/*
    SDL - Simple DirectMedia Layer
    Copyright (C) 1997-2010 Sam Lantinga

    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Lesser General Public
    License as published by the Free Software Foundation; either
    version 2.1 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
    Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public
    License along with this library; if not, write to the Free Software
    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

    Sam Lantinga
    slouken@libsdl.org
*/
#include "SDL_config.h"

#if SDL_VIDEO_RENDER_X11

#include <limits.h> /* For INT_MIN and INT_MAX */

#include "SDL_x11video.h"
#include "../SDL_rect_c.h"
#include "../SDL_pixels_c.h"
#include "../SDL_yuv_sw_c.h"

/* X11 renderer implementation */

static SDL_Renderer *X11_CreateRenderer(SDL_Window * window, Uint32 flags);
static int X11_DisplayModeChanged(SDL_Renderer * renderer);
static int X11_CreateTexture(SDL_Renderer * renderer, SDL_Texture * texture);
static int X11_QueryTexturePixels(SDL_Renderer * renderer,
                                  SDL_Texture * texture, void **pixels,
                                  int *pitch);
static int X11_SetTextureBlendMode(SDL_Renderer * renderer,
                                   SDL_Texture * texture);
static int X11_SetTextureScaleMode(SDL_Renderer * renderer,
                                   SDL_Texture * texture);
static int X11_UpdateTexture(SDL_Renderer * renderer, SDL_Texture * texture,
                             const SDL_Rect * rect, const void *pixels,
                             int pitch);
static int X11_LockTexture(SDL_Renderer * renderer, SDL_Texture * texture,
                           const SDL_Rect * rect, int markDirty,
                           void **pixels, int *pitch);
static void X11_UnlockTexture(SDL_Renderer * renderer, SDL_Texture * texture);
static int X11_SetDrawBlendMode(SDL_Renderer * renderer);
static int X11_RenderDrawPoints(SDL_Renderer * renderer,
                                const SDL_Point * points, int count);
static int X11_RenderDrawLines(SDL_Renderer * renderer,
                               const SDL_Point * points, int count);
static int X11_RenderDrawRects(SDL_Renderer * renderer,
                               const SDL_Rect ** rects, int count);
static int X11_RenderFillRects(SDL_Renderer * renderer,
                               const SDL_Rect ** rects, int count);
static int X11_RenderCopy(SDL_Renderer * renderer, SDL_Texture * texture,
                          const SDL_Rect * srcrect, const SDL_Rect * dstrect);
static int X11_RenderReadPixels(SDL_Renderer * renderer, const SDL_Rect * rect,
                                Uint32 format, void * pixels, int pitch);
static int X11_RenderWritePixels(SDL_Renderer * renderer, const SDL_Rect * rect,
                                 Uint32 format, const void * pixels, int pitch);
static void X11_RenderPresent(SDL_Renderer * renderer);
static void X11_DestroyTexture(SDL_Renderer * renderer,
                               SDL_Texture * texture);
static void X11_DestroyRenderer(SDL_Renderer * renderer);


SDL_RenderDriver X11_RenderDriver = {
    X11_CreateRenderer,
    {
     "x11",
     (SDL_RENDERER_SINGLEBUFFER | SDL_RENDERER_PRESENTCOPY |
      SDL_RENDERER_PRESENTFLIP2 | SDL_RENDERER_PRESENTFLIP3 |
      SDL_RENDERER_PRESENTDISCARD | SDL_RENDERER_ACCELERATED),
     SDL_TEXTUREMODULATE_NONE,
     SDL_BLENDMODE_NONE,
     SDL_TEXTURESCALEMODE_NONE,
     0,
     {0},
     0,
     0}
};

typedef struct
{
    Display *display;
    int screen;
    Visual *visual;
    int depth;
    int scanline_pad;
    Window xwindow;
    Pixmap pixmaps[3];
#ifdef SDL_VIDEO_DRIVER_X11_XRENDER
    Picture xwindow_pict;
    Picture pixmap_picts[3];
    Picture drawable_pict;
    XRenderPictFormat* xwindow_pict_fmt;
    XRenderPictureAttributes xwindow_pict_attr;
    unsigned int xwindow_pict_attr_valuemask;
    SDL_bool xrender_available;
#endif
    int current_pixmap;
    Drawable drawable;
    SDL_PixelFormat format;
    GC gc;
    SDL_DirtyRectList dirty;
    SDL_bool makedirty;
} X11_RenderData;

typedef struct
{
    SDL_SW_YUVTexture *yuv;
    Uint32 format;
    Pixmap pixmap;
#ifdef SDL_VIDEO_DRIVER_X11_XRENDER
    Picture picture;
    XRenderPictFormat* picture_fmt;
    XRenderPictureAttributes picture_attr;
    unsigned int picture_attr_valuemask;
    SDL_bool xrender_available;
#endif
    XImage *image;
#ifndef NO_SHARED_MEMORY
    /* MIT shared memory extension information */
    XShmSegmentInfo shminfo;
#endif
    XImage *scaling_image;
    void *pixels;
    int pitch;
} X11_TextureData;

#ifndef NO_SHARED_MEMORY
/* Shared memory error handler routine */
static int shm_error;
static int (*X_handler) (Display *, XErrorEvent *) = NULL;
static int
shm_errhandler(Display * d, XErrorEvent * e)
{
    if (e->error_code == BadAccess) {
        shm_error = True;
        return (0);
    } else {
        return (X_handler(d, e));
    }
}
#endif /* ! NO_SHARED_MEMORY */

static void
UpdateYUVTextureData(SDL_Texture * texture)
{
    X11_TextureData *data = (X11_TextureData *) texture->driverdata;
    SDL_Rect rect;

    rect.x = 0;
    rect.y = 0;
    rect.w = texture->w;
    rect.h = texture->h;
    SDL_SW_CopyYUVToRGB(data->yuv, &rect, data->format, texture->w,
                        texture->h, data->pixels, data->pitch);
}

void
X11_AddRenderDriver(_THIS)
{
    SDL_RendererInfo *info = &X11_RenderDriver.info;
    SDL_DisplayMode *mode = &SDL_CurrentDisplay->desktop_mode;
    int i;

    info->texture_formats[info->num_texture_formats++] = mode->format;
    info->texture_formats[info->num_texture_formats++] = SDL_PIXELFORMAT_YV12;
    info->texture_formats[info->num_texture_formats++] = SDL_PIXELFORMAT_IYUV;
    info->texture_formats[info->num_texture_formats++] = SDL_PIXELFORMAT_YUY2;
    info->texture_formats[info->num_texture_formats++] = SDL_PIXELFORMAT_UYVY;
    info->texture_formats[info->num_texture_formats++] = SDL_PIXELFORMAT_YVYU;

    for (i = 0; i < _this->num_displays; ++i) {
        SDL_AddRenderDriver(&_this->displays[i], &X11_RenderDriver);
    }
}

SDL_Renderer *
X11_CreateRenderer(SDL_Window * window, Uint32 flags)
{
    SDL_VideoDisplay *display = window->display;
    SDL_DisplayData *displaydata = (SDL_DisplayData *) display->driverdata;
    SDL_WindowData *windowdata = (SDL_WindowData *) window->driverdata;
    SDL_Renderer *renderer;
    X11_RenderData *data;
    XGCValues gcv;
    int i, n;
    int bpp;
    Uint32 Rmask, Gmask, Bmask, Amask;

    renderer = (SDL_Renderer *) SDL_calloc(1, sizeof(*renderer));
    if (!renderer) {
        SDL_OutOfMemory();
        return NULL;
    }

    data = (X11_RenderData *) SDL_calloc(1, sizeof(*data));
    if (!data) {
        X11_DestroyRenderer(renderer);
        SDL_OutOfMemory();
        return NULL;
    }
    data->display = windowdata->videodata->display;
    data->screen = displaydata->screen;
    data->visual = displaydata->visual;
    data->depth = displaydata->depth;
    data->scanline_pad = displaydata->scanline_pad;
    data->xwindow = windowdata->xwindow;
#ifdef SDL_VIDEO_DRIVER_X11_XRENDER
    int event_basep, error_basep;
    if(XRenderQueryExtension(data->display, &event_basep, &error_basep) == True) {
        data->xrender_available = SDL_TRUE;
        data->xwindow_pict_fmt = XRenderFindVisualFormat(data->display, data->visual);
        if(!data->xwindow_pict_fmt) {
            data->xrender_available = SDL_FALSE;
        }
        data->xwindow_pict = XRenderCreatePicture(data->display, data->xwindow, data->xwindow_pict_fmt,
                                                  0, None);
        if(!data->xwindow_pict) {
            data->xrender_available = SDL_FALSE;
        }
    }
    else {
        data->xrender_available = SDL_FALSE;
    }
#endif
    renderer->DisplayModeChanged = X11_DisplayModeChanged;
    renderer->CreateTexture = X11_CreateTexture;
    renderer->QueryTexturePixels = X11_QueryTexturePixels;
    renderer->SetTextureBlendMode = X11_SetTextureBlendMode;
    renderer->SetTextureScaleMode = X11_SetTextureScaleMode;
    renderer->UpdateTexture = X11_UpdateTexture;
    renderer->LockTexture = X11_LockTexture;
    renderer->UnlockTexture = X11_UnlockTexture;
    renderer->SetDrawBlendMode = X11_SetDrawBlendMode;
    renderer->RenderDrawPoints = X11_RenderDrawPoints;
    renderer->RenderDrawLines = X11_RenderDrawLines;
    renderer->RenderDrawRects = X11_RenderDrawRects;
    renderer->RenderFillRects = X11_RenderFillRects;
    renderer->RenderCopy = X11_RenderCopy;
    renderer->RenderReadPixels = X11_RenderReadPixels;
    renderer->RenderWritePixels = X11_RenderWritePixels;
    renderer->RenderPresent = X11_RenderPresent;
    renderer->DestroyTexture = X11_DestroyTexture;
    renderer->DestroyRenderer = X11_DestroyRenderer;
    renderer->info = X11_RenderDriver.info;
    renderer->window = window;
    renderer->driverdata = data;

    renderer->info.flags = SDL_RENDERER_ACCELERATED;

    if (flags & SDL_RENDERER_SINGLEBUFFER) {
        renderer->info.flags |=
            (SDL_RENDERER_SINGLEBUFFER | SDL_RENDERER_PRESENTCOPY);
        n = 0;
    } else if (flags & SDL_RENDERER_PRESENTFLIP2) {
        renderer->info.flags |= SDL_RENDERER_PRESENTFLIP2;
        n = 2;
    } else if (flags & SDL_RENDERER_PRESENTFLIP3) {
        renderer->info.flags |= SDL_RENDERER_PRESENTFLIP3;
        n = 3;
    } else {
        renderer->info.flags |= SDL_RENDERER_PRESENTCOPY;
        n = 1;
    }
    for (i = 0; i < n; ++i) {
        data->pixmaps[i] =
            XCreatePixmap(data->display, data->xwindow, window->w, window->h,
                          displaydata->depth);
        if (data->pixmaps[i] == None) {
            X11_DestroyRenderer(renderer);
            SDL_SetError("XCreatePixmap() failed");
            return NULL;
        }
#ifdef SDL_VIDEO_DRIVER_X11_XRENDER
        if(data->xrender_available == SDL_TRUE) {
            data->pixmap_picts[i] = 
                XRenderCreatePicture(data->display, data->pixmaps[i], data->xwindow_pict_fmt,
                                     0, None);
            if(!data->pixmap_picts[i]) {
                data->xrender_available = SDL_FALSE;
            }
            XRenderComposite(data->display, PictOpClear, data->pixmap_picts[i], None, data->pixmap_picts[i],
                             0, 0, 0, 0, 0, 0, window->w, window->h);
        }
#endif
    }
    if (n > 0) {
        data->drawable = data->pixmaps[0];
#ifdef SDL_VIDEO_DRIVER_X11_XRENDER
        if(data->xrender_available == SDL_TRUE)
            data->drawable_pict = data->pixmap_picts[0];
#endif
        data->makedirty = SDL_TRUE;
    } else {
        data->drawable = data->xwindow;
#ifdef SDL_VIDEO_DRIVER_X11_XRENDER
        if(data->xrender_available == SDL_TRUE)
            data->drawable_pict = data->xwindow_pict;
#endif
        data->makedirty = SDL_FALSE;
    }
    data->current_pixmap = 0;

    /* Get the format of the window */
    if (!SDL_PixelFormatEnumToMasks
        (display->current_mode.format, &bpp, &Rmask, &Gmask, &Bmask,
         &Amask)) {
        SDL_SetError("Unknown display format");
        X11_DestroyRenderer(renderer);
        return NULL;
    }
    SDL_InitFormat(&data->format, bpp, Rmask, Gmask, Bmask, Amask);

    /* Create the drawing context */
    gcv.graphics_exposures = False;
    data->gc =
        XCreateGC(data->display, data->xwindow, GCGraphicsExposures, &gcv);
    if (!data->gc) {
        X11_DestroyRenderer(renderer);
        SDL_SetError("XCreateGC() failed");
        return NULL;
    }

    return renderer;
}

static int
X11_DisplayModeChanged(SDL_Renderer * renderer)
{
    X11_RenderData *data = (X11_RenderData *) renderer->driverdata;
    SDL_Window *window = renderer->window;
    int i, n;

    if (renderer->info.flags & SDL_RENDERER_SINGLEBUFFER) {
        n = 0;
    } else if (renderer->info.flags & SDL_RENDERER_PRESENTFLIP2) {
        n = 2;
    } else if (renderer->info.flags & SDL_RENDERER_PRESENTFLIP3) {
        n = 3;
    } else {
        n = 1;
    }
    for (i = 0; i < n; ++i) {
        if (data->pixmaps[i] != None) {
            XFreePixmap(data->display, data->pixmaps[i]);
            data->pixmaps[i] = None;
#ifdef SDL_VIDEO_DRIVER_X11_XRENDER
            data->pixmap_picts[i] = None;
#endif
        }
    }
    for (i = 0; i < n; ++i) {
        data->pixmaps[i] =
            XCreatePixmap(data->display, data->xwindow, window->w, window->h,
                          data->depth);
        if (data->pixmaps[i] == None) {
            SDL_SetError("XCreatePixmap() failed");
            return -1;
        }
#ifdef SDL_VIDEO_DRIVER_X11_XRENDER
        if(data->xrender_available == SDL_TRUE) {
            data->pixmap_picts[i] = 
                XRenderCreatePicture(data->display, data->pixmaps[i], data->xwindow_pict_fmt,
                                     0, None);
            if(!data->pixmap_picts[i]) {
                data->xrender_available = SDL_FALSE;
            }
            XRenderComposite(data->display, PictOpClear, data->pixmap_picts[i], None, data->pixmap_picts[i],
                             0, 0, 0, 0, 0, 0, window->w, window->h);
        }
#endif
    }
    if (n > 0) {
        data->drawable = data->pixmaps[0];
#ifdef SDL_VIDEO_DRIVER_X11_XRENDER
        data->drawable_pict = data->pixmap_picts[0];
#endif
    }
    data->current_pixmap = 0;

    return 0;
}

static int
X11_CreateTexture(SDL_Renderer * renderer, SDL_Texture * texture)
{
    X11_RenderData *renderdata = (X11_RenderData *) renderer->driverdata;
    SDL_Window *window = renderer->window;
    SDL_VideoDisplay *display = window->display;
    X11_TextureData *data;
    int pitch_alignmask = ((renderdata->scanline_pad / 8) - 1);

    data = (X11_TextureData *) SDL_calloc(1, sizeof(*data));
    if (!data) {
        SDL_OutOfMemory();
        return -1;
    }

    texture->driverdata = data;
    if (SDL_ISPIXELFORMAT_FOURCC(texture->format)) {
        data->yuv =
            SDL_SW_CreateYUVTexture(texture->format, texture->w, texture->h);
        if (!data->yuv) {
            return -1;
        }
        data->format = display->current_mode.format;
    } else {
        /* If Xrender support is builtin we only need to check whether
           Xrender is available at runtime. If it is available there
           can be no BadMatch error since Xrender takes care of that.
        */
#ifdef SDL_VIDEO_DRIVER_X11_XRENDER
        // Assume the texture is supported by Xrender
        data->xrender_available = SDL_TRUE;
        if(renderdata->xrender_available == SDL_FALSE) {
            if (texture->format != display->current_mode.format) {
                SDL_SetError("Texture format doesn't match window format");
                return -1;
            }
        }
#else
        /* The image/pixmap depth must be the same as the window or you
           get a BadMatch error when trying to putimage or copyarea.
           This BadMatch error
        */
        if (texture->format != display->current_mode.format) {
            SDL_SetError("Texture format doesn't match window format");
            return -1;
        }
#endif
        data->format = texture->format;
    }
    data->pitch = texture->w * SDL_BYTESPERPIXEL(data->format);
    data->pitch = (data->pitch + pitch_alignmask) & ~pitch_alignmask;

    if (data->yuv || texture->access == SDL_TEXTUREACCESS_STREAMING) {
#ifndef NO_SHARED_MEMORY
        XShmSegmentInfo *shminfo = &data->shminfo;

        shm_error = True;

        if (SDL_X11_HAVE_SHM) {
            shminfo->shmid =
                shmget(IPC_PRIVATE, texture->h * data->pitch,
                       IPC_CREAT | 0777);
            if (shminfo->shmid >= 0) {
                shminfo->shmaddr = (char *) shmat(shminfo->shmid, 0, 0);
                shminfo->readOnly = False;
                if (shminfo->shmaddr != (char *) -1) {
                    shm_error = False;
                    X_handler = XSetErrorHandler(shm_errhandler);
                    XShmAttach(renderdata->display, shminfo);
                    XSync(renderdata->display, False);
                    XSetErrorHandler(X_handler);
                    if (shm_error) {
                        shmdt(shminfo->shmaddr);
                    }
                }
                shmctl(shminfo->shmid, IPC_RMID, NULL);
            }
        }
        if (!shm_error) {
            data->pixels = shminfo->shmaddr;

            data->image =
                XShmCreateImage(renderdata->display, renderdata->visual,
                                renderdata->depth, ZPixmap, shminfo->shmaddr,
                                shminfo, texture->w, texture->h);

            // This Pixmap is used by Xrender
            data->pixmap =
                XShmCreatePixmap(renderdata->display, renderdata->xwindow, shminfo->shmaddr,
                                 shminfo, texture->w, texture->h, renderdata->depth);

            if (!(data->pixmap && data->image)) {
                XShmDetach(renderdata->display, shminfo);
                XSync(renderdata->display, False);
                shmdt(shminfo->shmaddr);
                shm_error = True;
            }
        }
        if (shm_error) {
            shminfo->shmaddr = NULL;
        }
        if (!data->image)
#endif /* not NO_SHARED_MEMORY */
        {
            /* This is the case where the server does not have
               shared memory support and the texture is streaming.
               It does not make sense to use Xrender here because
               we would have to copy the data onto a server side
               pixmap with XPutImage first and only then can we 
               use Xrender
            */

            data->pixels = SDL_malloc(texture->h * data->pitch);
            if (!data->pixels) {
                X11_DestroyTexture(renderer, texture);
                SDL_OutOfMemory();
                return -1;
            }

            data->image =
                XCreateImage(renderdata->display, renderdata->visual,
                             renderdata->depth, ZPixmap, 0, data->pixels,
                             texture->w, texture->h,
                             SDL_BYTESPERPIXEL(data->format) * 8,
                             data->pitch);
            if (!data->image) {
                X11_DestroyTexture(renderer, texture);
                SDL_SetError("XCreateImage() failed");
                return -1;
            }
        }
    } 
    else {
        data->pixmap =
            XCreatePixmap(renderdata->display, renderdata->xwindow, texture->w,
                          texture->h, renderdata->depth);
        if (data->pixmap == None) {
            X11_DestroyTexture(renderer, texture);
            SDL_SetError("XCreatePixmap() failed");
            return -1;
        }
        data->image =
            XCreateImage(renderdata->display, renderdata->visual,
                         renderdata->depth, ZPixmap, 0, NULL,
                         texture->w, texture->h,
                         SDL_BYTESPERPIXEL(data->format) * 8,
                         data->pitch);
        if (!data->image) {
            X11_DestroyTexture(renderer, texture);
            SDL_SetError("XCreateImage() failed");
            return -1;
        }
    }
#ifdef SDL_VIDEO_DRIVER_X11_XRENDER
    if(renderdata->xrender_available && data->pixmap) {
        data->xrender_available = SDL_TRUE;
        unsigned long x11_fmt_mask; // Format mask
        XRenderPictFormat x11_templ_fmt; // Format template
        x11_fmt_mask =
            (PictFormatDepth | PictFormatRedMask | PictFormatGreenMask
            | PictFormatBlueMask);
        Uint32 Rmask, Gmask, Bmask, Amask;
        int bpp;
        SDL_PixelFormatEnumToMasks(data->format, &bpp, &Rmask, &Gmask, &Bmask, &Amask);
        x11_templ_fmt.depth = bpp;
        x11_templ_fmt.direct.redMask = Rmask;
        x11_templ_fmt.direct.greenMask = Gmask;
        x11_templ_fmt.direct.blueMask = Bmask;
        x11_templ_fmt.direct.alphaMask = Amask;
        /* Return one matching XRenderPictFormat */
        data->picture_fmt =
            XRenderFindFormat(renderdata->display, x11_fmt_mask, &x11_templ_fmt, 1);
        if(!data->picture_fmt) {
            data->xrender_available = SDL_FALSE;
        }
        data->picture_attr_valuemask = CPGraphicsExposure;
        (data->picture_attr).graphics_exposures = False;
        data->picture =
            XRenderCreatePicture(renderdata->display, data->pixmap, data->picture_fmt,
                            data->picture_attr_valuemask, &(data->picture_attr));
        if(!data->picture) {
            data->xrender_available = SDL_FALSE;
        }
    }
    /* We thought we could render the texture with Xrender but this was
        not possible for some reason. Now we must ensure that texture  
        format and window format match to avoid a BadMatch error.
    */
    if(data->xrender_available == SDL_FALSE) {
        if (texture->format != display->current_mode.format) {
            SDL_SetError("Texture format doesn't match window format");
            return -1;
        }
    }
#endif
    return 0;
}

static int
X11_QueryTexturePixels(SDL_Renderer * renderer, SDL_Texture * texture,
                       void **pixels, int *pitch)
{
    X11_TextureData *data = (X11_TextureData *) texture->driverdata;

    if (data->yuv) {
        return SDL_SW_QueryYUVTexturePixels(data->yuv, pixels, pitch);
    } else {
        *pixels = data->pixels;
        *pitch = data->pitch;
        return 0;
    }
}

static int
X11_SetTextureBlendMode(SDL_Renderer * renderer, SDL_Texture * texture)
{
    switch (texture->blendMode) {
    case SDL_BLENDMODE_NONE:
        return 0;
    default:
        SDL_Unsupported();
        texture->blendMode = SDL_BLENDMODE_NONE;
        return -1;
    }
}

static int
X11_SetTextureScaleMode(SDL_Renderer * renderer, SDL_Texture * texture)
{
    X11_TextureData *data = (X11_TextureData *) texture->driverdata;

    switch (texture->scaleMode) {
    case SDL_TEXTURESCALEMODE_NONE:
        return 0;
    case SDL_TEXTURESCALEMODE_FAST:
        /* We can sort of fake it for streaming textures */
        if (data->yuv || texture->access == SDL_TEXTUREACCESS_STREAMING) {
            return 0;
        }
        /* Fall through to unsupported case */
    default:
        SDL_Unsupported();
        texture->scaleMode = SDL_TEXTURESCALEMODE_NONE;
        return -1;
    }
    return 0;
}

static int
X11_UpdateTexture(SDL_Renderer * renderer, SDL_Texture * texture,
                  const SDL_Rect * rect, const void *pixels, int pitch)
{
    X11_TextureData *data = (X11_TextureData *) texture->driverdata;

    if (data->yuv) {
        if (SDL_SW_UpdateYUVTexture(data->yuv, rect, pixels, pitch) < 0) {
            return -1;
        }
        UpdateYUVTextureData(texture);
        return 0;
    } else {
        X11_RenderData *renderdata = (X11_RenderData *) renderer->driverdata;

        if (data->pixels) {
            // If we have already allocated memory or were given memory by XShm
            Uint8 *src, *dst;
            int row;
            size_t length;

            src = (Uint8 *) pixels;
            dst =
                (Uint8 *) data->pixels + rect->y * data->pitch +
                rect->x * SDL_BYTESPERPIXEL(texture->format);
            length = rect->w * SDL_BYTESPERPIXEL(texture->format);
            for (row = 0; row < rect->h; ++row) {
                SDL_memcpy(dst, src, length);
                src += pitch;
                dst += data->pitch;
            }
            /* If this is a static texture we would use Xrender for it
               but this requires that the server side Pixmap associated
               with this texture be updated with the data as well and 
               that the pixmap is not a shared memory pixmap.
               Hopefully the user will not update static textures so
               frequently as to cause a slowdown.
            */
            if (texture->access == SDL_TEXTUREACCESS_STATIC) {
#ifndef NO_SHARED_MEMORY
                if(!data->shminfo.shmaddr)
#endif
                {
                XPutImage(renderdata->display, data->pixmap, renderdata->gc,
                          data->image, 0, 0, rect->x, rect->y, rect->w, rect->h);
                }
            }

        } else {
            data->image->width = rect->w;
            data->image->height = rect->h;
            data->image->data = (char *) pixels;
            data->image->bytes_per_line = pitch;
            XPutImage(renderdata->display, data->pixmap, renderdata->gc,
                      data->image, 0, 0, rect->x, rect->y, rect->w, rect->h);
        }
        return 0;
    }
}

static int
X11_LockTexture(SDL_Renderer * renderer, SDL_Texture * texture,
                const SDL_Rect * rect, int markDirty, void **pixels,
                int *pitch)
{
    X11_TextureData *data = (X11_TextureData *) texture->driverdata;

    if (data->yuv) {
        return SDL_SW_LockYUVTexture(data->yuv, rect, markDirty, pixels,
                                     pitch);
    } else if (data->pixels) {
        *pixels =
            (void *) ((Uint8 *) data->pixels + rect->y * data->pitch +
                      rect->x * SDL_BYTESPERPIXEL(texture->format));
        *pitch = data->pitch;
        return 0;
    } else {
        SDL_SetError("No pixels available");
        return -1;
    }
}

static void
X11_UnlockTexture(SDL_Renderer * renderer, SDL_Texture * texture)
{
    X11_TextureData *data = (X11_TextureData *) texture->driverdata;

    if (data->yuv) {
        SDL_SW_UnlockYUVTexture(data->yuv);
        UpdateYUVTextureData(texture);
    }
}

static int
X11_SetDrawBlendMode(SDL_Renderer * renderer)
{
    switch (renderer->blendMode) {
    case SDL_BLENDMODE_NONE:
        return 0;
#ifdef SDL_VIDEO_DRIVER_X11_XRENDER
    case SDL_BLENDMODE_MASK: // Use src pict as mask
    case SDL_BLENDMODE_ADD: // PictOpAdd
    case SDL_BLENDMODE_BLEND: // PictOpOver
    /* FIXME case SDL_BLENDMODE_MOD: */
#endif
        return 0;
    default:
        SDL_Unsupported();
        renderer->blendMode = SDL_BLENDMODE_NONE;
        return -1;
    }
}

static Uint32
renderdrawcolor(SDL_Renderer * renderer, int premult)
{
    X11_RenderData *data = (X11_RenderData *) renderer->driverdata;
    Uint8 r = renderer->r;
    Uint8 g = renderer->g;
    Uint8 b = renderer->b;
    Uint8 a = renderer->a;
    if (premult)
        return SDL_MapRGBA(&data->format, ((int) r * (int) a) / 255,
                           ((int) g * (int) a) / 255,
                           ((int) b * (int) a) / 255, 255);
    else
        return SDL_MapRGBA(&data->format, r, g, b, a);
}

static XRenderColor
xrenderdrawcolor(SDL_Renderer *renderer)
{
    // Premultiply the color channels as well as modulate them to a 16 bit color space
    XRenderColor xrender_color;
    xrender_color.red = ((unsigned short)renderer->r + 1) * ((unsigned short)renderer->a + 1) - 1;
    xrender_color.green = ((unsigned short)renderer->g + 1) * ((unsigned short)renderer->a + 1) - 1;
    xrender_color.blue = ((unsigned short)renderer->b + 1) * ((unsigned short)renderer->a + 1) - 1;
    xrender_color.alpha = ((unsigned short)renderer->a + 1) * ((unsigned short)renderer->a + 1) - 1;
    return xrender_color;
}

static int
X11_RenderDrawPoints(SDL_Renderer * renderer, const SDL_Point * points,
                     int count)
{
    X11_RenderData *data = (X11_RenderData *) renderer->driverdata;
    SDL_Window *window = renderer->window;
    unsigned long foreground;
    XPoint *xpoints, *xpoint;
    int i, xcount;

    if (data->makedirty) {
        SDL_Rect rect;

        /* Get the smallest rectangle that contains everything */
        rect.x = 0;
        rect.y = 0;
        rect.w = window->w;
        rect.h = window->h;
        if (!SDL_EnclosePoints(points, count, &rect, &rect)) {
            /* Nothing to draw */
            return 0;
        }
        SDL_AddDirtyRect(&data->dirty, &rect);
    }

    foreground = renderdrawcolor(renderer, 1);
    XSetForeground(data->display, data->gc, foreground);

    xpoint = xpoints = SDL_stack_alloc(XPoint, count);
    xcount = 0;
    for (i = 0; i < count; ++i) {
        int x = points[i].x;
        int y = points[i].y;
        if (x < 0 || x >= window->w || y < 0 || y >= window->h) {
            continue;
        }
        xpoint->x = (short)x;
        xpoint->y = (short)y;
        ++xpoint;
        ++xcount;
    }
    if (xcount > 0) {
        XDrawPoints(data->display, data->drawable, data->gc, xpoints, xcount,
                    CoordModeOrigin);
    }
    SDL_stack_free(xpoints);

    return 0;
}

static int
X11_RenderDrawLines(SDL_Renderer * renderer, const SDL_Point * points,
                    int count)
{
    X11_RenderData *data = (X11_RenderData *) renderer->driverdata;
    SDL_Window *window = renderer->window;
    SDL_Rect clip;
    unsigned long foreground;
    XPoint *xpoints, *xpoint;
    int i, xcount;
    int minx, miny;
    int maxx, maxy;

    clip.x = 0;
    clip.y = 0;
    clip.w = window->w;
    clip.h = window->h;

    foreground = renderdrawcolor(renderer, 1);
    XSetForeground(data->display, data->gc, foreground);

    xpoint = xpoints = SDL_stack_alloc(XPoint, count);
    xcount = 0;
    minx = INT_MAX;
    miny = INT_MAX;
    maxx = INT_MIN;
    maxy = INT_MIN;
    for (i = 0; i < count; ++i) {
        int x = points[i].x;
        int y = points[i].y;

        /* If the point is inside the window, add it to the list */
        if (x >= 0 && x < window->w && y >= 0 && y < window->h) {
            if (x < minx) {
                minx = x;
            } else if (x > maxx) {
                maxx = x;
            }
            if (y < miny) {
                miny = y;
            } else if (y > maxy) {
                maxy = y;
            }
            xpoint->x = (short)x;
            xpoint->y = (short)y;
            ++xpoint;
            ++xcount;
            continue;
        }

        /* We need to clip the line segments joined by this point */
        if (xcount > 0) {
            int x1 = xpoint[-1].x;
            int y1 = xpoint[-1].y;
            int x2 = x;
            int y2 = y;
            if (SDL_IntersectRectAndLine(&clip, &x1, &y1, &x2, &y2)) {
                if (x2 < minx) {
                    minx = x2;
                } else if (x2 > maxx) {
                    maxx = x2;
                }
                if (y2 < miny) {
                    miny = y2;
                } else if (y2 > maxy) {
                    maxy = y2;
                }
                xpoint->x = (short)x2;
                xpoint->y = (short)y2;
                ++xpoint;
                ++xcount;
            }
            XDrawLines(data->display, data->drawable, data->gc,
                       xpoints, xcount, CoordModeOrigin);
            if (xpoints[0].x != x2 || xpoints[0].y != y2) {
                XDrawPoint(data->display, data->drawable, data->gc, x2, y2);
            }
            if (data->makedirty) {
                SDL_Rect rect;

                rect.x = minx;
                rect.y = miny;
                rect.w = (maxx - minx) + 1;
                rect.h = (maxy - miny) + 1;
                SDL_AddDirtyRect(&data->dirty, &rect);
            }
            xpoint = xpoints;
            xcount = 0;
            minx = INT_MAX;
            miny = INT_MAX;
            maxx = INT_MIN;
            maxy = INT_MIN;
        }
        if (i < (count-1)) {
            int x1 = x;
            int y1 = y;
            int x2 = points[i+1].x;
            int y2 = points[i+1].y;
            if (SDL_IntersectRectAndLine(&clip, &x1, &y1, &x2, &y2)) {
                if (x1 < minx) {
                    minx = x1;
                } else if (x1 > maxx) {
                    maxx = x1;
                }
                if (y1 < miny) {
                    miny = y1;
                } else if (y1 > maxy) {
                    maxy = y1;
                }
                xpoint->x = (short)x1;
                xpoint->y = (short)y1;
                ++xpoint;
                ++xcount;
            }
        }
    }
    if (xcount > 1) {
        int x2 = xpoint[-1].x;
        int y2 = xpoint[-1].y;
        XDrawLines(data->display, data->drawable, data->gc, xpoints, xcount,
                   CoordModeOrigin);
        if (xpoints[0].x != x2 || xpoints[0].y != y2) {
            XDrawPoint(data->display, data->drawable, data->gc, x2, y2);
        }
        if (data->makedirty) {
            SDL_Rect rect;

            rect.x = minx;
            rect.y = miny;
            rect.w = (maxx - minx) + 1;
            rect.h = (maxy - miny) + 1;
            SDL_AddDirtyRect(&data->dirty, &rect);
        }
    }
    SDL_stack_free(xpoints);

    return 0;
}

static int
X11_RenderDrawRects(SDL_Renderer * renderer, const SDL_Rect ** rects, int count)
{
    X11_RenderData *data = (X11_RenderData *) renderer->driverdata;
    SDL_Window *window = renderer->window;
    SDL_Rect clip, rect;
    unsigned long foreground;
    XRectangle *xrects, *xrect;
    int i, xcount;

    clip.x = 0;
    clip.y = 0;
    clip.w = window->w;
    clip.h = window->h;

#ifdef SDL_VIDEO_DRIVER_X11_XRENDER
    if(data->xrender_available == SDL_TRUE) {
        XRenderColor xrender_foreground;
        xrender_foreground = xrenderdrawcolor(renderer);
        
        xrects = SDL_stack_alloc(XRectangle, 4*count);
        xcount = 0;
        for(i = 0; i < 4*count; i+=4) {
            if(!SDL_IntersectRect(rects[i], &clip, &rect)) {
                continue;
            }
            
            xrects[xcount].x = rect.x;
            xrects[xcount].y = rect.y;
            xrects[xcount].width = 1;
            xrects[xcount].height = rect.h;
            ++xcount;
            xrects[xcount].x = rect.x;
            xrects[xcount].y = rect.y+rect.h;
            xrects[xcount].width = rect.w;
            xrects[xcount].height = 1;
            ++xcount;
            xrects[xcount].x = rect.x+rect.w;
            xrects[xcount].y = rect.y;
            xrects[xcount].width = 1;
            xrects[xcount].height = rect.h;
            ++xcount;
            xrects[xcount].x = rect.x;
            xrects[xcount].y = rect.y;
            xrects[xcount].width = rect.w;
            xrects[xcount].height = 1;
            ++xcount;
            if(data->makedirty) {
                SDL_AddDirtyRect(&data->dirty, &rect);
            }
        }
        XRenderFillRectangles(data->display, PictOpOver, data->drawable_pict,
                              &xrender_foreground, xrects, xcount);
    }
    else
#endif
    {
        foreground = renderdrawcolor(renderer, 1);
        XSetForeground(data->display, data->gc, foreground);
    
        xrect = xrects = SDL_stack_alloc(XRectangle, count);
        xcount = 0;
        for (i = 0; i < count; ++i) {
            if (!SDL_IntersectRect(rects[i], &clip, &rect)) {
                continue;
            }

            xrect->x = (short)rect.x;
            xrect->y = (short)rect.y;
            xrect->width = (unsigned short)rect.w;
            xrect->height = (unsigned short)rect.h;
            ++xrect;
            ++xcount;
    
            if (data->makedirty) {
                SDL_AddDirtyRect(&data->dirty, &rect);
            }
        }   
        if (xcount > 0) {
            XDrawRectangles(data->display, data->drawable, data->gc,
                            xrects, xcount);
        }
    }
    SDL_stack_free(xrects);

    return 0;
}

static int
X11_RenderFillRects(SDL_Renderer * renderer, const SDL_Rect ** rects, int count)
{
    X11_RenderData *data = (X11_RenderData *) renderer->driverdata;
    SDL_Window *window = renderer->window;
    SDL_Rect clip, rect;
    unsigned long foreground;
    XRectangle *xrects, *xrect;
    int i, xcount;

    clip.x = 0;
    clip.y = 0;
    clip.w = window->w;
    clip.h = window->h;

    foreground = renderdrawcolor(renderer, 1);
    XSetForeground(data->display, data->gc, foreground);

    xrect = xrects = SDL_stack_alloc(XRectangle, count);
    xcount = 0;
    for (i = 0; i < count; ++i) {
        if (!SDL_IntersectRect(rects[i], &clip, &rect)) {
            continue;
        }

        xrect->x = (short)rect.x;
        xrect->y = (short)rect.y;
        xrect->width = (unsigned short)rect.w;
        xrect->height = (unsigned short)rect.h;
        ++xrect;
        ++xcount;

        if (data->makedirty) {
            SDL_AddDirtyRect(&data->dirty, &rect);
        }
    }
    if (xcount > 0) {
#ifdef SDL_VIDEO_DRIVER_X11_XRENDER
        if(data->xrender_available == SDL_TRUE)
        {
            XRenderColor xrender_foreground_color;
            xrender_foreground_color = xrenderdrawcolor(renderer);
            XRenderFillRectangles(data->display, PictOpOver, data->drawable_pict,
                                  &xrender_foreground_color, xrects, xcount);
        }
        else
#endif
        {
        XFillRectangles(data->display, data->drawable, data->gc,
                        xrects, xcount);
        }
    }
    SDL_stack_free(xpoints);

    return 0;
}

static int
X11_RenderCopy(SDL_Renderer * renderer, SDL_Texture * texture,
               const SDL_Rect * srcrect, const SDL_Rect * dstrect)
{
    X11_RenderData *data = (X11_RenderData *) renderer->driverdata;
    X11_TextureData *texturedata = (X11_TextureData *) texture->driverdata;

    if (data->makedirty) {
        SDL_AddDirtyRect(&data->dirty, dstrect);
    }
    if (srcrect->w == dstrect->w && srcrect->h == dstrect->h) {
#ifndef NO_SHARED_MEMORY
        if (texturedata->shminfo.shmaddr) {
            XShmPutImage(data->display, data->drawable, data->gc,
                         texturedata->image, srcrect->x, srcrect->y,
                         dstrect->x, dstrect->y, srcrect->w, srcrect->h,
                         False);
        } else
#endif
        if (texturedata->pixels) {
            XPutImage(data->display, data->drawable, data->gc,
                      texturedata->image, srcrect->x, srcrect->y, dstrect->x,
                      dstrect->y, srcrect->w, srcrect->h);
        } else {
            XCopyArea(data->display, texturedata->pixmap, data->drawable,
                      data->gc, srcrect->x, srcrect->y, dstrect->w,
                      dstrect->h, dstrect->x, dstrect->y);
        }
    } else if (texturedata->yuv
               || texture->access == SDL_TEXTUREACCESS_STREAMING) {
        SDL_Surface src, dst;
        SDL_PixelFormat fmt;
        SDL_Rect rect;
        XImage *image = texturedata->scaling_image;

        if (!image) {
            void *pixels;
            int pitch;

            pitch = dstrect->w * SDL_BYTESPERPIXEL(texturedata->format);
            pixels = SDL_malloc(dstrect->h * pitch);
            if (!pixels) {
                SDL_OutOfMemory();
                return -1;
            }

            image =
                XCreateImage(data->display, data->visual, data->depth,
                             ZPixmap, 0, pixels, dstrect->w, dstrect->h,
                             SDL_BYTESPERPIXEL(texturedata->format) * 8,
                             pitch);
            if (!image) {
                SDL_SetError("XCreateImage() failed");
                return -1;
            }
            texturedata->scaling_image = image;

        } else if (image->width != dstrect->w || image->height != dstrect->h
                   || !image->data) {
            image->width = dstrect->w;
            image->height = dstrect->h;
            image->bytes_per_line =
                image->width * SDL_BYTESPERPIXEL(texturedata->format);
            image->data =
                (char *) SDL_realloc(image->data,
                                     image->height * image->bytes_per_line);
            if (!image->data) {
                SDL_OutOfMemory();
                return -1;
            }
        }

        /* Set up fake surfaces for SDL_SoftStretch() */
        SDL_zero(src);
        src.format = &fmt;
        src.w = texture->w;
        src.h = texture->h;
#ifndef NO_SHARED_MEMORY
        if (texturedata->shminfo.shmaddr) {
            src.pixels = texturedata->shminfo.shmaddr;
        } else
#endif
            src.pixels = texturedata->pixels;
        src.pitch = texturedata->pitch;

        SDL_zero(dst);
        dst.format = &fmt;
        dst.w = image->width;
        dst.h = image->height;
        dst.pixels = image->data;
        dst.pitch = image->bytes_per_line;

        fmt.BytesPerPixel = SDL_BYTESPERPIXEL(texturedata->format);

        rect.x = 0;
        rect.y = 0;
        rect.w = dstrect->w;
        rect.h = dstrect->h;
        if (SDL_SoftStretch(&src, srcrect, &dst, &rect) < 0) {
            return -1;
        }
        XPutImage(data->display, data->drawable, data->gc, image, 0, 0,
                  dstrect->x, dstrect->y, dstrect->w, dstrect->h);
    } else {
        XCopyArea(data->display, texturedata->pixmap, data->drawable,
                  data->gc, srcrect->x, srcrect->y, dstrect->w, dstrect->h,
                  srcrect->x, srcrect->y);
    }
    return 0;
}

static int
X11_RenderReadPixels(SDL_Renderer * renderer, const SDL_Rect * rect,
                     Uint32 format, void * pixels, int pitch)
{
    X11_RenderData *data = (X11_RenderData *) renderer->driverdata;
    SDL_Window *window = renderer->window;
    SDL_VideoDisplay *display = window->display;
    Uint32 screen_format = display->current_mode.format;
    XImage *image;

    image = XGetImage(data->display, data->drawable, rect->x, rect->y,
                      rect->w, rect->h, AllPlanes, ZPixmap);

    SDL_ConvertPixels(rect->w, rect->h,
                      screen_format, image->data, image->bytes_per_line,
                      format, pixels, pitch);

    XDestroyImage(image);
    return 0;
}

static int
X11_RenderWritePixels(SDL_Renderer * renderer, const SDL_Rect * rect,
                      Uint32 format, const void * pixels, int pitch)
{
    X11_RenderData *data = (X11_RenderData *) renderer->driverdata;
    SDL_Window *window = renderer->window;
    SDL_VideoDisplay *display = window->display;
    Uint32 screen_format = display->current_mode.format;
    XImage *image;
    void *image_pixels;
    int image_pitch;

    image_pitch = rect->w * SDL_BYTESPERPIXEL(screen_format);
    image_pixels = SDL_malloc(rect->h * image_pitch);
    if (!image_pixels) {
        SDL_OutOfMemory();
        return -1;
    }

    image = XCreateImage(data->display, data->visual,
                         data->depth, ZPixmap, 0, image_pixels,
                         rect->w, rect->h,
                         SDL_BYTESPERPIXEL(screen_format) * 8,
                         image_pitch);
    if (!image) {
        SDL_SetError("XCreateImage() failed");
        return -1;
    }

    SDL_ConvertPixels(rect->w, rect->h,
                      format, pixels, pitch,
                      screen_format, image->data, image->bytes_per_line);

    XPutImage(data->display, data->drawable, data->gc,
              image, 0, 0, rect->x, rect->y, rect->w, rect->h);

    image->data = NULL;
    XDestroyImage(image);

    SDL_free(image_pixels);
    return 0;
}

static void
X11_RenderPresent(SDL_Renderer * renderer)
{
    X11_RenderData *data = (X11_RenderData *) renderer->driverdata;
    SDL_DirtyRect *dirty;

    /* Send the data to the display */
    if (!(renderer->info.flags & SDL_RENDERER_SINGLEBUFFER)) {
        for (dirty = data->dirty.list; dirty; dirty = dirty->next) {
            const SDL_Rect *rect = &dirty->rect;
#ifdef SDL_VIDEO_DRIVER_X11_XRENDER
            if(data->xrender_available == SDL_TRUE)
            {
                XRenderComposite(data->display, PictOpOver, data->drawable_pict, None, data->xwindow_pict,
                                 rect->x, rect->y, 0, 0, rect->x, rect->y, rect->w+1, rect->h+1);
            }
            else
#endif
            {
            XCopyArea(data->display, data->drawable, data->xwindow,
                      data->gc, rect->x, rect->y, rect->w, rect->h,
                      rect->x, rect->y);
            }
        }
        SDL_ClearDirtyRects(&data->dirty);
/*#ifdef SDL_VIDEO_DRIVER_X11_XRENDER
        // Clear each pixmap after a render
        if(data->xrender_available == SDL_TRUE) {
            XRenderComposite(data->display, PictOpClear, data->drawable_pict, None, data->drawable_pict,
                             0, 0, 0, 0, 0, 0, renderer->window->w, renderer->window->h);
        }
#endif*/
    }
    XSync(data->display, False);

    /* Update the flipping chain, if any */
    if (renderer->info.flags & SDL_RENDERER_PRESENTFLIP2) {
        data->current_pixmap = (data->current_pixmap + 1) % 2;
        data->drawable = data->pixmaps[data->current_pixmap];
#ifdef SDL_VIDEO_DRIVER_X11_XRENDER
        data->drawable_pict = data->pixmap_picts[data->current_pixmap];
#endif
    } else if (renderer->info.flags & SDL_RENDERER_PRESENTFLIP3) {
        data->current_pixmap = (data->current_pixmap + 1) % 3;
        data->drawable = data->pixmaps[data->current_pixmap];
#ifdef SDL_VIDEO_DRIVER_X11_XRENDER
        data->drawable_pict = data->pixmap_picts[data->current_pixmap];
#endif
    }
}

static void
X11_DestroyTexture(SDL_Renderer * renderer, SDL_Texture * texture)
{
    X11_RenderData *renderdata = (X11_RenderData *) renderer->driverdata;
    X11_TextureData *data = (X11_TextureData *) texture->driverdata;

    if (!data) {
        return;
    }
    if (data->yuv) {
        SDL_SW_DestroyYUVTexture(data->yuv);
    }
    if (data->pixmap != None) {
        XFreePixmap(renderdata->display, data->pixmap);
    }
    if (data->image) {
        data->image->data = NULL;
        XDestroyImage(data->image);
    }
#ifndef NO_SHARED_MEMORY
    if (data->shminfo.shmaddr) {
        XShmDetach(renderdata->display, &data->shminfo);
        XSync(renderdata->display, False);
        shmdt(data->shminfo.shmaddr);
        data->pixels = NULL;
    }
#endif
    if (data->scaling_image) {
        SDL_free(data->scaling_image->data);
        data->scaling_image->data = NULL;
        XDestroyImage(data->scaling_image);
    }
    if (data->pixels) {
        SDL_free(data->pixels);
    }
    SDL_free(data);
    texture->driverdata = NULL;
}

static void
X11_DestroyRenderer(SDL_Renderer * renderer)
{
    X11_RenderData *data = (X11_RenderData *) renderer->driverdata;
    int i;

    if (data) {
        for (i = 0; i < SDL_arraysize(data->pixmaps); ++i) {
            if (data->pixmaps[i] != None) {
                XFreePixmap(data->display, data->pixmaps[i]);
            }
        }
        if (data->gc) {
            XFreeGC(data->display, data->gc);
        }
        SDL_FreeDirtyRects(&data->dirty);
        SDL_free(data);
    }
    SDL_free(renderer);
}

#endif /* SDL_VIDEO_RENDER_X11 */

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