/* -*- Mode: c; tab-width: 8; c-basic-offset: 4; indent-tabs-mode: t; -*- */

/* cairo - a vector graphics library with display and print output

 *

 * Copyright © 2002 University of Southern California

 * Copyright © 2005 Red Hat, Inc.

 * Copyright © 2011 Intel Corporation

 *

 * 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., 51 Franklin Street, Suite 500, Boston, MA 02110-1335, 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>

 *      Joonas Pihlaja <jpihlaja@cc.helsinki.fi>

 *  Chris Wilson <chris@chris-wilson.co.uk>

 */

#include "cairoint.h"

#include "cairo-compositor-private.h"

#include "cairo-clip-inline.h"

#include "cairo-clip-private.h"

#include "cairo-image-surface-private.h"

#include "cairo-paginated-private.h"

#include "cairo-pattern-inline.h"

#include "cairo-region-private.h"

#include "cairo-recording-surface-inline.h"

#include "cairo-spans-compositor-private.h"

#include "cairo-surface-subsurface-private.h"

#include "cairo-surface-snapshot-private.h"

#include "cairo-surface-observer-private.h"

typedef struct {

    cairo_polygon_t *polygon;

    cairo_fill_rule_t  fill_rule;

    cairo_antialias_t  antialias;

} composite_spans_info_t;

static cairo_int_status_t

composite_polygon (const cairo_spans_compositor_t *compositor,

       cairo_composite_rectangles_t    *extents,

       cairo_polygon_t      *polygon,

       cairo_fill_rule_t       fill_rule,

       cairo_antialias_t       antialias);

static cairo_int_status_t

composite_boxes (const cairo_spans_compositor_t *compositor,

     cairo_composite_rectangles_t *extents,

     cairo_boxes_t    *boxes);

static cairo_int_status_t

clip_and_composite_polygon (const cairo_spans_compositor_t  *compositor,

          cairo_composite_rectangles_t   *extents,

          cairo_polygon_t     *polygon,

          cairo_fill_rule_t      fill_rule,

          cairo_antialias_t      antialias);

static cairo_surface_t *

get_clip_surface (const cairo_spans_compositor_t *compositor,

      cairo_surface_t *dst,

      const cairo_clip_t *clip,

      const cairo_rectangle_int_t *extents)

{

    cairo_composite_rectangles_t composite;

    cairo_surface_t *surface;

    cairo_box_t box;

    cairo_polygon_t polygon;

    const cairo_clip_path_t *clip_path;

    cairo_antialias_t antialias;

    cairo_fill_rule_t fill_rule;

    cairo_int_status_t status;

    assert (clip->path);

    surface = _cairo_surface_create_scratch (dst,

               CAIRO_CONTENT_ALPHA,

               extents->width,

               extents->height,

               CAIRO_COLOR_TRANSPARENT);

    _cairo_box_from_rectangle (&box, extents);

    _cairo_polygon_init (&polygon, &box, 1);

    clip_path = clip->path;

    status = _cairo_path_fixed_fill_to_polygon (&clip_path->path,

            clip_path->tolerance,

            &polygon);

    if (unlikely (status))

  goto cleanup_polygon;

    polygon.num_limits = 0;

    antialias = clip_path->antialias;

    fill_rule = clip_path->fill_rule;

    if (clip->boxes) {

  cairo_polygon_t intersect;

  cairo_boxes_t tmp;

  _cairo_boxes_init_for_array (&tmp, clip->boxes, clip->num_boxes);

  status= _cairo_polygon_init_boxes (&intersect, &tmp);

  if (unlikely (status))

      goto cleanup_polygon;

  status = _cairo_polygon_intersect (&polygon, fill_rule,

             &intersect, CAIRO_FILL_RULE_WINDING);

  _cairo_polygon_fini (&intersect);

  if (unlikely (status))

      goto cleanup_polygon;

  fill_rule = CAIRO_FILL_RULE_WINDING;

    }

    polygon.limits = NULL;

    polygon.num_limits = 0;

    clip_path = clip_path->prev;

    while (clip_path) {

  if (clip_path->antialias == antialias) {

      cairo_polygon_t next;

      _cairo_polygon_init (&next, NULL, 0);

      status = _cairo_path_fixed_fill_to_polygon (&clip_path->path,

              clip_path->tolerance,

              &next);

      if (likely (status == CAIRO_INT_STATUS_SUCCESS))

    status = _cairo_polygon_intersect (&polygon, fill_rule,

               &next, clip_path->fill_rule);

      _cairo_polygon_fini (&next);

      if (unlikely (status))

    goto cleanup_polygon;

      fill_rule = CAIRO_FILL_RULE_WINDING;

  }

  clip_path = clip_path->prev;

    }

    _cairo_polygon_translate (&polygon, -extents->x, -extents->y);

    status = _cairo_composite_rectangles_init_for_polygon (&composite, surface,

                 CAIRO_OPERATOR_ADD,

                 &_cairo_pattern_white.base,

                 &polygon,

                 NULL);

    if (unlikely (status))

  goto cleanup_polygon;

    status = composite_polygon (compositor, &composite,

        &polygon, fill_rule, antialias);

    _cairo_composite_rectangles_fini (&composite);

    _cairo_polygon_fini (&polygon);

    if (unlikely (status))

  goto error;

    _cairo_polygon_init (&polygon, &box, 1);

    clip_path = clip->path;

    antialias = clip_path->antialias == CAIRO_ANTIALIAS_DEFAULT ? CAIRO_ANTIALIAS_NONE : CAIRO_ANTIALIAS_DEFAULT;

    clip_path = clip_path->prev;

    while (clip_path) {

  if (clip_path->antialias == antialias) {

      if (polygon.num_edges == 0) {

    status = _cairo_path_fixed_fill_to_polygon (&clip_path->path,

                  clip_path->tolerance,

                  &polygon);

    fill_rule = clip_path->fill_rule;

    polygon.limits = NULL;

    polygon.num_limits = 0;

      } else {

    cairo_polygon_t next;

    _cairo_polygon_init (&next, NULL, 0);

    status = _cairo_path_fixed_fill_to_polygon (&clip_path->path,

                  clip_path->tolerance,

                  &next);

    if (likely (status == CAIRO_INT_STATUS_SUCCESS))

        status = _cairo_polygon_intersect (&polygon, fill_rule,

                   &next, clip_path->fill_rule);

    _cairo_polygon_fini (&next);

    fill_rule = CAIRO_FILL_RULE_WINDING;

      }

      if (unlikely (status))

    goto error;

  }

  clip_path = clip_path->prev;

    }

    if (polygon.num_edges) {

  _cairo_polygon_translate (&polygon, -extents->x, -extents->y);

  status = _cairo_composite_rectangles_init_for_polygon (&composite, surface,

                     CAIRO_OPERATOR_IN,

                     &_cairo_pattern_white.base,

                     &polygon,

                     NULL);

  if (unlikely (status))

      goto cleanup_polygon;

  status = composite_polygon (compositor, &composite,

            &polygon, fill_rule, antialias);

  _cairo_composite_rectangles_fini (&composite);

  _cairo_polygon_fini (&polygon);

  if (unlikely (status))

      goto error;

    }

    return surface;

cleanup_polygon:

    _cairo_polygon_fini (&polygon);

error:

    cairo_surface_destroy (surface);

    return _cairo_int_surface_create_in_error (status);

}

static cairo_int_status_t

fixup_unbounded_mask (const cairo_spans_compositor_t *compositor,

          const cairo_composite_rectangles_t *extents,

          cairo_boxes_t *boxes)

{

    cairo_composite_rectangles_t composite;

    cairo_surface_t *clip;

    cairo_int_status_t status;

    TRACE((stderr, "%s\n", __FUNCTION__));

    clip = get_clip_surface (compositor, extents->surface, extents->clip,

           &extents->unbounded);

    if (unlikely (clip->status)) {

  if ((cairo_int_status_t)clip->status == CAIRO_INT_STATUS_NOTHING_TO_DO)

      return CAIRO_STATUS_SUCCESS;

  return clip->status;

    }

    status = _cairo_composite_rectangles_init_for_boxes (&composite,

               extents->surface,

               CAIRO_OPERATOR_CLEAR,

               &_cairo_pattern_clear.base,

               boxes,

               NULL);

    if (unlikely (status))

  goto cleanup_clip;

    _cairo_pattern_init_for_surface (&composite.mask_pattern.surface, clip);

    composite.mask_pattern.base.filter = CAIRO_FILTER_NEAREST;

    composite.mask_pattern.base.extend = CAIRO_EXTEND_NONE;

    status = composite_boxes (compositor, &composite, boxes);

    _cairo_pattern_fini (&composite.mask_pattern.base);

    _cairo_composite_rectangles_fini (&composite);

cleanup_clip:

    cairo_surface_destroy (clip);

    return status;

}

static cairo_int_status_t

fixup_unbounded_polygon (const cairo_spans_compositor_t *compositor,

       const cairo_composite_rectangles_t *extents,

       cairo_boxes_t *boxes)

{

    cairo_polygon_t polygon, intersect;

    cairo_composite_rectangles_t composite;

    cairo_fill_rule_t fill_rule;

    cairo_antialias_t antialias;

    cairo_int_status_t status;

    TRACE((stderr, "%s\n", __FUNCTION__));

    /* Can we treat the clip as a regular clear-polygon and use it to fill? */

    status = _cairo_clip_get_polygon (extents->clip, &polygon,

              &fill_rule, &antialias);

    if (status == CAIRO_INT_STATUS_UNSUPPORTED)

  return status;

    status= _cairo_polygon_init_boxes (&intersect, boxes);

    if (unlikely (status))

  goto cleanup_polygon;

    status = _cairo_polygon_intersect (&polygon, fill_rule,

               &intersect, CAIRO_FILL_RULE_WINDING);

    _cairo_polygon_fini (&intersect);

    if (unlikely (status))

  goto cleanup_polygon;

    status = _cairo_composite_rectangles_init_for_polygon (&composite,

                 extents->surface,

                 CAIRO_OPERATOR_CLEAR,

                 &_cairo_pattern_clear.base,

                 &polygon,

                 NULL);

    if (unlikely (status))

  goto cleanup_polygon;

    status = composite_polygon (compositor, &composite,

        &polygon, fill_rule, antialias);

    _cairo_composite_rectangles_fini (&composite);

cleanup_polygon:

    _cairo_polygon_fini (&polygon);

    return status;

}

static cairo_int_status_t

fixup_unbounded_boxes (const cairo_spans_compositor_t *compositor,

           const cairo_composite_rectangles_t *extents,

           cairo_boxes_t *boxes)

{

    cairo_boxes_t tmp, clear;

    cairo_box_t box;

    cairo_int_status_t status;

    assert (boxes->is_pixel_aligned);

    TRACE ((stderr, "%s\n", __FUNCTION__));

    if (extents->bounded.width  == extents->unbounded.width &&

  extents->bounded.height == extents->unbounded.height)

    {

  return CAIRO_STATUS_SUCCESS;

    }

    /* subtract the drawn boxes from the unbounded area */

    _cairo_boxes_init (&clear);

    box.p1.x = _cairo_fixed_from_int (extents->unbounded.x + extents->unbounded.width);

    box.p1.y = _cairo_fixed_from_int (extents->unbounded.y);

    box.p2.x = _cairo_fixed_from_int (extents->unbounded.x);

    box.p2.y = _cairo_fixed_from_int (extents->unbounded.y + extents->unbounded.height);

    if (boxes->num_boxes) {

  _cairo_boxes_init (&tmp);

  status = _cairo_boxes_add (&tmp, CAIRO_ANTIALIAS_DEFAULT, &box);

  assert (status == CAIRO_INT_STATUS_SUCCESS);

  tmp.chunks.next = &boxes->chunks;

  tmp.num_boxes += boxes->num_boxes;

  status = _cairo_bentley_ottmann_tessellate_boxes (&tmp,

                CAIRO_FILL_RULE_WINDING,

                &clear);

  tmp.chunks.next = NULL;

  if (unlikely (status))

      goto error;

    } else {

  box.p1.x = _cairo_fixed_from_int (extents->unbounded.x);

  box.p2.x = _cairo_fixed_from_int (extents->unbounded.x + extents->unbounded.width);

  status = _cairo_boxes_add (&clear, CAIRO_ANTIALIAS_DEFAULT, &box);

  assert (status == CAIRO_INT_STATUS_SUCCESS);

    }

    /* If we have a clip polygon, we need to intersect with that as well */

    if (extents->clip->path) {

  status = fixup_unbounded_polygon (compositor, extents, &clear);

  if (status == CAIRO_INT_STATUS_UNSUPPORTED)

      status = fixup_unbounded_mask (compositor, extents, &clear);

    } else {

  /* Otherwise just intersect with the clip boxes */

  if (extents->clip->num_boxes) {

      _cairo_boxes_init_for_array (&tmp,

           extents->clip->boxes,

           extents->clip->num_boxes);

      status = _cairo_boxes_intersect (&clear, &tmp, &clear);

      if (unlikely (status))

    goto error;

  }

  if (clear.is_pixel_aligned) {

      status = compositor->fill_boxes (extents->surface,

               CAIRO_OPERATOR_CLEAR,

               CAIRO_COLOR_TRANSPARENT,

               &clear);

  } else {

      cairo_composite_rectangles_t composite;

      status = _cairo_composite_rectangles_init_for_boxes (&composite,

                 extents->surface,

                 CAIRO_OPERATOR_CLEAR,

                 &_cairo_pattern_clear.base,

                 &clear,

                 NULL);

      if (likely (status == CAIRO_INT_STATUS_SUCCESS)) {

    status = composite_boxes (compositor, &composite, &clear);

    _cairo_composite_rectangles_fini (&composite);

      }

  }

    }

error:

    _cairo_boxes_fini (&clear);

    return status;

}

static cairo_surface_t *

unwrap_source (const cairo_pattern_t *pattern)

{

    cairo_rectangle_int_t limit;

    return _cairo_pattern_get_source ((cairo_surface_pattern_t *)pattern,

              &limit);

}

static cairo_bool_t

is_recording_pattern (const cairo_pattern_t *pattern)

{

    cairo_surface_t *surface;

    if (pattern->type != CAIRO_PATTERN_TYPE_SURFACE)

  return FALSE;

    surface = ((const cairo_surface_pattern_t *) pattern)->surface;

    return _cairo_surface_is_recording (surface);

}

static cairo_bool_t

recording_pattern_contains_sample (const cairo_pattern_t *pattern,

           const cairo_rectangle_int_t *sample)

{

    cairo_recording_surface_t *surface;

    if (! is_recording_pattern (pattern))

  return FALSE;

    if (pattern->extend == CAIRO_EXTEND_NONE)

  return TRUE;

    surface = (cairo_recording_surface_t *) unwrap_source (pattern);

    if (surface->unbounded)

  return TRUE;

    return _cairo_rectangle_contains_rectangle (&surface->extents, sample);

}

static cairo_bool_t

op_reduces_to_source (const cairo_composite_rectangles_t *extents,

          cairo_bool_t no_mask)

{

    if (extents->op == CAIRO_OPERATOR_SOURCE)

  return TRUE;

    if (extents->surface->is_clear)

  return extents->op == CAIRO_OPERATOR_OVER || extents->op == CAIRO_OPERATOR_ADD;

    if (no_mask && extents->op == CAIRO_OPERATOR_OVER)

  return _cairo_pattern_is_opaque (&extents->source_pattern.base,

           &extents->source_sample_area);

    return FALSE;

}

static cairo_status_t

upload_boxes (const cairo_spans_compositor_t *compositor,

        const cairo_composite_rectangles_t *extents,

        cairo_boxes_t *boxes)

{

    cairo_surface_t *dst = extents->surface;

    const cairo_surface_pattern_t *source = &extents->source_pattern.surface;

    cairo_surface_t *src;

    cairo_rectangle_int_t limit;

    cairo_int_status_t status;

    int tx, ty;

    TRACE ((stderr, "%s\n", __FUNCTION__));

    src = _cairo_pattern_get_source(source, &limit);

    if (!(src->type == CAIRO_SURFACE_TYPE_IMAGE || src->type == dst->type))

  return CAIRO_INT_STATUS_UNSUPPORTED;

    if (! _cairo_matrix_is_integer_translation (&source->base.matrix, &tx, &ty))

  return CAIRO_INT_STATUS_UNSUPPORTED;

    /* Check that the data is entirely within the image */

    if (extents->bounded.x + tx < limit.x || extents->bounded.y + ty < limit.y)

  return CAIRO_INT_STATUS_UNSUPPORTED;

    if (extents->bounded.x + extents->bounded.width  + tx > limit.x + limit.width ||

  extents->bounded.y + extents->bounded.height + ty > limit.y + limit.height)

  return CAIRO_INT_STATUS_UNSUPPORTED;

    tx += limit.x;

    ty += limit.y;

    if (src->type == CAIRO_SURFACE_TYPE_IMAGE)

  status = compositor->draw_image_boxes (dst,

                 (cairo_image_surface_t *)src,

                 boxes, tx, ty);

    else

  status = compositor->copy_boxes (dst, src, boxes, &extents->bounded,

           tx, ty);

    return status;

}

static cairo_bool_t

_clip_is_region (const cairo_clip_t *clip)

{

    int i;

    if (clip->is_region)

  return TRUE;

    if (clip->path)

  return FALSE;

    for (i = 0; i < clip->num_boxes; i++) {

  const cairo_box_t *b = &clip->boxes[i];

  if (!_cairo_fixed_is_integer (b->p1.x | b->p1.y |  b->p2.x | b->p2.y))

      return FALSE;

    }

    return TRUE;

}

static cairo_int_status_t

composite_aligned_boxes (const cairo_spans_compositor_t   *compositor,

       const cairo_composite_rectangles_t *extents,

       cairo_boxes_t        *boxes)

{

    cairo_surface_t *dst = extents->surface;

    cairo_operator_t op = extents->op;

    const cairo_pattern_t *source = &extents->source_pattern.base;

    cairo_int_status_t status;

    cairo_bool_t need_clip_mask = ! _clip_is_region (extents->clip);

    cairo_bool_t op_is_source;

    cairo_bool_t no_mask;

    cairo_bool_t inplace;

    TRACE ((stderr, "%s: need_clip_mask=%d, is-bounded=%d\n",

      __FUNCTION__, need_clip_mask, extents->is_bounded));

    if (need_clip_mask && ! extents->is_bounded) {

  TRACE ((stderr, "%s: unsupported clip\n", __FUNCTION__));

  return CAIRO_INT_STATUS_UNSUPPORTED;

    }

    no_mask = extents->mask_pattern.base.type == CAIRO_PATTERN_TYPE_SOLID &&

  CAIRO_COLOR_IS_OPAQUE (&extents->mask_pattern.solid.color);

    op_is_source = op_reduces_to_source (extents, no_mask);

    inplace = ! need_clip_mask && op_is_source && no_mask;

    TRACE ((stderr, "%s: op-is-source=%d [op=%d], no-mask=%d, inplace=%d\n",

      __FUNCTION__, op_is_source, op, no_mask, inplace));

    if (op == CAIRO_OPERATOR_SOURCE && (need_clip_mask || ! no_mask)) {

  /* SOURCE with a mask is actually a LERP in cairo semantics */

  if ((compositor->flags & CAIRO_SPANS_COMPOSITOR_HAS_LERP) == 0) {

      TRACE ((stderr, "%s: unsupported lerp\n", __FUNCTION__));

      return CAIRO_INT_STATUS_UNSUPPORTED;

  }

    }

    /* Are we just copying a recording surface? */

    if (inplace &&

  recording_pattern_contains_sample (&extents->source_pattern.base,

             &extents->source_sample_area))

    {

  cairo_clip_t *recording_clip;

  const cairo_pattern_t *source = &extents->source_pattern.base;

  const cairo_matrix_t *m;

  cairo_matrix_t matrix;

  /* XXX could also do tiling repeat modes... */

  /* first clear the area about to be overwritten */

  if (! dst->is_clear) {

      status = compositor->fill_boxes (dst,

               CAIRO_OPERATOR_CLEAR,

               CAIRO_COLOR_TRANSPARENT,

               boxes);

      if (unlikely (status))

    return status;

      dst->is_clear = TRUE;

  }

  m = &source->matrix;

  if (_cairo_surface_has_device_transform (dst)) {

      cairo_matrix_multiply (&matrix,

           &source->matrix,

           &dst->device_transform);

      m = &matrix;

  }

  recording_clip = _cairo_clip_from_boxes (boxes);

  status = _cairo_recording_surface_replay_with_clip (unwrap_source (source),

                  m, dst, recording_clip);

  _cairo_clip_destroy (recording_clip);

  return status;

    }

    status = CAIRO_INT_STATUS_UNSUPPORTED;

    if (! need_clip_mask && no_mask && source->type == CAIRO_PATTERN_TYPE_SOLID) {

  const cairo_color_t *color;

  color = &((cairo_solid_pattern_t *) source)->color;

  if (op_is_source)

      op = CAIRO_OPERATOR_SOURCE;

  status = compositor->fill_boxes (dst, op, color, boxes);

    } else if (inplace && source->type == CAIRO_PATTERN_TYPE_SURFACE) {

  status = upload_boxes (compositor, extents, boxes);

    }

    if (status == CAIRO_INT_STATUS_UNSUPPORTED) {

  cairo_surface_t *src;

  cairo_surface_t *mask = NULL;

  int src_x, src_y;

  int mask_x = 0, mask_y = 0;

  /* All typical cases will have been resolved before now... */

  if (need_clip_mask) {

      mask = get_clip_surface (compositor, dst, extents->clip,

             &extents->bounded);

      if (unlikely (mask->status))

    return mask->status;

      mask_x = -extents->bounded.x;

      mask_y = -extents->bounded.y;

  }

  /* XXX but this is still ugly */

  if (! no_mask) {

      src = compositor->pattern_to_surface (dst,

              &extents->mask_pattern.base,

              TRUE,

              &extents->bounded,

              &extents->mask_sample_area,

              &src_x, &src_y);

      if (unlikely (src->status)) {

    cairo_surface_destroy (mask);

    return src->status;

      }

      if (mask != NULL) {

    status = compositor->composite_boxes (mask, CAIRO_OPERATOR_IN,

                  src, NULL,

                  src_x, src_y,

                  0, 0,

                  mask_x, mask_y,

                  boxes, &extents->bounded);

    cairo_surface_destroy (src);

      } else {

    mask = src;

    mask_x = src_x;

    mask_y = src_y;

      }

  }

  src = compositor->pattern_to_surface (dst, source, FALSE,

                &extents->bounded,

                &extents->source_sample_area,

                &src_x, &src_y);

  if (likely (src->status == CAIRO_STATUS_SUCCESS)) {

      status = compositor->composite_boxes (dst, op, src, mask,

              src_x, src_y,

              mask_x, mask_y,

              0, 0,

              boxes, &extents->bounded);

      cairo_surface_destroy (src);

  } else

      status = src->status;

  cairo_surface_destroy (mask);

    }

    if (status == CAIRO_INT_STATUS_SUCCESS && ! extents->is_bounded)

  status = fixup_unbounded_boxes (compositor, extents, boxes);

    return status;

}

static cairo_bool_t

composite_needs_clip (const cairo_composite_rectangles_t *composite,

          const cairo_box_t *extents)

{

    return !_cairo_clip_contains_box (composite->clip, extents);

}

static cairo_int_status_t

composite_boxes (const cairo_spans_compositor_t *compositor,

     cairo_composite_rectangles_t *extents,

     cairo_boxes_t    *boxes)

{

    cairo_abstract_span_renderer_t renderer;

    cairo_rectangular_scan_converter_t converter;

    const struct _cairo_boxes_chunk *chunk;

    cairo_int_status_t status;

    cairo_box_t box;

    TRACE ((stderr, "%s\n", __FUNCTION__));

    _cairo_box_from_rectangle (&box, &extents->unbounded);

    if (composite_needs_clip (extents, &box)) {

  TRACE ((stderr, "%s: unsupported clip\n", __FUNCTION__));

  return CAIRO_INT_STATUS_UNSUPPORTED;

    }

    _cairo_rectangular_scan_converter_init (&converter, &extents->unbounded);

    for (chunk = &boxes->chunks; chunk != NULL; chunk = chunk->next) {

  const cairo_box_t *box = chunk->base;

  int i;

  for (i = 0; i < chunk->count; i++) {

      status = _cairo_rectangular_scan_converter_add_box (&converter, &box[i], 1);

      if (unlikely (status))

    goto cleanup_converter;

  }

    }

    status = compositor->renderer_init (&renderer, extents,

          CAIRO_ANTIALIAS_DEFAULT, FALSE);

    if (likely (status == CAIRO_INT_STATUS_SUCCESS))

  status = converter.base.generate (&converter.base, &renderer.base);

    compositor->renderer_fini (&renderer, status);

cleanup_converter:

    converter.base.destroy (&converter.base);

    return status;

}

static cairo_int_status_t

composite_polygon (const cairo_spans_compositor_t *compositor,

       cairo_composite_rectangles_t    *extents,

       cairo_polygon_t      *polygon,

       cairo_fill_rule_t       fill_rule,

       cairo_antialias_t       antialias)

{

    cairo_abstract_span_renderer_t renderer;

    cairo_scan_converter_t *converter;

    cairo_bool_t needs_clip;

    cairo_int_status_t status;

    if (extents->is_bounded)

  needs_clip = extents->clip->path != NULL;

    else

  needs_clip = !_clip_is_region (extents->clip) || extents->clip->num_boxes > 1;

    TRACE ((stderr, "%s - needs_clip=%d\n", __FUNCTION__, needs_clip));

    if (needs_clip) {

  TRACE ((stderr, "%s: unsupported clip\n", __FUNCTION__));

  return CAIRO_INT_STATUS_UNSUPPORTED;

  converter = _cairo_clip_tor_scan_converter_create (extents->clip,

                 polygon,

                 fill_rule, antialias);

    } else {

  const cairo_rectangle_int_t *r = &extents->unbounded;

  if (antialias == CAIRO_ANTIALIAS_FAST) {

      converter = _cairo_tor22_scan_converter_create (r->x, r->y,

                  r->x + r->width,

                  r->y + r->height,

                  fill_rule, antialias);

      status = _cairo_tor22_scan_converter_add_polygon (converter, polygon);

  } else if (antialias == CAIRO_ANTIALIAS_NONE) {

      converter = _cairo_mono_scan_converter_create (r->x, r->y,

                 r->x + r->width,

                 r->y + r->height,

                 fill_rule);

      status = _cairo_mono_scan_converter_add_polygon (converter, polygon);

  } else {

      converter = _cairo_tor_scan_converter_create (r->x, r->y,

                r->x + r->width,

                r->y + r->height,

                fill_rule, antialias);

      status = _cairo_tor_scan_converter_add_polygon (converter, polygon);

  }

    }

    if (unlikely (status))

  goto cleanup_converter;

    status = compositor->renderer_init (&renderer, extents,

          antialias, needs_clip);

    if (likely (status == CAIRO_INT_STATUS_SUCCESS))

  status = converter->generate (converter, &renderer.base);

    compositor->renderer_fini (&renderer, status);

cleanup_converter:

    converter->destroy (converter);

    return status;

}

static cairo_int_status_t

trim_extents_to_boxes (cairo_composite_rectangles_t *extents,

           cairo_boxes_t *boxes)

{

    cairo_box_t box;

    _cairo_boxes_extents (boxes, &box);

    return _cairo_composite_rectangles_intersect_mask_extents (extents, &box);

}

static cairo_int_status_t

trim_extents_to_polygon (cairo_composite_rectangles_t *extents,

       cairo_polygon_t *polygon)

{

    return _cairo_composite_rectangles_intersect_mask_extents (extents,

                     &polygon->extents);

}

static cairo_int_status_t

clip_and_composite_boxes (const cairo_spans_compositor_t  *compositor,

        cairo_composite_rectangles_t    *extents,

        cairo_boxes_t       *boxes)

{

    cairo_int_status_t status;

    cairo_polygon_t polygon;

    TRACE ((stderr, "%s\n", __FUNCTION__));

    status = trim_extents_to_boxes (extents, boxes);

    if (unlikely (status))

  return status;

    if (boxes->num_boxes == 0) {

  if (extents->is_bounded)

      return CAIRO_STATUS_SUCCESS;

  return fixup_unbounded_boxes (compositor, extents, boxes);

    }

    /* Can we reduce drawing through a clip-mask to simply drawing the clip? */

    if (extents->clip->path != NULL && extents->is_bounded) {

  cairo_polygon_t polygon;

  cairo_fill_rule_t fill_rule;

  cairo_antialias_t antialias;

  cairo_clip_t *clip;

  clip = _cairo_clip_copy (extents->clip);

  clip = _cairo_clip_intersect_boxes (clip, boxes);

  if (_cairo_clip_is_all_clipped (clip))

      return CAIRO_INT_STATUS_NOTHING_TO_DO;

  status = _cairo_clip_get_polygon (clip, &polygon,

            &fill_rule, &antialias);

  _cairo_clip_path_destroy (clip->path);

  clip->path = NULL;

  if (likely (status == CAIRO_INT_STATUS_SUCCESS)) {

      cairo_clip_t *saved_clip = extents->clip;

      extents->clip = clip;

      status = clip_and_composite_polygon (compositor, extents, &polygon,

             fill_rule, antialias);

      clip = extents->clip;

      extents->clip = saved_clip;

      _cairo_polygon_fini (&polygon);

  }

  _cairo_clip_destroy (clip);

  if (status != CAIRO_INT_STATUS_UNSUPPORTED)

      return status;

    }

    if (boxes->is_pixel_aligned) {

  status = composite_aligned_boxes (compositor, extents, boxes);

  if (status != CAIRO_INT_STATUS_UNSUPPORTED)

      return status;

    }

    status = composite_boxes (compositor, extents, boxes);

    if (status != CAIRO_INT_STATUS_UNSUPPORTED)

  return status;

    status = _cairo_polygon_init_boxes (&polygon, boxes);

    if (unlikely (status))

  return status;

    status = composite_polygon (compositor, extents, &polygon,

        CAIRO_FILL_RULE_WINDING,

        CAIRO_ANTIALIAS_DEFAULT);

    _cairo_polygon_fini (&polygon);

    return status;

}

static cairo_int_status_t

clip_and_composite_polygon (const cairo_spans_compositor_t  *compositor,

          cairo_composite_rectangles_t   *extents,

          cairo_polygon_t     *polygon,

          cairo_fill_rule_t      fill_rule,

          cairo_antialias_t      antialias)

{

    cairo_int_status_t status;

    TRACE ((stderr, "%s\n", __FUNCTION__));

    /* XXX simply uses polygon limits.point extemities, tessellation? */

    status = trim_extents_to_polygon (extents, polygon);

    if (unlikely (status))

  return status;

    if (_cairo_polygon_is_empty (polygon)) {

  cairo_boxes_t boxes;

  if (extents->is_bounded)

      return CAIRO_STATUS_SUCCESS;

  _cairo_boxes_init (&boxes);

  extents->bounded.width = extents->bounded.height = 0;

  return fixup_unbounded_boxes (compositor, extents, &boxes);

    }

    if (extents->is_bounded && extents->clip->path) {

  cairo_polygon_t clipper;

  cairo_antialias_t clip_antialias;

  cairo_fill_rule_t clip_fill_rule;

  TRACE((stderr, "%s - combining shape with clip polygon\n",

         __FUNCTION__));

  status = _cairo_clip_get_polygon (extents->clip,

            &clipper,

            &clip_fill_rule,

            &clip_antialias);

  if (likely (status == CAIRO_INT_STATUS_SUCCESS)) {

      cairo_clip_t *old_clip;

      if (clip_antialias == antialias) {

    status = _cairo_polygon_intersect (polygon, fill_rule,

               &clipper, clip_fill_rule);

    _cairo_polygon_fini (&clipper);

    if (unlikely (status))