src/video/ataricommon/SDL_atarigl.c

/*
    SDL - Simple DirectMedia Layer
    Copyright (C) 1997-2004 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
*/
#include "SDL_config.h"

/* Atari OSMesa.ldg implementation of SDL OpenGL support */

/*--- Includes ---*/

#if SDL_VIDEO_OPENGL
#include <GL/osmesa.h>
#endif

#include <mint/osbind.h>

#include "SDL_endian.h"
#include "SDL_video.h"
#include "SDL_atarigl_c.h"
#if SDL_VIDEO_OPENGL_OSMESA_DYNAMIC
#include "SDL_loadso.h"
#endif

/*--- Defines ---*/

#define PATH_OSMESA_LDG	"osmesa.ldg"
#define PATH_MESAGL_LDG	"mesa_gl.ldg"
#define PATH_TINYGL_LDG	"tiny_gl.ldg"

#define VDI_RGB	0xf

/*--- Functions prototypes ---*/

static void SDL_AtariGL_UnloadLibrary(_THIS);

#if SDL_VIDEO_OPENGL
static void CopyShadowNull(_THIS, SDL_Surface * surface);
static void CopyShadowDirect(_THIS, SDL_Surface * surface);
static void CopyShadowRGBTo555(_THIS, SDL_Surface * surface);
static void CopyShadowRGBTo565(_THIS, SDL_Surface * surface);
static void CopyShadowRGBSwap(_THIS, SDL_Surface * surface);
static void CopyShadowRGBToARGB(_THIS, SDL_Surface * surface);
static void CopyShadowRGBToABGR(_THIS, SDL_Surface * surface);
static void CopyShadowRGBToBGRA(_THIS, SDL_Surface * surface);
static void CopyShadowRGBToRGBA(_THIS, SDL_Surface * surface);
static void CopyShadow8888To555(_THIS, SDL_Surface * surface);
static void CopyShadow8888To565(_THIS, SDL_Surface * surface);

static void ConvertNull(_THIS, SDL_Surface * surface);
static void Convert565To555be(_THIS, SDL_Surface * surface);
static void Convert565To555le(_THIS, SDL_Surface * surface);
static void Convert565le(_THIS, SDL_Surface * surface);
static void ConvertBGRAToABGR(_THIS, SDL_Surface * surface);

static int InitNew(_THIS, SDL_Surface * current);
static int InitOld(_THIS, SDL_Surface * current);
#endif

/*--- Public functions ---*/

int
SDL_AtariGL_Init(_THIS, SDL_Surface * current)
{
#if SDL_VIDEO_OPENGL
    if (gl_oldmesa) {
        gl_active = InitOld(this, current);
    } else {
        gl_active = InitNew(this, current);
    }
#endif

    return (gl_active);
}

void
SDL_AtariGL_Quit(_THIS, SDL_bool unload)
{
#if SDL_VIDEO_OPENGL
    if (gl_oldmesa) {
        /* Old mesa implementations */
        if (this->gl_data->OSMesaDestroyLDG) {
            this->gl_data->OSMesaDestroyLDG();
        }
        if (gl_shadow) {
            Mfree(gl_shadow);
            gl_shadow = NULL;
        }
    } else {
        /* New mesa implementation */
        if (gl_ctx) {
            if (this->gl_data->OSMesaDestroyContext) {
                this->gl_data->OSMesaDestroyContext(gl_ctx);
            }
            gl_ctx = NULL;
        }
    }

    if (unload) {
        SDL_AtariGL_UnloadLibrary(this);
    }
#endif /* SDL_VIDEO_OPENGL */
    gl_active = 0;
}

int
SDL_AtariGL_LoadLibrary(_THIS, const char *path)
{
#if SDL_VIDEO_OPENGL

#if SDL_VIDEO_OPENGL_OSMESA_DYNAMIC
    void *handle;
    SDL_bool cancel_load;

    if (gl_active) {
        SDL_SetError("OpenGL context already created");
        return -1;
    }

    /* Unload previous driver */
    SDL_AtariGL_UnloadLibrary(this);

    /* Load library given by path */
    handle = SDL_LoadObject(path);
    if (handle == NULL) {
        /* Try to load another one */
        path = SDL_getenv("SDL_VIDEO_GL_DRIVER");
        if (path != NULL) {
            handle = SDL_LoadObject(path);
        }

        /* If it does not work, try some other */
        if (handle == NULL) {
            path = PATH_OSMESA_LDG;
            handle = SDL_LoadObject(path);
        }

        if (handle == NULL) {
            path = PATH_MESAGL_LDG;
            handle = SDL_LoadObject(path);
        }

        if (handle == NULL) {
            path = PATH_TINYGL_LDG;
            handle = SDL_LoadObject(path);
        }
    }

    if (handle == NULL) {
        SDL_SetError("Could not load OpenGL library");
        return -1;
    }

    this->gl_data->glGetIntegerv = SDL_LoadFunction(handle, "glGetIntegerv");
    this->gl_data->glFinish = SDL_LoadFunction(handle, "glFinish");
    this->gl_data->glFlush = SDL_LoadFunction(handle, "glFlush");

    cancel_load = SDL_FALSE;
    if (this->gl_data->glGetIntegerv == NULL) {
        cancel_load = SDL_TRUE;
    } else {
        /* We need either glFinish (OSMesa) or glFlush (TinyGL) */
        if ((this->gl_data->glFinish == NULL) &&
            (this->gl_data->glFlush == NULL)) {
            cancel_load = SDL_TRUE;
        }
    }
    if (cancel_load) {
        SDL_SetError("Could not retrieve OpenGL functions");
        SDL_UnloadObject(handle);
        /* Restore pointers to static library */
        SDL_AtariGL_InitPointers(this);
        return -1;
    }

    /* Load functions pointers (osmesa.ldg) */
    this->gl_data->OSMesaCreateContextExt =
        SDL_LoadFunction(handle, "OSMesaCreateContextExt");
    this->gl_data->OSMesaDestroyContext =
        SDL_LoadFunction(handle, "OSMesaDestroyContext");
    this->gl_data->OSMesaMakeCurrent =
        SDL_LoadFunction(handle, "OSMesaMakeCurrent");
    this->gl_data->OSMesaPixelStore =
        SDL_LoadFunction(handle, "OSMesaPixelStore");
    this->gl_data->OSMesaGetProcAddress =
        SDL_LoadFunction(handle, "OSMesaGetProcAddress");

    /* Load old functions pointers (mesa_gl.ldg, tiny_gl.ldg) */
    this->gl_data->OSMesaCreateLDG =
        SDL_LoadFunction(handle, "OSMesaCreateLDG");
    this->gl_data->OSMesaDestroyLDG =
        SDL_LoadFunction(handle, "OSMesaDestroyLDG");

    gl_oldmesa = 0;

    if ((this->gl_data->OSMesaCreateContextExt == NULL) ||
        (this->gl_data->OSMesaDestroyContext == NULL) ||
        (this->gl_data->OSMesaMakeCurrent == NULL) ||
        (this->gl_data->OSMesaPixelStore == NULL) ||
        (this->gl_data->OSMesaGetProcAddress == NULL)) {
        /* Hum, maybe old library ? */
        if ((this->gl_data->OSMesaCreateLDG == NULL) ||
            (this->gl_data->OSMesaDestroyLDG == NULL)) {
            SDL_SetError("Could not retrieve OSMesa functions");
            SDL_UnloadObject(handle);
            /* Restore pointers to static library */
            SDL_AtariGL_InitPointers(this);
            return -1;
        } else {
            gl_oldmesa = 1;
        }
    }

    this->gl_config.dll_handle = handle;
    if (path) {
        SDL_strlcpy(this->gl_config.driver_path, path,
                    SDL_arraysize(this->gl_config.driver_path));
    } else {
        *this->gl_config.driver_path = '\0';
    }

#endif
    this->gl_config.driver_loaded = 1;

    return 0;
#else
    return -1;
#endif
}

void *
SDL_AtariGL_GetProcAddress(_THIS, const char *proc)
{
    void *func = NULL;
#if SDL_VIDEO_OPENGL

    if (this->gl_config.dll_handle) {
        func = SDL_LoadFunction(this->gl_config.dll_handle, (void *) proc);
    } else if (this->gl_data->OSMesaGetProcAddress) {
        func = this->gl_data->OSMesaGetProcAddress(proc);
    }
#endif
    return func;
}

int
SDL_AtariGL_GetAttribute(_THIS, SDL_GLattr attrib, int *value)
{
#if SDL_VIDEO_OPENGL
    GLenum mesa_attrib;
    SDL_Surface *surface;

    if (!gl_active) {
        return -1;
    }

    switch (attrib) {
    case SDL_GL_RED_SIZE:
        mesa_attrib = GL_RED_BITS;
        break;
    case SDL_GL_GREEN_SIZE:
        mesa_attrib = GL_GREEN_BITS;
        break;
    case SDL_GL_BLUE_SIZE:
        mesa_attrib = GL_BLUE_BITS;
        break;
    case SDL_GL_ALPHA_SIZE:
        mesa_attrib = GL_ALPHA_BITS;
        break;
    case SDL_GL_DOUBLEBUFFER:
        surface = this->screen;
        *value = ((surface->flags & SDL_DOUBLEBUF) == SDL_DOUBLEBUF);
        return 0;
    case SDL_GL_DEPTH_SIZE:
        mesa_attrib = GL_DEPTH_BITS;
        break;
    case SDL_GL_STENCIL_SIZE:
        mesa_attrib = GL_STENCIL_BITS;
        break;
    case SDL_GL_ACCUM_RED_SIZE:
        mesa_attrib = GL_ACCUM_RED_BITS;
        break;
    case SDL_GL_ACCUM_GREEN_SIZE:
        mesa_attrib = GL_ACCUM_GREEN_BITS;
        break;
    case SDL_GL_ACCUM_BLUE_SIZE:
        mesa_attrib = GL_ACCUM_BLUE_BITS;
        break;
    case SDL_GL_ACCUM_ALPHA_SIZE:
        mesa_attrib = GL_ACCUM_ALPHA_BITS;
        break;
    default:
        return -1;
    }

    this->gl_data->glGetIntegerv(mesa_attrib, value);
    return 0;
#else
    return -1;
#endif
}

int
SDL_AtariGL_MakeCurrent(_THIS)
{
#if SDL_VIDEO_OPENGL
    SDL_Surface *surface;
    GLenum type;

    if (gl_oldmesa && gl_active) {
        return 0;
    }

    if (this->gl_config.dll_handle) {
        if ((this->gl_data->OSMesaMakeCurrent == NULL) ||
            (this->gl_data->OSMesaPixelStore == NULL)) {
            return -1;
        }
    }

    if (!gl_active) {
        SDL_SetError("Invalid OpenGL context");
        return -1;
    }

    surface = this->screen;

    if ((surface->format->BitsPerPixel == 15)
        || (surface->format->BitsPerPixel == 16)) {
        type = GL_UNSIGNED_SHORT_5_6_5;
    } else {
        type = GL_UNSIGNED_BYTE;
    }

    if (!
        (this->gl_data->
         OSMesaMakeCurrent(gl_ctx, surface->pixels, type, surface->w,
                           surface->h))) {
        SDL_SetError("Can not make OpenGL context current");
        return -1;
    }

    /* OSMesa draws upside down */
    this->gl_data->OSMesaPixelStore(OSMESA_Y_UP, 0);

    return 0;
#else
    return -1;
#endif
}

void
SDL_AtariGL_SwapBuffers(_THIS)
{
#if SDL_VIDEO_OPENGL
    if (gl_active) {
        if (this->gl_config.dll_handle) {
            if (this->gl_data->glFinish) {
                this->gl_data->glFinish();
            } else if (this->gl_data->glFlush) {
                this->gl_data->glFlush();
            }
        } else {
            this->gl_data->glFinish();
        }
        gl_copyshadow(this, this->screen);
        gl_convert(this, this->screen);
    }
#endif
}

void
SDL_AtariGL_InitPointers(_THIS)
{
#if SDL_VIDEO_OPENGL
    this->gl_data->OSMesaCreateContextExt = OSMesaCreateContextExt;
    this->gl_data->OSMesaDestroyContext = OSMesaDestroyContext;
    this->gl_data->OSMesaMakeCurrent = OSMesaMakeCurrent;
    this->gl_data->OSMesaPixelStore = OSMesaPixelStore;
    this->gl_data->OSMesaGetProcAddress = OSMesaGetProcAddress;

    this->gl_data->glGetIntegerv = glGetIntegerv;
    this->gl_data->glFinish = glFinish;
    this->gl_data->glFlush = glFlush;

    this->gl_data->OSMesaCreateLDG = NULL;
    this->gl_data->OSMesaDestroyLDG = NULL;
#endif
}

/*--- Private functions ---*/

static void
SDL_AtariGL_UnloadLibrary(_THIS)
{
#if SDL_VIDEO_OPENGL
    if (this->gl_config.dll_handle) {
        SDL_UnloadObject(this->gl_config.dll_handle);
        this->gl_config.dll_handle = NULL;

        /* Restore pointers to static library */
        SDL_AtariGL_InitPointers(this);
    }
#endif
}

/*--- Creation of an OpenGL context using new/old functions ---*/

#if SDL_VIDEO_OPENGL
static int
InitNew(_THIS, SDL_Surface * current)
{
    GLenum osmesa_format;
    SDL_PixelFormat *pixel_format;
    Uint32 redmask;
    int recreatecontext;
    GLint newaccumsize;

    if (this->gl_config.dll_handle) {
        if (this->gl_data->OSMesaCreateContextExt == NULL) {
            return 0;
        }
    }

    /* Init OpenGL context using OSMesa */
    gl_convert = ConvertNull;
    gl_copyshadow = CopyShadowNull;
    gl_upsidedown = SDL_FALSE;

    pixel_format = current->format;
    redmask = pixel_format->Rmask;
    switch (pixel_format->BitsPerPixel) {
    case 15:
        /* 1555, big and little endian, unsupported */
        gl_pixelsize = 2;
        osmesa_format = OSMESA_RGB_565;
        if (redmask == 31 << 10) {
            gl_convert = Convert565To555be;
        } else {
            gl_convert = Convert565To555le;
        }
        break;
    case 16:
        gl_pixelsize = 2;
        if (redmask == 31 << 11) {
            osmesa_format = OSMESA_RGB_565;
        } else {
            /* 565, little endian, unsupported */
            osmesa_format = OSMESA_RGB_565;
            gl_convert = Convert565le;
        }
        break;
    case 24:
        gl_pixelsize = 3;
        if (redmask == 255 << 16) {
            osmesa_format = OSMESA_RGB;
        } else {
            osmesa_format = OSMESA_BGR;
        }
        break;
    case 32:
        gl_pixelsize = 4;
        if (redmask == 255 << 16) {
            osmesa_format = OSMESA_ARGB;
        } else if (redmask == 255 << 8) {
            osmesa_format = OSMESA_BGRA;
        } else if (redmask == 255 << 24) {
            osmesa_format = OSMESA_RGBA;
        } else {
            /* ABGR format unsupported */
            osmesa_format = OSMESA_BGRA;
            gl_convert = ConvertBGRAToABGR;
        }
        break;
    default:
        gl_pixelsize = 1;
        osmesa_format = OSMESA_COLOR_INDEX;
        break;
    }

    /* Try to keep current context if possible */
    newaccumsize =
        this->gl_config.accum_red_size +
        this->gl_config.accum_green_size +
        this->gl_config.accum_blue_size + this->gl_config.accum_alpha_size;
    recreatecontext = 1;
    if (gl_ctx &&
        (gl_curformat == osmesa_format) &&
        (gl_curdepth == this->gl_config.depth_size) &&
        (gl_curstencil == this->gl_config.stencil_size) &&
        (gl_curaccum == newaccumsize)) {
        recreatecontext = 0;
    }
    if (recreatecontext) {
        SDL_AtariGL_Quit(this, SDL_FALSE);

        gl_ctx =
            this->gl_data->OSMesaCreateContextExt(osmesa_format,
                                                  this->gl_config.
                                                  depth_size,
                                                  this->gl_config.
                                                  stencil_size,
                                                  newaccumsize, NULL);

        if (gl_ctx) {
            gl_curformat = osmesa_format;
            gl_curdepth = this->gl_config.depth_size;
            gl_curstencil = this->gl_config.stencil_size;
            gl_curaccum = newaccumsize;
        } else {
            gl_curformat = 0;
            gl_curdepth = 0;
            gl_curstencil = 0;
            gl_curaccum = 0;
        }
    }

    return (gl_ctx != NULL);
}


static int
InitOld(_THIS, SDL_Surface * current)
{
    GLenum osmesa_format;
    SDL_PixelFormat *pixel_format;
    Uint32 redmask;
    int recreatecontext, tinygl_present;

    if (this->gl_config.dll_handle) {
        if (this->gl_data->OSMesaCreateLDG == NULL) {
            return 0;
        }
    }

    /* TinyGL only supports VDI_RGB (OSMESA_RGB) */
    tinygl_present = 0;
    if (this->gl_config.dll_handle) {
        if (this->gl_data->glFinish == NULL) {
            tinygl_present = 1;
        }
    }

    /* Init OpenGL context using OSMesa */
    gl_convert = ConvertNull;
    gl_copyshadow = CopyShadowNull;
    gl_upsidedown = SDL_FALSE;

    pixel_format = current->format;
    redmask = pixel_format->Rmask;
    switch (pixel_format->BitsPerPixel) {
    case 15:
        /* 15 bits unsupported */
        if (tinygl_present) {
            gl_pixelsize = 3;
            osmesa_format = VDI_RGB;
            if (redmask == 31 << 10) {
                gl_copyshadow = CopyShadowRGBTo555;
            } else {
                gl_copyshadow = CopyShadowRGBTo565;
                gl_convert = Convert565To555le;
            }
        } else {
            gl_pixelsize = 4;
            gl_upsidedown = SDL_TRUE;
            osmesa_format = OSMESA_ARGB;
            if (redmask == 31 << 10) {
                gl_copyshadow = CopyShadow8888To555;
            } else {
                gl_copyshadow = CopyShadow8888To565;
                gl_convert = Convert565To555le;
            }
        }
        break;
    case 16:
        /* 16 bits unsupported */
        if (tinygl_present) {
            gl_pixelsize = 3;
            osmesa_format = VDI_RGB;
            gl_copyshadow = CopyShadowRGBTo565;
            if (redmask != 31 << 11) {
                /* 565, little endian, unsupported */
                gl_convert = Convert565le;
            }
        } else {
            gl_pixelsize = 4;
            gl_upsidedown = SDL_TRUE;
            osmesa_format = OSMESA_ARGB;
            gl_copyshadow = CopyShadow8888To565;
            if (redmask != 31 << 11) {
                /* 565, little endian, unsupported */
                gl_convert = Convert565le;
            }
        }
        break;
    case 24:
        gl_pixelsize = 3;
        if (tinygl_present) {
            osmesa_format = VDI_RGB;
            gl_copyshadow = CopyShadowDirect;
            if (redmask != 255 << 16) {
                gl_copyshadow = CopyShadowRGBSwap;
            }
        } else {
            gl_copyshadow = CopyShadowDirect;
            gl_upsidedown = SDL_TRUE;
            if (redmask == 255 << 16) {
                osmesa_format = OSMESA_RGB;
            } else {
                osmesa_format = OSMESA_BGR;
            }
        }
        break;
    case 32:
        if (tinygl_present) {
            gl_pixelsize = 3;
            osmesa_format = VDI_RGB;
            gl_copyshadow = CopyShadowRGBToARGB;
            if (redmask == 255) {
                gl_convert = CopyShadowRGBToABGR;
            } else if (redmask == 255 << 8) {
                gl_convert = CopyShadowRGBToBGRA;
            } else if (redmask == 255 << 24) {
                gl_convert = CopyShadowRGBToRGBA;
            }
        } else {
            gl_pixelsize = 4;
            gl_upsidedown = SDL_TRUE;
            gl_copyshadow = CopyShadowDirect;
            if (redmask == 255 << 16) {
                osmesa_format = OSMESA_ARGB;
            } else if (redmask == 255 << 8) {
                osmesa_format = OSMESA_BGRA;
            } else if (redmask == 255 << 24) {
                osmesa_format = OSMESA_RGBA;
            } else {
                /* ABGR format unsupported */
                osmesa_format = OSMESA_BGRA;
                gl_convert = ConvertBGRAToABGR;
            }
        }
        break;
    default:
        if (tinygl_present) {
            SDL_AtariGL_Quit(this, SDL_FALSE);
            return 0;
        }
        gl_pixelsize = 1;
        gl_copyshadow = CopyShadowDirect;
        osmesa_format = OSMESA_COLOR_INDEX;
        break;
    }

    /* Try to keep current context if possible */
    recreatecontext = 1;
    if (gl_shadow &&
        (gl_curformat == osmesa_format) &&
        (gl_curwidth == current->w) && (gl_curheight == current->h)) {
        recreatecontext = 0;
    }
    if (recreatecontext) {
        SDL_AtariGL_Quit(this, SDL_FALSE);

        gl_shadow =
            this->gl_data->OSMesaCreateLDG(osmesa_format, GL_UNSIGNED_BYTE,
                                           current->w, current->h);

        if (gl_shadow) {
            gl_curformat = osmesa_format;
            gl_curwidth = current->w;
            gl_curheight = current->h;
        } else {
            gl_curformat = 0;
            gl_curwidth = 0;
            gl_curheight = 0;
        }
    }

    return (gl_shadow != NULL);
}

/*--- Conversions routines from shadow buffer to the screen ---*/

static void
CopyShadowNull(_THIS, SDL_Surface * surface)
{
}

static void
CopyShadowDirect(_THIS, SDL_Surface * surface)
{
    int y, srcpitch, dstpitch;
    Uint8 *srcline, *dstline;

    srcline = gl_shadow;
    srcpitch = surface->w * gl_pixelsize;
    dstline = surface->pixels;
    dstpitch = surface->pitch;
    if (gl_upsidedown) {
        srcline += (surface->h - 1) * srcpitch;
        srcpitch = -srcpitch;
    }

    for (y = 0; y < surface->h; y++) {
        SDL_memcpy(dstline, srcline, srcpitch);

        srcline += srcpitch;
        dstline += dstpitch;
    }
}

static void
CopyShadowRGBTo555(_THIS, SDL_Surface * surface)
{
    int x, y, srcpitch, dstpitch;
    Uint16 *dstline, *dstcol;
    Uint8 *srcline, *srccol;

    srcline = (Uint8 *) gl_shadow;
    srcpitch = surface->w * gl_pixelsize;
    dstline = surface->pixels;
    dstpitch = surface->pitch >> 1;
    if (gl_upsidedown) {
        srcline += (surface->h - 1) * srcpitch;
        srcpitch = -srcpitch;
    }

    for (y = 0; y < surface->h; y++) {
        srccol = srcline;
        dstcol = dstline;
        for (x = 0; x < surface->w; x++) {
            Uint16 dstcolor;

            dstcolor = ((*srccol++) << 7) & (31 << 10);
            dstcolor |= ((*srccol++) << 2) & (31 << 5);
            dstcolor |= ((*srccol++) >> 3) & 31;
            *dstcol++ = dstcolor;
        }

        srcline += srcpitch;
        dstline += dstpitch;
    }
}

static void
CopyShadowRGBTo565(_THIS, SDL_Surface * surface)
{
    int x, y, srcpitch, dstpitch;
    Uint16 *dstline, *dstcol;
    Uint8 *srcline, *srccol;

    srcline = (Uint8 *) gl_shadow;
    srcpitch = surface->w * gl_pixelsize;
    dstline = surface->pixels;
    dstpitch = surface->pitch >> 1;
    if (gl_upsidedown) {
        srcline += (surface->h - 1) * srcpitch;
        srcpitch = -srcpitch;
    }

    for (y = 0; y < surface->h; y++) {
        srccol = srcline;
        dstcol = dstline;

        for (x = 0; x < surface->w; x++) {
            Uint16 dstcolor;

            dstcolor = ((*srccol++) << 8) & (31 << 11);
            dstcolor |= ((*srccol++) << 3) & (63 << 5);
            dstcolor |= ((*srccol++) >> 3) & 31;
            *dstcol++ = dstcolor;
        }

        srcline += srcpitch;
        dstline += dstpitch;
    }
}

static void
CopyShadowRGBSwap(_THIS, SDL_Surface * surface)
{
    int x, y, srcpitch, dstpitch;
    Uint8 *dstline, *dstcol;
    Uint8 *srcline, *srccol;

    srcline = (Uint8 *) gl_shadow;
    srcpitch = surface->w * gl_pixelsize;
    dstline = surface->pixels;
    dstpitch = surface->pitch;
    if (gl_upsidedown) {
        srcline += (surface->h - 1) * srcpitch;
        srcpitch = -srcpitch;
    }

    for (y = 0; y < surface->h; y++) {
        srccol = srcline;
        dstcol = dstline;

        for (x = 0; x < surface->w; x++) {
            *dstcol++ = srccol[2];
            *dstcol++ = srccol[1];
            *dstcol++ = srccol[0];
            srccol += 3;
        }

        srcline += srcpitch;
        dstline += dstpitch;
    }
}

static void
CopyShadowRGBToARGB(_THIS, SDL_Surface * surface)
{
    int x, y, srcpitch, dstpitch;
    Uint32 *dstline, *dstcol;
    Uint8 *srcline, *srccol;

    srcline = (Uint8 *) gl_shadow;
    srcpitch = surface->w * gl_pixelsize;
    dstline = surface->pixels;
    dstpitch = surface->pitch >> 2;
    if (gl_upsidedown) {
        srcline += (surface->h - 1) * srcpitch;
        srcpitch = -srcpitch;
    }

    for (y = 0; y < surface->h; y++) {
        srccol = srcline;
        dstcol = dstline;

        for (x = 0; x < surface->w; x++) {
            Uint32 dstcolor;

            dstcolor = (*srccol++) << 16;
            dstcolor |= (*srccol++) << 8;
            dstcolor |= *srccol++;

            *dstcol++ = dstcolor;
        }

        srcline += srcpitch;
        dstline += dstpitch;
    }
}

static void
CopyShadowRGBToABGR(_THIS, SDL_Surface * surface)
{
    int x, y, srcpitch, dstpitch;
    Uint32 *dstline, *dstcol;
    Uint8 *srcline, *srccol;

    srcline = (Uint8 *) gl_shadow;
    srcpitch = surface->w * gl_pixelsize;
    dstline = surface->pixels;
    dstpitch = surface->pitch >> 2;
    if (gl_upsidedown) {
        srcline += (surface->h - 1) * srcpitch;
        srcpitch = -srcpitch;
    }

    for (y = 0; y < surface->h; y++) {
        srccol = srcline;
        dstcol = dstline;

        for (x = 0; x < surface->w; x++) {
            Uint32 dstcolor;

            dstcolor = *srccol++;
            dstcolor |= (*srccol++) << 8;
            dstcolor |= (*srccol++) << 16;

            *dstcol++ = dstcolor;
        }

        srcline += srcpitch;
        dstline += dstpitch;
    }
}

static void
CopyShadowRGBToBGRA(_THIS, SDL_Surface * surface)
{
    int x, y, srcpitch, dstpitch;
    Uint32 *dstline, *dstcol;
    Uint8 *srcline, *srccol;

    srcline = (Uint8 *) gl_shadow;
    srcpitch = surface->w * gl_pixelsize;
    dstline = surface->pixels;
    dstpitch = surface->pitch >> 2;
    if (gl_upsidedown) {
        srcline += (surface->h - 1) * srcpitch;
        srcpitch = -srcpitch;
    }

    for (y = 0; y < surface->h; y++) {
        srccol = srcline;
        dstcol = dstline;

        for (x = 0; x < surface->w; x++) {
            Uint32 dstcolor;

            dstcolor = (*srccol++) << 8;
            dstcolor |= (*srccol++) << 16;
            dstcolor |= (*srccol++) << 24;

            *dstcol++ = dstcolor;
        }

        srcline += srcpitch;
        dstline += dstpitch;
    }
}

static void
CopyShadowRGBToRGBA(_THIS, SDL_Surface * surface)
{
    int x, y, srcpitch, dstpitch;
    Uint32 *dstline, *dstcol;
    Uint8 *srcline, *srccol;

    srcline = (Uint8 *) gl_shadow;
    srcpitch = surface->w * gl_pixelsize;
    dstline = surface->pixels;
    dstpitch = surface->pitch >> 2;
    if (gl_upsidedown) {
        srcline += (surface->h - 1) * srcpitch;
        srcpitch = -srcpitch;
    }

    for (y = 0; y < surface->h; y++) {
        srccol = srcline;
        dstcol = dstline;

        for (x = 0; x < surface->w; x++) {
            Uint32 dstcolor;

            dstcolor = (*srccol++) << 24;
            dstcolor |= (*srccol++) << 16;
            dstcolor |= (*srccol++) << 8;

            *dstcol++ = dstcolor;
        }

        srcline += srcpitch;
        dstline += dstpitch;
    }
}

static void
CopyShadow8888To555(_THIS, SDL_Surface * surface)
{
    int x, y, srcpitch, dstpitch;
    Uint16 *dstline, *dstcol;
    Uint32 *srcline, *srccol;

    srcline = (Uint32 *) gl_shadow;
    srcpitch = (surface->w * gl_pixelsize) >> 2;
    dstline = surface->pixels;
    dstpitch = surface->pitch >> 1;
    if (gl_upsidedown) {
        srcline += (surface->h - 1) * srcpitch;
        srcpitch = -srcpitch;
    }

    for (y = 0; y < surface->h; y++) {
        srccol = srcline;
        dstcol = dstline;
        for (x = 0; x < surface->w; x++) {
            Uint32 srccolor;
            Uint16 dstcolor;

            srccolor = *srccol++;
            dstcolor = (srccolor >> 9) & (31 << 10);
            dstcolor |= (srccolor >> 6) & (31 << 5);
            dstcolor |= (srccolor >> 3) & 31;
            *dstcol++ = dstcolor;
        }

        srcline += srcpitch;
        dstline += dstpitch;
    }
}

static void
CopyShadow8888To565(_THIS, SDL_Surface * surface)
{
    int x, y, srcpitch, dstpitch;
    Uint16 *dstline, *dstcol;
    Uint32 *srcline, *srccol;

    srcline = (Uint32 *) gl_shadow;
    srcpitch = (surface->w * gl_pixelsize) >> 2;
    dstline = surface->pixels;
    dstpitch = surface->pitch >> 1;
    if (gl_upsidedown) {
        srcline += (surface->h - 1) * srcpitch;
        srcpitch = -srcpitch;
    }

    for (y = 0; y < surface->h; y++) {
        srccol = srcline;
        dstcol = dstline;

        for (x = 0; x < surface->w; x++) {
            Uint32 srccolor;
            Uint16 dstcolor;

            srccolor = *srccol++;
            dstcolor = (srccolor >> 8) & (31 << 11);
            dstcolor |= (srccolor >> 5) & (63 << 5);
            dstcolor |= (srccolor >> 3) & 31;
            *dstcol++ = dstcolor;
        }

        srcline += srcpitch;
        dstline += dstpitch;
    }
}

/*--- Conversions routines in the screen ---*/

static void
ConvertNull(_THIS, SDL_Surface * surface)
{
}

static void
Convert565To555be(_THIS, SDL_Surface * surface)
{
    int x, y, pitch;
    unsigned short *line, *pixel;

    line = surface->pixels;
    pitch = surface->pitch >> 1;
    for (y = 0; y < surface->h; y++) {
        pixel = line;
        for (x = 0; x < surface->w; x++) {
            unsigned short color = *pixel;

            *pixel++ = (color & 0x1f) | ((color >> 1) & 0xffe0);
        }

        line += pitch;
    }
}

static void
Convert565To555le(_THIS, SDL_Surface * surface)
{
    int x, y, pitch;
    unsigned short *line, *pixel;

    line = surface->pixels;
    pitch = surface->pitch >> 1;
    for (y = 0; y < surface->h; y++) {
        pixel = line;
        for (x = 0; x < surface->w; x++) {
            unsigned short color = *pixel;

            color = (color & 0x1f) | ((color >> 1) & 0xffe0);
            *pixel++ = SDL_Swap16(color);
        }

        line += pitch;
    }
}

static void
Convert565le(_THIS, SDL_Surface * surface)
{
    int x, y, pitch;
    unsigned short *line, *pixel;

    line = surface->pixels;
    pitch = surface->pitch >> 1;
    for (y = 0; y < surface->h; y++) {
        pixel = line;
        for (x = 0; x < surface->w; x++) {
            unsigned short color = *pixel;

            *pixel++ = SDL_Swap16(color);
        }

        line += pitch;
    }
}

static void
ConvertBGRAToABGR(_THIS, SDL_Surface * surface)
{
    int x, y, pitch;
    unsigned long *line, *pixel;

    line = surface->pixels;
    pitch = surface->pitch >> 2;
    for (y = 0; y < surface->h; y++) {
        pixel = line;
        for (x = 0; x < surface->w; x++) {
            unsigned long color = *pixel;

            *pixel++ = (color << 24) | (color >> 8);
        }

        line += pitch;
    }
}

#endif /* SDL_VIDEO_OPENGL */
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