/*

    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
    Pixmap stencil;
    Pixmap brush;
    Picture brush_pict;
    Picture xwindow_pict;
    Picture pixmap_picts[3];
    Picture drawable_pict;
    Picture stencil_pict;
    int blend_op;
    XRenderPictFormat *xwindow_pict_fmt;
    XRenderPictFormat *drawable_pict_fmt;
    GC stencil_gc;
    SDL_bool use_xrender;
#ifdef SDL_VIDEO_DRIVER_X11_XDAMAGE
    SDL_bool use_xdamage;
    Damage stencil_damage;
    XserverRegion stencil_parts;
#endif
#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;
    int depth;
    Visual *visual;
    GC gc;
#ifdef SDL_VIDEO_DRIVER_X11_XRENDER
    Picture picture;
    XRenderPictFormat* picture_fmt;
    int blend_op;
#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;
    info->texture_formats[info->num_texture_formats++] = SDL_PIXELFORMAT_ARGB8888;

    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;
    gcv.graphics_exposures = False;
    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;
    
    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;

#ifdef SDL_VIDEO_DRIVER_X11_XRENDER
    data->use_xrender = SDL_FALSE;
    data->use_xdamage = SDL_FALSE;
    int event_basep, error_basep;
    if (SDL_X11_HAVE_XRENDER) {
        /* Query the extension. This is the server runtime check. */
        if(XRenderQueryExtension(data->display,
                                 &event_basep, &error_basep) == True)
            data->use_xrender = SDL_TRUE;
    }
#ifdef SDL_VIDEO_DRIVER_X11_XDAMAGE
    if (data->use_xrender) {
        if(SDL_X11_HAVE_XDAMAGE && SDL_X11_HAVE_XFIXES) {
        /* Query XDamage and XFixes */
            if(XDamageQueryExtension(data->display,
                                     &event_basep,
                                     &error_basep) == True && 
               (XFixesQueryExtension(data->display,
                                        &event_basep,
                                        &error_basep) == True)) {
                    int major_version, minor_version;
                    XFixesQueryVersion(data->display,
                                       &major_version,
                                       &minor_version);
                    /* Only XFixes v 2 or greater
                     * Required for XFixesSetPictureClipRegion() */
                    if(major_version >= 2)
                        data->use_xdamage = SDL_TRUE;
            }
        }
#endif
        /* Find the PictFormat from the visual.
         * Should be an RGB PictFormat most of the time. */
        data->xwindow_pict_fmt = XRenderFindVisualFormat(data->display,
                                                         data->visual);
        if (!data->xwindow_pict_fmt) {
            SDL_SetError("XRenderFindVisualFormat() failed");
            return NULL;
        }
        data->xwindow_pict = XRenderCreatePicture(data->display,
                                                  data->xwindow,
                                                  data->xwindow_pict_fmt,
                                                  0, NULL);
        if (!data->xwindow_pict) {
            SDL_SetError("XRenderCreatePicture() failed");
            return NULL;
        }
        // FIXME: Clear the window. Is this required?
        XRenderComposite(data->display,
                         PictOpClear,
                         data->xwindow_pict,
                         None,
                         data->xwindow_pict,
                         0, 0,
                         0, 0,
                         0, 0,
                         window->w, window->h);
        /* Add some blending modes to the list of supported blending modes */
        renderer->info.blend_modes |=
            (SDL_BLENDMODE_BLEND | SDL_BLENDMODE_ADD | SDL_BLENDMODE_MASK);
        /* Create a clip mask that is used for rendering primitives. */
        data->stencil = XCreatePixmap(data->display, data->xwindow,
                                   window->w, window->h, 8);
        
        /* Create the GC for the clip mask. */
        data->stencil_gc = XCreateGC(data->display, data->stencil,
                                  GCGraphicsExposures, &gcv);
        XSetBackground(data->display, data->stencil_gc, 0x00);
        XSetForeground(data->display, data->stencil_gc, 0x00);
        XFillRectangle(data->display, data->stencil, data->stencil_gc,
                       0, 0, window->w, window->h);
        XSetForeground(data->display, data->stencil_gc, 0xFF);
        data->stencil_pict =
            XRenderCreatePicture(data->display, data->stencil,
                                 XRenderFindStandardFormat(data->display,
                                                           PictStandardA8),
                                 0, NULL);
#ifdef SDL_VIDEO_DRIVER_X11_XDAMAGE
        if (data->use_xdamage) {
            data->stencil_damage =
                XDamageCreate(data->display, data->stencil, XDamageReportNonEmpty);
            XDamageSubtract(data->display, data->stencil_damage, None, data->stencil_parts);
        }
#endif
        data->brush =
            XCreatePixmap(data->display, data->xwindow, 1, 1, 32);
        XRenderPictureAttributes brush_attr;
        brush_attr.repeat = RepeatNormal;
        data->brush_pict =
            XRenderCreatePicture(data->display, data->brush,
                                 XRenderFindStandardFormat(data->display,
                                                           PictStandardARGB32),
                                 CPRepeat, &brush_attr);
        // Set the default blending mode.
        renderer->blendMode = SDL_BLENDMODE_BLEND;
        data->blend_op = PictOpOver;
    }
#endif
    
    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;
    }
#ifdef SDL_VIDEO_DRIVER_X11_XRENDER
    if (data->use_xrender) {
        if (n > 0)
            data->drawable_pict_fmt =
                XRenderFindStandardFormat(data->display, PictStandardARGB32);
        else
            data->drawable_pict_fmt = data->xwindow_pict_fmt;
    }
#endif
    for (i = 0; i < n; ++i) {
#ifdef SDL_VIDEO_DRIVER_X11_XRENDER
        if (data->use_xrender) {
            data->pixmaps[i] = XCreatePixmap(data->display,
                                             data->xwindow,
                                             window->w,
                                             window->h,
                                             32);
        }
        else
#endif
        {
            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->use_xrender) {
            /* Create xrender pictures for each of the pixmaps
             * and clear the pixmaps. */
            data->pixmap_picts[i] = 
                XRenderCreatePicture(data->display,
                                     data->pixmaps[i],
                                     XRenderFindStandardFormat(data->display,
                                                               PictStandardARGB32),
                                     0, None);
            if (!data->pixmap_picts[i]) {
                SDL_SetError("XRenderCreatePicture() failed");
                return NULL;
            }

            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->use_xrender == 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->use_xrender == SDL_TRUE)
            data->drawable_pict = data->xwindow_pict;
#endif
        data->makedirty = SDL_FALSE;
    }
    data->current_pixmap = 0;

#ifdef SDL_VIDEO_DRIVER_X11_XRENDER
    if (data->use_xrender) {
        bpp = data->drawable_pict_fmt->depth;
        Rmask = ((data->drawable_pict_fmt->direct.redMask)
                    << (data->drawable_pict_fmt->direct.red));
        Gmask = ((data->drawable_pict_fmt->direct.greenMask)
                    << (data->drawable_pict_fmt->direct.green));
        Bmask = ((data->drawable_pict_fmt->direct.blueMask)
                    << (data->drawable_pict_fmt->direct.blue));
        Amask = ((data->drawable_pict_fmt->direct.alphaMask)
                    << (data->drawable_pict_fmt->direct.alpha));
    }
    else
#endif
    {
        /* 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->drawable, 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;

#ifdef SDL_VIDEO_DRIVER_X11_XRENDER
    if (data->use_xrender) {
        XRenderFreePicture(data->display, data->xwindow_pict);
        data->xwindow_pict_fmt =
            XRenderFindVisualFormat(data->display, data->visual);
        data->xwindow_pict =
            XRenderCreatePicture(data->display, data->xwindow,
                                 data->xwindow_pict_fmt, 0, NULL);
    }
#endif
    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
            XRenderFreePicture(data->display, data->pixmap_picts[i]);
            data->pixmap_picts[i] = None;
#endif
        }
    }
    for (i = 0; i < n; ++i) {
#ifdef SDL_VIDEO_DRIVER_X11_XRENDER
        if (data->use_xrender) {
            data->pixmaps[i] =
                XCreatePixmap(data->display,
                              data->xwindow,
                              window->w,
                              window->h,
                              32);
        }
        else
#endif
        {
            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->use_xrender) {
            data->pixmap_picts[i] = 
                XRenderCreatePicture(data->display,
                                     data->pixmaps[i],
                                     XRenderFindStandardFormat(data->display,
                                                               PictStandardARGB32),
                                     0, None);
            if (!data->pixmap_picts[i]) {
                SDL_SetError("XRenderCreatePicture() failed");
                return -1;
            }
            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;
}

#ifdef SDL_VIDEO_DRIVER_X11_XRENDER
static void
SDLMaskToXRenderMask(Uint32 sdl_mask, short *comp, short *compMask) {
    (*comp) = 0;
    (*compMask) = 0;
    while(!(sdl_mask & 1)) {
        (*comp)++;
        sdl_mask >>= 1;
    }
    while(sdl_mask & 1) {
        (*compMask) = ((*compMask) << 1) | 1;
        sdl_mask >>= 1;
    }
}

static XRenderPictFormat*
PixelFormatEnumToXRenderPictFormat(SDL_Renderer * renderer, Uint32 format) {
    XRenderPictFormat* pict_fmt = NULL;
    X11_RenderData *data = (X11_RenderData *) renderer->driverdata;

    if (data->use_xrender) {

        int bpp;
        Uint32 Amask, Rmask, Gmask, Bmask;
        SDL_PixelFormatEnumToMasks(format, &bpp, &Rmask, &Gmask, &Bmask, &Amask);

        XRenderPictFormat templ;
        unsigned long mask = (PictFormatType | PictFormatDepth | PictFormatRed |
                              PictFormatRedMask | PictFormatGreen | PictFormatGreenMask |
                              PictFormatBlue | PictFormatBlueMask | PictFormatAlpha |
                              PictFormatAlphaMask);

        templ.type = PictTypeDirect;
        templ.depth = bpp;
        SDLMaskToXRenderMask(Amask, &(templ.direct.alpha), &(templ.direct.alphaMask));
        SDLMaskToXRenderMask(Rmask, &(templ.direct.red), &(templ.direct.redMask));
        SDLMaskToXRenderMask(Gmask, &(templ.direct.green), &(templ.direct.greenMask));
        SDLMaskToXRenderMask(Bmask, &(templ.direct.blue), &(templ.direct.blueMask));

        pict_fmt = XRenderFindFormat(data->display, mask, &templ, 0);
    }
    
    return pict_fmt;
}


static Visual*
PixelFormatEnumToVisual(SDL_Renderer * renderer, Uint32 format) {
    X11_RenderData *data = (X11_RenderData *) renderer->driverdata;

    if (data->use_xrender) {
        int bpp;
        Uint32 Amask, Rmask, Gmask, Bmask;
        SDL_PixelFormatEnumToMasks(format, &bpp, &Rmask, &Gmask, &Bmask, &Amask);

        XVisualInfo vinfo_templ;
        long vinfo_mask;
        int nitems_return;

        vinfo_mask = (VisualDepthMask | VisualRedMaskMask |
                      VisualGreenMaskMask | VisualBlueMaskMask);
        vinfo_templ.depth = bpp;
        vinfo_templ.red_mask = Rmask;
        vinfo_templ.green_mask = Gmask;
        vinfo_templ.blue_mask = Bmask;

        XVisualInfo * ret = XGetVisualInfo(data->display, vinfo_mask,
                                           &vinfo_templ, &nitems_return);
        
        if (nitems_return) {
            return ret[0].visual;
        }
    }

    return NULL;
}
#endif

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);
    XGCValues gcv;
    
    data = (X11_TextureData *) SDL_calloc(1, sizeof(*data));
    if (!data) {
        SDL_OutOfMemory();
        return -1;
    }
    data->depth = renderdata->depth;
    data->visual = renderdata->visual;
    data->gc = renderdata->gc;

    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
        if (renderdata->use_xrender == SDL_FALSE) {
            if (texture->format != display->current_mode.format) {
                SDL_SetError("Texture format doesn't match window format");
                return -1;
            }
        } else {
            Uint32 Amask, Rmask, Gmask, Bmask;
            SDL_PixelFormatEnumToMasks(texture->format, &(data->depth),
                                       &Rmask, &Gmask, &Bmask, &Amask);
            data->visual = PixelFormatEnumToVisual(renderer, texture->format);
        }
#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->pixmap =
                XCreatePixmap(renderdata->display, renderdata->xwindow, texture->w,
                              texture->h, data->depth);
            if (data->pixmap == None) {
                X11_DestroyTexture(renderer, texture);
                SDL_SetError("XCreatePixmap() failed");
                return -1;
            }
            data->image =
                XShmCreateImage(renderdata->display, data->visual,
                                data->depth, ZPixmap, shminfo->shmaddr,
                                shminfo, texture->w, texture->h);

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

            data->pixmap =
                XCreatePixmap(renderdata->display, renderdata->xwindow, texture->w,
                              texture->h, data->depth);
            if (data->pixmap == None) {
                X11_DestroyTexture(renderer, texture);
                SDL_SetError("XCreatePixmap() failed");
                return -1;
            }
            data->image =
                XCreateImage(renderdata->display, data->visual,
                             data->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, data->depth);
        if (data->pixmap == None) {
            X11_DestroyTexture(renderer, texture);
            SDL_SetError("XCreatePixmap() failed");
            return -1;
        }
        data->image =
            XCreateImage(renderdata->display, data->visual,
                         data->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->use_xrender) {
        gcv.graphics_exposures = False;
        data->gc =
            XCreateGC(renderdata->display, data->pixmap, GCGraphicsExposures, &gcv);
        if (!data->gc) {
            SDL_SetError("XCreateGC() failed");
            return -1;
        }
        data->picture_fmt =
            PixelFormatEnumToXRenderPictFormat(renderer, texture->format);
        if (data->picture_fmt == NULL) {
            X11_DestroyTexture(renderer, texture);
            SDL_SetError("Texture format not supported by driver");
            return -1;
        }
        data->picture =
            XRenderCreatePicture(renderdata->display, data->pixmap,
                                 data->picture_fmt, 0, NULL);
        if (!data->picture) {
            X11_DestroyTexture(renderer, texture);
            SDL_SetError("XRenderCreatePicture() failed");
            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)
{
    X11_TextureData *data = (X11_TextureData *) texture->driverdata;
    switch (texture->blendMode) {
    case SDL_BLENDMODE_NONE:
#ifdef SDL_VIDEO_DRIVER_X11_XRENDER
        data->blend_op = PictOpSrc;
        return 0;
    case SDL_BLENDMODE_BLEND:
        data->blend_op = PictOpOver;
        return 0;
    case SDL_BLENDMODE_ADD:
        data->blend_op = PictOpAdd;
        return 0;
#endif
    default:
        SDL_Unsupported();
        texture->blendMode = SDL_BLENDMODE_NONE;
#ifdef SDL_VIDEO_DRIVER_X11_XRENDER
        texture->blendMode = SDL_BLENDMODE_BLEND;
        data->blend_op = PictOpOver;
#endif
        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) {
            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;
            }
        } 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, data->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)
{
    X11_RenderData *data = (X11_RenderData *) renderer->driverdata;
    switch (renderer->blendMode) {
    case SDL_BLENDMODE_NONE:
#ifdef SDL_VIDEO_DRIVER_X11_XRENDER
        //PictOpSrc
        data->blend_op = PictOpSrc;
        return 0;
    case SDL_BLENDMODE_BLEND: // PictOpOver
        data->blend_op = PictOpOver;
        return 0;
    case SDL_BLENDMODE_ADD: // PictOpAdd
        data->blend_op = PictOpAdd;
        return 0;
    /* FIXME case SDL_BLENDMODE_MOD: */
#endif
        return 0;
    default:
        SDL_Unsupported();
#ifdef SDL_VIDEO_DRIVER_X11_XRENDER
        if(data->use_xrender) {
            renderer->blendMode = SDL_BLENDMODE_BLEND;
            data->blend_op = PictOpOver;
        }
        else
#endif
        {
            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;
    double alphad;
    if(renderer->blendMode == SDL_BLENDMODE_NONE)
        alphad = 1.0;
    else
        alphad = (renderer->a) / 255.0;

    xrender_color.alpha = (unsigned short) ((renderer->a / 255.0) * 0xFFFF);

    xrender_color.red =
        (unsigned short) ((renderer->r / 255.0) * alphad * 0xFFFF);
    xrender_color.green =
        (unsigned short) ((renderer->g / 255.0) * alphad * 0xFFFF);
    xrender_color.blue =
        (unsigned short) ((renderer->b / 255.0) * alphad * 0xFFFF);
    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;
    XPoint *xpoints, *xpoint;
    int i, xcount;
    SDL_Rect clip;

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

#ifdef SDL_VIDEO_DRIVER_X11_XRENDER
        if (data->use_xrender &&
            (renderer->blendMode != SDL_BLENDMODE_NONE) &&
            !(renderer->a == 0xFF &&
              renderer->blendMode != SDL_BLENDMODE_ADD &&
              renderer->blendMode != SDL_BLENDMODE_MOD))
        {
            XSetForeground(data->display, data->stencil_gc, 0x00);
#ifdef SDL_VIDEO_DRIVER_X11_XDAMAGE
            if (data->use_xdamage)
            {
                /* Update only those parts which were changed
                * in the previous drawing operation */
                XFixesSetGCClipRegion(data->display, data->stencil_gc,
                                      0, 0, data->stencil_parts);
            }
#endif
            XFillRectangle(data->display, data->stencil, data->stencil_gc,
                           0, 0, window->w, window->h);
#ifdef SDL_VIDEO_DRIVER_X11_XDAMAGE
            if (data->use_xdamage)
            {
                XFixesSetGCClipRegion(data->display, data->stencil_gc, 0, 0, None);
            }
#endif
            XSetForeground(data->display, data->stencil_gc, 0xFF);

            XDrawPoints(data->display, data->stencil, data->stencil_gc, xpoints, xcount,
                        CoordModeOrigin);
#ifdef SDL_VIDEO_DRIVER_X11_XDAMAGE
            if (data->use_xdamage)
            {
                /* Store the damaged region in stencil_parts */
                XDamageSubtract(data->display, data->stencil_damage, None, data->stencil_parts);
            }
#endif
        }
#endif
    }

#ifdef SDL_VIDEO_DRIVER_X11_XRENDER
    if (data->use_xrender &&
            (renderer->blendMode != SDL_BLENDMODE_NONE) &&
            !(renderer->a == 0xFF &&
              renderer->blendMode != SDL_BLENDMODE_ADD &&
              renderer->blendMode != SDL_BLENDMODE_MOD))
    {
        XRenderColor foreground;
        foreground = xrenderdrawcolor(renderer);

        XRenderFillRectangle(data->display, PictOpSrc, data->brush_pict,
                             &foreground, 0, 0, 1, 1);
#ifdef SDL_VIDEO_DRIVER_X11_XDAMAGE
        if (data->use_xdamage)
        {
            /* Update only those parts which drawn
             * to in the current drawing operation */
            XFixesSetPictureClipRegion(data->display, data->drawable_pict,
                                       0, 0, data->stencil_parts);
        }
#endif
        XRenderComposite(data->display, data->blend_op, data->brush_pict,
                         data->stencil_pict, data->drawable_pict,
                         0, 0, 0, 0, 0, 0, window->w, window->h);
#ifdef SDL_VIDEO_DRIVER_X11_XDAMAGE
        if (data->use_xdamage)
        {
            XFixesSetPictureClipRegion(data->display, data->drawable_pict, 0, 0, None);
        }
#endif
    }
    else
#endif
    {
        unsigned long foreground = renderdrawcolor(renderer, 1);
        XSetForeground(data->display, data->gc, foreground);


        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;
    {
        Pixmap drawable;
        GC gc;
#ifdef SDL_VIDEO_DRIVER_X11_XRENDER
       if (data->use_xrender &&
            (renderer->blendMode != SDL_BLENDMODE_NONE) &&
            !(renderer->a == 0xFF &&
              renderer->blendMode != SDL_BLENDMODE_ADD &&
              renderer->blendMode != SDL_BLENDMODE_MOD))
       { 
            drawable = data->stencil;
            gc = data->stencil_gc;

            XSetForeground(data->display, data->stencil_gc, 0x00);
#ifdef SDL_VIDEO_DRIVER_X11_XDAMAGE
            if (data->use_xdamage)
                XFixesSetGCClipRegion(data->display, data->stencil_gc,
                                      0, 0, data->stencil_parts);
#endif
            XFillRectangle(data->display, data->stencil, data->stencil_gc,
                           0, 0, window->w, window->h);
#ifdef SDL_VIDEO_DRIVER_X11_XDAMAGE
            if (data->use_xdamage)
                XFixesSetGCClipRegion(data->display, data->stencil_gc,
                                      0, 0, None);
#endif
            XSetForeground(data->display, data->stencil_gc, 0xFF);
        }
        else
#endif
        {
            drawable = data->drawable;
            gc = data->gc;
        }

        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, drawable, gc,
                           xpoints, xcount, CoordModeOrigin);
                if (xpoints[0].x != x2 || xpoints[0].y != y2) {
                    XDrawPoint(data->display, drawable, 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, drawable, gc, xpoints, xcount,
                       CoordModeOrigin);
            if (xpoints[0].x != x2 || xpoints[0].y != y2) {
                XDrawPoint(data->display, drawable, 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);
            }
        }
    }
#ifdef SDL_VIDEO_DRIVER_X11_XRENDER
    if (data->use_xrender &&
            (renderer->blendMode != SDL_BLENDMODE_NONE) &&
            !(renderer->a == 0xFF &&
              renderer->blendMode != SDL_BLENDMODE_ADD &&
              renderer->blendMode != SDL_BLENDMODE_MOD))
    {
        XRenderColor xrforeground = xrenderdrawcolor(renderer);
        XRenderFillRectangle(data->display, PictOpSrc, data->brush_pict,
                             &xrforeground, 0, 0, 1, 1);
#ifdef SDL_VIDEO_DRIVER_X11_XDAMAGE
        if (data->use_xdamage)
        {
            XDamageSubtract(data->display, data->stencil_damage, None, data->stencil_parts);

            XFixesSetPictureClipRegion(data->display, data->drawable_pict,
                                       0, 0, data->stencil_parts);
        }
#endif
        XRenderComposite(data->display, data->blend_op, data->brush_pict,
                         data->stencil_pict, data->drawable_pict,
                         0, 0, 0, 0, 0, 0, window->w, window->h);
#ifdef SDL_VIDEO_DRIVER_X11_XDAMAGE
        if (data->use_xdamage)
            XFixesSetPictureClipRegion(data->display, data->drawable_pict,
                                       0, 0, None);
#endif
    }
#endif
    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;
    int i, xcount;
    XRectangle *xrects, *xrect;
    xrect = xrects = SDL_stack_alloc(XRectangle, count);
    xcount = 0;
    
    clip.x = 0;
    clip.y = 0;
    clip.w = window->w;
    clip.h = window->h;
    {

        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);
            }
        }
#ifdef SDL_VIDEO_DRIVER_X11_XRENDER
        if (data->use_xrender &&
            (renderer->blendMode != SDL_BLENDMODE_NONE) &&
            !(renderer->a == 0xFF &&
              renderer->blendMode != SDL_BLENDMODE_ADD &&
              renderer->blendMode != SDL_BLENDMODE_MOD))
        {
            XSetForeground(data->display, data->stencil_gc, 0x00);
#ifdef SDL_VIDEO_DRIVER_X11_XDAMAGE
            if (data->use_xdamage)
                XFixesSetGCClipRegion(data->display, data->stencil_gc,
                                      0, 0, data->stencil_parts);
#endif
            XFillRectangle(data->display, data->stencil, data->stencil_gc,
                           0, 0, window->w, window->h);
#ifdef SDL_VIDEO_DRIVER_X11_XDAMAGE
            if (data->use_xdamage)
                XFixesSetGCClipRegion(data->display, data->stencil_gc,
                                      0, 0, None);
#endif
            XSetForeground(data->display, data->stencil_gc, 0xFF);

            XDrawRectangles(data->display, data->stencil, data->stencil_gc, xrects, xcount);

#ifdef SDL_VIDEO_DRIVER_X11_XDAMAGE
            if (data->use_xdamage)
                XDamageSubtract(data->display, data->stencil_damage,
                                None, data->stencil_parts);
#endif
        }
#endif
    }
#ifdef SDL_VIDEO_DRIVER_X11_XRENDER
    if (data->use_xrender &&
            (renderer->blendMode != SDL_BLENDMODE_NONE) &&
            !(renderer->a == 0xFF &&
              renderer->blendMode != SDL_BLENDMODE_ADD &&
              renderer->blendMode != SDL_BLENDMODE_MOD))
    {
        XRenderColor foreground;
        foreground = xrenderdrawcolor(renderer);
        XRenderFillRectangle(data->display, PictOpSrc, data->brush_pict,
                             &foreground, 0, 0, 1, 1);
#ifdef SDL_VIDEO_DRIVER_X11_XDAMAGE
        if (data->use_xdamage)
            XFixesSetPictureClipRegion(data->display, data->drawable_pict,
                                       0, 0, data->stencil_parts);
#endif
        XRenderComposite(data->display, data->blend_op, data->brush_pict,
                         data->stencil_pict, data->drawable_pict,
                         0, 0, 0, 0, 0, 0, window->w, window->h);
#ifdef SDL_VIDEO_DRIVER_X11_XDAMAGE
        if (data->use_xdamage)
            XFixesSetPictureClipRegion(data->display, data->drawable_pict,
                                       0, 0, None);
#endif
    }
    else
#endif
    {
        unsigned long foreground;
        
        foreground = renderdrawcolor(renderer, 1);
        XSetForeground(data->display, data->gc, foreground);
    
        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;
    
    clip.x = 0;
    clip.y = 0;
    clip.w = window->w;
    clip.h = window->h;
    
    int i, xcount;
    XRectangle *xrects, *xrect;
    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);
        }
    }

#ifdef SDL_VIDEO_DRIVER_X11_XRENDER
    if (data->use_xrender) {
        XRenderColor foreground;
        foreground = xrenderdrawcolor(renderer);
        if (xcount == 1) {
            XRenderFillRectangle(data->display, data->blend_op, data->drawable_pict,
                                 &foreground, xrects[0].x, xrects[0].y,
                                 xrects[0].width, xrects[0].height);
        }
        else if (xcount > 1) {
            XRenderFillRectangles(data->display, data->blend_op, data->drawable_pict,
                                  &foreground, xrects, xcount);
        }
    }
    else
#endif
    {
        unsigned long foreground;
        
        foreground = renderdrawcolor(renderer, 1);
        XSetForeground(data->display, data->gc, foreground);
 
        XFillRectangles(data->display, data->drawable, data->gc,
                        xrects, xcount);
    }

    SDL_stack_free(xrects);
    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);
    }
#ifdef SDL_VIDEO_DRIVER_X11_XRENDER
    if (data->use_xrender) {
        if(texture->access == SDL_TEXTUREACCESS_STREAMING) {
#ifndef NO_SHARED_MEMORY
            if(texturedata->shminfo.shmaddr) {
                XShmPutImage(data->display, texturedata->pixmap, data->gc,
                             texturedata->image, srcrect->x, srcrect->y,
                             srcrect->x, srcrect->y, srcrect->w, srcrect->h,
                             False);
            }
            else
#endif
            if (texturedata->pixels) {
                XPutImage(data->display, texturedata->pixmap, data->gc,
                          texturedata->image, srcrect->x, srcrect->y, dstrect->x,
                          dstrect->y, srcrect->w, srcrect->h);
            }
        }
        Picture pict;
        if(texture->blendMode == SDL_BLENDMODE_NONE)
            pict = None;
        else
            pict = texturedata->picture;
        if(srcrect->w == dstrect->w && srcrect->h == dstrect->h) {
            XRenderComposite(data->display, texturedata->blend_op, texturedata->picture,
                         pict, data->drawable_pict, srcrect->x, srcrect->y,
                         srcrect->x, srcrect->y, dstrect->x, dstrect->y,
                         srcrect->w, srcrect->h);
        } else {
            double xscale = ((double) dstrect->w) / srcrect->w;
            double yscale = ((double) dstrect->h) / srcrect->h;
            XTransform xform = {{
                    {XDoubleToFixed(xscale), XDoubleToFixed(0), XDoubleToFixed(0)},
                    {XDoubleToFixed(0), XDoubleToFixed(yscale), XDoubleToFixed(0)},
                    {XDoubleToFixed(0), XDoubleToFixed(0), XDoubleToFixed(xscale * yscale)}}};
            XRenderSetPictureTransform(data->display, texturedata->picture, &xform);

            XRenderComposite(data->display, texturedata->blend_op,
                             texturedata->picture, pict, data->drawable_pict,
                             0, 0, 0, 0, dstrect->x, dstrect->y,
                             dstrect->w, dstrect->h);
            
            XTransform identity = {{
                    {XDoubleToFixed(1), XDoubleToFixed(0), XDoubleToFixed(0)},
                    {XDoubleToFixed(0), XDoubleToFixed(1), XDoubleToFixed(0)},
                    {XDoubleToFixed(0), XDoubleToFixed(0), XDoubleToFixed(1)}}};
            XRenderSetPictureTransform(data->display, texturedata->picture, &identity);
        }
    }
    else
#endif
    {
        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->use_xrender)
            {
                XRenderComposite(data->display,
                                 data->blend_op,
                                 data->drawable_pict,
                                 None,
                                 data->xwindow_pict,
                                 rect->x, rect->y,
                                 0, 0,
                                 rect->x, rect->y,
                                 rect->w, rect->h);
            }
            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);
    }
    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]);
            }
#ifdef SDL_VIDEO_DRIVER_X11_XRENDER
            if (data->pixmap_picts[i] != None) {
                XRenderFreePicture(data->display, data->pixmap_picts[i]);
            }
#endif
        }
        if (data->gc) {
            XFreeGC(data->display, data->gc);
        }
#ifdef SDL_VIDEO_DRIVER_X11_XRENDER
        if (data->stencil_gc) {
            XFreeGC(data->display, data->stencil_gc);
        }
        if (data->stencil) {
            XFreePixmap(data->display, data->stencil);
        }
        if (data->drawable_pict) {
            XRenderFreePicture(data->display, data->drawable_pict);
        }
        if (data->xwindow_pict) {
            XRenderFreePicture(data->display, data->xwindow_pict);
        }
#endif
        SDL_FreeDirtyRects(&data->dirty);
        SDL_free(data);
    }
    SDL_free(renderer);
}

#endif /* SDL_VIDEO_RENDER_X11 */

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