view src/video/photon/SDL_ph_video.c @ 320:66f815c147ed

Date: Thu, 28 Mar 2002 09:20:03 +0200 From: "Mike Gorchak" <mike@malva.ua> Subject: New QNX patch. Hi ! 1. Removed warning (possible bug) with invalid type, passing to the function in ph_WarpedMotion. 2. Rewritten handler of Ph_WM_RESIZE message, now works, but buggy (old handler doesn't work at all). 3. Added stub handler for Ph_WM_MAX (maximize) message. 4. Added more #ifdef HAVE_OPENGL to disable OpenGL stuff when it not needed. 5. Added support for SDL_NOFRAME and SDL_RESIZABLE flags (in OpenGL windows too). 6. Added cosmetic changes, if no SDL_RESIZABLE flag defined, disable resize handlers in window border and maximize button at caption. 7. Fixed my bug with invalid arguments count passed to PtCreateWidget call. 8. Fixed some palette problems. 9. Updated README.QNX file. And I changed testgl.c test application: 10. Added in testgl.c application support for SDL_NOFRAME flag and option -noframe.
author Sam Lantinga <slouken@libsdl.org>
date Thu, 28 Mar 2002 16:20:10 +0000
parents 3333b6e68289
children ba72f259bc88
line wrap: on
line source

/*
    SDL - Simple DirectMedia Layer
    Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002  Sam Lantinga

    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Library General Public
    License as published by the Free Software Foundation; either
    version 2 of the License, or (at your option) any later version.

    This library is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    Library General Public License for more details.

    You should have received a copy of the GNU Library General Public
    License along with this library; if not, write to the Free
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

    Sam Lantinga
    slouken@libsdl.org
*/

#ifdef SAVE_RCSID
static char rcsid =
 "@(#) $Id$";
#endif

#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include <string.h>
#include <sys/ioctl.h>

#include "SDL.h"
#include "SDL_error.h"
#include "SDL_timer.h"
#include "SDL_thread.h"
#include "SDL_video.h"
#include "SDL_mouse.h"
#include "SDL_endian.h"
#include "SDL_sysvideo.h"
#include "SDL_pixels_c.h"
#include "SDL_events_c.h"
#include "SDL_ph_video.h"
#include "SDL_ph_modes_c.h"
#include "SDL_ph_image_c.h"
#include "SDL_ph_events_c.h"
#include "SDL_ph_mouse_c.h"
#include "SDL_ph_wm_c.h"
#include "SDL_phyuv_c.h"
#include "blank_cursor.h"

static int ph_VideoInit(_THIS, SDL_PixelFormat *vformat);
static SDL_Surface *ph_SetVideoMode(_THIS, SDL_Surface *current,
                int width, int height, int bpp, Uint32 flags);
static int ph_SetColors(_THIS, int firstcolor, int ncolors, SDL_Color *colors);
static void ph_VideoQuit(_THIS);
static void ph_DeleteDevice(SDL_VideoDevice *device);

#ifdef HAVE_OPENGL
int ph_SetupOpenGLContext(_THIS, int width, int height, int bpp, Uint32 flags);
static void ph_GL_SwapBuffers(_THIS);
static int ph_GL_GetAttribute(_THIS, SDL_GLattr attrib, int* value);
#endif /* HAVE_OPENGL */

static int ph_Available(void)
{
    int phstat=-1;

    phstat=PtInit(0);
    if (phstat==0)
    {
       return 1;
    }
    else
    {
       return 0;
    }
}

static SDL_VideoDevice *ph_CreateDevice(int devindex)
{
    SDL_VideoDevice *device;

    /* Initialize all variables that we clean on shutdown */
    device = (SDL_VideoDevice *)malloc(sizeof(SDL_VideoDevice));
    if (device) {
        memset(device, 0, (sizeof *device));
        device->hidden = (struct SDL_PrivateVideoData *)
                malloc((sizeof *device->hidden));
        device->gl_data = NULL;
    }
    if ( (device == NULL) || (device->hidden == NULL) ) {
        SDL_OutOfMemory();
        ph_DeleteDevice(device);
        return(0);
    }
    memset(device->hidden, 0, (sizeof *device->hidden));

    /* Set the driver flags */
    device->handles_any_size = 1; /* JB not true for fullscreen */

    /* Set the function pointers */
    device->CreateYUVOverlay = ph_CreateYUVOverlay;
    device->VideoInit = ph_VideoInit;
    device->ListModes = ph_ListModes;
    device->SetVideoMode = ph_SetVideoMode;
    device->ToggleFullScreen = ph_ToggleFullScreen;
    device->UpdateMouse = NULL;	
    device->SetColors = ph_SetColors;
    device->UpdateRects = NULL;         /* ph_ResizeImage */
    device->VideoQuit = ph_VideoQuit;
    device->AllocHWSurface = ph_AllocHWSurface;
    device->CheckHWBlit = NULL;
    device->FillHWRect = NULL;
    device->SetHWColorKey = NULL;
    device->SetHWAlpha = NULL;
    device->LockHWSurface = ph_LockHWSurface;
    device->UnlockHWSurface = ph_UnlockHWSurface;
    device->FlipHWSurface = ph_FlipHWSurface;
    device->FreeHWSurface = ph_FreeHWSurface;
    device->SetCaption = ph_SetCaption;
    device->SetIcon = NULL;
    device->IconifyWindow = ph_IconifyWindow;
    device->GrabInput = ph_GrabInput;
    device->GetWMInfo = ph_GetWMInfo;
    device->FreeWMCursor = ph_FreeWMCursor;
    device->CreateWMCursor = ph_CreateWMCursor;
    device->ShowWMCursor = ph_ShowWMCursor;
    device->WarpWMCursor = ph_WarpWMCursor;
    device->CheckMouseMode = ph_CheckMouseMode;
    device->InitOSKeymap = ph_InitOSKeymap;
    device->PumpEvents = ph_PumpEvents;

    /* OpenGL support. */
    device->GL_LoadLibrary = NULL;
    device->GL_GetProcAddress = NULL;
    device->GL_MakeCurrent = NULL;
#ifdef HAVE_OPENGL
    device->GL_SwapBuffers = ph_GL_SwapBuffers;
    device->GL_GetAttribute = ph_GL_GetAttribute;
#else
    device->GL_SwapBuffers = NULL;
    device->GL_GetAttribute = NULL;
#endif /* HAVE_OPENGL */

    device->free = ph_DeleteDevice;

    return device;
}

VideoBootStrap ph_bootstrap = {
    "photon", "QNX Photon video output",
    ph_Available, ph_CreateDevice
};

static void ph_DeleteDevice(SDL_VideoDevice *device)
{
    if (device)
    {
        if (device->hidden)
        {
            free(device->hidden);
            device->hidden = NULL;
        }
        if (device->gl_data)
        {
            free(device->gl_data);
            device->gl_data = NULL;
        }
        free(device);
        device = NULL;
    }
}

static int ph_VideoInit(_THIS, SDL_PixelFormat *vformat)
{
    PgVideoModeInfo_t my_mode_info;
    PgHWCaps_t my_hwcaps;

    window=NULL;
    desktoppal=SDLPH_PAL_NONE;
#ifdef HAVE_OPENGL
    oglctx=NULL;
#endif /* HAVE_OPENGL */
    
    captionflag=0;
    old_video_mode=-1;
    old_refresh_rate=-1;
	
    if (NULL == (event = malloc(EVENT_SIZE)))
    {
        exit(EXIT_FAILURE);
    }

    /* Create the blank cursor */
    SDL_BlankCursor = this->CreateWMCursor(this, blank_cdata, blank_cmask,
                                          (int)BLANK_CWIDTH, (int)BLANK_CHEIGHT,
                                          (int)BLANK_CHOTX, (int)BLANK_CHOTY);

    if (SDL_BlankCursor == NULL)
    {
        printf("ph_VideoInit: could not create blank cursor\n");
    }

    if (PgGetGraphicsHWCaps(&my_hwcaps) < 0)
    {
        fprintf(stderr,"ph_VideoInit: GetGraphicsHWCaps failed!! \n");
    }

    if (PgGetVideoModeInfo(my_hwcaps.current_video_mode, &my_mode_info) < 0)
    {
        fprintf(stderr,"ph_VideoInit:  PgGetVideoModeInfo failed\n");
    }

    /* We need to return BytesPerPixel as it in used by CreateRGBsurface */
    vformat->BitsPerPixel = my_mode_info.bits_per_pixel;
    vformat->BytesPerPixel = my_mode_info.bytes_per_scanline/my_mode_info.width;
    desktopbpp = my_mode_info.bits_per_pixel;
    
    /* save current palette */
    if (desktopbpp==8)
    {
        PgGetPalette(ph_palette);
    }
         
    currently_fullscreen = 0;
    
    this->info.wm_available = 1;
    
    return 0;
}

static SDL_Surface *ph_SetVideoMode(_THIS, SDL_Surface *current,
                int width, int height, int bpp, Uint32 flags)
{
    PgDisplaySettings_t settings;
    int mode;
    PtArg_t arg[32];
    PhDim_t dim;
    int rtnval;
    int i;
    unsigned long *tempptr;
    int pargc;

    dim.w=width;
    dim.h=height;

    /* Lock the event thread, in multi-threading environments */
    SDL_Lock_EventThread();

    current->flags = flags;

    /* create window if no OpenGL support selected */
    if ((flags & SDL_OPENGL)!=SDL_OPENGL)
    {
        pargc=0;

        PtSetArg(&arg[pargc++], Pt_ARG_DIM, &dim, 0);
        PtSetArg(&arg[pargc++], Pt_ARG_RESIZE_FLAGS, Pt_FALSE, Pt_RESIZE_XY_AS_REQUIRED);

        /* enable window minimizing */
        PtSetArg(&arg[pargc++], Pt_ARG_WINDOW_MANAGED_FLAGS, Pt_TRUE, Ph_WM_HIDE);

        /* remove border and caption if no frame flag selected */
        if ((flags & SDL_NOFRAME) == SDL_NOFRAME)
        {
            PtSetArg(&arg[pargc++], Pt_ARG_WINDOW_RENDER_FLAGS, Pt_FALSE, Ph_WM_RENDER_TITLE | Ph_WM_RENDER_BORDER);
        }
        else
        {
            PtSetArg(&arg[pargc++], Pt_ARG_WINDOW_RENDER_FLAGS, Pt_TRUE, Ph_WM_RENDER_TITLE | Ph_WM_RENDER_BORDER);
        }

        /* if window is not resizable then remove resize handles and maximize button */
        if ((flags & SDL_RESIZABLE) != SDL_RESIZABLE)
        {
            PtSetArg(&arg[pargc++], Pt_ARG_WINDOW_RENDER_FLAGS, Pt_FALSE, Ph_WM_RENDER_RESIZE | Ph_WM_RENDER_MAX);
            PtSetArg(&arg[pargc++], Pt_ARG_WINDOW_MANAGED_FLAGS, Pt_FALSE, Ph_WM_RESIZE | Ph_WM_MAX);
            PtSetArg(&arg[pargc++], Pt_ARG_WINDOW_NOTIFY_FLAGS, Pt_FALSE, Ph_WM_RESIZE | Ph_WM_MAX);
        }
        else
        {
            PtSetArg(&arg[pargc++], Pt_ARG_WINDOW_RENDER_FLAGS, Pt_TRUE, Ph_WM_RENDER_RESIZE | Ph_WM_RENDER_MAX);
            /* it is need to be Pt_FALSE to allow the application to process the resize callback */
            PtSetArg(&arg[pargc++], Pt_ARG_WINDOW_MANAGED_FLAGS, Pt_FALSE, Ph_WM_RESIZE | Ph_WM_MAX);
            PtSetArg(&arg[pargc++], Pt_ARG_WINDOW_NOTIFY_FLAGS, Pt_TRUE, Ph_WM_RESIZE | Ph_WM_MAX);
        }

        if (window!=NULL)
        {
            PtUnrealizeWidget(window);
            PtDestroyWidget(window);
            window=NULL;
        }

        window=PtCreateWidget(PtWindow, NULL, pargc, arg);
        PtRealizeWidget(window);
        
        PtFlush();
    }

#ifdef HAVE_OPENGL
    if (flags & SDL_OPENGL)
    {
        /* ph_SetupOpenGLContext creates also window as need */
        if (ph_SetupOpenGLContext(this, width, height, bpp, flags)==0)
        {
            /* setup OGL update function ... ugly method */
            ph_ResizeImage(this, current, flags); 
        }
        else
        {
            /* if context creation fail, report no OpenGL to high level */
            current->flags=(flags & (~SDL_OPENGL));
        }
#else
    if (flags & SDL_OPENGL) /* if no built-in OpenGL support */
    {
        fprintf(stderr, "error: no OpenGL support, try to recompile library.\n");
        current->flags=(flags & (~SDL_OPENGL));
        return NULL;
#endif /* HAVE_OPENGL */
    }
    else
    {
        /* Initialize the window */
        if (flags & SDL_FULLSCREEN) /* Direct Context , assume SDL_HWSURFACE also set */
        {
            /* Get the video mode and set it */
            if (flags & SDL_ANYFORMAT)
            {
                if ((mode = get_mode_any_format(width, height, bpp)) == 0)
                {
                    fprintf(stderr,"error: get_mode_any_format failed\n");
                    exit(1);
                }
            }
            else
            {
                if ((mode = get_mode(width, height, bpp)) == 0)
                {
                    fprintf(stderr,"error: get_mode failed\n");
                    exit(1);
                }
            }
            
            if (bpp==8)
            {
               desktoppal=SDLPH_PAL_SYSTEM;
            }
            
            /* save old video mode caps */
            PgGetVideoMode(&settings);
            old_video_mode=settings.mode;
            old_refresh_rate=settings.refresh;

            /* setup new video mode */
            settings.mode = mode;
            settings.refresh = 0;
            settings.flags = 0;

            if (PgSetVideoMode(&settings) < 0)
            {
                fprintf(stderr,"error: PgSetVideoMode failed\n");
            }

            current->flags = (flags & (~SDL_RESIZABLE)); /* no resize for Direct Context */

            /* Begin direct mode */
            ph_EnterFullScreen(this);

        } /* end fullscreen flag */
        else
        {
            /* Use offscreen memory iff SDL_HWSURFACE flag is set */
            if (flags & SDL_HWSURFACE)
            {
                /* no stretch blit in offscreen context */
                current->flags = (flags & (~SDL_RESIZABLE));
            }

            /* using palette emulation code in window mode */
            if (bpp==8)
            {
                if (desktopbpp>=15)
                {
                    desktoppal=SDLPH_PAL_EMULATE;
                }
                else
                {
                    desktoppal=SDLPH_PAL_SYSTEM;
                }
            }
            else
            {
               desktoppal=SDLPH_PAL_NONE;
            }
        }

	/* If we are setting video to use the palette make sure we have allocated memory for it */
	if (bpp==8)
	{
            current->format->palette = malloc(sizeof(SDL_Palette));
            memset(current->format->palette, 0, sizeof(SDL_Palette));
            current->format->palette->ncolors = 256;
            current->format->palette->colors = (SDL_Color *)malloc(256 *sizeof(SDL_Color));
            /* fill the palette */
            rtnval = PgGetPalette(ph_palette);

            tempptr = (unsigned long *)current->format->palette->colors;

            for(i=0; i<256; i++)
            {
                *tempptr = (((unsigned long)ph_palette[i]) << 8);
                tempptr++;
            }
        }

    }

    current->w = width;
    current->h = height;
    current->format->BitsPerPixel = bpp;
    current->format->BytesPerPixel = (bpp+7)/8;
    current->pitch = SDL_CalculatePitch(current);
    /* Must call at least once it setup image planes */
    ph_ResizeImage(this, current, flags);

    /* delayed set caption call */
    if (captionflag)
    {
        ph_SetCaption(this, this->wm_title, NULL);
    }

    /* finish window drawing */
    PtFlush();

    SDL_Unlock_EventThread();

    /* We're done! */
    return (current);
}

static void ph_VideoQuit(_THIS)
{
#ifdef HAVE_OPENGL
    PhRegion_t region_info;
#endif /* HAVE_OPENGL */

    ph_DestroyImage(this, SDL_VideoSurface); 

    if (currently_fullscreen)
    {
        ph_LeaveFullScreen(this);
    }

#ifdef HAVE_OPENGL
    /* prevent double SEGFAULT during parachute mode */
    if (this->screen)
    {
        if (((this->screen->flags & SDL_FULLSCREEN)==SDL_FULLSCREEN) &&
            ((this->screen->flags & SDL_OPENGL)==SDL_OPENGL))
        {
            region_info.cursor_type=Ph_CURSOR_POINTER;
            region_info.rid=PtWidgetRid(window);
            PhRegionChange(Ph_REGION_CURSOR, 0, &region_info, NULL, NULL);
        }
    }

    PtFlush();
#endif /* HAVE_OPENGL */
    
    if (window)
    {
        PtUnrealizeWidget(window);
        PtDestroyWidget(window);
        window=NULL;
    }
    
    /* restore palette */
    if (desktoppal!=SDLPH_PAL_NONE)
    {
        PgSetPalette(ph_palette, 0, 0, _Pg_MAX_PALETTE, Pg_PALSET_GLOBAL | Pg_PALSET_FORCE_EXPOSE, 0);
    }

#ifdef HAVE_OPENGL
    if (oglctx)
    {
        PhDCSetCurrent(NULL);
        PhDCRelease(oglctx);
        oglctx=NULL;
    }
#endif /* HAVE_OPENGL */
}

static int ph_SetColors(_THIS, int firstcolor, int ncolors, SDL_Color *colors)
{
    int i;
    PhPoint_t point={0, 0};
    PgColor_t syspalph[_Pg_MAX_PALETTE];

    /* palette emulation code, using palette of the PhImage_t struct */
    if (desktoppal==SDLPH_PAL_EMULATE)
    {
        if ((SDL_Image) && (SDL_Image->palette))
        {
            for (i=firstcolor; i<firstcolor+ncolors; i++)
            {
                SDL_Image->palette[i]  = 0x00000000UL;
                SDL_Image->palette[i] |= colors[i-firstcolor].r<<16;
                SDL_Image->palette[i] |= colors[i-firstcolor].g<<8;
                SDL_Image->palette[i] |= colors[i-firstcolor].b;
            }
        }
        /* image needs to be redrawed, very slow method */
        PgDrawPhImage(&point, SDL_Image, 0);
    }
    else
    {
        if (desktoppal==SDLPH_PAL_SYSTEM)
        {
            for (i=firstcolor; i<firstcolor+ncolors; i++)
            {
                syspalph[i]  = 0x00000000UL;
                syspalph[i] |= colors[i-firstcolor].r<<16;
                syspalph[i] |= colors[i-firstcolor].g<<8;
                syspalph[i] |= colors[i-firstcolor].b;
            }

            if ((this->screen->flags & SDL_FULLSCREEN) != SDL_FULLSCREEN)
            {
                /* window mode must use soft palette */
                PgSetPalette((PgColor_t*)&syspalph[firstcolor], 0, firstcolor, ncolors, Pg_PALSET_SOFT, 0);
                /* image needs to be redrawed, very slow method */
                PgDrawPhImage(&point, SDL_Image, 0);
            }
            else
            {
                /* fullscreen mode must use hardware palette */
                PgSetPalette((PgColor_t*)&syspalph[firstcolor], 0, firstcolor, ncolors, Pg_PALSET_GLOBAL, 0);
            }
        }
        else
        {
            /* SDLPH_PAL_NONE do nothing */
        }
    }
    
    return 1;
}

#ifdef HAVE_OPENGL

int ph_SetupOpenGLContext(_THIS, int width, int height, int bpp, Uint32 flags)
{
    PtArg_t args[8];
    PhDim_t dim;
    uint64_t OGLAttrib[PH_OGL_MAX_ATTRIBS];
    int OGLargc;
    int pargc;

    dim.w=width;
    dim.h=height;
    
    if (oglctx!=NULL)
    {
       PhDCSetCurrent(NULL);
       PhDCRelease(oglctx);
       oglctx=NULL;
    }

    OGLargc=0;
    if (this->gl_config.depth_size)
    {
        OGLAttrib[OGLargc++]=PHOGL_ATTRIB_DEPTH_BITS;
        OGLAttrib[OGLargc++]=this->gl_config.depth_size;
    }
    if (this->gl_config.stencil_size)
    {
        OGLAttrib[OGLargc++]=PHOGL_ATTRIB_STENCIL_BITS;
        OGLAttrib[OGLargc++]=this->gl_config.stencil_size;
    }
    OGLAttrib[OGLargc++]=PHOGL_ATTRIB_FORCE_SW;
    if (flags & SDL_FULLSCREEN)
    {
        OGLAttrib[OGLargc++]=PHOGL_ATTRIB_FULLSCREEN;
        OGLAttrib[OGLargc++]=PHOGL_ATTRIB_DIRECT;
        OGLAttrib[OGLargc++]=PHOGL_ATTRIB_FULLSCREEN_BEST;
        OGLAttrib[OGLargc++]=PHOGL_ATTRIB_FULLSCREEN_CENTER;
    }
    OGLAttrib[OGLargc++]=PHOGL_ATTRIB_NONE;

    if (this->gl_config.double_buffer)
    {
        oglctx=PdCreateOpenGLContext(2, &dim, 0, OGLAttrib);
    }
    else
    {
        oglctx=PdCreateOpenGLContext(1, &dim, 0, OGLAttrib);
    }

    if (oglctx==NULL)
    {
        fprintf(stderr,"ph_SetupOpenGLContext: cannot create OpenGL context.\n");
        return (-1);
    }

    PhDCSetCurrent(oglctx);

    pargc=0;

    PtSetArg(&args[pargc++], Pt_ARG_DIM, &dim, 0);
    PtSetArg(&args[pargc++], Pt_ARG_RESIZE_FLAGS, Pt_FALSE, Pt_RESIZE_XY_AS_REQUIRED);
    PtSetArg(&args[pargc++], Pt_ARG_FILL_COLOR, Pg_BLACK, 0);

    if (flags & SDL_FULLSCREEN)
    {
        PhPoint_t pos;

        pos.x=0;
        pos.y=0;

        PtSetArg(&args[pargc++], Pt_ARG_WINDOW_RENDER_FLAGS, Pt_FALSE, ~0);
        PtSetArg(&args[pargc++], Pt_ARG_WINDOW_MANAGED_FLAGS, Pt_TRUE, Ph_WM_FFRONT | Ph_WM_CLOSE | Ph_WM_TOFRONT | Ph_WM_CONSWITCH);
        PtSetArg(&args[pargc++], Pt_ARG_WINDOW_STATE, Pt_TRUE, Ph_WM_STATE_ISFRONT | Ph_WM_STATE_ISFOCUS);
        PtSetArg(&args[pargc++], Pt_ARG_POS, &pos, 0);
    }
    else
    {
        /* remove border and caption if no frame flag selected */
        if ((flags & SDL_NOFRAME) == SDL_NOFRAME)
        {
            PtSetArg(&args[pargc++], Pt_ARG_WINDOW_RENDER_FLAGS, 0, Ph_WM_RENDER_TITLE | Ph_WM_RENDER_BORDER);
        }
        else
        {
           /* if window is not resizable then remove resize handles */
           if ((flags & SDL_RESIZABLE) != SDL_RESIZABLE)
           {
               PtSetArg(&args[pargc++], Pt_ARG_WINDOW_RENDER_FLAGS, 0, Ph_WM_RENDER_RESIZE);
           }
        }
    }

    if (window!=NULL)
    {
        PtUnrealizeWidget(window);
        PtDestroyWidget(window);
        window=NULL;
    }

    window=PtCreateWidget(PtWindow, NULL, pargc, args);
    PtRealizeWidget(window);

    /* disable mouse for fullscreen */
    if (flags & SDL_FULLSCREEN)
    {
        PhRegion_t region_info;

        region_info.cursor_type=Ph_CURSOR_NONE;
        region_info.rid=PtWidgetRid(window);
        PhRegionChange(Ph_REGION_CURSOR, 0, &region_info, NULL, NULL);
    }

    PtFlush();

    return 0;
}

void ph_GL_SwapBuffers(_THIS)
{
    PgSetRegion(PtWidgetRid(window));
    PdOpenGLContextSwapBuffers(oglctx);
}

int ph_GL_GetAttribute(_THIS, SDL_GLattr attrib, int* value)
{
    switch (attrib)
    {
        case SDL_GL_DOUBLEBUFFER:
             *value=this->gl_config.double_buffer;
             break;
        case SDL_GL_STENCIL_SIZE:
             *value=this->gl_config.stencil_size;
             break;
        case SDL_GL_DEPTH_SIZE:
             *value=this->gl_config.depth_size;
             break;
        default:
             *value=0;
             return(-1);
    }
    return 0;
}

#endif /* HAVE_OPENGL */