went.. \"well\".....\n" );
 632    glfwTerminate();
 633 }
 634
 635 /*
 636  * Immediately transfer away from calling thread into a safe loop, signal for
 637  * others to shutdown, then free everything once the user closes the window.
 638  *
 639  * FIXME(bug): glfwWindowShouldClose() never returns 1 in windows via wine, ONLY
 640  *             when calling the program from outside its normal directory.
 641  */
 642 VG_STATIC void vg_fatal_exit_loop( const char *error )
 643 {
 644    /*
 645     *    https://www.gnu.org/software/libc/manual/html_node/Backtraces.html
 646     *    thanks gnu <3
 647     *
 648     *    TODO: this on windows?
 649     */
 650
 651 #ifndef _WIN32
 652
 653    void *array[20];
 654    char **strings;
 655    int size, i;
 656
 657    size = backtrace( array, 20 );
 658    strings = backtrace_symbols( array, size );
 659
 660    if( strings != NULL )
 661    {
 662       vg_error( "---------------- gnu backtrace -------------\n" );
 663
 664       for( int i=0; i<size; i++ )
 665          vg_info( "%s\n", strings[i] );
 666
 667       vg_error( "---------------- gnu backtrace -------------\n" );
 668    }
 669
 670    free( strings );
 671
 672 #endif
 673
 674    vg_error( "Fatal error: %s\n", error );
 675    assert( vg_semaphore_trywait( &vg.sem_fatal ) );
 676
 677    vg_mutex_lock( &vg.mux_engine_status );
 678
 679    if( vg.engine_status == k_engine_status_none )
 680    {
 681       vg_mutex_unlock( &vg.mux_engine_status );
 682
 683       /* TODO: Correct shutdown before other systems */
 684       exit(0);
 685    }
 686    else
 687    {
 688       vg_mutex_unlock( &vg.mux_engine_status );
 689
 690       /*
 691        * if main
 692        *    if loader running
 693        *       wait until loader checks in, it will die
 694        *    else
 695        *       pass immediately
 696        * else
 697        *    if have context
 698        *       pass immediately
 699        *    else
 700        *       wait for main to get to us, it will never be used again
 701        *
 702        * undefined behaviour:
 703        *    fatal_exit_loop is called in both threads, preventing an appropriate
 704        *                    reaction to the crash. This *should* be made
 705        *                    obvious by the assertion
 706        */
 707       vg_acquire_thread_sync();
 708
 709       vg_mutex_lock( &vg.mux_engine_status );
 710       vg.engine_status = k_engine_status_crashed;
 711       vg.str_const_engine_err = error;
 712       vg_mutex_unlock( &vg.mux_engine_status );
 713
 714       /*
 715        * Wait for loader to finish what it was doing, if it was running.
 716        * Then we can continue in our nice error screen
 717        */
 718       if( vg_thread_info.purpose == k_thread_purpose_main )
 719       {
 720          vg_semaphore_wait( &vg.sem_loader );
 721       }
 722       vg_audio_free(NULL);
 723
 724       while(1)
 725       {
 726          if( glfwWindowShouldClose( vg.window ) )
 727             break;
 728
 729          if( glfwGetKey( vg.window, GLFW_KEY_ESCAPE ) )
 730             break;
 731
 732          glfwPollEvents();
 733
 734          glBindFramebuffer( GL_FRAMEBUFFER, 0 );
 735          glEnable(GL_BLEND);
 736          glDisable(GL_DEPTH_TEST);
 737          glBlendFunc(GL_ONE_MINUS_DST_ALPHA, GL_DST_ALPHA);
 738          glBlendEquation(GL_FUNC_ADD);
 739
 740          glClearColor( 0.15f + sinf(glfwGetTime())*0.1f, 0.0f, 0.0f,1.0f );
 741          glClear( GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT );
 742          glViewport( 0,0, vg.window_x, vg.window_y );
 743
 744          vg_render_log();
 745
 746          glfwSwapBuffers( vg.window );
 747       }
 748
 749       /* Can now shutdown and EXIT */
 750       vg_loader_free();
 751       glfwTerminate();
 752       exit(0);
 753    }
 754 }
 755
 756 #else
 757
 758 VG_STATIC void vg_fatal_exit_loop( const char *error )
 759 {
 760    vg_error( "Fatal error: %s\n", error );
 761    exit(0);
 762 }
 763
 764 #endif
 765
 766 /*
 767  * Graphic cards will check these to force it to use the GPU
 768  */
 769 u32 NvOptimusEnablement = 0x00000001;
 770 int AmdPowerXpressRequestHighPerformance = 1;
 771
 772 #endif