add cairo

1 files changed, 895 insertions, 0 deletions

diff --git a/libs/cairo-1.16.0/src/cairo-bentley-ottmann-rectangular.c b/libs/cairo-1.16.0/src/cairo-bentley-ottmann-rectangular.c
new file mode 100644
index 0000000..65f95d7
--- /dev/null
+++ b/libs/cairo-1.16.0/src/cairo-bentley-ottmann-rectangular.c
@@ -0,0 +1,895 @@
+/*
+ * Copyright © 2004 Carl Worth
+ * Copyright © 2006 Red Hat, Inc.
+ * Copyright © 2009 Chris Wilson
+ *
+ * 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 Carl Worth
+ *
+ * Contributor(s):
+ *	Carl D. Worth <cworth@cworth.org>
+ *	Chris Wilson <chris@chris-wilson.co.uk>
+ */
+
+/* Provide definitions for standalone compilation */
+#include "cairoint.h"
+
+#include "cairo-boxes-private.h"
+#include "cairo-error-private.h"
+#include "cairo-combsort-inline.h"
+#include "cairo-list-private.h"
+#include "cairo-traps-private.h"
+
+#include <setjmp.h>
+
+typedef struct _rectangle rectangle_t;
+typedef struct _edge edge_t;
+
+struct _edge {
+    edge_t *next, *prev;
+    edge_t *right;
+    cairo_fixed_t x, top;
+    int dir;
+};
+
+struct _rectangle {
+    edge_t left, right;
+    int32_t top, bottom;
+};
+
+#define UNROLL3(x) x x x
+
+/* the parent is always given by index/2 */
+#define PQ_PARENT_INDEX(i) ((i) >> 1)
+#define PQ_FIRST_ENTRY 1
+
+/* left and right children are index * 2 and (index * 2) +1 respectively */
+#define PQ_LEFT_CHILD_INDEX(i) ((i) << 1)
+
+typedef struct _sweep_line {
+    rectangle_t **rectangles;
+    rectangle_t **stop;
+    edge_t head, tail, *insert, *cursor;
+    int32_t current_y;
+    int32_t last_y;
+    int stop_size;
+
+    int32_t insert_x;
+    cairo_fill_rule_t fill_rule;
+
+    cairo_bool_t do_traps;
+    void *container;
+
+    jmp_buf unwind;
+} sweep_line_t;
+
+#define DEBUG_TRAPS 0
+
+#if DEBUG_TRAPS
+static void
+dump_traps (cairo_traps_t *traps, const char *filename)
+{
+    FILE *file;
+    int n;
+
+    if (getenv ("CAIRO_DEBUG_TRAPS") == NULL)
+	return;
+
+    file = fopen (filename, "a");
+    if (file != NULL) {
+	for (n = 0; n < traps->num_traps; n++) {
+	    fprintf (file, "%d %d L:(%d, %d), (%d, %d) R:(%d, %d), (%d, %d)\n",
+		     traps->traps[n].top,
+		     traps->traps[n].bottom,
+		     traps->traps[n].left.p1.x,
+		     traps->traps[n].left.p1.y,
+		     traps->traps[n].left.p2.x,
+		     traps->traps[n].left.p2.y,
+		     traps->traps[n].right.p1.x,
+		     traps->traps[n].right.p1.y,
+		     traps->traps[n].right.p2.x,
+		     traps->traps[n].right.p2.y);
+	}
+	fprintf (file, "\n");
+	fclose (file);
+    }
+}
+#else
+#define dump_traps(traps, filename)
+#endif
+
+static inline int
+rectangle_compare_start (const rectangle_t *a,
+			 const rectangle_t *b)
+{
+    return a->top - b->top;
+}
+
+static inline int
+rectangle_compare_stop (const rectangle_t *a,
+			 const rectangle_t *b)
+{
+    return a->bottom - b->bottom;
+}
+
+static inline void
+pqueue_push (sweep_line_t *sweep, rectangle_t *rectangle)
+{
+    rectangle_t **elements;
+    int i, parent;
+
+    elements = sweep->stop;
+    for (i = ++sweep->stop_size;
+	 i != PQ_FIRST_ENTRY &&
+	 rectangle_compare_stop (rectangle,
+				 elements[parent = PQ_PARENT_INDEX (i)]) < 0;
+	 i = parent)
+    {
+	elements[i] = elements[parent];
+    }
+
+    elements[i] = rectangle;
+}
+
+static inline void
+rectangle_pop_stop (sweep_line_t *sweep)
+{
+    rectangle_t **elements = sweep->stop;
+    rectangle_t *tail;
+    int child, i;
+
+    tail = elements[sweep->stop_size--];
+    if (sweep->stop_size == 0) {
+	elements[PQ_FIRST_ENTRY] = NULL;
+	return;
+    }
+
+    for (i = PQ_FIRST_ENTRY;
+	 (child = PQ_LEFT_CHILD_INDEX (i)) <= sweep->stop_size;
+	 i = child)
+    {
+	if (child != sweep->stop_size &&
+	    rectangle_compare_stop (elements[child+1],
+				    elements[child]) < 0)
+	{
+	    child++;
+	}
+
+	if (rectangle_compare_stop (elements[child], tail) >= 0)
+	    break;
+
+	elements[i] = elements[child];
+    }
+    elements[i] = tail;
+}
+
+static inline rectangle_t *
+rectangle_pop_start (sweep_line_t *sweep_line)
+{
+    return *sweep_line->rectangles++;
+}
+
+static inline rectangle_t *
+rectangle_peek_stop (sweep_line_t *sweep_line)
+{
+    return sweep_line->stop[PQ_FIRST_ENTRY];
+}
+
+CAIRO_COMBSORT_DECLARE (_rectangle_sort,
+			rectangle_t *,
+			rectangle_compare_start)
+
+static void
+sweep_line_init (sweep_line_t	 *sweep_line,
+		 rectangle_t	**rectangles,
+		 int		  num_rectangles,
+		 cairo_fill_rule_t fill_rule,
+		 cairo_bool_t	 do_traps,
+		 void		*container)
+{
+    rectangles[-2] = NULL;
+    rectangles[-1] = NULL;
+    rectangles[num_rectangles] = NULL;
+    sweep_line->rectangles = rectangles;
+    sweep_line->stop = rectangles - 2;
+    sweep_line->stop_size = 0;
+
+    sweep_line->insert = NULL;
+    sweep_line->insert_x = INT_MAX;
+    sweep_line->cursor = &sweep_line->tail;
+
+    sweep_line->head.dir = 0;
+    sweep_line->head.x = INT32_MIN;
+    sweep_line->head.right = NULL;
+    sweep_line->head.prev = NULL;
+    sweep_line->head.next = &sweep_line->tail;
+    sweep_line->tail.prev = &sweep_line->head;
+    sweep_line->tail.next = NULL;
+    sweep_line->tail.right = NULL;
+    sweep_line->tail.x = INT32_MAX;
+    sweep_line->tail.dir = 0;
+
+    sweep_line->current_y = INT32_MIN;
+    sweep_line->last_y = INT32_MIN;
+
+    sweep_line->fill_rule = fill_rule;
+    sweep_line->container = container;
+    sweep_line->do_traps = do_traps;
+}
+
+static void
+edge_end_box (sweep_line_t *sweep_line, edge_t *left, int32_t bot)
+{
+    cairo_status_t status = CAIRO_STATUS_SUCCESS;
+
+    /* Only emit (trivial) non-degenerate trapezoids with positive height. */
+    if (likely (left->top < bot)) {
+	if (sweep_line->do_traps) {
+	    cairo_line_t _left = {
+		{ left->x, left->top },
+		{ left->x, bot },
+	    }, _right = {
+		{ left->right->x, left->top },
+		{ left->right->x, bot },
+	    };
+	    _cairo_traps_add_trap (sweep_line->container, left->top, bot, &_left, &_right);
+	    status = _cairo_traps_status ((cairo_traps_t *) sweep_line->container);
+	} else {
+	    cairo_box_t box;
+
+	    box.p1.x = left->x;
+	    box.p1.y = left->top;
+	    box.p2.x = left->right->x;
+	    box.p2.y = bot;
+
+	    status = _cairo_boxes_add (sweep_line->container,
+				       CAIRO_ANTIALIAS_DEFAULT,
+				       &box);
+	}
+    }
+    if (unlikely (status))
+	longjmp (sweep_line->unwind, status);
+
+    left->right = NULL;
+}
+
+/* Start a new trapezoid at the given top y coordinate, whose edges
+ * are `edge' and `edge->next'. If `edge' already has a trapezoid,
+ * then either add it to the traps in `traps', if the trapezoid's
+ * right edge differs from `edge->next', or do nothing if the new
+ * trapezoid would be a continuation of the existing one. */
+static inline void
+edge_start_or_continue_box (sweep_line_t *sweep_line,
+			    edge_t	*left,
+			    edge_t	*right,
+			    int		 top)
+{
+    if (left->right == right)
+	return;
+
+    if (left->right != NULL) {
+	if (left->right->x == right->x) {
+	    /* continuation on right, so just swap edges */
+	    left->right = right;
+	    return;
+	}
+
+	edge_end_box (sweep_line, left, top);
+    }
+
+    if (left->x != right->x) {
+	left->top = top;
+	left->right = right;
+    }
+}
+/*
+ * Merge two sorted edge lists.
+ * Input:
+ *  - head_a: The head of the first list.
+ *  - head_b: The head of the second list; head_b cannot be NULL.
+ * Output:
+ * Returns the head of the merged list.
+ *
+ * Implementation notes:
+ * To make it fast (in particular, to reduce to an insertion sort whenever
+ * one of the two input lists only has a single element) we iterate through
+ * a list until its head becomes greater than the head of the other list,
+ * then we switch their roles. As soon as one of the two lists is empty, we
+ * just attach the other one to the current list and exit.
+ * Writes to memory are only needed to "switch" lists (as it also requires
+ * attaching to the output list the list which we will be iterating next) and
+ * to attach the last non-empty list.
+ */
+static edge_t *
+merge_sorted_edges (edge_t *head_a, edge_t *head_b)
+{
+    edge_t *head, *prev;
+    int32_t x;
+
+    prev = head_a->prev;
+    if (head_a->x <= head_b->x) {
+	head = head_a;
+    } else {
+	head_b->prev = prev;
+	head = head_b;
+	goto start_with_b;
+    }
+
+    do {
+	x = head_b->x;
+	while (head_a != NULL && head_a->x <= x) {
+	    prev = head_a;
+	    head_a = head_a->next;
+	}
+
+	head_b->prev = prev;
+	prev->next = head_b;
+	if (head_a == NULL)
+	    return head;
+
+start_with_b:
+	x = head_a->x;
+	while (head_b != NULL && head_b->x <= x) {
+	    prev = head_b;
+	    head_b = head_b->next;
+	}
+
+	head_a->prev = prev;
+	prev->next = head_a;
+	if (head_b == NULL)
+	    return head;
+    } while (1);
+}
+
+/*
+ * Sort (part of) a list.
+ * Input:
+ *  - list: The list to be sorted; list cannot be NULL.
+ *  - limit: Recursion limit.
+ * Output:
+ *  - head_out: The head of the sorted list containing the first 2^(level+1) elements of the
+ *              input list; if the input list has fewer elements, head_out be a sorted list
+ *              containing all the elements of the input list.
+ * Returns the head of the list of unprocessed elements (NULL if the sorted list contains
+ * all the elements of the input list).
+ *
+ * Implementation notes:
+ * Special case single element list, unroll/inline the sorting of the first two elements.
+ * Some tail recursion is used since we iterate on the bottom-up solution of the problem
+ * (we start with a small sorted list and keep merging other lists of the same size to it).
+ */
+static edge_t *
+sort_edges (edge_t  *list,
+	    unsigned int  level,
+	    edge_t **head_out)
+{
+    edge_t *head_other, *remaining;
+    unsigned int i;
+
+    head_other = list->next;
+
+    if (head_other == NULL) {
+	*head_out = list;
+	return NULL;
+    }
+
+    remaining = head_other->next;
+    if (list->x <= head_other->x) {
+	*head_out = list;
+	head_other->next = NULL;
+    } else {
+	*head_out = head_other;
+	head_other->prev = list->prev;
+	head_other->next = list;
+	list->prev = head_other;
+	list->next = NULL;
+    }
+
+    for (i = 0; i < level && remaining; i++) {
+	remaining = sort_edges (remaining, i, &head_other);
+	*head_out = merge_sorted_edges (*head_out, head_other);
+    }
+
+    return remaining;
+}
+
+static edge_t *
+merge_unsorted_edges (edge_t *head, edge_t *unsorted)
+{
+    sort_edges (unsorted, UINT_MAX, &unsorted);
+    return merge_sorted_edges (head, unsorted);
+}
+
+static void
+active_edges_insert (sweep_line_t *sweep)
+{
+    edge_t *prev;
+    int x;
+
+    x = sweep->insert_x;
+    prev = sweep->cursor;
+    if (prev->x > x) {
+	do {
+	    prev = prev->prev;
+	} while (prev->x > x);
+    } else {
+	while (prev->next->x < x)
+	    prev = prev->next;
+    }
+
+    prev->next = merge_unsorted_edges (prev->next, sweep->insert);
+    sweep->cursor = sweep->insert;
+    sweep->insert = NULL;
+    sweep->insert_x = INT_MAX;
+}
+
+static inline void
+active_edges_to_traps (sweep_line_t *sweep)
+{
+    int top = sweep->current_y;
+    edge_t *pos;
+
+    if (sweep->last_y == sweep->current_y)
+	return;
+
+    if (sweep->insert)
+	active_edges_insert (sweep);
+
+    pos = sweep->head.next;
+    if (pos == &sweep->tail)
+	return;
+
+    if (sweep->fill_rule == CAIRO_FILL_RULE_WINDING) {
+	do {
+	    edge_t *left, *right;
+	    int winding;
+
+	    left = pos;
+	    winding = left->dir;
+
+	    right = left->next;
+
+	    /* Check if there is a co-linear edge with an existing trap */
+	    while (right->x == left->x) {
+		if (right->right != NULL) {
+		    assert (left->right == NULL);
+		    /* continuation on left */
+		    left->top = right->top;
+		    left->right = right->right;
+		    right->right = NULL;
+		}
+		winding += right->dir;
+		right = right->next;
+	    }
+
+	    if (winding == 0) {
+		if (left->right != NULL)
+		    edge_end_box (sweep, left, top);
+		pos = right;
+		continue;
+	    }
+
+	    do {
+		/* End all subsumed traps */
+		if (unlikely (right->right != NULL))
+		    edge_end_box (sweep, right, top);
+
+		/* Greedily search for the closing edge, so that we generate
+		 * the * maximal span width with the minimal number of
+		 * boxes.
+		 */
+		winding += right->dir;
+		if (winding == 0 && right->x != right->next->x)
+		    break;
+
+		right = right->next;
+	    } while (TRUE);
+
+	    edge_start_or_continue_box (sweep, left, right, top);
+
+	    pos = right->next;
+	} while (pos != &sweep->tail);
+    } else {
+	do {
+	    edge_t *right = pos->next;
+	    int count = 0;
+
+	    do {
+		/* End all subsumed traps */
+		if (unlikely (right->right != NULL))
+		    edge_end_box (sweep, right, top);
+
+		    /* skip co-linear edges */
+		if (++count & 1 && right->x != right->next->x)
+		    break;
+
+		right = right->next;
+	    } while (TRUE);
+
+	    edge_start_or_continue_box (sweep, pos, right, top);
+
+	    pos = right->next;
+	} while (pos != &sweep->tail);
+    }
+
+    sweep->last_y = sweep->current_y;
+}
+
+static inline void
+sweep_line_delete_edge (sweep_line_t *sweep, edge_t *edge)
+{
+    if (edge->right != NULL) {
+	edge_t *next = edge->next;
+	if (next->x == edge->x) {
+	    next->top = edge->top;
+	    next->right = edge->right;
+	} else
+	    edge_end_box (sweep, edge, sweep->current_y);
+    }
+
+    if (sweep->cursor == edge)
+	sweep->cursor = edge->prev;
+
+    edge->prev->next = edge->next;
+    edge->next->prev = edge->prev;
+}
+
+static inline cairo_bool_t
+sweep_line_delete (sweep_line_t	*sweep, rectangle_t *rectangle)
+{
+    cairo_bool_t update;
+
+    update = TRUE;
+    if (sweep->fill_rule == CAIRO_FILL_RULE_WINDING &&
+	rectangle->left.prev->dir == rectangle->left.dir)
+    {
+	update = rectangle->left.next != &rectangle->right;
+    }
+
+    sweep_line_delete_edge (sweep, &rectangle->left);
+    sweep_line_delete_edge (sweep, &rectangle->right);
+
+    rectangle_pop_stop (sweep);
+    return update;
+}
+
+static inline void
+sweep_line_insert (sweep_line_t	*sweep, rectangle_t *rectangle)
+{
+    if (sweep->insert)
+	sweep->insert->prev = &rectangle->right;
+    rectangle->right.next = sweep->insert;
+    rectangle->right.prev = &rectangle->left;
+    rectangle->left.next = &rectangle->right;
+    rectangle->left.prev = NULL;
+    sweep->insert = &rectangle->left;
+    if (rectangle->left.x < sweep->insert_x)
+	sweep->insert_x = rectangle->left.x;
+
+    pqueue_push (sweep, rectangle);
+}
+
+static cairo_status_t
+_cairo_bentley_ottmann_tessellate_rectangular (rectangle_t	**rectangles,
+					       int			  num_rectangles,
+					       cairo_fill_rule_t	  fill_rule,
+					       cairo_bool_t		 do_traps,
+					       void			*container)
+{
+    sweep_line_t sweep_line;
+    rectangle_t *rectangle;
+    cairo_status_t status;
+    cairo_bool_t update;
+
+    sweep_line_init (&sweep_line,
+		     rectangles, num_rectangles,
+		     fill_rule,
+		     do_traps, container);
+    if ((status = setjmp (sweep_line.unwind)))
+	return status;
+
+    update = FALSE;
+
+    rectangle = rectangle_pop_start (&sweep_line);
+    do {
+	if (rectangle->top != sweep_line.current_y) {
+	    rectangle_t *stop;
+
+	    stop = rectangle_peek_stop (&sweep_line);
+	    while (stop != NULL && stop->bottom < rectangle->top) {
+		if (stop->bottom != sweep_line.current_y) {
+		    if (update) {
+			active_edges_to_traps (&sweep_line);
+			update = FALSE;
+		    }
+
+		    sweep_line.current_y = stop->bottom;
+		}
+
+		update |= sweep_line_delete (&sweep_line, stop);
+		stop = rectangle_peek_stop (&sweep_line);
+	    }
+
+	    if (update) {
+		active_edges_to_traps (&sweep_line);
+		update = FALSE;
+	    }
+
+	    sweep_line.current_y = rectangle->top;
+	}
+
+	do {
+	    sweep_line_insert (&sweep_line, rectangle);
+	} while ((rectangle = rectangle_pop_start (&sweep_line)) != NULL &&
+		 sweep_line.current_y == rectangle->top);
+	update = TRUE;
+    } while (rectangle);
+
+    while ((rectangle = rectangle_peek_stop (&sweep_line)) != NULL) {
+	if (rectangle->bottom != sweep_line.current_y) {
+	    if (update) {
+		active_edges_to_traps (&sweep_line);
+		update = FALSE;
+	    }
+	    sweep_line.current_y = rectangle->bottom;
+	}
+
+	update |= sweep_line_delete (&sweep_line, rectangle);
+    }
+
+    return CAIRO_STATUS_SUCCESS;
+}
+
+cairo_status_t
+_cairo_bentley_ottmann_tessellate_rectangular_traps (cairo_traps_t *traps,
+						     cairo_fill_rule_t fill_rule)
+{
+    rectangle_t stack_rectangles[CAIRO_STACK_ARRAY_LENGTH (rectangle_t)];
+    rectangle_t *stack_rectangles_ptrs[ARRAY_LENGTH (stack_rectangles) + 3];
+    rectangle_t *rectangles, **rectangles_ptrs;
+    cairo_status_t status;
+    int i;
+
+   assert (traps->is_rectangular);
+
+    if (unlikely (traps->num_traps <= 1)) {
+        if (traps->num_traps == 1) {
+            cairo_trapezoid_t *trap = traps->traps;
+            if (trap->left.p1.x > trap->right.p1.x) {
+                cairo_line_t tmp = trap->left;
+                trap->left = trap->right;
+                trap->right = tmp;
+            }
+        }
+	return CAIRO_STATUS_SUCCESS;
+    }
+
+    dump_traps (traps, "bo-rects-traps-in.txt");
+
+    rectangles = stack_rectangles;
+    rectangles_ptrs = stack_rectangles_ptrs;
+    if (traps->num_traps > ARRAY_LENGTH (stack_rectangles)) {
+	rectangles = _cairo_malloc_ab_plus_c (traps->num_traps,
+					      sizeof (rectangle_t) +
+					      sizeof (rectangle_t *),
+					      3*sizeof (rectangle_t *));
+	if (unlikely (rectangles == NULL))
+	    return _cairo_error (CAIRO_STATUS_NO_MEMORY);
+
+	rectangles_ptrs = (rectangle_t **) (rectangles + traps->num_traps);
+    }
+
+    for (i = 0; i < traps->num_traps; i++) {
+	if (traps->traps[i].left.p1.x < traps->traps[i].right.p1.x) {
+	    rectangles[i].left.x = traps->traps[i].left.p1.x;
+	    rectangles[i].left.dir = 1;
+
+	    rectangles[i].right.x = traps->traps[i].right.p1.x;
+	    rectangles[i].right.dir = -1;
+	} else {
+	    rectangles[i].right.x = traps->traps[i].left.p1.x;
+	    rectangles[i].right.dir = 1;
+
+	    rectangles[i].left.x = traps->traps[i].right.p1.x;
+	    rectangles[i].left.dir = -1;
+	}
+
+	rectangles[i].left.right = NULL;
+	rectangles[i].right.right = NULL;
+
+	rectangles[i].top = traps->traps[i].top;
+	rectangles[i].bottom = traps->traps[i].bottom;
+
+	rectangles_ptrs[i+2] = &rectangles[i];
+    }
+    /* XXX incremental sort */
+    _rectangle_sort (rectangles_ptrs+2, i);
+
+    _cairo_traps_clear (traps);
+    status = _cairo_bentley_ottmann_tessellate_rectangular (rectangles_ptrs+2, i,
+							    fill_rule,
+							    TRUE, traps);
+    traps->is_rectilinear = TRUE;
+    traps->is_rectangular = TRUE;
+
+    if (rectangles != stack_rectangles)
+	free (rectangles);
+
+    dump_traps (traps, "bo-rects-traps-out.txt");
+
+    return status;
+}
+
+cairo_status_t
+_cairo_bentley_ottmann_tessellate_boxes (const cairo_boxes_t *in,
+					 cairo_fill_rule_t fill_rule,
+					 cairo_boxes_t *out)
+{
+    rectangle_t stack_rectangles[CAIRO_STACK_ARRAY_LENGTH (rectangle_t)];
+    rectangle_t *stack_rectangles_ptrs[ARRAY_LENGTH (stack_rectangles) + 3];
+    rectangle_t *rectangles, **rectangles_ptrs;
+    rectangle_t *stack_rectangles_chain[CAIRO_STACK_ARRAY_LENGTH (rectangle_t *) ];
+    rectangle_t **rectangles_chain = NULL;
+    const struct _cairo_boxes_chunk *chunk;
+    cairo_status_t status;
+    int i, j, y_min, y_max;
+
+    if (unlikely (in->num_boxes == 0)) {
+	_cairo_boxes_clear (out);
+	return CAIRO_STATUS_SUCCESS;
+    }
+
+    if (in->num_boxes == 1) {
+	if (in == out) {
+	    cairo_box_t *box = &in->chunks.base[0];
+
+	    if (box->p1.x > box->p2.x) {
+		cairo_fixed_t tmp = box->p1.x;
+		box->p1.x = box->p2.x;
+		box->p2.x = tmp;
+	    }
+	} else {
+	    cairo_box_t box = in->chunks.base[0];
+
+	    if (box.p1.x > box.p2.x) {
+		cairo_fixed_t tmp = box.p1.x;
+		box.p1.x = box.p2.x;
+		box.p2.x = tmp;
+	    }
+
+	    _cairo_boxes_clear (out);
+	    status = _cairo_boxes_add (out, CAIRO_ANTIALIAS_DEFAULT, &box);
+	    assert (status == CAIRO_STATUS_SUCCESS);
+	}
+	return CAIRO_STATUS_SUCCESS;
+    }
+
+    y_min = INT_MAX; y_max = INT_MIN;
+    for (chunk = &in->chunks; chunk != NULL; chunk = chunk->next) {
+	const cairo_box_t *box = chunk->base;
+	for (i = 0; i < chunk->count; i++) {
+	    if (box[i].p1.y < y_min)
+		y_min = box[i].p1.y;
+	    if (box[i].p1.y > y_max)
+		y_max = box[i].p1.y;
+	}
+    }
+    y_min = _cairo_fixed_integer_floor (y_min);
+    y_max = _cairo_fixed_integer_floor (y_max) + 1;
+    y_max -= y_min;
+
+    if (y_max < in->num_boxes) {
+	rectangles_chain = stack_rectangles_chain;
+	if (y_max > ARRAY_LENGTH (stack_rectangles_chain)) {
+	    rectangles_chain = _cairo_malloc_ab (y_max, sizeof (rectangle_t *));
+	    if (unlikely (rectangles_chain == NULL))
+		return _cairo_error (CAIRO_STATUS_NO_MEMORY);
+	}
+	memset (rectangles_chain, 0, y_max * sizeof (rectangle_t*));
+    }
+
+    rectangles = stack_rectangles;
+    rectangles_ptrs = stack_rectangles_ptrs;
+    if (in->num_boxes > ARRAY_LENGTH (stack_rectangles)) {
+	rectangles = _cairo_malloc_ab_plus_c (in->num_boxes,
+					      sizeof (rectangle_t) +
+					      sizeof (rectangle_t *),
+					      3*sizeof (rectangle_t *));
+	if (unlikely (rectangles == NULL)) {
+	    if (rectangles_chain != stack_rectangles_chain)
+		free (rectangles_chain);
+	    return _cairo_error (CAIRO_STATUS_NO_MEMORY);
+	}
+
+	rectangles_ptrs = (rectangle_t **) (rectangles + in->num_boxes);
+    }
+
+    j = 0;
+    for (chunk = &in->chunks; chunk != NULL; chunk = chunk->next) {
+	const cairo_box_t *box = chunk->base;
+	for (i = 0; i < chunk->count; i++) {
+	    int h;
+
+	    if (box[i].p1.x < box[i].p2.x) {
+		rectangles[j].left.x = box[i].p1.x;
+		rectangles[j].left.dir = 1;
+
+		rectangles[j].right.x = box[i].p2.x;
+		rectangles[j].right.dir = -1;
+	    } else {
+		rectangles[j].right.x = box[i].p1.x;
+		rectangles[j].right.dir = 1;
+
+		rectangles[j].left.x = box[i].p2.x;
+		rectangles[j].left.dir = -1;
+	    }
+
+	    rectangles[j].left.right = NULL;
+	    rectangles[j].right.right = NULL;
+
+	    rectangles[j].top = box[i].p1.y;
+	    rectangles[j].bottom = box[i].p2.y;
+
+	    if (rectangles_chain) {
+		h = _cairo_fixed_integer_floor (box[i].p1.y) - y_min;
+		rectangles[j].left.next = (edge_t *)rectangles_chain[h];
+		rectangles_chain[h] = &rectangles[j];
+	    } else {
+		rectangles_ptrs[j+2] = &rectangles[j];
+	    }
+	    j++;
+	}
+    }
+
+    if (rectangles_chain) {
+	j = 2;
+	for (y_min = 0; y_min < y_max; y_min++) {
+	    rectangle_t *r;
+	    int start = j;
+	    for (r = rectangles_chain[y_min]; r; r = (rectangle_t *)r->left.next)
+		rectangles_ptrs[j++] = r;
+	    if (j > start + 1)
+		_rectangle_sort (rectangles_ptrs + start, j - start);
+	}
+
+	if (rectangles_chain != stack_rectangles_chain)
+	    free (rectangles_chain);
+
+	j -= 2;
+    } else {
+	_rectangle_sort (rectangles_ptrs + 2, j);
+    }
+
+    _cairo_boxes_clear (out);
+    status = _cairo_bentley_ottmann_tessellate_rectangular (rectangles_ptrs+2, j,
+							    fill_rule,
+							    FALSE, out);
+    if (rectangles != stack_rectangles)
+	free (rectangles);
+
+    return status;
+}