Introduce a new compositor architecture

Having spent the last dev cycle looking at how we could specialize the
compositors for various backends, we once again look for the
commonalities in order to reduce the duplication. In part this is
motivated by the idea that spans is a good interface for both the
existent GL backend and pixman, and so they deserve a dedicated
compositor. xcb/xlib target an identical rendering system and so they
should be using the same compositor, and it should be possible to run
that same compositor locally against pixman to generate reference tests.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

P.S. This brings massive upheaval (read breakage) I've tried delaying in
order to fix as many things as possible but now this one patch does far,
far, far too much. Apologies in advance for breaking your favourite
backend, but trust me in that the end result will be much better. :)

1 files changed, 2032 insertions, 0 deletions

diff --git a/src/cairo-traps-compositor.c b/src/cairo-traps-compositor.c
new file mode 100644
index 000000000..92c8665a8
--- /dev/null
+++ b/src/cairo-traps-compositor.c
@@ -0,0 +1,2032 @@
+/* -*- 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-box-private.h"
+#include "cairo-boxes-private.h"
+#include "cairo-clip-private.h"
+#include "cairo-composite-rectangles-private.h"
+#include "cairo-compositor-private.h"
+#include "cairo-error-private.h"
+#include "cairo-image-surface-private.h"
+#include "cairo-pattern-private.h"
+#include "cairo-paginated-private.h"
+#include "cairo-recording-surface-private.h"
+#include "cairo-surface-subsurface-private.h"
+#include "cairo-surface-snapshot-private.h"
+#include "cairo-surface-observer-private.h"
+#include "cairo-region-private.h"
+#include "cairo-spans-private.h"
+#include "cairo-traps-private.h"
+#include "cairo-tristrip-private.h"
+
+typedef cairo_int_status_t
+(*draw_func_t) (const cairo_traps_compositor_t *compositor,
+		cairo_surface_t			*dst,
+		void				*closure,
+		cairo_operator_t		 op,
+		cairo_surface_t		*src,
+		int				 src_x,
+		int				 src_y,
+		int				 dst_x,
+		int				 dst_y,
+		const cairo_rectangle_int_t	*extents,
+		cairo_clip_t			*clip);
+
+static void do_unaligned_row(void (*blt)(void *closure,
+					 int16_t x, int16_t y,
+					 int16_t w, int16_t h,
+					 uint16_t coverage),
+			     void *closure,
+			     const cairo_box_t *b,
+			     int tx, int y, int h,
+			     uint16_t coverage)
+{
+    int x1 = _cairo_fixed_integer_part (b->p1.x) - tx;
+    int x2 = _cairo_fixed_integer_part (b->p2.x) - tx;
+    if (x2 > x1) {
+	if (! _cairo_fixed_is_integer (b->p1.x)) {
+	    blt(closure, x1, y, 1, h,
+		coverage * (256 - _cairo_fixed_fractional_part (b->p1.x)));
+	    x1++;
+	}
+
+	if (x2 > x1)
+	    blt(closure, x1, y, x2-x1, h, (coverage << 8) - (coverage >> 8));
+
+	if (! _cairo_fixed_is_integer (b->p2.x))
+	    blt(closure, x2, y, 1, h,
+		coverage * _cairo_fixed_fractional_part (b->p2.x));
+    } else
+	blt(closure, x1, y, 1, h,
+	    coverage * (b->p2.x - b->p1.x));
+}
+
+static void do_unaligned_box(void (*blt)(void *closure,
+					 int16_t x, int16_t y,
+					 int16_t w, int16_t h,
+					 uint16_t coverage),
+			     void *closure,
+			     const cairo_box_t *b, int tx, int ty)
+{
+    int y1 = _cairo_fixed_integer_part (b->p1.y) - ty;
+    int y2 = _cairo_fixed_integer_part (b->p2.y) - ty;
+    if (y2 > y1) {
+	if (! _cairo_fixed_is_integer (b->p1.y)) {
+	    do_unaligned_row(blt, closure, b, tx, y1, 1,
+			     256 - _cairo_fixed_fractional_part (b->p1.y));
+	    y1++;
+	}
+
+	if (y2 > y1)
+	    do_unaligned_row(blt, closure, b, tx, y1, y2-y1, 256);
+
+	if (! _cairo_fixed_is_integer (b->p2.y))
+	    do_unaligned_row(blt, closure, b, tx, y2, 1,
+			     _cairo_fixed_fractional_part (b->p2.y));
+    } else
+	do_unaligned_row(blt, closure, b, tx, y1, 1,
+			 b->p2.y - b->p1.y);
+}
+
+struct blt_in {
+    const cairo_traps_compositor_t *compositor;
+    cairo_surface_t *dst;
+    cairo_boxes_t boxes;
+};
+
+static void blt_in(void *closure,
+		   int16_t x, int16_t y,
+		   int16_t w, int16_t h,
+		   uint16_t coverage)
+{
+    struct blt_in *info = closure;
+    cairo_color_t color;
+
+    if (CAIRO_ALPHA_SHORT_IS_OPAQUE (coverage))
+	return;
+
+    _cairo_box_from_integers (&info->boxes.chunks.base[0], x, y, w, h);
+
+    _cairo_color_init_rgba (&color, 0, 0, 0, coverage / (double) 0xffff);
+    info->compositor->fill_boxes (info->dst,
+				  CAIRO_OPERATOR_IN, &color,
+				  &info->boxes);
+}
+
+static cairo_int_status_t
+combine_clip_as_traps (const cairo_traps_compositor_t *compositor,
+		       cairo_surface_t *mask,
+		       const cairo_clip_t *clip,
+		       const cairo_rectangle_int_t *extents)
+{
+    cairo_polygon_t polygon;
+    cairo_fill_rule_t fill_rule;
+    cairo_antialias_t antialias;
+    cairo_traps_t traps;
+    cairo_surface_t *src;
+    int src_x, src_y;
+    cairo_int_status_t status;
+
+    status = _cairo_clip_get_polygon (clip, &polygon,
+				      &fill_rule, &antialias);
+    if (status)
+	return status;
+
+    _cairo_traps_init (&traps);
+    status = _cairo_bentley_ottmann_tessellate_polygon (&traps,
+							&polygon,
+							fill_rule);
+    _cairo_polygon_fini (&polygon);
+    if (unlikely (status))
+	return status;
+
+    src = compositor->pattern_to_surface (mask, NULL, FALSE,
+					  extents, NULL,
+					  &src_x, &src_y);
+    if (unlikely (src->status)) {
+	_cairo_traps_fini (&traps);
+	return src->status;
+    }
+
+    status = compositor->composite_traps (mask, CAIRO_OPERATOR_IN, src,
+					  src_x, src_y,
+					  extents->x, extents->y,
+					  extents,
+					  antialias, &traps);
+
+    cairo_surface_destroy (src);
+    _cairo_traps_fini (&traps);
+
+    return status;
+}
+
+static cairo_surface_t *
+traps_get_clip_surface (const cairo_traps_compositor_t *compositor,
+			cairo_surface_t *target,
+			const cairo_clip_t *clip,
+			const cairo_rectangle_int_t *extents)
+{
+    cairo_surface_t *surface;
+    cairo_int_status_t status;
+
+    surface = _cairo_surface_create_similar_solid (target,
+						   CAIRO_CONTENT_ALPHA,
+						   extents->width,
+						   extents->height,
+						   CAIRO_COLOR_WHITE);
+    if (unlikely (surface->status))
+	return surface;
+
+    status = compositor->acquire (surface);
+    if (unlikely (status)) {
+	cairo_surface_destroy (surface);
+	return _cairo_surface_create_in_error (status);
+    }
+
+    status = combine_clip_as_traps (compositor, surface, clip, extents);
+    if (status == CAIRO_INT_STATUS_UNSUPPORTED) {
+	status = _cairo_clip_combine_with_surface (clip, surface,
+						   extents->x, extents->y);
+    }
+    compositor->release (surface);
+
+    return surface;
+}
+
+static cairo_surface_t *
+create_composite_mask (const cairo_traps_compositor_t *compositor,
+		       cairo_surface_t		*dst,
+		       void			*draw_closure,
+		       draw_func_t		 draw_func,
+		       draw_func_t		 mask_func,
+		       const cairo_composite_rectangles_t *extents)
+{
+    cairo_surface_t *surface, *src;
+    cairo_int_status_t status;
+    struct blt_in info;
+    int src_x, src_y;
+    int i;
+
+    surface = _cairo_surface_create_similar_solid (dst,
+						   CAIRO_CONTENT_ALPHA,
+						   extents->bounded.width,
+						   extents->bounded.height,
+						   CAIRO_COLOR_TRANSPARENT);
+    if (unlikely (surface->status))
+	return surface;
+
+    src = compositor->pattern_to_surface (surface,
+					  &_cairo_pattern_white.base,
+					  FALSE,
+					  &extents->bounded,
+					  &extents->bounded,
+					  &src_x, &src_y);
+    if (unlikely (src->status))
+	return src;
+
+    status = compositor->acquire (surface);
+    if (unlikely (status)) {
+	cairo_surface_destroy (src);
+	cairo_surface_destroy (surface);
+	return _cairo_surface_create_in_error (status);
+    }
+
+    if (mask_func) {
+	status = mask_func (compositor, surface, draw_closure,
+			    CAIRO_OPERATOR_SOURCE, src, src_x, src_y,
+			    extents->bounded.x, extents->bounded.y,
+			    &extents->bounded, extents->clip);
+	if (likely (status != CAIRO_INT_STATUS_UNSUPPORTED)) {
+	    cairo_surface_destroy (src);
+	    goto out;
+	}
+    }
+
+    /* Is it worth setting the clip region here? */
+    status = draw_func (compositor, surface, draw_closure,
+			CAIRO_OPERATOR_ADD, src, src_x, src_y,
+			extents->bounded.x, extents->bounded.y,
+			&extents->bounded, NULL);
+    cairo_surface_destroy (src);
+    if (unlikely (status))
+	goto error;
+
+    info.compositor = compositor;
+    info.dst = surface;
+    _cairo_boxes_init (&info.boxes);
+    info.boxes.num_boxes = 1;
+    for (i = 0; i < extents->clip->num_boxes; i++) {
+	cairo_box_t *b = &extents->clip->boxes[i];
+
+	if (! _cairo_fixed_is_integer (b->p1.x) ||
+	    ! _cairo_fixed_is_integer (b->p1.y) ||
+	    ! _cairo_fixed_is_integer (b->p2.x) ||
+	    ! _cairo_fixed_is_integer (b->p2.y))
+	{
+	    do_unaligned_box(blt_in, &info, b,
+			     extents->bounded.x,
+			     extents->bounded.y);
+	}
+    }
+
+    if (extents->clip->path != NULL) {
+	status = combine_clip_as_traps (compositor, surface,
+					extents->clip, &extents->bounded);
+	if (status == CAIRO_INT_STATUS_UNSUPPORTED) {
+	    status = _cairo_clip_combine_with_surface (extents->clip, surface,
+						       extents->bounded.x,
+						       extents->bounded.y);
+	}
+	if (unlikely (status))
+	    goto error;
+    }
+
+out:
+    compositor->release (surface);
+    surface->is_clear = FALSE;
+    return surface;
+
+error:
+    cairo_surface_destroy (surface);
+    surface = _cairo_surface_create_in_error (status);
+    compositor->release (surface);
+    return surface;
+}
+
+/* Handles compositing with a clip surface when the operator allows
+ * us to combine the clip with the mask
+ */
+static cairo_status_t
+clip_and_composite_with_mask (const cairo_traps_compositor_t *compositor,
+			      const cairo_composite_rectangles_t*extents,
+			      draw_func_t		 draw_func,
+			      draw_func_t		 mask_func,
+			      void			*draw_closure,
+			      cairo_operator_t		 op,
+			      cairo_surface_t	*src,
+			      int src_x, int src_y)
+{
+    cairo_surface_t *dst = extents->surface;
+    cairo_surface_t *mask;
+
+    mask = create_composite_mask (compositor, dst, draw_closure,
+				  draw_func, mask_func,
+				  extents);
+    if (unlikely (mask->status))
+	return mask->status;
+
+    if (src != NULL || dst->content != CAIRO_CONTENT_ALPHA) {
+	compositor->composite (dst, op, src, mask,
+			       extents->bounded.x + src_x,
+			       extents->bounded.y + src_y,
+			       0, 0,
+			       extents->bounded.x,      extents->bounded.y,
+			       extents->bounded.width,  extents->bounded.height);
+    } else {
+	compositor->composite (dst, op, mask, NULL,
+			       0, 0,
+			       0, 0,
+			       extents->bounded.x,      extents->bounded.y,
+			       extents->bounded.width,  extents->bounded.height);
+    }
+    cairo_surface_destroy (mask);
+
+    return CAIRO_STATUS_SUCCESS;
+}
+
+/* Handles compositing with a clip surface when we have to do the operation
+ * in two pieces and combine them together.
+ */
+static cairo_status_t
+clip_and_composite_combine (const cairo_traps_compositor_t *compositor,
+			    const cairo_composite_rectangles_t*extents,
+			    draw_func_t		 draw_func,
+			    void			*draw_closure,
+			    cairo_operator_t		 op,
+			    cairo_surface_t	*src,
+			    int src_x, int src_y)
+{
+    cairo_surface_t *dst = extents->surface;
+    cairo_surface_t *tmp, *clip;
+    cairo_status_t status;
+
+    tmp = _cairo_surface_create_similar_scratch (dst, dst->content,
+						 extents->bounded.width,
+						 extents->bounded.height);
+    if (unlikely (tmp->status))
+	return tmp->status;
+
+    status = compositor->acquire (tmp);
+    if (unlikely (status)) {
+	cairo_surface_destroy (tmp);
+	return status;
+    }
+
+    compositor->composite (tmp,
+			   dst->is_clear ? CAIRO_OPERATOR_CLEAR : CAIRO_OPERATOR_SOURCE,
+			   dst, NULL,
+			   extents->bounded.x,      extents->bounded.y,
+			   0, 0,
+			   0, 0,
+			   extents->bounded.width,  extents->bounded.height);
+
+    status = draw_func (compositor, tmp, draw_closure, op,
+			src, src_x, src_y,
+			extents->bounded.x, extents->bounded.y,
+			&extents->bounded, NULL);
+
+    if (unlikely (status))
+	goto cleanup;
+
+    clip = traps_get_clip_surface (compositor, dst, extents->clip,
+				   &extents->bounded);
+    if (unlikely ((status = clip->status)))
+	goto cleanup;
+
+    if (dst->is_clear) {
+	compositor->composite (dst, CAIRO_OPERATOR_SOURCE, tmp, clip,
+			       0, 0,
+			       0, 0,
+			       extents->bounded.x,      extents->bounded.y,
+			       extents->bounded.width,  extents->bounded.height);
+    } else {
+	compositor->lerp (dst, tmp, clip,
+			  0, 0,
+			  0,0,
+			  extents->bounded.x,     extents->bounded.y,
+			  extents->bounded.width, extents->bounded.height);
+    }
+    cairo_surface_destroy (clip);
+
+cleanup:
+    compositor->release (tmp);
+    cairo_surface_destroy (tmp);
+
+    return status;
+}
+
+/* Handles compositing for %CAIRO_OPERATOR_SOURCE, which is special; it's
+ * defined as (src IN mask IN clip) ADD (dst OUT (mask IN clip))
+ */
+static cairo_status_t
+clip_and_composite_source (const cairo_traps_compositor_t	*compositor,
+			   cairo_surface_t			*dst,
+			   draw_func_t				 draw_func,
+			   draw_func_t				 mask_func,
+			   void					*draw_closure,
+			   cairo_surface_t		*src,
+			   int src_x,
+			   int src_y,
+			   const cairo_composite_rectangles_t	*extents)
+{
+    cairo_surface_t *mask;
+
+    /* Create a surface that is mask IN clip */
+    mask = create_composite_mask (compositor, dst, draw_closure,
+				  draw_func, mask_func,
+				  extents);
+    if (unlikely (mask->status))
+	return mask->status;
+
+    if (dst->is_clear) {
+	compositor->composite (dst, CAIRO_OPERATOR_SOURCE, src, mask,
+			       extents->bounded.x + src_x, extents->bounded.y + src_y,
+			       0, 0,
+			       extents->bounded.x,      extents->bounded.y,
+			       extents->bounded.width,  extents->bounded.height);
+    } else {
+	compositor->lerp (dst, src, mask,
+			  extents->bounded.x + src_x, extents->bounded.y + src_y,
+			  0, 0,
+			  extents->bounded.x,     extents->bounded.y,
+			  extents->bounded.width, extents->bounded.height);
+    }
+
+    cairo_surface_destroy (mask);
+
+    return CAIRO_STATUS_SUCCESS;
+}
+
+static cairo_bool_t
+can_reduce_alpha_op (cairo_operator_t op)
+{
+    int iop = op;
+    switch (iop) {
+    case CAIRO_OPERATOR_OVER:
+    case CAIRO_OPERATOR_SOURCE:
+    case CAIRO_OPERATOR_ADD:
+	return TRUE;
+    default:
+	return FALSE;
+    }
+}
+
+static cairo_bool_t
+reduce_alpha_op (cairo_composite_rectangles_t *extents)
+{
+    cairo_surface_t *dst = extents->surface;
+    cairo_operator_t op = extents->op;
+    const cairo_pattern_t *pattern = &extents->source_pattern.base;
+    return dst->is_clear &&
+	   dst->content == CAIRO_CONTENT_ALPHA &&
+	   _cairo_pattern_is_opaque_solid (pattern) &&
+	   can_reduce_alpha_op (op);
+}
+
+static cairo_status_t
+fixup_unbounded_with_mask (const cairo_traps_compositor_t *compositor,
+			   const cairo_composite_rectangles_t *extents)
+{
+    cairo_surface_t *dst = extents->surface;
+    cairo_clip_t *clip = extents->clip;
+    cairo_surface_t *mask;
+
+    /* XXX can we avoid querying the clip surface again? */
+    mask = traps_get_clip_surface (compositor, dst, clip, &extents->unbounded);
+    if (unlikely (mask->status))
+	return mask->status;
+
+    /* top */
+    if (extents->bounded.y != extents->unbounded.y) {
+	int x = extents->unbounded.x;
+	int y = extents->unbounded.y;
+	int width = extents->unbounded.width;
+	int height = extents->bounded.y - y;
+
+	compositor->composite (dst, CAIRO_OPERATOR_DEST_OUT, mask, NULL,
+			       0, 0,
+			       0, 0,
+			       x, y,
+			       width, height);
+    }
+
+    /* left */
+    if (extents->bounded.x != extents->unbounded.x) {
+	int x = extents->unbounded.x;
+	int y = extents->bounded.y;
+	int width = extents->bounded.x - x;
+	int height = extents->bounded.height;
+
+	compositor->composite (dst, CAIRO_OPERATOR_DEST_OUT, mask, NULL,
+			       0, y - extents->unbounded.y,
+			       0, 0,
+			       x, y,
+			       width, height);
+    }
+
+    /* right */
+    if (extents->bounded.x + extents->bounded.width != extents->unbounded.x + extents->unbounded.width) {
+	int x = extents->bounded.x + extents->bounded.width;
+	int y = extents->bounded.y;
+	int width = extents->unbounded.x + extents->unbounded.width - x;
+	int height = extents->bounded.height;
+
+	compositor->composite (dst, CAIRO_OPERATOR_DEST_OUT, mask, NULL,
+			       x - extents->unbounded.x, y - extents->unbounded.y,
+			       0, 0,
+			       x, y,
+			       width, height);
+    }
+
+    /* bottom */
+    if (extents->bounded.y + extents->bounded.height != extents->unbounded.y + extents->unbounded.height) {
+	int x = extents->unbounded.x;
+	int y = extents->bounded.y + extents->bounded.height;
+	int width = extents->unbounded.width;
+	int height = extents->unbounded.y + extents->unbounded.height - y;
+
+	compositor->composite (dst, CAIRO_OPERATOR_DEST_OUT, mask, NULL,
+			       0, y - extents->unbounded.y,
+			       0, 0,
+			       x, y,
+			       width, height);
+    }
+
+    cairo_surface_destroy (mask);
+
+    return CAIRO_STATUS_SUCCESS;
+}
+
+static void
+add_rect (cairo_boxes_t *boxes, int x1, int y1, int x2, int y2)
+{
+    cairo_box_t box;
+    cairo_int_status_t status;
+
+    box.p1.x = _cairo_fixed_from_int (x1);
+    box.p1.y = _cairo_fixed_from_int (y1);
+    box.p2.x = _cairo_fixed_from_int (x2);
+    box.p2.y = _cairo_fixed_from_int (y2);
+
+    status = _cairo_boxes_add (boxes, CAIRO_ANTIALIAS_DEFAULT, &box);
+    assert (status == CAIRO_INT_STATUS_SUCCESS);
+}
+
+static cairo_status_t
+fixup_unbounded (const cairo_traps_compositor_t *compositor,
+		 cairo_composite_rectangles_t *extents,
+		 cairo_boxes_t *boxes)
+{
+    cairo_surface_t *dst = extents->surface;
+    cairo_boxes_t clear, tmp;
+    cairo_box_t box;
+    cairo_int_status_t status;
+
+    if (extents->bounded.width  == extents->unbounded.width &&
+	extents->bounded.height == extents->unbounded.height)
+    {
+	return CAIRO_STATUS_SUCCESS;
+    }
+
+    assert (extents->clip->path == NULL);
+
+    /* 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 == NULL) {
+	if (extents->bounded.width == 0 || extents->bounded.height == 0) {
+	    goto empty;
+	} else {
+	    /* top */
+	    if (extents->bounded.y != extents->unbounded.y) {
+		add_rect (&clear,
+			  extents->unbounded.x, extents->unbounded.y,
+			  extents->unbounded.x + extents->unbounded.width,
+			  extents->bounded.y);
+	    }
+	    /* left */
+	    if (extents->bounded.x != extents->unbounded.x) {
+		add_rect (&clear,
+			  extents->unbounded.x, extents->bounded.y,
+			  extents->bounded.x,
+			  extents->bounded.y + extents->bounded.height);
+	    }
+	    /* right */
+	    if (extents->bounded.x + extents->bounded.width != extents->unbounded.x + extents->unbounded.width) {
+		add_rect (&clear,
+			  extents->bounded.x + extents->bounded.width,
+			  extents->bounded.y,
+			  extents->unbounded.x + extents->unbounded.width,
+			  extents->bounded.y + extents->bounded.height);
+	    }
+	    /* bottom */
+	    if (extents->bounded.y + extents->bounded.height != extents->unbounded.y + extents->unbounded.height) {
+		add_rect (&clear,
+			  extents->unbounded.x,
+			  extents->bounded.y + extents->bounded.height,
+			  extents->unbounded.x + extents->unbounded.width,
+			  extents->unbounded.y + extents->unbounded.height);
+	    }
+	}
+    } else if (boxes->num_boxes) {
+	_cairo_boxes_init (&tmp);
+
+	assert (boxes->is_pixel_aligned);
+
+	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 {
+empty:
+	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);
+    }
+
+    /* Now 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;
+    }
+
+    status = compositor->fill_boxes (dst,
+				     CAIRO_OPERATOR_CLEAR,
+				     CAIRO_COLOR_TRANSPARENT,
+				     &clear);
+
+error:
+    _cairo_boxes_fini (&clear);
+    return status;
+}
+
+enum {
+    NEED_CLIP_REGION = 0x1,
+    NEED_CLIP_SURFACE = 0x2,
+    FORCE_CLIP_REGION = 0x4,
+};
+
+static cairo_bool_t
+need_bounded_clip (cairo_composite_rectangles_t *extents)
+{
+    unsigned int flags = 0;
+
+    if (extents->unbounded.width < extents->destination.width ||
+	extents->unbounded.height < extents->destination.height)
+    {
+	flags |= NEED_CLIP_REGION;
+    }
+
+    if (! _cairo_clip_is_region (extents->clip))
+	flags |= NEED_CLIP_SURFACE;
+
+    return flags;
+}
+
+static cairo_bool_t
+need_unbounded_clip (cairo_composite_rectangles_t *extents)
+{
+    unsigned int flags = 0;
+    if (! extents->is_bounded) {
+	flags |= NEED_CLIP_REGION;
+	if (! _cairo_clip_is_region (extents->clip))
+	    flags |= NEED_CLIP_SURFACE;
+    }
+    if (extents->clip->path != NULL)
+	flags |= NEED_CLIP_SURFACE;
+    return flags;
+}
+
+static cairo_status_t
+clip_and_composite (const cairo_traps_compositor_t *compositor,
+		    cairo_composite_rectangles_t *extents,
+		    draw_func_t		 draw_func,
+		    draw_func_t		 mask_func,
+		    void		*draw_closure,
+		    unsigned int need_clip)
+{
+    cairo_surface_t *dst = extents->surface;
+    cairo_operator_t op = extents->op;
+    cairo_pattern_t *source = &extents->source_pattern.base;
+    cairo_surface_t *src;
+    int src_x, src_y;
+    cairo_region_t *clip_region = NULL;
+    cairo_status_t status;
+
+    if (reduce_alpha_op (extents)) {
+	op = CAIRO_OPERATOR_ADD;
+	source = NULL;
+    }
+
+    if (op == CAIRO_OPERATOR_CLEAR) {
+	op = CAIRO_OPERATOR_DEST_OUT;
+	source = NULL;
+    }
+
+    src = compositor->pattern_to_surface (dst, source, FALSE,
+					  &extents->bounded,
+					  &extents->source_sample_area,
+					  &src_x, &src_y);
+    if (unlikely (src->status))
+	return src->status;
+
+    compositor->acquire (dst);
+
+    if (need_clip & NEED_CLIP_REGION) {
+	const cairo_rectangle_int_t *limit;
+
+	if ((need_clip & FORCE_CLIP_REGION) == 0)
+	    limit = &extents->unbounded;
+	else
+	    limit = &extents->destination;
+
+	clip_region = _cairo_clip_get_region (extents->clip);
+	if (clip_region != NULL &&
+	    cairo_region_contains_rectangle (clip_region,
+					     limit) == CAIRO_REGION_OVERLAP_IN)
+	    clip_region = NULL;
+
+	if (clip_region != NULL) {
+	    status = compositor->set_clip_region (dst, clip_region);
+	    if (unlikely (status)) {
+		compositor->release (dst);
+		return status;
+	    }
+	}
+    }
+
+    if (op == CAIRO_OPERATOR_SOURCE) {
+	status = clip_and_composite_source (compositor, dst,
+					    draw_func, mask_func, draw_closure,
+					    src, src_x, src_y,
+					    extents);
+    } else {
+	if (need_clip & NEED_CLIP_SURFACE) {
+	    if (extents->is_bounded) {
+		status = clip_and_composite_with_mask (compositor, extents,
+						       draw_func, mask_func,
+						       draw_closure,
+						       op, src, src_x, src_y);
+	    } else {
+		status = clip_and_composite_combine (compositor, extents,
+						     draw_func, draw_closure,
+						     op, src, src_x, src_y);
+	    }
+	} else {
+	    status = draw_func (compositor,
+				dst, draw_closure,
+				op, src, src_x, src_y,
+				0, 0,
+				&extents->bounded,
+				extents->clip);
+	}
+    }
+
+    if (status == CAIRO_STATUS_SUCCESS && ! extents->is_bounded) {
+	if (need_clip & NEED_CLIP_SURFACE)
+	    status = fixup_unbounded_with_mask (compositor, extents);
+	else
+	    status = fixup_unbounded (compositor, extents, NULL);
+    }
+
+    if (clip_region)
+	compositor->set_clip_region (dst, NULL);
+
+    cairo_surface_destroy (src);
+    compositor->release (dst);
+
+    return status;
+}
+
+/* meta-ops */
+
+typedef struct {
+    cairo_traps_t traps;
+    cairo_antialias_t antialias;
+} composite_traps_info_t;
+
+static cairo_int_status_t
+composite_traps (const cairo_traps_compositor_t *compositor,
+		 cairo_surface_t		*dst,
+		 void				 *closure,
+		 cairo_operator_t		 op,
+		 cairo_surface_t		*src,
+		 int src_x, int src_y,
+		 int dst_x, int dst_y,
+		 const cairo_rectangle_int_t *extents,
+		 cairo_clip_t			*clip)
+{
+    composite_traps_info_t *info = closure;
+
+    return compositor->composite_traps (dst, op, src,
+					src_x - dst_x, src_y - dst_y,
+					dst_x, dst_y,
+					extents,
+					info->antialias, &info->traps);
+}
+
+typedef struct {
+    cairo_tristrip_t strip;
+    cairo_antialias_t antialias;
+} composite_tristrip_info_t;
+
+static cairo_int_status_t
+composite_tristrip (const cairo_traps_compositor_t *compositor,
+		    cairo_surface_t		*dst,
+		    void				 *closure,
+		    cairo_operator_t		 op,
+		    cairo_surface_t		*src,
+		    int src_x, int src_y,
+		    int dst_x, int dst_y,
+		    const cairo_rectangle_int_t *extents,
+		    cairo_clip_t			*clip)
+{
+    composite_tristrip_info_t *info = closure;
+
+    return compositor->composite_tristrip (dst, op, src,
+					   src_x - dst_x, src_y - dst_y,
+					   dst_x, dst_y,
+					   extents,
+					   info->antialias, &info->strip);
+}
+
+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;
+    if (_cairo_surface_is_paginated (surface))
+	surface = _cairo_paginated_surface_get_recording (surface);
+    if (_cairo_surface_is_snapshot (surface))
+	surface = _cairo_surface_snapshot_get_target (surface);
+    return _cairo_surface_is_recording (surface);
+}
+
+static cairo_surface_t *
+recording_pattern_get_surface (const cairo_pattern_t *pattern)
+{
+    cairo_surface_t *surface;
+
+    surface = ((const cairo_surface_pattern_t *) pattern)->surface;
+    if (_cairo_surface_is_paginated (surface))
+	surface = _cairo_paginated_surface_get_recording (surface);
+    if (_cairo_surface_is_snapshot (surface))
+	surface = _cairo_surface_snapshot_get_target (surface);
+    return 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 *) recording_pattern_get_surface (pattern);
+    if (surface->unbounded)
+	return TRUE;
+
+    if (sample->x >= surface->extents.x &&
+	sample->y >= surface->extents.y &&
+	sample->x + sample->width <= surface->extents.x + surface->extents.width &&
+	sample->y + sample->height <= surface->extents.y + surface->extents.height)
+    {
+	return TRUE;
+    }
+
+    return FALSE;
+}
+
+static cairo_bool_t
+op_reduces_to_source (cairo_composite_rectangles_t *extents)
+{
+    if (extents->op == CAIRO_OPERATOR_SOURCE)
+	return TRUE;
+
+    if (extents->surface->is_clear)
+	return extents->op == CAIRO_OPERATOR_OVER || extents->op == CAIRO_OPERATOR_ADD;
+
+    return FALSE;
+}
+
+static cairo_status_t
+composite_aligned_boxes (const cairo_traps_compositor_t *compositor,
+			 cairo_composite_rectangles_t *extents,
+			 cairo_boxes_t *boxes)
+{
+    cairo_surface_t *dst = extents->surface;
+    cairo_operator_t op = extents->op;
+    cairo_bool_t need_clip_mask = extents->clip->path != NULL;
+    cairo_bool_t op_is_source;
+    cairo_status_t status;
+
+    if (need_clip_mask &&
+	(! extents->is_bounded || extents->op == CAIRO_OPERATOR_SOURCE))
+    {
+	return CAIRO_INT_STATUS_UNSUPPORTED;
+    }
+
+    op_is_source = op_reduces_to_source (extents);
+
+    /* Are we just copying a recording surface? */
+    if (! need_clip_mask && op_is_source &&
+	recording_pattern_contains_sample (&extents->source_pattern.base,
+					   &extents->source_sample_area))
+    {
+	cairo_clip_t *recording_clip;
+	cairo_pattern_t *source = &extents->source_pattern.base;
+
+	/* XXX could also do tiling repeat modes... */
+
+	/* first clear the area about to be overwritten */
+	if (! dst->is_clear) {
+	    status = compositor->acquire (dst);
+	    if (unlikely (status))
+		return status;
+
+	    status = compositor->fill_boxes (dst,
+					     CAIRO_OPERATOR_CLEAR,
+					     CAIRO_COLOR_TRANSPARENT,
+					     boxes);
+	    compositor->release (dst);
+	    if (unlikely (status))
+		return status;
+	}
+
+	recording_clip = _cairo_clip_from_boxes (boxes);
+	status = _cairo_recording_surface_replay_with_clip (recording_pattern_get_surface (source),
+							    &source->matrix,
+							    dst, recording_clip);
+	_cairo_clip_destroy (recording_clip);
+
+	return status;
+    }
+
+    status = compositor->acquire (dst);
+    if (unlikely (status))
+	return status;
+
+    if (! need_clip_mask &&
+	(op == CAIRO_OPERATOR_CLEAR ||
+	 extents->source_pattern.base.type == CAIRO_PATTERN_TYPE_SOLID))
+    {
+	const cairo_color_t *color;
+
+	if (op == CAIRO_OPERATOR_CLEAR) {
+	    color = CAIRO_COLOR_TRANSPARENT;
+	} else {
+	    color = &((cairo_solid_pattern_t *) &extents->source_pattern)->color;
+	    if (op_is_source)
+		op = CAIRO_OPERATOR_SOURCE;
+	}
+
+	status = compositor->fill_boxes (dst, op, color, boxes);
+    }
+    else
+    {
+	cairo_surface_t *src, *mask = NULL;
+	cairo_pattern_t *source = &extents->source_pattern.base;
+	int src_x, src_y;
+	int mask_x = 0, mask_y = 0;
+
+	if (need_clip_mask) {
+	    mask = _cairo_clip_get_surface (extents->clip, dst,
+					    &mask_x, &mask_y);
+	    if (unlikely (mask->status))
+		return mask->status;
+
+	    mask_x = -mask_x;
+	    mask_y = -mask_y;
+
+	    if (op == CAIRO_OPERATOR_CLEAR) {
+		source = NULL;
+		op = CAIRO_OPERATOR_DEST_OUT;
+	    }
+	} else if (op_is_source)
+	    op = CAIRO_OPERATOR_SOURCE;
+
+	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_STATUS_SUCCESS && ! extents->is_bounded)
+	status = fixup_unbounded (compositor, extents, boxes);
+
+    compositor->release (dst);
+
+    return status;
+}
+
+static cairo_status_t
+upload_boxes (const cairo_traps_compositor_t *compositor,
+	      cairo_composite_rectangles_t *extents,
+	      cairo_boxes_t *boxes)
+{
+    cairo_surface_t *dst = extents->surface;
+    const cairo_pattern_t *source = &extents->source_pattern.base;
+    const cairo_surface_pattern_t *pattern;
+    cairo_surface_t *src;
+    cairo_rectangle_int_t limit;
+    cairo_int_status_t status;
+    int tx, ty;
+
+    pattern = (const cairo_surface_pattern_t *) source;
+    src = pattern->surface;
+    if (!(src->type == CAIRO_SURFACE_TYPE_IMAGE || src->type == dst->type))
+	return CAIRO_INT_STATUS_UNSUPPORTED;
+
+    if (! _cairo_matrix_is_integer_translation (&source->matrix, &tx, &ty))
+	return CAIRO_INT_STATUS_UNSUPPORTED;
+
+    if (_cairo_surface_is_snapshot (src))
+	src = _cairo_surface_snapshot_get_target (src);
+    if (_cairo_surface_is_observer (src))
+	src = _cairo_surface_observer_get_target (src);
+    if (_cairo_surface_is_subsurface (src)) {
+	_cairo_surface_subsurface_offset (src, &tx, &ty);
+	src = _cairo_surface_subsurface_get_target (src);
+    }
+
+    /* Check that the data is entirely within the image */
+    if (extents->bounded.x + tx < 0 || extents->bounded.y + ty < 0)
+	return CAIRO_INT_STATUS_UNSUPPORTED;
+
+    _cairo_surface_get_extents (pattern->surface, &limit);
+    if (extents->bounded.x + extents->bounded.width  + tx > limit.width ||
+	extents->bounded.y + extents->bounded.height + ty > limit.height)
+	return CAIRO_INT_STATUS_UNSUPPORTED;
+
+    if (pattern->surface->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_int_status_t
+trim_extents_to_traps (cairo_composite_rectangles_t *extents,
+		       cairo_traps_t *traps)
+{
+    cairo_box_t box;
+
+    _cairo_traps_extents (traps, &box);
+    return _cairo_composite_rectangles_intersect_mask_extents (extents, &box);
+}
+
+static cairo_int_status_t
+trim_extents_to_tristrip (cairo_composite_rectangles_t *extents,
+			  cairo_tristrip_t *strip)
+{
+    cairo_box_t box;
+
+    _cairo_tristrip_extents (strip, &box);
+    return _cairo_composite_rectangles_intersect_mask_extents (extents, &box);
+}
+
+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
+boxes_for_traps (cairo_boxes_t *boxes,
+		 cairo_traps_t *traps,
+		 cairo_antialias_t antialias)
+{
+    int i;
+
+    /* first check that the traps are rectilinear */
+    if (antialias == CAIRO_ANTIALIAS_NONE) {
+	for (i = 0; i < traps->num_traps; i++) {
+	    const cairo_trapezoid_t *t = &traps->traps[i];
+	    if (_cairo_fixed_integer_round_down (t->left.p1.x) !=
+		_cairo_fixed_integer_round_down (t->left.p2.x) ||
+		_cairo_fixed_integer_round_down (t->right.p1.x) !=
+		_cairo_fixed_integer_round_down (t->right.p2.x))
+	    {
+		return CAIRO_INT_STATUS_UNSUPPORTED;
+	    }
+	}
+    } else {
+	for (i = 0; i < traps->num_traps; i++) {
+	    const cairo_trapezoid_t *t = &traps->traps[i];
+	    if (t->left.p1.x != t->left.p2.x || t->right.p1.x != t->right.p2.x)
+		return CAIRO_INT_STATUS_UNSUPPORTED;
+	}
+    }
+
+    _cairo_boxes_init (boxes);
+
+    boxes->num_boxes    = traps->num_traps;
+    boxes->chunks.base  = (cairo_box_t *) traps->traps;
+    boxes->chunks.count = traps->num_traps;
+    boxes->chunks.size  = traps->num_traps;
+
+    if (antialias != CAIRO_ANTIALIAS_NONE) {
+	for (i = 0; i < traps->num_traps; i++) {
+	    /* Note the traps and boxes alias so we need to take the local copies first. */
+	    cairo_fixed_t x1 = traps->traps[i].left.p1.x;
+	    cairo_fixed_t x2 = traps->traps[i].right.p1.x;
+	    cairo_fixed_t y1 = traps->traps[i].top;
+	    cairo_fixed_t y2 = traps->traps[i].bottom;
+
+	    boxes->chunks.base[i].p1.x = x1;
+	    boxes->chunks.base[i].p1.y = y1;
+	    boxes->chunks.base[i].p2.x = x2;
+	    boxes->chunks.base[i].p2.y = y2;
+
+	    if (boxes->is_pixel_aligned) {
+		boxes->is_pixel_aligned =
+		    _cairo_fixed_is_integer (x1) && _cairo_fixed_is_integer (y1) &&
+		    _cairo_fixed_is_integer (x2) && _cairo_fixed_is_integer (y2);
+	    }
+	}
+    } else {
+	boxes->is_pixel_aligned = TRUE;
+
+	for (i = 0; i < traps->num_traps; i++) {
+	    /* Note the traps and boxes alias so we need to take the local copies first. */
+	    cairo_fixed_t x1 = traps->traps[i].left.p1.x;
+	    cairo_fixed_t x2 = traps->traps[i].right.p1.x;
+	    cairo_fixed_t y1 = traps->traps[i].top;
+	    cairo_fixed_t y2 = traps->traps[i].bottom;
+
+	    /* round down here to match Pixman's behavior when using traps. */
+	    boxes->chunks.base[i].p1.x = _cairo_fixed_round_down (x1);
+	    boxes->chunks.base[i].p1.y = _cairo_fixed_round_down (y1);
+	    boxes->chunks.base[i].p2.x = _cairo_fixed_round_down (x2);
+	    boxes->chunks.base[i].p2.y = _cairo_fixed_round_down (y2);
+	}
+    }
+
+    return CAIRO_INT_STATUS_SUCCESS;
+}
+
+static cairo_status_t
+clip_and_composite_boxes (const cairo_traps_compositor_t *compositor,
+			  cairo_composite_rectangles_t *extents,
+			  cairo_boxes_t *boxes);
+
+static cairo_status_t
+clip_and_composite_polygon (const cairo_traps_compositor_t *compositor,
+			    cairo_composite_rectangles_t *extents,
+			    cairo_polygon_t *polygon,
+			    cairo_antialias_t antialias,
+			    cairo_fill_rule_t fill_rule)
+{
+    composite_traps_info_t traps;
+    cairo_surface_t *dst = extents->surface;
+    cairo_bool_t clip_surface = ! _cairo_clip_is_region (extents->clip);
+    cairo_int_status_t status;
+
+    if (polygon->num_edges == 0) {
+	status = CAIRO_INT_STATUS_SUCCESS;
+
+	if (! extents->is_bounded) {
+	    cairo_region_t *clip_region = _cairo_clip_get_region (extents->clip);
+
+	    if (clip_region &&
+		cairo_region_contains_rectangle (clip_region,
+						 &extents->unbounded) == CAIRO_REGION_OVERLAP_IN)
+		clip_region = NULL;
+
+	    if (clip_region != NULL) {
+		status = compositor->set_clip_region (dst, clip_region);
+		if (unlikely (status))
+		    return status;
+	    }
+
+	    if (clip_surface)
+		status = fixup_unbounded_with_mask (compositor, extents);
+	    else
+		status = fixup_unbounded (compositor, extents, NULL);
+
+	    if (clip_region != NULL)
+		compositor->set_clip_region (dst, NULL);
+	}
+
+	return status;
+    }
+
+    if (extents->clip->path != NULL && extents->is_bounded) {
+	cairo_polygon_t clipper;
+	cairo_fill_rule_t clipper_fill_rule;
+	cairo_antialias_t clipper_antialias;
+
+	status = _cairo_clip_get_polygon (extents->clip,
+					  &clipper,
+					  &clipper_fill_rule,
+					  &clipper_antialias);
+	if (likely (status == CAIRO_INT_STATUS_SUCCESS)) {
+	    if (clipper_antialias == antialias) {
+		status = _cairo_polygon_intersect (polygon, fill_rule,
+						   &clipper, clipper_fill_rule);
+		if (likely (status == CAIRO_INT_STATUS_SUCCESS)) {
+		    cairo_clip_t * clip = _cairo_clip_copy_region (extents->clip);
+		    _cairo_clip_destroy (extents->clip);
+		    extents->clip = clip;
+
+		    fill_rule = CAIRO_FILL_RULE_WINDING;
+		}
+		_cairo_polygon_fini (&clipper);
+	    }
+	}
+    }
+
+    _cairo_traps_init (&traps.traps);
+
+    status = _cairo_bentley_ottmann_tessellate_polygon (&traps.traps, polygon, fill_rule);
+    if (unlikely (status))
+	goto CLEANUP_TRAPS;
+
+    status = trim_extents_to_traps (extents, &traps.traps);
+    if (unlikely (status))
+	goto CLEANUP_TRAPS;
+
+    /* Use a fast path if the trapezoids consist of a set of boxes.  */
+    status = CAIRO_INT_STATUS_UNSUPPORTED;
+    if (1) {
+	cairo_boxes_t boxes;
+
+	status = boxes_for_traps (&boxes, &traps.traps, antialias);
+	if (status == CAIRO_INT_STATUS_SUCCESS) {
+	    status = clip_and_composite_boxes (compositor, extents, &boxes);
+	    /* XXX need to reconstruct the traps! */
+	    assert (status != CAIRO_INT_STATUS_UNSUPPORTED);
+	}
+    }
+    if (status == CAIRO_INT_STATUS_UNSUPPORTED) {
+	/* Otherwise render the trapezoids to a mask and composite in the usual
+	 * fashion.
+	 */
+	unsigned int flags = 0;
+
+	/* For unbounded operations, the X11 server will estimate the
+	 * affected rectangle and apply the operation to that. However,
+	 * there are cases where this is an overestimate (e.g. the
+	 * clip-fill-{eo,nz}-unbounded test).
+	 *
+	 * The clip will trim that overestimate to our expectations.
+	 */
+	if (! extents->is_bounded)
+		flags |= FORCE_CLIP_REGION;
+
+	traps.antialias = antialias;
+	status = clip_and_composite (compositor, extents,
+				     composite_traps, NULL, &traps,
+				     need_unbounded_clip (extents) | flags);
+    }
+
+CLEANUP_TRAPS:
+    _cairo_traps_fini (&traps.traps);
+
+    return status;
+}
+
+struct composite_opacity_info {
+    const cairo_traps_compositor_t *compositor;
+    uint8_t op;
+    cairo_surface_t *dst;
+    cairo_surface_t *src;
+    int src_x, src_y;
+    double opacity;
+};
+
+static void composite_opacity(void *closure,
+			      int16_t x, int16_t y,
+			      int16_t w, int16_t h,
+			      uint16_t coverage)
+{
+    struct composite_opacity_info *info = closure;
+    const cairo_traps_compositor_t *compositor = info->compositor;
+    cairo_surface_t *mask;
+    int mask_x, mask_y;
+    cairo_color_t color;
+    cairo_solid_pattern_t solid;
+
+    _cairo_color_init_rgba (&color, 0, 0, 0, info->opacity * coverage);
+    _cairo_pattern_init_solid (&solid, &color);
+    mask = compositor->pattern_to_surface (info->dst, &solid.base, TRUE,
+					   &_cairo_unbounded_rectangle,
+					   &_cairo_unbounded_rectangle,
+					   &mask_x, &mask_y);
+    if (likely (mask->status == CAIRO_STATUS_SUCCESS)) {
+	if (info->src) {
+	    compositor->composite (info->dst, info->op, info->src, mask,
+				   x + info->src_x,  y + info->src_y,
+				   mask_x,           mask_y,
+				   x,                y,
+				   w,                h);
+	} else {
+	    compositor->composite (info->dst, info->op, mask, NULL,
+				   mask_x,            mask_y,
+				   0,                 0,
+				   x,                 y,
+				   w,                 h);
+	}
+    }
+
+    cairo_surface_destroy (mask);
+}
+
+
+static cairo_int_status_t
+composite_opacity_boxes (const cairo_traps_compositor_t *compositor,
+			 cairo_surface_t		*dst,
+			 void				*closure,
+			 cairo_operator_t		 op,
+			 cairo_surface_t		*src,
+			 int				 src_x,
+			 int				 src_y,
+			 int				 dst_x,
+			 int				 dst_y,
+			 const cairo_rectangle_int_t	*extents,
+			 cairo_clip_t			*clip)
+{
+    const cairo_solid_pattern_t *mask = closure;
+    struct composite_opacity_info info;
+    int i;
+
+    info.compositor = compositor;
+    info.op = op;
+    info.dst = dst;
+
+    info.src = src;
+    info.src_x = src_x;
+    info.src_y = src_y;
+
+    info.opacity = mask->color.alpha / (double) 0xffff;
+
+    /* XXX for lots of boxes create a clip region for the fully opaque areas */
+    for (i = 0; i < clip->num_boxes; i++)
+	do_unaligned_box(composite_opacity, &info,
+			 &clip->boxes[i], dst_x, dst_y);
+
+    return CAIRO_STATUS_SUCCESS;
+}
+
+static cairo_int_status_t
+composite_boxes (const cairo_traps_compositor_t *compositor,
+		 cairo_surface_t		*dst,
+		 void				*closure,
+		 cairo_operator_t		 op,
+		 cairo_surface_t		*src,
+		 int				 src_x,
+		 int				 src_y,
+		 int				 dst_x,
+		 int				 dst_y,
+		 const cairo_rectangle_int_t	*extents,
+		 cairo_clip_t			*clip)
+{
+    const cairo_boxes_t *boxes = closure;
+    const struct _cairo_boxes_chunk *chunk;
+    struct composite_opacity_info info;
+    int i;
+
+    info.compositor = compositor;
+    info.op = op;
+    info.dst = dst;
+
+    info.src = src;
+    info.src_x = src_x;
+    info.src_y = src_y;
+
+    info.opacity = 1. / (double) 0xffff;
+
+    /* XXX for lots of boxes create a clip region for the fully opaque areas */
+    for (chunk = &boxes->chunks; chunk != NULL; chunk = chunk->next) {
+	for (i = 0; i < chunk->count; i++)
+	    do_unaligned_box(composite_opacity, &info,
+			     &chunk->base[i], dst_x, dst_y);
+    }
+
+    return CAIRO_STATUS_SUCCESS;
+}
+
+static cairo_status_t
+clip_and_composite_boxes (const cairo_traps_compositor_t *compositor,
+			  cairo_composite_rectangles_t *extents,
+			  cairo_boxes_t *boxes)
+{
+    cairo_int_status_t status;
+
+    if (boxes->num_boxes == 0 && extents->is_bounded)
+	return CAIRO_STATUS_SUCCESS;
+
+    status = trim_extents_to_boxes (extents, boxes);
+    if (unlikely (status))
+	return status;
+
+    if (boxes->is_pixel_aligned && extents->clip->path == NULL &&
+	extents->source_pattern.base.type == CAIRO_PATTERN_TYPE_SURFACE &&
+	(op_reduces_to_source (extents) ||
+	 (extents->op == CAIRO_OPERATOR_OVER &&
+	  (extents->source_pattern.surface.surface->content & CAIRO_CONTENT_ALPHA) == 0)))
+    {
+	status = upload_boxes (compositor, extents, boxes);
+	if (status != CAIRO_INT_STATUS_UNSUPPORTED)
+	    return status;
+    }
+
+    /* 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);
+	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,
+						 antialias, fill_rule);
+
+	    clip = extents->clip;
+	    extents->clip = saved_clip;
+
+	    _cairo_polygon_fini (&polygon);
+	}
+	_cairo_clip_destroy (clip);
+
+	if (status != CAIRO_INT_STATUS_UNSUPPORTED)
+	    return status;
+    }
+
+    /* Use a fast path if the boxes are pixel aligned (or nearly aligned!) */
+    if (boxes->is_pixel_aligned) {
+	status = composite_aligned_boxes (compositor, extents, boxes);
+	if (status != CAIRO_INT_STATUS_UNSUPPORTED)
+	    return status;
+    }
+
+    return clip_and_composite (compositor, extents,
+			       composite_boxes, composite_boxes, boxes,
+			       need_unbounded_clip (extents));
+}
+
+static cairo_int_status_t
+composite_traps_as_boxes (const cairo_traps_compositor_t *compositor,
+			  cairo_composite_rectangles_t *extents,
+			  composite_traps_info_t *info)
+{
+    cairo_boxes_t boxes;
+
+    if (! _cairo_traps_to_boxes (&info->traps, info->antialias, &boxes))
+	return CAIRO_INT_STATUS_UNSUPPORTED;
+
+    return clip_and_composite_boxes (compositor, extents, &boxes);
+}
+
+static cairo_int_status_t
+clip_and_composite_traps (const cairo_traps_compositor_t *compositor,
+			  cairo_composite_rectangles_t *extents,
+			  composite_traps_info_t *info)
+{
+    cairo_int_status_t status;
+
+    status = trim_extents_to_traps (extents, &info->traps);
+    if (unlikely (status != CAIRO_INT_STATUS_SUCCESS))
+	return status;
+
+    status = composite_traps_as_boxes (compositor, extents, info);
+    if (status == CAIRO_INT_STATUS_UNSUPPORTED) {
+	unsigned int flags = 0;
+
+	/* For unbounded operations, the X11 server will estimate the
+	 * affected rectangle and apply the operation to that. However,
+	 * there are cases where this is an overestimate (e.g. the
+	 * clip-fill-{eo,nz}-unbounded test).
+	 *
+	 * The clip will trim that overestimate to our expectations.
+	 */
+	if (! extents->is_bounded)
+	    flags |= FORCE_CLIP_REGION;
+
+	status = clip_and_composite (compositor, extents,
+				     composite_traps, NULL, info,
+				     need_unbounded_clip (extents) | flags);
+    }
+
+    return status;
+}
+
+static cairo_int_status_t
+clip_and_composite_tristrip (const cairo_traps_compositor_t *compositor,
+			     cairo_composite_rectangles_t *extents,
+			     composite_tristrip_info_t *info)
+{
+    cairo_int_status_t status;
+    unsigned int flags = 0;
+
+    status = trim_extents_to_tristrip (extents, &info->strip);
+    if (unlikely (status != CAIRO_INT_STATUS_SUCCESS))
+	return status;
+
+    if (! extents->is_bounded)
+	flags |= FORCE_CLIP_REGION;
+
+    status = clip_and_composite (compositor, extents,
+				 composite_tristrip, NULL, info,
+				 need_unbounded_clip (extents) | flags);
+
+    return status;
+}
+
+struct composite_mask {
+    cairo_surface_t *mask;
+    int mask_x, mask_y;
+};
+
+static cairo_int_status_t
+composite_mask (const cairo_traps_compositor_t *compositor,
+		cairo_surface_t			*dst,
+		void				*closure,
+		cairo_operator_t		 op,
+		cairo_surface_t			*src,
+		int				 src_x,
+		int				 src_y,
+		int				 dst_x,
+		int				 dst_y,
+		const cairo_rectangle_int_t	*extents,
+		cairo_clip_t			*clip)
+{
+    struct composite_mask *data = closure;
+
+    if (src != NULL) {
+	compositor->composite (dst, op, src, data->mask,
+			       extents->x + src_x, extents->y + src_y,
+			       extents->x + data->mask_x, extents->y + data->mask_y,
+			       extents->x - dst_x,  extents->y - dst_y,
+			       extents->width,      extents->height);
+    } else {
+	compositor->composite (dst, op, data->mask, NULL,
+			       extents->x + data->mask_x, extents->y + data->mask_y,
+			       0, 0,
+			       extents->x - dst_x,  extents->y - dst_y,
+			       extents->width,      extents->height);
+    }
+
+    return CAIRO_STATUS_SUCCESS;
+}
+
+struct composite_box_info {
+    const cairo_traps_compositor_t *compositor;
+    cairo_surface_t *dst;
+    cairo_surface_t *src;
+    int src_x, src_y;
+    uint8_t op;
+};
+
+static void composite_box(void *closure,
+			  int16_t x, int16_t y,
+			  int16_t w, int16_t h,
+			  uint16_t coverage)
+{
+    struct composite_box_info *info = closure;
+    const cairo_traps_compositor_t *compositor = info->compositor;
+
+    if (! CAIRO_ALPHA_SHORT_IS_OPAQUE (coverage)) {
+	cairo_surface_t *mask;
+	cairo_color_t color;
+	cairo_solid_pattern_t solid;
+	int mask_x, mask_y;
+
+	_cairo_color_init_rgba (&color, 0, 0, 0, coverage / (double)0xffff);
+	_cairo_pattern_init_solid (&solid, &color);
+
+	mask = compositor->pattern_to_surface (info->dst, &solid.base, FALSE,
+					       &_cairo_unbounded_rectangle,
+					       &_cairo_unbounded_rectangle,
+					       &mask_x, &mask_y);
+
+	if (likely (mask->status == CAIRO_STATUS_SUCCESS)) {
+	    compositor->composite (info->dst, info->op, info->src, mask,
+				   x + info->src_x,  y + info->src_y,
+				   mask_x,           mask_y,
+				   x,                y,
+				   w,                h);
+	}
+
+	cairo_surface_destroy (mask);
+    } else {
+	compositor->composite (info->dst, info->op, info->src, NULL,
+			       x + info->src_x,  y + info->src_y,
+			       0,                0,
+			       x,                y,
+			       w,                h);
+    }
+}
+
+static cairo_int_status_t
+composite_mask_clip_boxes (const cairo_traps_compositor_t *compositor,
+			   cairo_surface_t		*dst,
+			   void				*closure,
+			   cairo_operator_t		 op,
+			   cairo_surface_t		*src,
+			   int				 src_x,
+			   int				 src_y,
+			   int				 dst_x,
+			   int				 dst_y,
+			   const cairo_rectangle_int_t	*extents,
+			   cairo_clip_t			*clip)
+{
+    struct composite_mask *data = closure;
+    struct composite_box_info info;
+    int i;
+
+    info.compositor = compositor;
+    info.op = CAIRO_OPERATOR_SOURCE;
+    info.dst = dst;
+    info.src = data->mask;
+    info.src_x = data->mask_x;
+    info.src_y = data->mask_y;
+
+    info.src_x += dst_x;
+    info.src_y += dst_y;
+
+    for (i = 0; i < clip->num_boxes; i++)
+	do_unaligned_box(composite_box, &info, &clip->boxes[i], dst_x, dst_y);
+
+    return CAIRO_STATUS_SUCCESS;
+}
+
+static cairo_int_status_t
+composite_mask_clip (const cairo_traps_compositor_t *compositor,
+		     cairo_surface_t			*dst,
+		     void				*closure,
+		     cairo_operator_t			 op,
+		     cairo_surface_t			*src,
+		     int				 src_x,
+		     int				 src_y,
+		     int				 dst_x,
+		     int				 dst_y,
+		     const cairo_rectangle_int_t	*extents,
+		     cairo_clip_t			*clip)
+{
+    struct composite_mask *data = closure;
+    cairo_polygon_t polygon;
+    cairo_fill_rule_t fill_rule;
+    composite_traps_info_t info;
+    cairo_status_t status;
+
+    status = _cairo_clip_get_polygon (clip, &polygon,
+				      &fill_rule, &info.antialias);
+    if (unlikely (status))
+	return status;
+
+    _cairo_traps_init (&info.traps);
+    status = _cairo_bentley_ottmann_tessellate_polygon (&info.traps,
+							&polygon,
+							fill_rule);
+    _cairo_polygon_fini (&polygon);
+    if (unlikely (status))
+	return status;
+
+    status = composite_traps (compositor, dst, &info,
+			      CAIRO_OPERATOR_SOURCE,
+			      data->mask,
+			      data->mask_x + dst_x, data->mask_y + dst_y,
+			      dst_x, dst_y,
+			      extents, NULL);
+    _cairo_traps_fini (&info.traps);
+
+    return status;
+}
+
+/* high-level compositor interface */
+
+static cairo_int_status_t
+_cairo_traps_compositor_paint (const cairo_compositor_t *_compositor,
+			       cairo_composite_rectangles_t *extents)
+{
+    cairo_traps_compositor_t *compositor = (cairo_traps_compositor_t*)_compositor;
+    cairo_boxes_t boxes;
+    cairo_int_status_t status;
+
+     _cairo_clip_steal_boxes (extents->clip, &boxes);
+     status = clip_and_composite_boxes (compositor, extents, &boxes);
+     _cairo_clip_unsteal_boxes (extents->clip, &boxes);
+
+    return status;
+}
+
+static cairo_int_status_t
+_cairo_traps_compositor_mask (const cairo_compositor_t *_compositor,
+			      cairo_composite_rectangles_t *extents)
+{
+    const cairo_traps_compositor_t *compositor = (cairo_traps_compositor_t*)_compositor;
+    cairo_int_status_t status;
+
+    if (extents->mask_pattern.base.type == CAIRO_PATTERN_TYPE_SOLID &&
+	extents->clip->path == NULL) {
+	status = clip_and_composite (compositor, extents,
+				     composite_opacity_boxes,
+				     composite_opacity_boxes,
+				     &extents->mask_pattern,
+				     need_unbounded_clip (extents));
+    } else {
+	struct composite_mask data;
+
+	data.mask = compositor->pattern_to_surface (extents->surface,
+						    &extents->mask_pattern.base,
+						    TRUE,
+						    &extents->bounded,
+						    &extents->mask_sample_area,
+						    &data.mask_x,
+						    &data.mask_y);
+
+	status = clip_and_composite (compositor, extents,
+				     composite_mask,
+				     extents->clip->path ? composite_mask_clip : composite_mask_clip_boxes,
+				     &data, need_bounded_clip (extents));
+
+	cairo_surface_destroy (data.mask);
+    }
+
+    return status;
+}
+
+static cairo_int_status_t
+_cairo_traps_compositor_stroke (const cairo_compositor_t *_compositor,
+				cairo_composite_rectangles_t *extents,
+				const cairo_path_fixed_t *path,
+				const cairo_stroke_style_t *style,
+				const cairo_matrix_t	*ctm,
+				const cairo_matrix_t	*ctm_inverse,
+				double			 tolerance,
+				cairo_antialias_t	 antialias)
+{
+    const cairo_traps_compositor_t *compositor = (cairo_traps_compositor_t *)_compositor;
+    cairo_int_status_t status;
+
+    status = CAIRO_INT_STATUS_UNSUPPORTED;
+    if (_cairo_path_fixed_stroke_is_rectilinear (path)) {
+	cairo_boxes_t boxes;
+
+	_cairo_boxes_init_with_clip (&boxes, extents->clip);
+	status = _cairo_path_fixed_stroke_rectilinear_to_boxes (path,
+								style,
+								ctm,
+								antialias,
+								&boxes);
+	if (likely (status == CAIRO_INT_STATUS_SUCCESS))
+	    status = clip_and_composite_boxes (compositor, extents, &boxes);
+	_cairo_boxes_fini (&boxes);
+    }
+
+    if (status == CAIRO_INT_STATUS_UNSUPPORTED && 0 &&
+	_cairo_clip_is_region (extents->clip)) /* XXX */
+    {
+	composite_tristrip_info_t info;
+
+	info.antialias = antialias;
+	_cairo_tristrip_init_with_clip (&info.strip, extents->clip);
+	status = _cairo_path_fixed_stroke_to_tristrip (path, style,
+						       ctm, ctm_inverse,
+						       tolerance,
+						       &info.strip);
+	if (likely (status == CAIRO_INT_STATUS_SUCCESS))
+	    status = clip_and_composite_tristrip (compositor, extents, &info);
+	_cairo_tristrip_fini (&info.strip);
+    }
+
+    if (status == CAIRO_INT_STATUS_UNSUPPORTED) {
+	composite_traps_info_t info;
+
+	info.antialias = antialias;
+	_cairo_traps_init_with_clip (&info.traps, extents->clip);
+	status = _cairo_path_fixed_stroke_to_traps (path, style,
+						    ctm, ctm_inverse,
+						    tolerance,
+						    &info.traps);
+	if (likely (status == CAIRO_INT_STATUS_SUCCESS))
+	    status = clip_and_composite_traps (compositor, extents, &info);
+	_cairo_traps_fini (&info.traps);
+    }
+
+    return status;
+}
+
+static cairo_int_status_t
+_cairo_traps_compositor_fill (const cairo_compositor_t *_compositor,
+			      cairo_composite_rectangles_t *extents,
+			      const cairo_path_fixed_t	*path,
+			      cairo_fill_rule_t		 fill_rule,
+			      double			 tolerance,
+			      cairo_antialias_t		 antialias)
+{
+    const cairo_traps_compositor_t *compositor = (cairo_traps_compositor_t *)_compositor;
+    cairo_int_status_t status;
+
+    status = CAIRO_INT_STATUS_UNSUPPORTED;
+    if (_cairo_path_fixed_fill_is_rectilinear (path)) {
+	cairo_boxes_t boxes;
+
+	_cairo_boxes_init_with_clip (&boxes, extents->clip);
+	status = _cairo_path_fixed_fill_rectilinear_to_boxes (path,
+							      fill_rule,
+							      antialias,
+							      &boxes);
+	if (likely (status == CAIRO_INT_STATUS_SUCCESS))
+	    status = clip_and_composite_boxes (compositor, extents, &boxes);
+	_cairo_boxes_fini (&boxes);
+    }
+
+    if (status == CAIRO_INT_STATUS_UNSUPPORTED) {
+	cairo_polygon_t polygon;
+
+#if 0
+	if (extents->mask.width  > extents->unbounded.width ||
+	    extents->mask.height > extents->unbounded.height)
+	{
+	    cairo_box_t limits;
+	    _cairo_box_from_rectangle (&limits, &extents->unbounded);
+	    _cairo_polygon_init (&polygon, &limits, 1);
+	}
+	else
+	{
+	    _cairo_polygon_init (&polygon, NULL, 0);
+	}
+
+	status = _cairo_path_fixed_fill_to_polygon (path, tolerance, &polygon);
+	if (likely (status == CAIRO_INT_STATUS_SUCCESS)) {
+	    status = _cairo_polygon_intersect_with_boxes (&polygon, &fill_rule,
+							  extents->clip->boxes,
+							  extents->clip->num_boxes);
+	}
+#else
+	_cairo_polygon_init_with_clip (&polygon, extents->clip);
+	status = _cairo_path_fixed_fill_to_polygon (path, tolerance, &polygon);
+#endif
+	if (likely (status == CAIRO_INT_STATUS_SUCCESS)) {
+	    status = clip_and_composite_polygon (compositor, extents, &polygon,
+						 antialias, fill_rule);
+	}
+	_cairo_polygon_fini (&polygon);
+    }
+
+    return status;
+}
+
+static cairo_int_status_t
+composite_glyphs (const cairo_traps_compositor_t *compositor,
+		  cairo_surface_t	*dst,
+		  void *closure,
+		  cairo_operator_t	 op,
+		  cairo_surface_t	*src,
+		  int src_x, int src_y,
+		  int dst_x, int dst_y,
+		  const cairo_rectangle_int_t *extents,
+		  cairo_clip_t		*clip)
+{
+    cairo_composite_glyphs_info_t *info = closure;
+
+    if (op == CAIRO_OPERATOR_ADD && (dst->content & CAIRO_CONTENT_COLOR) == 0)
+	info->use_mask = 0;
+
+    return compositor->composite_glyphs (dst, op, src,
+					 src_x, src_y,
+					 dst_x, dst_y,
+					 info);
+}
+
+static cairo_int_status_t
+_cairo_traps_compositor_glyphs (const cairo_compositor_t	*_compositor,
+				cairo_composite_rectangles_t	*extents,
+				cairo_scaled_font_t		*scaled_font,
+				cairo_glyph_t			*glyphs,
+				int				 num_glyphs,
+				cairo_bool_t			 overlap)
+{
+    const cairo_traps_compositor_t *compositor = (cairo_traps_compositor_t *)_compositor;
+    cairo_int_status_t status;
+
+    _cairo_scaled_font_freeze_cache (scaled_font);
+    status = compositor->check_composite_glyphs (extents,
+						 scaled_font, glyphs,
+						 &num_glyphs);
+    if (likely (status == CAIRO_INT_STATUS_SUCCESS)) {
+	cairo_composite_glyphs_info_t info;
+	unsigned flags = 0;
+
+	info.font = scaled_font;
+	info.glyphs = glyphs;
+	info.num_glyphs = num_glyphs;
+	info.use_mask = overlap || ! extents->is_bounded;
+	info.extents = extents->bounded;
+
+	if (extents->mask.width > extents->bounded.width ||
+	    extents->mask.height > extents->bounded.height)
+	{
+	    flags |= FORCE_CLIP_REGION;
+	}
+
+	status = clip_and_composite (compositor, extents,
+				     composite_glyphs, NULL, &info,
+				     need_bounded_clip (extents) |
+				     flags);
+    }
+    _cairo_scaled_font_thaw_cache (scaled_font);
+
+    return status;
+}
+
+void
+_cairo_traps_compositor_init (cairo_traps_compositor_t *compositor,
+			      const cairo_compositor_t  *delegate)
+{
+    compositor->base.delegate = delegate;
+
+    compositor->base.paint = _cairo_traps_compositor_paint;
+    compositor->base.mask = _cairo_traps_compositor_mask;
+    compositor->base.fill = _cairo_traps_compositor_fill;
+    compositor->base.stroke = _cairo_traps_compositor_stroke;
+    compositor->base.glyphs = _cairo_traps_compositor_glyphs;
+}