added MouseWheel event support for Silverlight 3.0

[moon.git] / cairo / src / cairo-xcb-surface.c

/* cairo - a vector graphics library with display and print output
 *
 * Copyright © 2002 University of Southern California
 *
 * This library is free software; you can redistribute it and/or
 * modify it either under the terms of the GNU Lesser General Public
 * License version 2.1 as published by the Free Software Foundation
 * (the "LGPL") or, at your option, under the terms of the Mozilla
 * Public License Version 1.1 (the "MPL"). If you do not alter this
 * notice, a recipient may use your version of this file under either
 * the MPL or the LGPL.
 *
 * You should have received a copy of the LGPL along with this library
 * in the file COPYING-LGPL-2.1; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 * You should have received a copy of the MPL along with this library
 * in the file COPYING-MPL-1.1
 *
 * The contents of this file are subject to the Mozilla Public License
 * Version 1.1 (the "License"); you may not use this file except in
 * compliance with the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY
 * OF ANY KIND, either express or implied. See the LGPL or the MPL for
 * the specific language governing rights and limitations.
 *
 * The Original Code is the cairo graphics library.
 *
 * The Initial Developer of the Original Code is University of Southern
 * California.
 *
 * Contributor(s):
 *      Carl D. Worth <cworth@cworth.org>
 */

#include "cairoint.h"
#include "cairo-xcb.h"
#include "cairo-xcb-xrender.h"
#include "cairo-clip-private.h"
#include <xcb/xcb_renderutil.h>

#define AllPlanes               ((unsigned long)~0L)

slim_hidden_proto (cairo_xcb_surface_create_with_xrender_format);

/*
 * Instead of taking two round trips for each blending request,
 * assume that if a particular drawable fails GetImage that it will
 * fail for a "while"; use temporary pixmaps to avoid the errors
 */

#define CAIRO_ASSUME_PIXMAP     20

typedef struct cairo_xcb_surface {
    cairo_surface_t base;

    xcb_connection_t *dpy;
    xcb_screen_t *screen;

    xcb_gcontext_t gc;
    xcb_drawable_t drawable;
    cairo_bool_t owns_pixmap;
    xcb_visualtype_t *visual;

    int use_pixmap;

    int render_major;
    int render_minor;

    int width;
    int height;
    int depth;

    cairo_bool_t have_clip_rects;
    xcb_rectangle_t *clip_rects;
    int num_clip_rects;

    xcb_render_picture_t src_picture, dst_picture;
    xcb_render_pictforminfo_t xrender_format;
} cairo_xcb_surface_t;

#define CAIRO_SURFACE_RENDER_AT_LEAST(surface, major, minor)    \
        (((surface)->render_major > major) ||                   \
         (((surface)->render_major == major) && ((surface)->render_minor >= minor)))

#define CAIRO_SURFACE_RENDER_HAS_CREATE_PICTURE(surface)                CAIRO_SURFACE_RENDER_AT_LEAST((surface), 0, 0)
#define CAIRO_SURFACE_RENDER_HAS_COMPOSITE(surface)             CAIRO_SURFACE_RENDER_AT_LEAST((surface), 0, 0)
#define CAIRO_SURFACE_RENDER_HAS_COMPOSITE_TEXT(surface)        CAIRO_SURFACE_RENDER_AT_LEAST((surface), 0, 0)

#define CAIRO_SURFACE_RENDER_HAS_FILL_RECTANGLE(surface)                CAIRO_SURFACE_RENDER_AT_LEAST((surface), 0, 1)
#define CAIRO_SURFACE_RENDER_HAS_FILL_RECTANGLES(surface)               CAIRO_SURFACE_RENDER_AT_LEAST((surface), 0, 1)

#define CAIRO_SURFACE_RENDER_HAS_DISJOINT(surface)                      CAIRO_SURFACE_RENDER_AT_LEAST((surface), 0, 2)
#define CAIRO_SURFACE_RENDER_HAS_CONJOINT(surface)                      CAIRO_SURFACE_RENDER_AT_LEAST((surface), 0, 2)

#define CAIRO_SURFACE_RENDER_HAS_TRAPEZOIDS(surface)            CAIRO_SURFACE_RENDER_AT_LEAST((surface), 0, 4)
#define CAIRO_SURFACE_RENDER_HAS_TRIANGLES(surface)             CAIRO_SURFACE_RENDER_AT_LEAST((surface), 0, 4)
#define CAIRO_SURFACE_RENDER_HAS_TRISTRIP(surface)                      CAIRO_SURFACE_RENDER_AT_LEAST((surface), 0, 4)
#define CAIRO_SURFACE_RENDER_HAS_TRIFAN(surface)                        CAIRO_SURFACE_RENDER_AT_LEAST((surface), 0, 4)

#define CAIRO_SURFACE_RENDER_HAS_PICTURE_TRANSFORM(surface)     CAIRO_SURFACE_RENDER_AT_LEAST((surface), 0, 6)
#define CAIRO_SURFACE_RENDER_HAS_FILTERS(surface)       CAIRO_SURFACE_RENDER_AT_LEAST((surface), 0, 6)

static void
_cairo_xcb_surface_ensure_gc (cairo_xcb_surface_t *surface);

static int
_CAIRO_FORMAT_DEPTH (cairo_format_t format)
{
    switch (format) {
    case CAIRO_FORMAT_A1:
        return 1;
    case CAIRO_FORMAT_A8:
        return 8;
    case CAIRO_FORMAT_RGB24:
        return 24;
    case CAIRO_FORMAT_ARGB32:
    default:
        return 32;
    }
}

static xcb_render_pictforminfo_t *
_CAIRO_FORMAT_TO_XRENDER_FORMAT(xcb_connection_t *dpy, cairo_format_t format)
{
    xcb_pict_standard_t std_format;
    switch (format) {
    case CAIRO_FORMAT_A1:
        std_format = XCB_PICT_STANDARD_A_1; break;
    case CAIRO_FORMAT_A8:
        std_format = XCB_PICT_STANDARD_A_8; break;
    case CAIRO_FORMAT_RGB24:
        std_format = XCB_PICT_STANDARD_RGB_24; break;
    case CAIRO_FORMAT_ARGB32:
    default:
        std_format = XCB_PICT_STANDARD_ARGB_32; break;
    }
    return xcb_render_util_find_standard_format (xcb_render_util_query_formats (dpy), std_format);
}

static cairo_content_t
_xcb_render_format_to_content (xcb_render_pictforminfo_t *xrender_format)
{
    cairo_bool_t xrender_format_has_alpha;
    cairo_bool_t xrender_format_has_color;

    /* This only happens when using a non-Render server. Let's punt
     * and say there's no alpha here. */
    if (xrender_format == NULL)
        return CAIRO_CONTENT_COLOR;

    xrender_format_has_alpha = (xrender_format->direct.alpha_mask != 0);
    xrender_format_has_color = (xrender_format->direct.red_mask   != 0 ||
                                xrender_format->direct.green_mask != 0 ||
                                xrender_format->direct.blue_mask  != 0);

    if (xrender_format_has_alpha)
        if (xrender_format_has_color)
            return CAIRO_CONTENT_COLOR_ALPHA;
        else
            return CAIRO_CONTENT_ALPHA;
    else
        return CAIRO_CONTENT_COLOR;
}

static cairo_surface_t *
_cairo_xcb_surface_create_similar (void                *abstract_src,
                                   cairo_content_t      content,
                                   int                  width,
                                   int                  height)
{
    cairo_xcb_surface_t *src = abstract_src;
    xcb_connection_t *dpy = src->dpy;
    xcb_pixmap_t pixmap;
    cairo_xcb_surface_t *surface;
    cairo_format_t format = _cairo_format_from_content (content);
    xcb_render_pictforminfo_t *xrender_format;

    /* As a good first approximation, if the display doesn't have COMPOSITE,
     * we're better off using image surfaces for all temporary operations
     */
    if (!CAIRO_SURFACE_RENDER_HAS_COMPOSITE (src)) {
        return cairo_image_surface_create (format, width, height);
    }

    pixmap = xcb_generate_id (dpy);
    xcb_create_pixmap (dpy, _CAIRO_FORMAT_DEPTH (format),
                     pixmap, src->drawable,
                     width <= 0 ? 1 : width,
                     height <= 0 ? 1 : height);

    xrender_format = _CAIRO_FORMAT_TO_XRENDER_FORMAT (dpy, format);
    /* XXX: what to do if xrender_format is null? */
    surface = (cairo_xcb_surface_t *)
        cairo_xcb_surface_create_with_xrender_format (dpy, pixmap, src->screen,
                                                      xrender_format,
                                                      width, height);
    if (surface->base.status)
        return &surface->base;

    surface->owns_pixmap = TRUE;

    return &surface->base;
}

static cairo_status_t
_cairo_xcb_surface_finish (void *abstract_surface)
{
    cairo_xcb_surface_t *surface = abstract_surface;
    if (surface->dst_picture != XCB_NONE)
        xcb_render_free_picture (surface->dpy, surface->dst_picture);

    if (surface->src_picture != XCB_NONE)
        xcb_render_free_picture (surface->dpy, surface->src_picture);

    if (surface->owns_pixmap)
        xcb_free_pixmap (surface->dpy, surface->drawable);

    if (surface->gc != XCB_NONE)
        xcb_free_gc (surface->dpy, surface->gc);

    free (surface->clip_rects);

    surface->dpy = NULL;

    return CAIRO_STATUS_SUCCESS;
}

static int
_bits_per_pixel(xcb_connection_t *c, int depth)
{
    xcb_format_t *fmt = xcb_setup_pixmap_formats(xcb_get_setup(c));
    xcb_format_t *fmtend = fmt + xcb_setup_pixmap_formats_length(xcb_get_setup(c));

    for(; fmt != fmtend; ++fmt)
        if(fmt->depth == depth)
            return fmt->bits_per_pixel;

    if(depth <= 4)
        return 4;
    if(depth <= 8)
        return 8;
    if(depth <= 16)
        return 16;
    return 32;
}

static int
_bytes_per_line(xcb_connection_t *c, int width, int bpp)
{
    int bitmap_pad = xcb_get_setup(c)->bitmap_format_scanline_pad;
    return ((bpp * width + bitmap_pad - 1) & -bitmap_pad) >> 3;
}

static cairo_bool_t
_CAIRO_MASK_FORMAT (cairo_format_masks_t *masks, cairo_format_t *format)
{
    switch (masks->bpp) {
    case 32:
        if (masks->alpha_mask == 0xff000000 &&
            masks->red_mask == 0x00ff0000 &&
            masks->green_mask == 0x0000ff00 &&
            masks->blue_mask == 0x000000ff)
        {
            *format = CAIRO_FORMAT_ARGB32;
            return TRUE;
        }
        if (masks->alpha_mask == 0x00000000 &&
            masks->red_mask == 0x00ff0000 &&
            masks->green_mask == 0x0000ff00 &&
            masks->blue_mask == 0x000000ff)
        {
            *format = CAIRO_FORMAT_RGB24;
            return TRUE;
        }
        break;
    case 8:
        if (masks->alpha_mask == 0xff)
        {
            *format = CAIRO_FORMAT_A8;
            return TRUE;
        }
        break;
    case 1:
        if (masks->alpha_mask == 0x1)
        {
            *format = CAIRO_FORMAT_A1;
            return TRUE;
        }
        break;
    }
    return FALSE;
}

static cairo_status_t
_get_image_surface (cairo_xcb_surface_t     *surface,
                    cairo_rectangle_int_t   *interest_rect,
                    cairo_image_surface_t  **image_out,
                    cairo_rectangle_int_t   *image_rect)
{
    cairo_image_surface_t *image;
    xcb_get_image_reply_t *imagerep;
    int bpp, bytes_per_line;
    cairo_rectangle_int_t extents;
    unsigned char *data;
    cairo_format_masks_t masks;
    cairo_format_t format;

    extents.x = 0;
    extents.y = 0;
    extents.width  = surface->width;
    extents.height = surface->height;

    if (interest_rect) {
        if (! _cairo_rectangle_intersect (&extents, interest_rect)) {
            *image_out = NULL;
            return CAIRO_STATUS_SUCCESS;
        }
    }

    if (image_rect)
        *image_rect = extents;

    /* XXX: This should try to use the XShm extension if available */

    if (surface->use_pixmap == 0)
    {
        xcb_generic_error_t *error;
        imagerep = xcb_get_image_reply(surface->dpy,
                                    xcb_get_image(surface->dpy, XCB_IMAGE_FORMAT_Z_PIXMAP,
                                                surface->drawable,
                                                extents.x, extents.y,
                                                extents.width, extents.height,
                                                AllPlanes), &error);

        /* If we get an error, the surface must have been a window,
         * so retry with the safe code path.
         */
        if (error)
            surface->use_pixmap = CAIRO_ASSUME_PIXMAP;
    }
    else
    {
        surface->use_pixmap--;
        imagerep = NULL;
    }

    if (!imagerep)
    {
        /* xcb_get_image_t from a window is dangerous because it can
         * produce errors if the window is unmapped or partially
         * outside the screen. We could check for errors and
         * retry, but to keep things simple, we just create a
         * temporary pixmap
         */
        xcb_pixmap_t pixmap;
        pixmap = xcb_generate_id (surface->dpy);
        xcb_create_pixmap (surface->dpy,
                         surface->depth,
                         pixmap,
                         surface->drawable,
                         extents.width, extents.height);
        _cairo_xcb_surface_ensure_gc (surface);

        xcb_copy_area (surface->dpy, surface->drawable, pixmap, surface->gc,
                     extents.x, extents.y, 0, 0, extents.width, extents.height);

        imagerep = xcb_get_image_reply(surface->dpy,
                                    xcb_get_image(surface->dpy, XCB_IMAGE_FORMAT_Z_PIXMAP,
                                                pixmap,
                                                extents.x, extents.y,
                                                extents.width, extents.height,
                                                AllPlanes), 0);
        xcb_free_pixmap (surface->dpy, pixmap);

    }
    if (!imagerep)
        return _cairo_error (CAIRO_STATUS_NO_MEMORY);

    bpp = _bits_per_pixel(surface->dpy, imagerep->depth);
    bytes_per_line = _bytes_per_line(surface->dpy, surface->width, bpp);

    data = _cairo_malloc_ab (surface->height, bytes_per_line);
    if (data == NULL) {
        free (imagerep);
        return _cairo_error (CAIRO_STATUS_NO_MEMORY);
    }

    memcpy (data, xcb_get_image_data (imagerep), bytes_per_line * surface->height);
    free (imagerep);

    /*
     * Compute the pixel format masks from either an xcb_visualtype_t or
     * a xcb_render_pctforminfo_t, failing we assume the drawable is an
     * alpha-only pixmap as it could only have been created that way
     * through the cairo_xlib_surface_create_for_bitmap function.
     */
    if (surface->visual) {
        masks.bpp = bpp;
        masks.alpha_mask = 0;
        masks.red_mask = surface->visual->red_mask;
        masks.green_mask = surface->visual->green_mask;
        masks.blue_mask = surface->visual->blue_mask;
    } else if (surface->xrender_format.id != XCB_NONE) {
        masks.bpp = bpp;
        masks.red_mask = (unsigned long)surface->xrender_format.direct.red_mask << surface->xrender_format.direct.red_shift;
        masks.green_mask = (unsigned long)surface->xrender_format.direct.green_mask << surface->xrender_format.direct.green_shift;
        masks.blue_mask = (unsigned long)surface->xrender_format.direct.blue_mask << surface->xrender_format.direct.blue_shift;
        masks.alpha_mask = (unsigned long)surface->xrender_format.direct.alpha_mask << surface->xrender_format.direct.alpha_shift;
    } else {
        masks.bpp = bpp;
        masks.red_mask = 0;
        masks.green_mask = 0;
        masks.blue_mask = 0;
        if (surface->depth < 32)
            masks.alpha_mask = (1 << surface->depth) - 1;
        else
            masks.alpha_mask = 0xffffffff;
    }

    /*
     * Prefer to use a standard pixman format instead of the
     * general masks case.
     */
    if (_CAIRO_MASK_FORMAT (&masks, &format)) {
        image = (cairo_image_surface_t *)
            cairo_image_surface_create_for_data (data,
                                                 format,
                                                 extents.width,
                                                 extents.height,
                                                 bytes_per_line);
        if (image->base.status)
            goto FAIL;
    } else {
        /*
         * XXX This can't work.  We must convert the data to one of the
         * supported pixman formats.  Pixman needs another function
         * which takes data in an arbitrary format and converts it
         * to something supported by that library.
         */
        image = (cairo_image_surface_t *)
            _cairo_image_surface_create_with_masks (data,
                                                    &masks,
                                                    extents.width,
                                                    extents.height,
                                                    bytes_per_line);
        if (image->base.status)
            goto FAIL;
    }

    /* Let the surface take ownership of the data */
    _cairo_image_surface_assume_ownership_of_data (image);

    *image_out = image;
    return CAIRO_STATUS_SUCCESS;

 FAIL:
    free (data);
    return _cairo_error (CAIRO_STATUS_NO_MEMORY);
}

static void
_cairo_xcb_surface_ensure_src_picture (cairo_xcb_surface_t    *surface)
{
    if (!surface->src_picture) {
        surface->src_picture = xcb_generate_id(surface->dpy);
        xcb_render_create_picture (surface->dpy,
                                   surface->src_picture,
                                   surface->drawable,
                                   surface->xrender_format.id,
                                   0, NULL);
    }
}

static void
_cairo_xcb_surface_set_picture_clip_rects (cairo_xcb_surface_t *surface)
{
    if (surface->have_clip_rects)
        xcb_render_set_picture_clip_rectangles (surface->dpy, surface->dst_picture,
                                           0, 0,
                                           surface->num_clip_rects,
                                           surface->clip_rects);
}

static void
_cairo_xcb_surface_set_gc_clip_rects (cairo_xcb_surface_t *surface)
{
    if (surface->have_clip_rects)
        xcb_set_clip_rectangles(surface->dpy, XCB_CLIP_ORDERING_YX_SORTED, surface->gc,
                             0, 0,
                             surface->num_clip_rects,
                             surface->clip_rects );
}

static void
_cairo_xcb_surface_ensure_dst_picture (cairo_xcb_surface_t    *surface)
{
    if (!surface->dst_picture) {
        surface->dst_picture = xcb_generate_id(surface->dpy);
        xcb_render_create_picture (surface->dpy,
                                   surface->dst_picture,
                                   surface->drawable,
                                   surface->xrender_format.id,
                                   0, NULL);
        _cairo_xcb_surface_set_picture_clip_rects (surface);
    }

}

static void
_cairo_xcb_surface_ensure_gc (cairo_xcb_surface_t *surface)
{
    if (surface->gc)
        return;

    surface->gc = xcb_generate_id(surface->dpy);
    xcb_create_gc (surface->dpy, surface->gc, surface->drawable, 0, 0);
    _cairo_xcb_surface_set_gc_clip_rects(surface);
}

static cairo_status_t
_draw_image_surface (cairo_xcb_surface_t    *surface,
                     cairo_image_surface_t  *image,
                     int                    src_x,
                     int                    src_y,
                     int                    width,
                     int                    height,
                     int                    dst_x,
                     int                    dst_y)
{
    int bpp, bpl;
    uint32_t data_len;
    uint8_t *data, left_pad=0;

    /* equivalent of XPutImage(..., src_x,src_y, dst_x,dst_y, width,height); */
    /* XXX: assumes image and surface formats and depths are the same */
    /* XXX: assumes depth is a multiple of 8 (not bitmap) */

    /* fit src_{x,y,width,height} within image->{0,0,width,height} */
    if (src_x < 0) {
        width += src_x;
        src_x = 0;
    }
    if (src_y < 0) {
        height += src_y;
        src_y = 0;
    }
    if (width + src_x > image->width)
        width = image->width - src_x;
    if (height + src_y > image->height)
        height = image->height - src_y;
    if (width <= 0 || height <= 0)
        return CAIRO_STATUS_SUCCESS;

    bpp = _bits_per_pixel(surface->dpy, image->depth);
    /* XXX: could use bpl = image->stride? */
    bpl = _bytes_per_line(surface->dpy, image->width, bpp);

    if (src_x == 0 && width == image->width) {
        /* can work in-place */
        data_len = height * bpl;
        data = image->data + src_y * bpl;
    } else {
        /* must copy {src_x,src_y,width,height} into new data */
        int line = 0;
        uint8_t *data_line, *image_line;
        int data_bpl = _bytes_per_line(surface->dpy, width, bpp);
        data_len = height * data_bpl;
        data_line = data = malloc(data_len);
        if (data == NULL)
            return _cairo_error (CAIRO_STATUS_NO_MEMORY);

        image_line = image->data + src_y * bpl + (src_x * bpp / 8);
        while (line++ < height) {
            memcpy(data_line, image_line, data_bpl);
            data_line += data_bpl;
            image_line += bpl;
        }
    }
    _cairo_xcb_surface_ensure_gc (surface);
    xcb_put_image (surface->dpy, XCB_IMAGE_FORMAT_Z_PIXMAP,
        surface->drawable, surface->gc,
        width, height,
        dst_x, dst_y,
        left_pad, image->depth,
        data_len, data);

    if (data < image->data || data >= image->data + image->height * bpl)
        free(data);

    return CAIRO_STATUS_SUCCESS;
}

static cairo_status_t
_cairo_xcb_surface_acquire_source_image (void                    *abstract_surface,
                                         cairo_image_surface_t  **image_out,
                                         void                   **image_extra)
{
    cairo_xcb_surface_t *surface = abstract_surface;
    cairo_image_surface_t *image;
    cairo_status_t status;

    status = _get_image_surface (surface, NULL, &image, NULL);
    if (status)
        return status;

    *image_out = image;
    *image_extra = NULL;

    return CAIRO_STATUS_SUCCESS;
}

static void
_cairo_xcb_surface_release_source_image (void                   *abstract_surface,
                                         cairo_image_surface_t  *image,
                                         void                   *image_extra)
{
    cairo_surface_destroy (&image->base);
}

static cairo_status_t
_cairo_xcb_surface_acquire_dest_image (void                    *abstract_surface,
                                       cairo_rectangle_int_t   *interest_rect,
                                       cairo_image_surface_t  **image_out,
                                       cairo_rectangle_int_t   *image_rect_out,
                                       void                   **image_extra)
{
    cairo_xcb_surface_t *surface = abstract_surface;
    cairo_image_surface_t *image;
    cairo_status_t status;

    status = _get_image_surface (surface, interest_rect, &image, image_rect_out);
    if (status)
        return status;

    *image_out = image;
    *image_extra = NULL;

    return CAIRO_STATUS_SUCCESS;
}

static void
_cairo_xcb_surface_release_dest_image (void                   *abstract_surface,
                                       cairo_rectangle_int_t  *interest_rect,
                                       cairo_image_surface_t  *image,
                                       cairo_rectangle_int_t  *image_rect,
                                       void                   *image_extra)
{
    cairo_xcb_surface_t *surface = abstract_surface;

    /* ignore errors */
    _draw_image_surface (surface, image, 0, 0, image->width, image->height,
                         image_rect->x, image_rect->y);

    cairo_surface_destroy (&image->base);
}

/*
 * Return whether two xcb surfaces share the same
 * screen.  Both core and Render drawing require this
 * when using multiple drawables in an operation.
 */
static cairo_bool_t
_cairo_xcb_surface_same_screen (cairo_xcb_surface_t *dst,
                                cairo_xcb_surface_t *src)
{
    return dst->dpy == src->dpy && dst->screen == src->screen;
}

static cairo_status_t
_cairo_xcb_surface_clone_similar (void                  *abstract_surface,
                                  cairo_surface_t       *src,
                                  int                    src_x,
                                  int                    src_y,
                                  int                    width,
                                  int                    height,
                                  int                   *clone_offset_x,
                                  int                   *clone_offset_y,
                                  cairo_surface_t     **clone_out)
{
    cairo_xcb_surface_t *surface = abstract_surface;
    cairo_xcb_surface_t *clone;

    if (src->backend == surface->base.backend ) {
        cairo_xcb_surface_t *xcb_src = (cairo_xcb_surface_t *)src;

        if (_cairo_xcb_surface_same_screen(surface, xcb_src)) {
            *clone_offset_x = 0;
            *clone_offset_y = 0;
            *clone_out = cairo_surface_reference (src);

            return CAIRO_STATUS_SUCCESS;
        }
    } else if (_cairo_surface_is_image (src)) {
        cairo_image_surface_t *image_src = (cairo_image_surface_t *)src;
        cairo_content_t content = _cairo_content_from_format (image_src->format);
        cairo_status_t status;

        if (surface->base.status)
            return surface->base.status;

        clone = (cairo_xcb_surface_t *)
            _cairo_xcb_surface_create_similar (surface, content, width, height);
        if (clone == NULL)
            return CAIRO_INT_STATUS_UNSUPPORTED;
        if (clone->base.status)
            return clone->base.status;

        status = _draw_image_surface (clone, image_src,
                                      src_x, src_y,
                                      width, height,
                                      0, 0);
        if (status) {
            cairo_surface_destroy (&clone->base);
            return status;
        }

        *clone_offset_x = src_x;
        *clone_offset_y = src_y;
        *clone_out = &clone->base;

        return CAIRO_STATUS_SUCCESS;
    }

    return CAIRO_INT_STATUS_UNSUPPORTED;
}

static cairo_status_t
_cairo_xcb_surface_set_matrix (cairo_xcb_surface_t *surface,
                               cairo_matrix_t      *matrix)
{
    xcb_render_transform_t xtransform;

    if (!surface->src_picture)
        return CAIRO_STATUS_SUCCESS;

    xtransform.matrix11 = _cairo_fixed_16_16_from_double (matrix->xx);
    xtransform.matrix12 = _cairo_fixed_16_16_from_double (matrix->xy);
    xtransform.matrix13 = _cairo_fixed_16_16_from_double (matrix->x0);

    xtransform.matrix21 = _cairo_fixed_16_16_from_double (matrix->yx);
    xtransform.matrix22 = _cairo_fixed_16_16_from_double (matrix->yy);
    xtransform.matrix23 = _cairo_fixed_16_16_from_double (matrix->y0);

    xtransform.matrix31 = 0;
    xtransform.matrix32 = 0;
    xtransform.matrix33 = 1 << 16;

    if (!CAIRO_SURFACE_RENDER_HAS_PICTURE_TRANSFORM (surface))
    {
        static const xcb_render_transform_t identity = {
            1 << 16, 0x00000, 0x00000,
            0x00000, 1 << 16, 0x00000,
            0x00000, 0x00000, 1 << 16
        };

        if (memcmp (&xtransform, &identity, sizeof (xcb_render_transform_t)) == 0)
            return CAIRO_STATUS_SUCCESS;

        return CAIRO_INT_STATUS_UNSUPPORTED;
    }

    xcb_render_set_picture_transform (surface->dpy, surface->src_picture, xtransform);

    return CAIRO_STATUS_SUCCESS;
}

static cairo_status_t
_cairo_xcb_surface_set_filter (cairo_xcb_surface_t *surface,
                               cairo_filter_t      filter)
{
    const char *render_filter;

    if (!surface->src_picture)
        return CAIRO_STATUS_SUCCESS;

    if (!CAIRO_SURFACE_RENDER_HAS_FILTERS (surface))
    {
        if (filter == CAIRO_FILTER_FAST || filter == CAIRO_FILTER_NEAREST)
            return CAIRO_STATUS_SUCCESS;

        return CAIRO_INT_STATUS_UNSUPPORTED;
    }

    switch (filter) {
    case CAIRO_FILTER_FAST:
        render_filter = "fast";
        break;
    case CAIRO_FILTER_GOOD:
        render_filter = "good";
        break;
    case CAIRO_FILTER_BEST:
        render_filter = "best";
        break;
    case CAIRO_FILTER_NEAREST:
        render_filter = "nearest";
        break;
    case CAIRO_FILTER_BILINEAR:
        render_filter = "bilinear";
        break;
    case CAIRO_FILTER_GAUSSIAN:
    default:
        render_filter = "best";
        break;
    }

    xcb_render_set_picture_filter(surface->dpy, surface->src_picture,
                             strlen(render_filter), render_filter, 0, NULL);

    return CAIRO_STATUS_SUCCESS;
}

static cairo_status_t
_cairo_xcb_surface_set_repeat (cairo_xcb_surface_t *surface, int repeat)
{
    uint32_t mask = XCB_RENDER_CP_REPEAT;
    uint32_t pa[] = { repeat };

    if (!surface->src_picture)
        return CAIRO_STATUS_SUCCESS;

    xcb_render_change_picture (surface->dpy, surface->src_picture, mask, pa);

    return CAIRO_STATUS_SUCCESS;
}

static cairo_int_status_t
_cairo_xcb_surface_set_attributes (cairo_xcb_surface_t        *surface,
                                   cairo_surface_attributes_t *attributes)
{
    cairo_int_status_t status;

    _cairo_xcb_surface_ensure_src_picture (surface);

    status = _cairo_xcb_surface_set_matrix (surface, &attributes->matrix);
    if (status)
        return status;

    switch (attributes->extend) {
    case CAIRO_EXTEND_NONE:
        _cairo_xcb_surface_set_repeat (surface, 0);
        break;
    case CAIRO_EXTEND_REPEAT:
        _cairo_xcb_surface_set_repeat (surface, 1);
        break;
    case CAIRO_EXTEND_REFLECT:
    case CAIRO_EXTEND_PAD:
        return CAIRO_INT_STATUS_UNSUPPORTED;
    }

    status = _cairo_xcb_surface_set_filter (surface, attributes->filter);
    if (status)
        return status;

    return CAIRO_STATUS_SUCCESS;
}

/* Checks whether we can can directly draw from src to dst with
 * the core protocol: either with CopyArea or using src as a
 * a tile in a GC.
 */
static cairo_bool_t
_surfaces_compatible (cairo_xcb_surface_t *dst,
                      cairo_xcb_surface_t *src)
{
    /* same screen */
    if (!_cairo_xcb_surface_same_screen (dst, src))
        return FALSE;

    /* same depth (for core) */
    if (src->depth != dst->depth)
        return FALSE;

    /* if Render is supported, match picture formats */
    if (src->xrender_format.id != dst->xrender_format.id)
        return FALSE;
    else if (src->xrender_format.id != XCB_NONE)
        return TRUE;

    /* Without Render, match visuals instead */
    if (src->visual == dst->visual)
        return TRUE;

    return FALSE;
}

static cairo_bool_t
_surface_has_alpha (cairo_xcb_surface_t *surface)
{
    if (surface->xrender_format.id != XCB_NONE) {
        if (surface->xrender_format.type == XCB_RENDER_PICT_TYPE_DIRECT &&
            surface->xrender_format.direct.alpha_mask != 0)
            return TRUE;
        else
            return FALSE;
    } else {

        /* In the no-render case, we never have alpha */
        return FALSE;
    }
}

/* Returns true if the given operator and source-alpha combination
 * requires alpha compositing to complete.
 */
static cairo_bool_t
_operator_needs_alpha_composite (cairo_operator_t op,
                                 cairo_bool_t     surface_has_alpha)
{
    if (op == CAIRO_OPERATOR_SOURCE ||
        (!surface_has_alpha &&
         (op == CAIRO_OPERATOR_OVER ||
          op == CAIRO_OPERATOR_ATOP ||
          op == CAIRO_OPERATOR_IN)))
        return FALSE;

    return TRUE;
}

/* There is a bug in most older X servers with compositing using a
 * untransformed repeating source pattern when the source is in off-screen
 * video memory, and another with repeated transformed images using a
 * general transform matrix. When these bugs could be triggered, we need a
 * fallback: in the common case where we have no transformation and the
 * source and destination have the same format/visual, we can do the
 * operation using the core protocol for the first bug, otherwise, we need
 * a software fallback.
 *
 * We can also often optimize a compositing operation by calling XCopyArea
 * for some common cases where there is no alpha compositing to be done.
 * We figure that out here as well.
 */
typedef enum {
    DO_RENDER,          /* use render */
    DO_XCOPYAREA,       /* core protocol XCopyArea optimization/fallback */
    DO_XTILE,           /* core protocol XSetTile optimization/fallback */
    DO_UNSUPPORTED      /* software fallback */
} composite_operation_t;

/* Initial check for the render bugs; we need to recheck for the
 * offscreen-memory bug after we turn patterns into surfaces, since that
 * may introduce a repeating pattern for gradient patterns.  We don't need
 * to check for the repeat+transform bug because gradient surfaces aren't
 * transformed.
 *
 * All we do here is reject cases where we *know* are going to
 * hit the bug and won't be able to use a core protocol fallback.
 */
static composite_operation_t
_categorize_composite_operation (cairo_xcb_surface_t *dst,
                                 cairo_operator_t      op,
                                 cairo_pattern_t      *src_pattern,
                                 cairo_bool_t          have_mask)

{
#if XXX_BUGGY_REPEAT
    if (!dst->buggy_repeat)
        return DO_RENDER;

    if (src_pattern->type == CAIRO_PATTERN_TYPE_SURFACE)
    {
        cairo_surface_pattern_t *surface_pattern = (cairo_surface_pattern_t *)src_pattern;

        if (_cairo_matrix_is_integer_translation (&src_pattern->matrix, NULL, NULL) &&
            src_pattern->extend == CAIRO_EXTEND_REPEAT)
        {
            /* This is the case where we have the bug involving
             * untransformed repeating source patterns with off-screen
             * video memory; reject some cases where a core protocol
             * fallback is impossible.
             */
            if (have_mask ||
                !(op == CAIRO_OPERATOR_SOURCE || op == CAIRO_OPERATOR_OVER))
                return DO_UNSUPPORTED;

            if (_cairo_surface_is_xcb (surface_pattern->surface)) {
                cairo_xcb_surface_t *src = (cairo_xcb_surface_t *)surface_pattern->surface;

                if (op == CAIRO_OPERATOR_OVER && _surface_has_alpha (src))
                    return DO_UNSUPPORTED;

                /* If these are on the same screen but otherwise incompatible,
                 * make a copy as core drawing can't cross depths and doesn't
                 * work rightacross visuals of the same depth
                 */
                if (_cairo_xcb_surface_same_screen (dst, src) &&
                    !_surfaces_compatible (dst, src))
                    return DO_UNSUPPORTED;
            }
        }

        /* Check for the other bug involving repeat patterns with general
         * transforms. */
        if (!_cairo_matrix_is_integer_translation (&src_pattern->matrix, NULL, NULL) &&
            src_pattern->extend == CAIRO_EXTEND_REPEAT)
            return DO_UNSUPPORTED;
    }
#endif
    return DO_RENDER;
}

/* Recheck for composite-repeat once we've turned patterns into Xlib surfaces
 * If we end up returning DO_UNSUPPORTED here, we're throwing away work we
 * did to turn gradients into a pattern, but most of the time we can handle
 * that case with core protocol fallback.
 *
 * Also check here if we can just use XCopyArea, instead of going through
 * Render.
 */
static composite_operation_t
_recategorize_composite_operation (cairo_xcb_surface_t        *dst,
                                   cairo_operator_t            op,
                                   cairo_xcb_surface_t        *src,
                                   cairo_surface_attributes_t *src_attr,
                                   cairo_bool_t                have_mask)
{
    cairo_bool_t is_integer_translation =
        _cairo_matrix_is_integer_translation (&src_attr->matrix, NULL, NULL);
    cairo_bool_t needs_alpha_composite =
        _operator_needs_alpha_composite (op, _surface_has_alpha (src));

    if (!have_mask &&
        is_integer_translation &&
        src_attr->extend == CAIRO_EXTEND_NONE &&
        !needs_alpha_composite &&
        _surfaces_compatible(src, dst))
    {
        return DO_XCOPYAREA;
    }
#if XXX_BUGGY_REPEAT
    if (!dst->buggy_repeat)
        return DO_RENDER;

    if (is_integer_translation &&
        src_attr->extend == CAIRO_EXTEND_REPEAT &&
        (src->width != 1 || src->height != 1))
    {
        if (!have_mask &&
            !needs_alpha_composite &&
            _surfaces_compatible (dst, src))
        {
            return DO_XTILE;
        }

        return DO_UNSUPPORTED;
    }
#endif
    return DO_RENDER;
}

static int
_render_operator (cairo_operator_t op)
{
    switch (op) {
    case CAIRO_OPERATOR_CLEAR:
        return XCB_RENDER_PICT_OP_CLEAR;
    case CAIRO_OPERATOR_SOURCE:
        return XCB_RENDER_PICT_OP_SRC;
    case CAIRO_OPERATOR_DEST:
        return XCB_RENDER_PICT_OP_DST;
    case CAIRO_OPERATOR_OVER:
        return XCB_RENDER_PICT_OP_OVER;
    case CAIRO_OPERATOR_DEST_OVER:
        return XCB_RENDER_PICT_OP_OVER_REVERSE;
    case CAIRO_OPERATOR_IN:
        return XCB_RENDER_PICT_OP_IN;
    case CAIRO_OPERATOR_DEST_IN:
        return XCB_RENDER_PICT_OP_IN_REVERSE;
    case CAIRO_OPERATOR_OUT:
        return XCB_RENDER_PICT_OP_OUT;
    case CAIRO_OPERATOR_DEST_OUT:
        return XCB_RENDER_PICT_OP_OUT_REVERSE;
    case CAIRO_OPERATOR_ATOP:
        return XCB_RENDER_PICT_OP_ATOP;
    case CAIRO_OPERATOR_DEST_ATOP:
        return XCB_RENDER_PICT_OP_ATOP_REVERSE;
    case CAIRO_OPERATOR_XOR:
        return XCB_RENDER_PICT_OP_XOR;
    case CAIRO_OPERATOR_ADD:
        return XCB_RENDER_PICT_OP_ADD;
    case CAIRO_OPERATOR_SATURATE:
        return XCB_RENDER_PICT_OP_SATURATE;
    default:
        return XCB_RENDER_PICT_OP_OVER;
    }
}

static cairo_int_status_t
_cairo_xcb_surface_composite (cairo_operator_t          op,
                              cairo_pattern_t           *src_pattern,
                              cairo_pattern_t           *mask_pattern,
                              void                      *abstract_dst,
                              int                       src_x,
                              int                       src_y,
                              int                       mask_x,
                              int                       mask_y,
                              int                       dst_x,
                              int                       dst_y,
                              unsigned int              width,
                              unsigned int              height)
{
    cairo_surface_attributes_t  src_attr, mask_attr;
    cairo_xcb_surface_t         *dst = abstract_dst;
    cairo_xcb_surface_t         *src;
    cairo_xcb_surface_t         *mask;
    cairo_int_status_t          status;
    composite_operation_t       operation;
    int                         itx, ity;
    cairo_bool_t                is_integer_translation;

    if (!CAIRO_SURFACE_RENDER_HAS_COMPOSITE (dst))
        return CAIRO_INT_STATUS_UNSUPPORTED;

    operation = _categorize_composite_operation (dst, op, src_pattern,
                                                 mask_pattern != NULL);
    if (operation == DO_UNSUPPORTED)
        return CAIRO_INT_STATUS_UNSUPPORTED;

    status = _cairo_pattern_acquire_surfaces (src_pattern, mask_pattern,
                                              &dst->base,
                                              src_x, src_y,
                                              mask_x, mask_y,
                                              width, height,
                                              (cairo_surface_t **) &src,
                                              (cairo_surface_t **) &mask,
                                              &src_attr, &mask_attr);
    if (status)
        return status;

    operation = _recategorize_composite_operation (dst, op, src, &src_attr,
                                                   mask_pattern != NULL);
    if (operation == DO_UNSUPPORTED) {
        status = CAIRO_INT_STATUS_UNSUPPORTED;
        goto BAIL;
    }

    status = _cairo_xcb_surface_set_attributes (src, &src_attr);
    if (status)
        goto BAIL;

    switch (operation)
    {
    case DO_RENDER:
        _cairo_xcb_surface_ensure_dst_picture (dst);
        if (mask) {
            status = _cairo_xcb_surface_set_attributes (mask, &mask_attr);
            if (status)
                goto BAIL;

            xcb_render_composite (dst->dpy,
                              _render_operator (op),
                              src->src_picture,
                              mask->src_picture,
                              dst->dst_picture,
                              src_x + src_attr.x_offset,
                              src_y + src_attr.y_offset,
                              mask_x + mask_attr.x_offset,
                              mask_y + mask_attr.y_offset,
                              dst_x, dst_y,
                              width, height);
        } else {
            static xcb_render_picture_t maskpict = { XCB_NONE };

            xcb_render_composite (dst->dpy,
                                _render_operator (op),
                                src->src_picture,
                                maskpict,
                                dst->dst_picture,
                                src_x + src_attr.x_offset,
                                src_y + src_attr.y_offset,
                                0, 0,
                                dst_x, dst_y,
                                width, height);
        }
        break;

    case DO_XCOPYAREA:
        _cairo_xcb_surface_ensure_gc (dst);
        xcb_copy_area (dst->dpy,
                   src->drawable,
                   dst->drawable,
                   dst->gc,
                   src_x + src_attr.x_offset,
                   src_y + src_attr.y_offset,
                   dst_x, dst_y,
                   width, height);
        break;

    case DO_XTILE:
        /* This case is only used for bug fallbacks, though it is theoretically
         * applicable to the case where we don't have the RENDER extension as
         * well.
         *
         * We've checked that we have a repeating unscaled source in
         * _recategorize_composite_operation.
         */

        _cairo_xcb_surface_ensure_gc (dst);
        is_integer_translation =
            _cairo_matrix_is_integer_translation (&src_attr.matrix, &itx, &ity);
        assert (is_integer_translation == TRUE);
        {
            uint32_t mask = XCB_GC_FILL_STYLE | XCB_GC_TILE
                          | XCB_GC_TILE_STIPPLE_ORIGIN_X
                          | XCB_GC_TILE_STIPPLE_ORIGIN_Y;
            uint32_t values[] = {
                XCB_FILL_STYLE_TILED, src->drawable,
                - (itx + src_attr.x_offset),
                - (ity + src_attr.y_offset)
            };
            xcb_rectangle_t rect = { dst_x, dst_y, width, height };

            xcb_change_gc( dst->dpy, dst->gc, mask, values );
            xcb_poly_fill_rectangle(dst->dpy, dst->drawable, dst->gc, 1, &rect);
        }
        break;

    case DO_UNSUPPORTED:
    default:
        ASSERT_NOT_REACHED;
    }

    if (!_cairo_operator_bounded_by_source (op))
      status = _cairo_surface_composite_fixup_unbounded (&dst->base,
                                                         &src_attr, src->width, src->height,
                                                         mask ? &mask_attr : NULL,
                                                         mask ? mask->width : 0,
                                                         mask ? mask->height : 0,
                                                         src_x, src_y,
                                                         mask_x, mask_y,
                                                         dst_x, dst_y, width, height);

 BAIL:
    if (mask)
        _cairo_pattern_release_surface (mask_pattern, &mask->base, &mask_attr);

    _cairo_pattern_release_surface (src_pattern, &src->base, &src_attr);

    return status;
}

static cairo_int_status_t
_cairo_xcb_surface_fill_rectangles (void                             *abstract_surface,
                                     cairo_operator_t         op,
                                     const cairo_color_t        *     color,
                                     cairo_rectangle_int_t *rects,
                                     int                              num_rects)
{
    cairo_xcb_surface_t *surface = abstract_surface;
    xcb_render_color_t render_color;
    xcb_rectangle_t static_xrects[16];
    xcb_rectangle_t *xrects = static_xrects;
    int i;

    if (!CAIRO_SURFACE_RENDER_HAS_FILL_RECTANGLE (surface))
        return CAIRO_INT_STATUS_UNSUPPORTED;

    render_color.red   = color->red_short;
    render_color.green = color->green_short;
    render_color.blue  = color->blue_short;
    render_color.alpha = color->alpha_short;

    if (num_rects > ARRAY_LENGTH(static_xrects)) {
        xrects = _cairo_malloc_ab (num_rects, sizeof(xcb_rectangle_t));
        if (xrects == NULL)
            return _cairo_error (CAIRO_STATUS_NO_MEMORY);
    }

    for (i = 0; i < num_rects; i++) {
        xrects[i].x = rects[i].x;
        xrects[i].y = rects[i].y;
        xrects[i].width = rects[i].width;
        xrects[i].height = rects[i].height;
    }

    _cairo_xcb_surface_ensure_dst_picture (surface);
    xcb_render_fill_rectangles (surface->dpy,
                           _render_operator (op),
                           surface->dst_picture,
                           render_color, num_rects, xrects);

    if (xrects != static_xrects)
        free(xrects);

    return CAIRO_STATUS_SUCCESS;
}

/* Creates an A8 picture of size @width x @height, initialized with @color
 */
static xcb_render_picture_t
_create_a8_picture (cairo_xcb_surface_t *surface,
                    xcb_render_color_t   *color,
                    int                   width,
                    int                   height,
                    cairo_bool_t          repeat)
{
    uint32_t values[] = { TRUE };
    uint32_t mask = repeat ? XCB_RENDER_CP_REPEAT : 0;

    xcb_pixmap_t pixmap = xcb_generate_id (surface->dpy);
    xcb_render_picture_t picture = xcb_generate_id (surface->dpy);

    xcb_render_pictforminfo_t *format
        = _CAIRO_FORMAT_TO_XRENDER_FORMAT (surface->dpy, CAIRO_FORMAT_A8);
    xcb_rectangle_t rect = { 0, 0, width, height };

    xcb_create_pixmap (surface->dpy, 8, pixmap, surface->drawable,
                       width <= 0 ? 1 : width,
                       height <= 0 ? 1 : height);
    xcb_render_create_picture (surface->dpy, picture, pixmap, format->id, mask, values);
    xcb_render_fill_rectangles (surface->dpy, XCB_RENDER_PICT_OP_SRC, picture, *color, 1, &rect);
    xcb_free_pixmap (surface->dpy, pixmap);

    return picture;
}

/* Creates a temporary mask for the trapezoids covering the area
 * [@dst_x, @dst_y, @width, @height] of the destination surface.
 */
static cairo_status_t
_create_trapezoid_mask (cairo_xcb_surface_t *dst,
                        cairo_trapezoid_t    *traps,
                        int                   num_traps,
                        int                   dst_x,
                        int                   dst_y,
                        int                   width,
                        int                   height,
                        xcb_render_pictforminfo_t *pict_format,
                        xcb_render_picture_t *mask_picture_out)
{
    xcb_render_color_t transparent = { 0, 0, 0, 0 };
    xcb_render_color_t solid = { 0xffff, 0xffff, 0xffff, 0xffff };
    xcb_render_picture_t mask_picture, solid_picture;
    xcb_render_trapezoid_t *offset_traps;
    int i;

    /* This would be considerably simpler using XRenderAddTraps(), but since
     * we are only using this in the unbounded-operator case, we stick with
     * XRenderCompositeTrapezoids, which is available on older versions
     * of RENDER rather than conditionalizing. We should still hit an
     * optimization that avoids creating another intermediate surface on
     * the servers that have XRenderAddTraps().
     */
    mask_picture = _create_a8_picture (dst, &transparent, width, height, FALSE);
    solid_picture = _create_a8_picture (dst, &solid, width, height, TRUE);

    offset_traps = _cairo_malloc_ab (num_traps, sizeof (xcb_render_trapezoid_t));
    if (offset_traps == NULL)
        return  _cairo_error (CAIRO_STATUS_NO_MEMORY);

    for (i = 0; i < num_traps; i++) {
        offset_traps[i].top = _cairo_fixed_to_16_16(traps[i].top) - 0x10000 * dst_y;
        offset_traps[i].bottom = _cairo_fixed_to_16_16(traps[i].bottom) - 0x10000 * dst_y;
        offset_traps[i].left.p1.x = _cairo_fixed_to_16_16(traps[i].left.p1.x) - 0x10000 * dst_x;
        offset_traps[i].left.p1.y = _cairo_fixed_to_16_16(traps[i].left.p1.y) - 0x10000 * dst_y;
        offset_traps[i].left.p2.x = _cairo_fixed_to_16_16(traps[i].left.p2.x) - 0x10000 * dst_x;
        offset_traps[i].left.p2.y = _cairo_fixed_to_16_16(traps[i].left.p2.y) - 0x10000 * dst_y;
        offset_traps[i].right.p1.x = _cairo_fixed_to_16_16(traps[i].right.p1.x) - 0x10000 * dst_x;
        offset_traps[i].right.p1.y = _cairo_fixed_to_16_16(traps[i].right.p1.y) - 0x10000 * dst_y;
        offset_traps[i].right.p2.x = _cairo_fixed_to_16_16(traps[i].right.p2.x) - 0x10000 * dst_x;
        offset_traps[i].right.p2.y = _cairo_fixed_to_16_16(traps[i].right.p2.y) - 0x10000 * dst_y;
    }

    xcb_render_trapezoids (dst->dpy, XCB_RENDER_PICT_OP_ADD,
                                solid_picture, mask_picture,
                                pict_format->id,
                                0, 0,
                                num_traps, offset_traps);

    xcb_render_free_picture (dst->dpy, solid_picture);
    free (offset_traps);

    *mask_picture_out = mask_picture;
    return CAIRO_STATUS_SUCCESS;
}

static cairo_int_status_t
_cairo_xcb_surface_composite_trapezoids (cairo_operator_t       op,
                                         cairo_pattern_t        *pattern,
                                         void                   *abstract_dst,
                                         cairo_antialias_t      antialias,
                                         int                    src_x,
                                         int                    src_y,
                                         int                    dst_x,
                                         int                    dst_y,
                                         unsigned int           width,
                                         unsigned int           height,
                                         cairo_trapezoid_t      *traps,
                                         int                    num_traps)
{
    cairo_surface_attributes_t  attributes;
    cairo_xcb_surface_t         *dst = abstract_dst;
    cairo_xcb_surface_t         *src;
    cairo_int_status_t          status;
    composite_operation_t       operation;
    int                         render_reference_x, render_reference_y;
    int                         render_src_x, render_src_y;
    int                         cairo_format;
    xcb_render_pictforminfo_t   *render_format;

    if (!CAIRO_SURFACE_RENDER_HAS_TRAPEZOIDS (dst))
        return CAIRO_INT_STATUS_UNSUPPORTED;

    operation = _categorize_composite_operation (dst, op, pattern, TRUE);
    if (operation == DO_UNSUPPORTED)
        return CAIRO_INT_STATUS_UNSUPPORTED;

    status = _cairo_pattern_acquire_surface (pattern, &dst->base,
                                             src_x, src_y, width, height,
                                             (cairo_surface_t **) &src,
                                             &attributes);
    if (status)
        return status;

    operation = _recategorize_composite_operation (dst, op, src, &attributes, TRUE);
    if (operation == DO_UNSUPPORTED) {
        status = CAIRO_INT_STATUS_UNSUPPORTED;
        goto BAIL;
    }

    switch (antialias) {
    case CAIRO_ANTIALIAS_NONE:
        cairo_format = CAIRO_FORMAT_A1;
        break;
    case CAIRO_ANTIALIAS_GRAY:
    case CAIRO_ANTIALIAS_SUBPIXEL:
    case CAIRO_ANTIALIAS_DEFAULT:
    default:
        cairo_format = CAIRO_FORMAT_A8;
        break;
    }
    render_format = _CAIRO_FORMAT_TO_XRENDER_FORMAT (dst->dpy, cairo_format);
    /* XXX: what to do if render_format is null? */

    if (traps[0].left.p1.y < traps[0].left.p2.y) {
        render_reference_x = _cairo_fixed_integer_floor (traps[0].left.p1.x);
        render_reference_y = _cairo_fixed_integer_floor (traps[0].left.p1.y);
    } else {
        render_reference_x = _cairo_fixed_integer_floor (traps[0].left.p2.x);
        render_reference_y = _cairo_fixed_integer_floor (traps[0].left.p2.y);
    }

    render_src_x = src_x + render_reference_x - dst_x;
    render_src_y = src_y + render_reference_y - dst_y;

    _cairo_xcb_surface_ensure_dst_picture (dst);
    status = _cairo_xcb_surface_set_attributes (src, &attributes);
    if (status)
        goto BAIL;

    if (!_cairo_operator_bounded_by_mask (op)) {
        /* xcb_render_composite+trapezoids() creates a mask only large enough for the
         * trapezoids themselves, but if the operator is unbounded, then we need
         * to actually composite all the way out to the bounds, so we create
         * the mask and composite ourselves. There actually would
         * be benefit to doing this in all cases, since RENDER implementations
         * will frequently create a too temporary big mask, ignoring destination
         * bounds and clip. (xcb_render_add_traps() could be used to make creating
         * the mask somewhat cheaper.)
         */
        xcb_render_picture_t mask_picture = 0; /* silence compiler */

        status = _create_trapezoid_mask (dst, traps, num_traps,
                                         dst_x, dst_y, width, height,
                                         render_format,
                                         &mask_picture);
        if (status)
            goto BAIL;

        xcb_render_composite (dst->dpy,
                          _render_operator (op),
                          src->src_picture,
                          mask_picture,
                          dst->dst_picture,
                          src_x + attributes.x_offset,
                          src_y + attributes.y_offset,
                          0, 0,
                          dst_x, dst_y,
                          width, height);

        xcb_render_free_picture (dst->dpy, mask_picture);

        status = _cairo_surface_composite_shape_fixup_unbounded (&dst->base,
                                                                 &attributes, src->width, src->height,
                                                                 width, height,
                                                                 src_x, src_y,
                                                                 0, 0,
                                                                 dst_x, dst_y, width, height);

    } else {
        xcb_render_trapezoid_t xtraps_stack[16];
        xcb_render_trapezoid_t *xtraps = xtraps_stack;
        int i;

        if (num_traps > ARRAY_LENGTH(xtraps_stack)) {
            xtraps = _cairo_malloc_ab (num_traps, sizeof(xcb_render_trapezoid_t));
            if (xtraps == NULL) {
                status = _cairo_error (CAIRO_STATUS_NO_MEMORY);
                goto BAIL;
            }
        }

        for (i = 0; i < num_traps; i++) {
            xtraps[i].top = _cairo_fixed_to_16_16(traps[i].top);
            xtraps[i].bottom = _cairo_fixed_to_16_16(traps[i].bottom);
            xtraps[i].left.p1.x = _cairo_fixed_to_16_16(traps[i].left.p1.x);
            xtraps[i].left.p1.y = _cairo_fixed_to_16_16(traps[i].left.p1.y);
            xtraps[i].left.p2.x = _cairo_fixed_to_16_16(traps[i].left.p2.x);
            xtraps[i].left.p2.y = _cairo_fixed_to_16_16(traps[i].left.p2.y);
            xtraps[i].right.p1.x = _cairo_fixed_to_16_16(traps[i].right.p1.x);
            xtraps[i].right.p1.y = _cairo_fixed_to_16_16(traps[i].right.p1.y);
            xtraps[i].right.p2.x = _cairo_fixed_to_16_16(traps[i].right.p2.x);
            xtraps[i].right.p2.y = _cairo_fixed_to_16_16(traps[i].right.p2.y);
        }

        xcb_render_trapezoids (dst->dpy,
                                    _render_operator (op),
                                    src->src_picture, dst->dst_picture,
                                    render_format->id,
                                    render_src_x + attributes.x_offset,
                                    render_src_y + attributes.y_offset,
                                    num_traps, xtraps);

        if (xtraps != xtraps_stack)
            free(xtraps);
    }

 BAIL:
    _cairo_pattern_release_surface (pattern, &src->base, &attributes);

    return status;
}

static cairo_int_status_t
_cairo_xcb_surface_set_clip_region (void           *abstract_surface,
                                    cairo_region_t *region)
{
    cairo_xcb_surface_t *surface = abstract_surface;

    if (surface->clip_rects) {
        free (surface->clip_rects);
        surface->clip_rects = NULL;
    }

    surface->have_clip_rects = FALSE;
    surface->num_clip_rects = 0;

    if (region == NULL) {
        uint32_t none[] = { XCB_NONE };
        if (surface->gc)
            xcb_change_gc (surface->dpy, surface->gc, XCB_GC_CLIP_MASK, none);

        if (surface->xrender_format.id != XCB_NONE && surface->dst_picture)
            xcb_render_change_picture (surface->dpy, surface->dst_picture,
                XCB_RENDER_CP_CLIP_MASK, none);
    } else {
        cairo_box_int_t *boxes;
        cairo_status_t status;
        xcb_rectangle_t *rects = NULL;
        int n_boxes, i;

        status = _cairo_region_get_boxes (region, &n_boxes, &boxes);
        if (status)
            return status;

        if (n_boxes > 0) {
            rects = _cairo_malloc_ab (n_boxes, sizeof(xcb_rectangle_t));
            if (rects == NULL) {
                _cairo_region_boxes_fini (region, boxes);
                return _cairo_error (CAIRO_STATUS_NO_MEMORY);
            }
        } else {
            rects = NULL;
        }

        for (i = 0; i < n_boxes; i++) {
            rects[i].x = boxes[i].p1.x;
            rects[i].y = boxes[i].p1.y;
            rects[i].width = boxes[i].p2.x - boxes[i].p1.x;
            rects[i].height = boxes[i].p2.y - boxes[i].p1.y;
        }

        _cairo_region_boxes_fini (region, boxes);

        surface->have_clip_rects = TRUE;
        surface->clip_rects = rects;
        surface->num_clip_rects = n_boxes;

        if (surface->gc)
            _cairo_xcb_surface_set_gc_clip_rects (surface);

        if (surface->dst_picture)
            _cairo_xcb_surface_set_picture_clip_rects (surface);
    }

    return CAIRO_STATUS_SUCCESS;
}

static cairo_int_status_t
_cairo_xcb_surface_get_extents (void                    *abstract_surface,
                                cairo_rectangle_int_t   *rectangle)
{
    cairo_xcb_surface_t *surface = abstract_surface;

    rectangle->x = 0;
    rectangle->y = 0;

    rectangle->width  = surface->width;
    rectangle->height = surface->height;

    return CAIRO_STATUS_SUCCESS;
}

/* XXX: _cairo_xcb_surface_get_font_options */

static void
_cairo_xcb_surface_scaled_font_fini (cairo_scaled_font_t *scaled_font);

static void
_cairo_xcb_surface_scaled_glyph_fini (cairo_scaled_glyph_t *scaled_glyph,
                                       cairo_scaled_font_t  *scaled_font);

static cairo_int_status_t
_cairo_xcb_surface_show_glyphs (void                *abstract_dst,
                                 cairo_operator_t     op,
                                 cairo_pattern_t     *src_pattern,
                                 cairo_glyph_t       *glyphs,
                                 int                  num_glyphs,
                                 cairo_scaled_font_t *scaled_font,
                                 int                 *remaining_glyphs);

static cairo_bool_t
_cairo_xcb_surface_is_similar (void *surface_a,
                               void *surface_b,
                               cairo_content_t content)
{
    cairo_xcb_surface_t *a = surface_a;
    cairo_xcb_surface_t *b = surface_b;
    xcb_render_pictforminfo_t *xrender_format;

    /* XXX: disable caching by the solid pattern cache until we implement
     * display notification to avoid issuing xcb calls from the wrong thread
     * or accessing the surface after the Display has been closed.
     */
    return FALSE;

    if (! _cairo_xcb_surface_same_screen (a, b))
        return FALSE;

    /* now check that the target is a similar format */
    xrender_format = _CAIRO_FORMAT_TO_XRENDER_FORMAT (b->dpy,
            _cairo_format_from_content (content));

    return a->xrender_format.id == xrender_format->id;
}

static cairo_status_t
_cairo_xcb_surface_reset (void *abstract_surface)
{
    cairo_xcb_surface_t *surface = abstract_surface;
    cairo_status_t status;

    status = _cairo_xcb_surface_set_clip_region (surface, NULL);
    if (status)
        return status;

    return CAIRO_STATUS_SUCCESS;
}


/* XXX: move this to the bottom of the file, XCB and Xlib */

static const cairo_surface_backend_t cairo_xcb_surface_backend = {
    CAIRO_SURFACE_TYPE_XCB,
    _cairo_xcb_surface_create_similar,
    _cairo_xcb_surface_finish,
    _cairo_xcb_surface_acquire_source_image,
    _cairo_xcb_surface_release_source_image,
    _cairo_xcb_surface_acquire_dest_image,
    _cairo_xcb_surface_release_dest_image,
    _cairo_xcb_surface_clone_similar,
    _cairo_xcb_surface_composite,
    _cairo_xcb_surface_fill_rectangles,
    _cairo_xcb_surface_composite_trapezoids,
    NULL, /* copy_page */
    NULL, /* show_page */
    _cairo_xcb_surface_set_clip_region,
    NULL, /* intersect_clip_path */
    _cairo_xcb_surface_get_extents,
    NULL, /* old_show_glyphs */
    NULL, /* get_font_options */
    NULL, /* flush */
    NULL, /* mark_dirty_rectangle */
    _cairo_xcb_surface_scaled_font_fini,
    _cairo_xcb_surface_scaled_glyph_fini,

    NULL, /* paint */
    NULL, /* mask */
    NULL, /* stroke */
    NULL, /* fill */
    _cairo_xcb_surface_show_glyphs,
    NULL,  /* snapshot */

    _cairo_xcb_surface_is_similar,

    _cairo_xcb_surface_reset
};

/**
 * _cairo_surface_is_xcb:
 * @surface: a #cairo_surface_t
 *
 * Checks if a surface is a #cairo_xcb_surface_t
 *
 * Return value: True if the surface is an xcb surface
 **/
static cairo_bool_t
_cairo_surface_is_xcb (cairo_surface_t *surface)
{
    return surface->backend == &cairo_xcb_surface_backend;
}

static cairo_surface_t *
_cairo_xcb_surface_create_internal (xcb_connection_t         *dpy,
                                    xcb_drawable_t                    drawable,
                                    xcb_screen_t                     *screen,
                                    xcb_visualtype_t         *visual,
                                    xcb_render_pictforminfo_t    *xrender_format,
                                    int                       width,
                                    int                       height,
                                    int                       depth)
{
    cairo_xcb_surface_t *surface;
    const xcb_render_query_version_reply_t *r;

    surface = malloc (sizeof (cairo_xcb_surface_t));
    if (surface == NULL)
        return _cairo_surface_create_in_error (_cairo_error (CAIRO_STATUS_NO_MEMORY));

    if (xrender_format) {
        depth = xrender_format->depth;
    } else if (visual) {
        xcb_depth_iterator_t depths;
        xcb_visualtype_iterator_t visuals;

        /* This is ugly, but we have to walk over all visuals
         * for the screen to find the depth.
         */
        depths = xcb_screen_allowed_depths_iterator(screen);
        for(; depths.rem; xcb_depth_next(&depths))
        {
            visuals = xcb_depth_visuals_iterator(depths.data);
            for(; visuals.rem; xcb_visualtype_next(&visuals))
            {
                if(visuals.data->visual_id == visual->visual_id)
                {
                    depth = depths.data->depth;
                    goto found;
                }
            }
        }
    found:
        ;
    }

    r = xcb_render_util_query_version(dpy);
    if (r) {
        surface->render_major = r->major_version;
        surface->render_minor = r->minor_version;
    } else {
        surface->render_major = -1;
        surface->render_minor = -1;
    }

    if (CAIRO_SURFACE_RENDER_HAS_CREATE_PICTURE (surface)) {
        if (!xrender_format) {
            if (visual) {
                const xcb_render_query_pict_formats_reply_t *formats;
                xcb_render_pictvisual_t *pict_visual;
                formats = xcb_render_util_query_formats (dpy);
                pict_visual = xcb_render_util_find_visual_format (formats, visual->visual_id);
                if (pict_visual) {
                    xcb_render_pictforminfo_t template;
                    template.id = pict_visual->format;
                    xrender_format = xcb_render_util_find_format (formats, XCB_PICT_FORMAT_ID, &template, 0);
                }
            } else if (depth == 1) {
                xrender_format = _CAIRO_FORMAT_TO_XRENDER_FORMAT (dpy, CAIRO_FORMAT_A1);
            }
        }
    } else {
        xrender_format = NULL;
    }

    _cairo_surface_init (&surface->base, &cairo_xcb_surface_backend,
                         _xcb_render_format_to_content (xrender_format));

    surface->dpy = dpy;

    surface->gc = XCB_NONE;
    surface->drawable = drawable;
    surface->screen = screen;
    surface->owns_pixmap = FALSE;
    surface->use_pixmap = 0;
    surface->width = width;
    surface->height = height;

    /* XXX: set buggy_repeat based on ServerVendor and VendorRelease */

    surface->dst_picture = XCB_NONE;
    surface->src_picture = XCB_NONE;

    surface->visual = visual;
    surface->xrender_format.id = XCB_NONE;
    if (xrender_format) surface->xrender_format = *xrender_format;
    surface->depth = depth;

    surface->have_clip_rects = FALSE;
    surface->clip_rects = NULL;
    surface->num_clip_rects = 0;

    return (cairo_surface_t *) surface;
}

static xcb_screen_t *
_cairo_xcb_screen_from_visual (xcb_connection_t *c, xcb_visualtype_t *visual)
{
    xcb_depth_iterator_t d;
    xcb_screen_iterator_t s = xcb_setup_roots_iterator(xcb_get_setup(c));
    for (; s.rem; xcb_screen_next(&s))
    {
        if (s.data->root_visual == visual->visual_id)
            return s.data;

        d = xcb_screen_allowed_depths_iterator(s.data);
        for (; d.rem; xcb_depth_next(&d))
        {
            xcb_visualtype_iterator_t v = xcb_depth_visuals_iterator(d.data);
            for (; v.rem; xcb_visualtype_next(&v))
            {
                if (v.data->visual_id == visual->visual_id)
                    return s.data;
            }
        }
    }
    return NULL;
}

/**
 * cairo_xcb_surface_create:
 * @c: an XCB connection
 * @drawable: an XCB drawable
 * @visual: the visual to use for drawing to @drawable. The depth
 *          of the visual must match the depth of the drawable.
 *          Currently, only TrueColor visuals are fully supported.
 * @width: the current width of @drawable.
 * @height: the current height of @drawable.
 *
 * Creates an XCB surface that draws to the given drawable.
 * The way that colors are represented in the drawable is specified
 * by the provided visual.
 *
 * Note: If @drawable is a window, then the function
 * cairo_xcb_surface_set_size() must be called whenever the size of the
 * window changes.
 *
 * Return value: the newly created surface
 **/
cairo_surface_t *
cairo_xcb_surface_create (xcb_connection_t *c,
                          xcb_drawable_t         drawable,
                          xcb_visualtype_t *visual,
                          int            width,
                          int            height)
{
    xcb_screen_t        *screen = _cairo_xcb_screen_from_visual (c, visual);

    if (screen == NULL)
        return _cairo_surface_create_in_error (_cairo_error (CAIRO_STATUS_INVALID_VISUAL));

    return _cairo_xcb_surface_create_internal (c, drawable, screen,
                                               visual, NULL,
                                               width, height, 0);
}

/**
 * cairo_xcb_surface_create_for_bitmap:
 * @c: an XCB connection
 * @bitmap: an XCB Pixmap (a depth-1 pixmap)
 * @screen: an XCB Screen
 * @width: the current width of @bitmap
 * @height: the current height of @bitmap
 *
 * Creates an XCB surface that draws to the given bitmap.
 * This will be drawn to as a %CAIRO_FORMAT_A1 object.
 *
 * Return value: the newly created surface
 **/
cairo_surface_t *
cairo_xcb_surface_create_for_bitmap (xcb_connection_t     *c,
                                     xcb_pixmap_t               bitmap,
                                     xcb_screen_t              *screen,
                                     int                width,
                                     int                height)
{
    return _cairo_xcb_surface_create_internal (c, bitmap, screen,
                                               NULL, NULL,
                                               width, height, 1);
}

/**
 * cairo_xcb_surface_create_with_xrender_format:
 * @c: an XCB connection
 * @drawable: an XCB drawable
 * @screen: the XCB screen associated with @drawable
 * @format: the picture format to use for drawing to @drawable. The
 *          depth of @format mush match the depth of the drawable.
 * @width: the current width of @drawable
 * @height: the current height of @drawable
 *
 * Creates an XCB surface that draws to the given drawable.
 * The way that colors are represented in the drawable is specified
 * by the provided picture format.
 *
 * Note: If @drawable is a Window, then the function
 * cairo_xcb_surface_set_size() must be called whenever the size of the
 * window changes.
 *
 * Return value: the newly created surface.
 **/
cairo_surface_t *
cairo_xcb_surface_create_with_xrender_format (xcb_connection_t      *c,
                                              xcb_drawable_t         drawable,
                                              xcb_screen_t                  *screen,
                                              xcb_render_pictforminfo_t *format,
                                              int                    width,
                                              int                    height)
{
    return _cairo_xcb_surface_create_internal (c, drawable, screen,
                                               NULL, format,
                                               width, height, 0);
}
slim_hidden_def (cairo_xcb_surface_create_with_xrender_format);

/**
 * cairo_xcb_surface_set_size:
 * @surface: a #cairo_surface_t for the XCB backend
 * @width: the new width of the surface
 * @height: the new height of the surface
 *
 * Informs cairo of the new size of the XCB drawable underlying the
 * surface. For a surface created for a window (rather than a pixmap),
 * this function must be called each time the size of the window
 * changes. (For a subwindow, you are normally resizing the window
 * yourself, but for a toplevel window, it is necessary to listen for
 * ConfigureNotify events.)
 *
 * A pixmap can never change size, so it is never necessary to call
 * this function on a surface created for a pixmap.
 **/
void
cairo_xcb_surface_set_size (cairo_surface_t *abstract_surface,
                             int              width,
                             int              height)
{
    cairo_xcb_surface_t *surface = (cairo_xcb_surface_t *) abstract_surface;
    cairo_status_t status_ignored;

    if (! _cairo_surface_is_xcb (abstract_surface)) {
        status_ignored = _cairo_surface_set_error (abstract_surface,
                                  CAIRO_STATUS_SURFACE_TYPE_MISMATCH);
        return;
    }

    surface->width = width;
    surface->height = height;
}

/*
 *  Glyph rendering support
 */

typedef struct _cairo_xcb_surface_font_private {
    xcb_connection_t            *dpy;
    xcb_render_glyphset_t       glyphset;
    cairo_format_t              format;
    xcb_render_pictforminfo_t   *xrender_format;
} cairo_xcb_surface_font_private_t;

static cairo_status_t
_cairo_xcb_surface_font_init (xcb_connection_t              *dpy,
                               cairo_scaled_font_t  *scaled_font,
                               cairo_format_t        format)
{
    cairo_xcb_surface_font_private_t    *font_private;

    font_private = malloc (sizeof (cairo_xcb_surface_font_private_t));
    if (!font_private)
        return _cairo_error (CAIRO_STATUS_NO_MEMORY);

    font_private->dpy = dpy;
    font_private->format = format;
    font_private->xrender_format = _CAIRO_FORMAT_TO_XRENDER_FORMAT(dpy, format);
    font_private->glyphset = xcb_generate_id(dpy);
    xcb_render_create_glyph_set (dpy, font_private->glyphset, font_private->xrender_format->id);

    scaled_font->surface_private = font_private;
    scaled_font->surface_backend = &cairo_xcb_surface_backend;
    return CAIRO_STATUS_SUCCESS;
}

static void
_cairo_xcb_surface_scaled_font_fini (cairo_scaled_font_t *scaled_font)
{
    cairo_xcb_surface_font_private_t    *font_private = scaled_font->surface_private;

    if (font_private) {
        xcb_render_free_glyph_set (font_private->dpy, font_private->glyphset);
        free (font_private);
    }
}

static void
_cairo_xcb_surface_scaled_glyph_fini (cairo_scaled_glyph_t *scaled_glyph,
                                       cairo_scaled_font_t  *scaled_font)
{
    cairo_xcb_surface_font_private_t    *font_private = scaled_font->surface_private;

    if (font_private != NULL && scaled_glyph->surface_private != NULL) {
        xcb_render_glyph_t glyph_index = _cairo_scaled_glyph_index(scaled_glyph);
        xcb_render_free_glyphs (font_private->dpy,
                           font_private->glyphset,
                           1, &glyph_index);
    }
}

static cairo_bool_t
_native_byte_order_lsb (void)
{
    int x = 1;

    return *((char *) &x) == 1;
}

static cairo_status_t
_cairo_xcb_surface_add_glyph (xcb_connection_t *dpy,
                               cairo_scaled_font_t  *scaled_font,
                               cairo_scaled_glyph_t *scaled_glyph)
{
    xcb_render_glyphinfo_t glyph_info;
    xcb_render_glyph_t glyph_index;
    unsigned char *data;
    cairo_status_t status = CAIRO_STATUS_SUCCESS;
    cairo_xcb_surface_font_private_t *font_private;
    cairo_image_surface_t *glyph_surface = scaled_glyph->surface;

    if (scaled_font->surface_private == NULL) {
        status = _cairo_xcb_surface_font_init (dpy, scaled_font,
                                                glyph_surface->format);
        if (status)
            return status;
    }
    font_private = scaled_font->surface_private;

    /* If the glyph format does not match the font format, then we
     * create a temporary surface for the glyph image with the font's
     * format.
     */
    if (glyph_surface->format != font_private->format) {
        cairo_t *cr;
        cairo_surface_t *tmp_surface;
        double x_offset, y_offset;

        tmp_surface = cairo_image_surface_create (font_private->format,
                                                  glyph_surface->width,
                                                  glyph_surface->height);
        cr = cairo_create (tmp_surface);
        cairo_surface_get_device_offset (&glyph_surface->base, &x_offset, &y_offset);
        cairo_set_source_surface (cr, &glyph_surface->base, x_offset, y_offset);
        cairo_set_operator (cr, CAIRO_OPERATOR_SOURCE);
        cairo_paint (cr);

        status = cairo_status (cr);

        cairo_destroy (cr);

        tmp_surface->device_transform = glyph_surface->base.device_transform;
        tmp_surface->device_transform_inverse = glyph_surface->base.device_transform_inverse;

        glyph_surface = (cairo_image_surface_t *) tmp_surface;

        if (status)
            goto BAIL;
    }

    /* XXX: FRAGILE: We're ignore device_transform scaling here. A bug? */
    glyph_info.x = _cairo_lround (glyph_surface->base.device_transform.x0);
    glyph_info.y = _cairo_lround (glyph_surface->base.device_transform.y0);
    glyph_info.width = glyph_surface->width;
    glyph_info.height = glyph_surface->height;
    glyph_info.x_off = 0;
    glyph_info.y_off = 0;

    data = glyph_surface->data;

    /* flip formats around */
    switch (scaled_glyph->surface->format) {
    case CAIRO_FORMAT_A1:
        /* local bitmaps are always stored with bit == byte */
        if (_native_byte_order_lsb() != (xcb_get_setup(dpy)->bitmap_format_bit_order == XCB_IMAGE_ORDER_LSB_FIRST)) {
            int             c = glyph_surface->stride * glyph_surface->height;
            unsigned char   *d;
            unsigned char   *new, *n;

            new = malloc (c);
            if (!new) {
                status = _cairo_error (CAIRO_STATUS_NO_MEMORY);
                goto BAIL;
            }
            n = new;
            d = data;
            while (c--)
            {
                char    b = *d++;
                b = ((b << 1) & 0xaa) | ((b >> 1) & 0x55);
                b = ((b << 2) & 0xcc) | ((b >> 2) & 0x33);
                b = ((b << 4) & 0xf0) | ((b >> 4) & 0x0f);
                *n++ = b;
            }
            data = new;
        }
        break;
    case CAIRO_FORMAT_A8:
        break;
    case CAIRO_FORMAT_ARGB32:
        if (_native_byte_order_lsb() != (xcb_get_setup(dpy)->image_byte_order == XCB_IMAGE_ORDER_LSB_FIRST)) {
            unsigned int    c = glyph_surface->stride * glyph_surface->height;
            unsigned char   *d;
            unsigned char   *new, *n;

            new = malloc (c);
            if (new == NULL) {
                status = _cairo_error (CAIRO_STATUS_NO_MEMORY);
                goto BAIL;
            }
            n = new;
            d = data;
            while (c >= 4)
            {
                n[3] = d[0];
                n[2] = d[1];
                n[1] = d[2];
                n[0] = d[3];
                d += 4;
                n += 4;
                c -= 4;
            }
            data = new;
        }
        break;
    case CAIRO_FORMAT_RGB24:
    default:
        ASSERT_NOT_REACHED;
        break;
    }
    /* XXX assume X server wants pixman padding. Xft assumes this as well */

    glyph_index = _cairo_scaled_glyph_index (scaled_glyph);

    xcb_render_add_glyphs (dpy, font_private->glyphset,
                      1, &glyph_index, &glyph_info,
                      glyph_surface->stride * glyph_surface->height,
                      data);

    if (data != glyph_surface->data)
        free (data);

 BAIL:
    if (glyph_surface != scaled_glyph->surface)
        cairo_surface_destroy (&glyph_surface->base);

    return status;
}

#define N_STACK_BUF 1024

static cairo_status_t
_cairo_xcb_surface_show_glyphs_8  (cairo_xcb_surface_t *dst,
                                   cairo_operator_t op,
                                   cairo_xcb_surface_t *src,
                                   int src_x_offset, int src_y_offset,
                                   const cairo_glyph_t *glyphs,
                                   int num_glyphs,
                                   cairo_scaled_font_t *scaled_font)
{
    cairo_xcb_surface_font_private_t *font_private = scaled_font->surface_private;
    xcb_render_util_composite_text_stream_t *stream;
    int i;
    int thisX, thisY;
    int lastX = 0, lastY = 0;
    uint8_t glyph;

    stream = xcb_render_util_composite_text_stream (font_private->glyphset, num_glyphs, 0);

    for (i = 0; i < num_glyphs; ++i) {
        thisX = _cairo_lround (glyphs[i].x);
        thisY = _cairo_lround (glyphs[i].y);
        glyph = glyphs[i].index;
        xcb_render_util_glyphs_8 (stream, thisX - lastX, thisY - lastY, 1, &glyph);
        lastX = thisX;
        lastY = thisY;
    }

    xcb_render_util_composite_text (dst->dpy,
                            _render_operator (op),
                            src->src_picture,
                            dst->dst_picture,
                            font_private->xrender_format->id,
                            src_x_offset + _cairo_lround (glyphs[0].x),
                            src_y_offset + _cairo_lround (glyphs[0].y),
                            stream);

    xcb_render_util_composite_text_free (stream);

    return CAIRO_STATUS_SUCCESS;
}

static cairo_status_t
_cairo_xcb_surface_show_glyphs_16 (cairo_xcb_surface_t *dst,
                                   cairo_operator_t op,
                                   cairo_xcb_surface_t *src,
                                   int src_x_offset, int src_y_offset,
                                   const cairo_glyph_t *glyphs,
                                   int num_glyphs,
                                   cairo_scaled_font_t *scaled_font)
{
    cairo_xcb_surface_font_private_t *font_private = scaled_font->surface_private;
    xcb_render_util_composite_text_stream_t *stream;
    int i;
    int thisX, thisY;
    int lastX = 0, lastY = 0;
    uint16_t glyph;

    stream = xcb_render_util_composite_text_stream (font_private->glyphset, num_glyphs, 0);

    for (i = 0; i < num_glyphs; ++i) {
        thisX = _cairo_lround (glyphs[i].x);
        thisY = _cairo_lround (glyphs[i].y);
        glyph = glyphs[i].index;
        xcb_render_util_glyphs_16 (stream, thisX - lastX, thisY - lastY, 1, &glyph);
        lastX = thisX;
        lastY = thisY;
    }

    xcb_render_util_composite_text (dst->dpy,
                            _render_operator (op),
                            src->src_picture,
                            dst->dst_picture,
                            font_private->xrender_format->id,
                            src_x_offset + _cairo_lround (glyphs[0].x),
                            src_y_offset + _cairo_lround (glyphs[0].y),
                            stream);

    xcb_render_util_composite_text_free (stream);

    return CAIRO_STATUS_SUCCESS;
}

static cairo_status_t
_cairo_xcb_surface_show_glyphs_32 (cairo_xcb_surface_t *dst,
                                   cairo_operator_t op,
                                   cairo_xcb_surface_t *src,
                                   int src_x_offset, int src_y_offset,
                                   const cairo_glyph_t *glyphs,
                                   int num_glyphs,
                                   cairo_scaled_font_t *scaled_font)
{
    cairo_xcb_surface_font_private_t *font_private = scaled_font->surface_private;
    xcb_render_util_composite_text_stream_t *stream;
    int i;
    int thisX, thisY;
    int lastX = 0, lastY = 0;
    uint32_t glyph;

    stream = xcb_render_util_composite_text_stream (font_private->glyphset, num_glyphs, 0);

    for (i = 0; i < num_glyphs; ++i) {
        thisX = _cairo_lround (glyphs[i].x);
        thisY = _cairo_lround (glyphs[i].y);
        glyph = glyphs[i].index;
        xcb_render_util_glyphs_32 (stream, thisX - lastX, thisY - lastY, 1, &glyph);
        lastX = thisX;
        lastY = thisY;
    }

    xcb_render_util_composite_text (dst->dpy,
                            _render_operator (op),
                            src->src_picture,
                            dst->dst_picture,
                            font_private->xrender_format->id,
                            src_x_offset + _cairo_lround (glyphs[0].x),
                            src_y_offset + _cairo_lround (glyphs[0].y),
                            stream);

    xcb_render_util_composite_text_free (stream);

    return CAIRO_STATUS_SUCCESS;
}

typedef cairo_status_t (*cairo_xcb_surface_show_glyphs_func_t)
    (cairo_xcb_surface_t *, cairo_operator_t, cairo_xcb_surface_t *, int, int,
     const cairo_glyph_t *, int, cairo_scaled_font_t *);

static cairo_bool_t
_cairo_xcb_surface_owns_font (cairo_xcb_surface_t *dst,
                              cairo_scaled_font_t *scaled_font)
{
    cairo_xcb_surface_font_private_t *font_private;

    font_private = scaled_font->surface_private;
    if ((scaled_font->surface_backend != NULL &&
         scaled_font->surface_backend != &cairo_xcb_surface_backend) ||
        (font_private != NULL && font_private->dpy != dst->dpy))
    {
        return FALSE;
    }

    return TRUE;
}



static cairo_status_t
_cairo_xcb_surface_emit_glyphs (cairo_xcb_surface_t *dst,
                                cairo_glyph_t       *glyphs,
                                int                  num_glyphs,
                                cairo_scaled_font_t *scaled_font,
                                cairo_operator_t     op,
                                cairo_xcb_surface_t *src,
                                cairo_surface_attributes_t *attributes,
                                int                 *remaining_glyphs)
{
    cairo_scaled_glyph_t *scaled_glyph;
    int i, o;
    unsigned long max_index = 0;
    cairo_status_t status;
    cairo_glyph_t *output_glyphs;
    const cairo_glyph_t *glyphs_chunk;
    int glyphs_remaining, chunk_size, max_chunk_size;
    cairo_xcb_surface_show_glyphs_func_t show_glyphs_func;

    /* We make a copy of the glyphs so that we can elide any size-zero
     * glyphs to workaround an X server bug, (present in at least Xorg
     * 7.1 without EXA). */
    output_glyphs = _cairo_malloc_ab (num_glyphs, sizeof (cairo_glyph_t));
    if (output_glyphs == NULL)
        return _cairo_error (CAIRO_STATUS_NO_MEMORY);

    for (i = 0, o = 0; i < num_glyphs; i++) {
        if (glyphs[i].index > max_index)
            max_index = glyphs[i].index;
        status = _cairo_scaled_glyph_lookup (scaled_font,
                                             glyphs[i].index,
                                             CAIRO_SCALED_GLYPH_INFO_SURFACE,
                                             &scaled_glyph);
        if (status) {
            free (output_glyphs);
            return status;
        }

        /* Don't put any size-zero glyphs into output_glyphs to avoid
         * an X server bug which stops rendering glyphs after the
         * first size-zero glyph. */
        if (scaled_glyph->surface->width && scaled_glyph->surface->height) {
            output_glyphs[o++] = glyphs[i];
            if (scaled_glyph->surface_private == NULL) {
                _cairo_xcb_surface_add_glyph (dst->dpy, scaled_font, scaled_glyph);
                scaled_glyph->surface_private = (void *) 1;
            }
        }
    }
    num_glyphs = o;

    _cairo_xcb_surface_ensure_dst_picture (dst);

    max_chunk_size = xcb_get_maximum_request_length (dst->dpy);
    if (max_index < 256) {
        /* XXX: these are all the same size! (28) */
        max_chunk_size -= sizeof(xcb_render_composite_glyphs_8_request_t);
        show_glyphs_func = _cairo_xcb_surface_show_glyphs_8;
    } else if (max_index < 65536) {
        max_chunk_size -= sizeof(xcb_render_composite_glyphs_16_request_t);
        show_glyphs_func = _cairo_xcb_surface_show_glyphs_16;
    } else {
        max_chunk_size -= sizeof(xcb_render_composite_glyphs_32_request_t);
        show_glyphs_func = _cairo_xcb_surface_show_glyphs_32;
    }
    /* XXX: I think this is wrong; this is only the header size (2 longs) */
    /*      but should also include the glyph (1 long) */
    /* max_chunk_size /= sz_xGlyphElt; */
    max_chunk_size /= 3*sizeof(uint32_t);

    for (glyphs_remaining = num_glyphs, glyphs_chunk = output_glyphs;
         glyphs_remaining;
         glyphs_remaining -= chunk_size, glyphs_chunk += chunk_size)
    {
        chunk_size = MIN (glyphs_remaining, max_chunk_size);

        status = show_glyphs_func (dst, op, src,
                                   attributes->x_offset, attributes->y_offset,
                                   glyphs_chunk, chunk_size, scaled_font);
        if (status) {
            free (output_glyphs);
            return status;
        }
    }

    return CAIRO_STATUS_SUCCESS;
}

static cairo_int_status_t
_cairo_xcb_surface_show_glyphs (void                *abstract_dst,
                                cairo_operator_t     op,
                                cairo_pattern_t     *src_pattern,
                                cairo_glyph_t       *glyphs,
                                int                   num_glyphs,
                                cairo_scaled_font_t *scaled_font,
                                int                  *remaining_glyphs)
{
    cairo_int_status_t status = CAIRO_STATUS_SUCCESS;
    cairo_xcb_surface_t *dst = abstract_dst;

    composite_operation_t operation;
    cairo_surface_attributes_t attributes;
    cairo_xcb_surface_t *src = NULL;

    cairo_solid_pattern_t solid_pattern;

    if (!CAIRO_SURFACE_RENDER_HAS_COMPOSITE_TEXT (dst) || dst->xrender_format.id == XCB_NONE)
        return CAIRO_INT_STATUS_UNSUPPORTED;

    /* Just let unbounded operators go through the fallback code
     * instead of trying to do the fixups here */
    if (!_cairo_operator_bounded_by_mask (op))
        return CAIRO_INT_STATUS_UNSUPPORTED;

    /* Render <= 0.10 seems to have a bug with PictOpSrc and glyphs --
     * the solid source seems to be multiplied by the glyph mask, and
     * then the entire thing is copied to the destination surface,
     * including the fully transparent "background" of the rectangular
     * glyph surface. */
    if (op == CAIRO_OPERATOR_SOURCE &&
        !CAIRO_SURFACE_RENDER_AT_LEAST(dst, 0, 11))
        return CAIRO_INT_STATUS_UNSUPPORTED;

    /* We can only use our code if we either have no clip or
     * have a real native clip region set.  If we're using
     * fallback clip masking, we have to go through the full
     * fallback path.
     */
    if (dst->base.clip &&
        (dst->base.clip->mode != CAIRO_CLIP_MODE_REGION ||
         dst->base.clip->surface != NULL))
        return CAIRO_INT_STATUS_UNSUPPORTED;

    operation = _categorize_composite_operation (dst, op, src_pattern, TRUE);
    if (operation == DO_UNSUPPORTED)
        return CAIRO_INT_STATUS_UNSUPPORTED;

    if (! _cairo_xcb_surface_owns_font (dst, scaled_font))
        return CAIRO_INT_STATUS_UNSUPPORTED;

    /* After passing all those tests, we're now committed to rendering
     * these glyphs or to fail trying. We first upload any glyphs to
     * the X server that it doesn't have already, then we draw
     * them. We tie into the scaled_font's glyph cache and remove
     * glyphs from the X server when they are ejected from the
     * scaled_font cache.
     */

    /* PictOpClear doesn't seem to work with CompositeText; it seems to ignore
     * the mask (the glyphs).  This code below was executed as a side effect
     * of going through the _clip_and_composite fallback code for old_show_glyphs,
     * so PictOpClear was never used with CompositeText before.
     */
    if (op == CAIRO_OPERATOR_CLEAR) {
        _cairo_pattern_init_solid (&solid_pattern, CAIRO_COLOR_WHITE,
                                   CAIRO_CONTENT_COLOR);
        src_pattern = &solid_pattern.base;
        op = CAIRO_OPERATOR_DEST_OUT;
    }

    if (src_pattern->type == CAIRO_PATTERN_TYPE_SOLID) {
        status = _cairo_pattern_acquire_surface (src_pattern, &dst->base,
                                                 0, 0, 1, 1,
                                                 (cairo_surface_t **) &src,
                                                 &attributes);
    } else {
        cairo_rectangle_int_t glyph_extents;

        status = _cairo_scaled_font_glyph_device_extents (scaled_font,
                                                          glyphs,
                                                          num_glyphs,
                                                          &glyph_extents);
        if (status)
            goto BAIL;

        status = _cairo_pattern_acquire_surface (src_pattern, &dst->base,
                                                 glyph_extents.x, glyph_extents.y,
                                                 glyph_extents.width, glyph_extents.height,
                                                 (cairo_surface_t **) &src,
                                                 &attributes);
    }

    if (status)
        goto BAIL;

    operation = _recategorize_composite_operation (dst, op, src, &attributes, TRUE);
    if (operation == DO_UNSUPPORTED) {
        status = CAIRO_INT_STATUS_UNSUPPORTED;
        goto BAIL;
    }

    status = _cairo_xcb_surface_set_attributes (src, &attributes);
    if (status)
        goto BAIL;

    /* Send all unsent glyphs to the server, and count the max of the glyph indices */
    _cairo_scaled_font_freeze_cache (scaled_font);

    if (_cairo_xcb_surface_owns_font (dst, scaled_font))
        status = _cairo_xcb_surface_emit_glyphs (dst,
                                                 glyphs, num_glyphs,
                                                 scaled_font,
                                                 op,
                                                 src,
                                                 &attributes,
                                                 remaining_glyphs);
    else
        status = CAIRO_INT_STATUS_UNSUPPORTED;
    _cairo_scaled_font_thaw_cache (scaled_font);

  BAIL:
    if (src)
        _cairo_pattern_release_surface (src_pattern, &src->base, &attributes);
    if (src_pattern == &solid_pattern.base)
        _cairo_pattern_fini (&solid_pattern.base);

    return status;
}