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SDL2 + OpenGL how to open screen properly (Win 8.1 problems)

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I get a rare bug with Window 8.1 (on some computers only) regarding fullscreen. The screen is "cut" (right part is not displayed) and/or mouse does not map properly on the screen (but that one is rarer). It's on some machines only and I'm unable to recreate the bug.





Here is what my open screen code does:


SDL_GetDesktopDisplayMode() to get desktop width & height
SDL_GL_SetSwapInterval( enablevsync ); to enable/disable vsync
GL clear, GL hints, GL viewport, GL perspective, etc

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Can you show the actual code you use to do this. Also do you have any info about the computers that have this problem, do they have multiple monitors or anything? Seeing your full initialisation code will help.

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I suppose that & should be a | instead? This pseudo-pseudo-code really isn't helping...


Also by any chance does DPI have an influence on it? Since I'm not seeing you marking the window as high DPI aware.

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Can you show the actual code you use to do this. Also do you have any info about the computers that have this problem, do they have multiple monitors or anything? Seeing your full initialisation code will help.

Just standard stuff, like a laptop, no suspicious features (except posession of the Win 8.1 biggrin.png). Besides, I use it on dual monitors without problems, so unles Win 8.1 handles it differently it should not be the problem.




The code (yes, I know it's messy smile.png):

int easydrawInit(int w, int h,int fullscreen,int enableaudio)
    Config.screenwidth=w; Config.screenheight=h; Config.fullscreen=fullscreen;
    EasyDrawSystem.gldrawpixelsmode=0; // Always in this version!
    int enablevsync=Config.vsync;
    if(!enablevsync) Debug("Vsync disabled.\n");

    //SDL_putenv("SDL_VIDEODRIVER=directx"); //! PORTABILITY PROBLEM !
    //SDL_GL_SetAttribute( SDL_GL_SWAP_CONTROL, 0 );

    if(enableaudio) {if(SDL_Init(SDL_INIT_VIDEO | SDL_INIT_AUDIO) < 0 ) return 0;}
    else {if(SDL_Init(SDL_INIT_VIDEO) < 0 ) return 0;}

    SDL_GL_SetAttribute( SDL_GL_RED_SIZE, 8 );
    SDL_GL_SetAttribute( SDL_GL_GREEN_SIZE, 8 );
    SDL_GL_SetAttribute( SDL_GL_BLUE_SIZE, 8 );
    SDL_GL_SetAttribute( SDL_GL_DEPTH_SIZE, 16 );
    SDL_GL_SetAttribute( SDL_GL_DOUBLEBUFFER, 1 );

    if(strlen(SDL_GetError())) {Debug("easydrawInit() '%s'",SDL_GetError()); SDL_ClearError();}

    // Create an application window with the following settings:
    int flags=SDL_WINDOW_OPENGL;
    if(fullscreen==0) flags|=SDL_WINDOW_RESIZABLE;
    if(fullscreen==2) flags|=SDL_WINDOW_FULLSCREEN;
    //if(fullscreen==1) flags|=SDL_WINDOW_FULLSCREEN_DESKTOP;
    if(fullscreen==1) flags|=SDL_WINDOW_BORDERLESS;
        SDL_DisplayMode dm;
        if(SDL_GetDesktopDisplayMode(0, &dm) != 0)    {Log.e("easydrawInit()  SDL_GetDesktopDisplayMode failed: %s", SDL_GetError());}
    if(fullscreen<0 || fullscreen>2) {Log.fe("easydrawInit() invalid 'fullscreen' param.\n");}

    sdlWindow = SDL_CreateWindow("Unnamed window",SDL_WINDOWPOS_UNDEFINED,SDL_WINDOWPOS_UNDEFINED, Config.screenwidth,Config.screenheight, flags); // will be renamed in UpdateWindow below
    if(sdlWindow==NULL) {Debug("Could not create window: %s\n", SDL_GetError()); return 0;}

    SDL_GLContext glcontext = SDL_GL_CreateContext(sdlWindow);
    SDL_GL_SetSwapInterval( enablevsync );

    easydrawUpdateWindow(); // set OpenGL, set window icon, etc

    Config.newscreenwidth=Config.screenwidth; Config.newscreenheight=Config.screenheight; Config.newfullscreen=Config.fullscreen; Config.newvsync=Config.vsync; Config.newconfinemousetowindow=Config.confinemousetowindow;

    //char buf[256]; SDL_VideoDriverName(buf,256); Debug("VideoDriverName: %s\n",buf);
    Debug("Screen Opened %dx%d Fullscreen:%d Flags:%d\n",Config.screenwidth,Config.screenheight, Config.fullscreen,flags);
       Debug("Platform: %s\n", SDL_GetPlatform());
    Debug("OpenGL Vendor: %s\n", glGetString( GL_VENDOR ) );
    Debug("OpenGL Renderer: %s\n", glGetString( GL_RENDERER ) );
    Debug("OpenGL Version: %s\n", glGetString( GL_VERSION ) );
    //Debug("OpenGL Extensions : %s\n", glGetString( GL_EXTENSIONS ) );
    int value;    SDL_GL_GetAttribute( SDL_GL_ACCELERATED_VISUAL, &value );    Debug("SDL_GL_ACCELERATED_VISUAL: %d\n", value );
    //SDL_GL_GetAttribute( SDL_GL_SWAP_CONTROL, &value );    Debug("SDL_GL_SWAP_CONTROL: %d\n", value );
    //const SDL_VideoInfo* ptr = SDL_GetVideoInfo(); Debug("VRAM: %dKb\n",ptr->video_mem); Debug("SDL Hardware acceleration status: %d,%d,%d,%d\n",ptr->hw_available, ptr->blit_hw, ptr->blit_hw_A, ptr->blit_hw_CC);
    Debug("OpenGLExtension GL_ARB_texture_rectangle: %d\n", easydrawINTERNAL_glQueryExtension("GL_ARB_texture_rectangle"));
    Debug("OpenGLExtension ARB_texture_non_power_of_two: %d\n", easydrawINTERNAL_glQueryExtension("ARB_texture_non_power_of_two"));
    //GLint texture_units; glGetIntegerv(GL_MAX_TEXTURE_IMAGE_UNITS, &texture_units); Debug("GL_MAX_TEXTURE_IMAGE_UNITS: %d\n", texture_units); // per shader?
    //GLint combined_texture_units; glGetIntegerv(GL_MAX_COMBINED_TEXTURE_IMAGE_UNITS, &combined_texture_units); Debug("GL_MAX_COMBINED_TEXTURE_IMAGE_UNITS: %d\n", combined_texture_units); // total?
    GLint texSize; glGetIntegerv(GL_MAX_TEXTURE_SIZE, &texSize); Debug("OpenGL Max texture size: %d\n", texSize);
    //GLint maxLights; glGetIntegerv(GL_MAX_LIGHTS , &maxLights); Debug("OpenGL MAX_LIGHTS: %d\n", maxLights);
    Debug("VideoDriver: %s\n",SDL_GetCurrentVideoDriver());
    Debug("NumVideoDrivers: %d NumVideoModes: %d NumDisplayModes: %d\n",SDL_GetNumVideoDrivers(),SDL_GetNumVideoDisplays(),SDL_GetNumDisplayModes(0));
    //Debug("[config] glDrawPixelsMode: %d\n",EasyDrawSystem.gldrawpixelsmode);
    Debug("Number of logical CPU cores: %d\nSystem Memory: %d MB\n", SDL_GetCPUCount(),SDL_GetSystemRAM());

    SDL_version compiled_version,link_version; SDL_VERSION(&compiled_version); SDL_GetVersion(&link_version);
    Debug("SDL_version - CompiledVersion: %d.%d.%d  ", compiled_version.major,compiled_version.minor,compiled_version.patch);
    Debug("LinkedVersion: %d.%d.%d\n", link_version.major, link_version.minor, link_version.patch);

    //Initialize PNG loading
    int imgFlags = IMG_INIT_PNG;
    if(!(IMG_Init(imgFlags) & imgFlags)) {Debug( "SDL_image could not initialize! SDL_image Error: %s\n",IMG_GetError());}
    SDL_version compile_version; SDL_IMAGE_VERSION(&compile_version); const SDL_version *link_version=IMG_Linked_Version();
    Debug("SDL_image_version - CompiledVersion: %d.%d.%d  ", compile_version.major, compile_version.minor, compile_version.patch);
    Debug("LinkedVersion: %d.%d.%d\n", link_version->major, link_version->minor, link_version->patch);

    //Config.logeasydraw=Config.logfont=1; Debug("[notice] Changed Config to allow logging (in easydrawInit()).\n");
    if(!Config.logeasydraw) Debug("Disabled log easydraw.\n");
    if(!Config.logfont) Debug("Disabled log font.\n");

    if(strlen(SDL_GetError())) {Debug("easydrawInit() '%s'",SDL_GetError()); SDL_ClearError();}

    return 1;

void easydrawUpdateWindow() // Run it after window resize/screen resolution change
	1. GL clear, GL hints, GL viewport, GL perspective, etc
	2. SDL_SetWindowTitle(sdlWindow,buf);
	3. SDL_SetWindowIcon()
	4. SDL_SetWindowGrab(sdlWindow,SDL_FALSE);

	int width=Config.screenwidth; int height=Config.screenheight;

	// OpenGL
	glEnable(GL_BLEND);     // Turn Blending On
	glDepthFunc(GL_LEQUAL);                         // The Type Of Depth Testing To Do
	glClearDepth(1.0f);                         // Depth Buffer Setup
    glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST);          // Really Nice Perspective
    /* Our shading model--Gouraud (smooth). */
    glShadeModel( GL_SMOOTH );
    /* Culling. */
    glCullFace( GL_BACK );
    glFrontFace( GL_CCW );
    glEnable( GL_CULL_FACE );
    /* Set the clear color. */
    glClearColor( 0, 0, 0, 0 );

    /* Setup our viewport. */
    glViewport( 0, 0, width, height );

    /* Change to the projection matrix and set our viewing volume.  */
    glMatrixMode( GL_PROJECTION );
    glLoadIdentity( );

	float ratio = (float) width / (float) height;
    gluPerspective( 60, ratio, 1.0, 1024.0 );

    // SDL (app icon and window name)
    char buf[256]; snprintf(buf,255,"%s %s",GAMENAME,GAMEVERSION);	SDL_SetWindowTitle(sdlWindow,buf);
	// Window grab (confine mouse to window)
  	if(Config.confinemousetowindow && Config.fullscreen!=0) SDL_SetWindowGrab(sdlWindow,SDL_TRUE); else SDL_SetWindowGrab(sdlWindow,SDL_FALSE);

  	if(strlen(SDL_GetError())) {Debug("easydrawUpdateWindow() '%s'",SDL_GetError()); SDL_ClearError();}

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Found a dirty fix, go to file's compatibility tab and echeck 'Disable display scaling on high DPI settings'. It fixes it.


Is there a way to do it on the SDL level? Tried to add "SDL_WINDOW_ALLOW_HIGHDPI" to openwindow flags but it does not do the trick...

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Got it.To anyone having the same problem, use: SDL_SetHint(SDL_HINT_VIDEO_HIGHDPI_DISABLED,"1");

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Windows 8.1 has three versions (latest was Update 3 when I upgraded to Windows 10) , maybe check if it's latest one might reveal that it's already fixed.

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