summaryrefslogtreecommitdiff
path: root/src/cairo-tristrip.c
diff options
context:
space:
mode:
Diffstat (limited to 'src/cairo-tristrip.c')
-rw-r--r--src/cairo-tristrip.c185
1 files changed, 185 insertions, 0 deletions
diff --git a/src/cairo-tristrip.c b/src/cairo-tristrip.c
new file mode 100644
index 000000000..bb4972f50
--- /dev/null
+++ b/src/cairo-tristrip.c
@@ -0,0 +1,185 @@
+/* -*- Mode: c; tab-width: 8; c-basic-offset: 4; indent-tabs-mode: t; -*- */
+/*
+ * 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 Chris Wilson
+ *
+ * Contributor(s):
+ * Chris Wilson <chris@chris-wilsonc.co.uk>
+ */
+
+#include "cairoint.h"
+
+#include "cairo-error-private.h"
+#include "cairo-tristrip-private.h"
+
+void
+_cairo_tristrip_init (cairo_tristrip_t *strip)
+{
+ VG (VALGRIND_MAKE_MEM_UNDEFINED (strip, sizeof (cairo_tristrip_t)));
+
+ strip->status = CAIRO_STATUS_SUCCESS;
+
+ strip->num_limits = 0;
+ strip->num_points = 0;
+
+ strip->size_points = ARRAY_LENGTH (strip->points_embedded);
+ strip->points = strip->points_embedded;
+}
+
+void
+_cairo_tristrip_fini (cairo_tristrip_t *strip)
+{
+ if (strip->points != strip->points_embedded)
+ free (strip->points);
+
+ VG (VALGRIND_MAKE_MEM_NOACCESS (strip, sizeof (cairo_tristrip_t)));
+}
+
+
+void
+_cairo_tristrip_limit (cairo_tristrip_t *strip,
+ const cairo_box_t *limits,
+ int num_limits)
+{
+ strip->limits = limits;
+ strip->num_limits = num_limits;
+}
+
+void
+_cairo_tristrip_init_with_clip (cairo_tristrip_t *strip,
+ const cairo_clip_t *clip)
+{
+ _cairo_tristrip_init (strip);
+ if (clip)
+ _cairo_tristrip_limit (strip, clip->boxes, clip->num_boxes);
+}
+
+/* make room for at least one more trap */
+static cairo_bool_t
+_cairo_tristrip_grow (cairo_tristrip_t *strip)
+{
+ cairo_point_t *points;
+ int new_size = 4 * strip->size_points;
+
+ if (CAIRO_INJECT_FAULT ()) {
+ strip->status = _cairo_error (CAIRO_STATUS_NO_MEMORY);
+ return FALSE;
+ }
+
+ if (strip->points == strip->points_embedded) {
+ points = _cairo_malloc_ab (new_size, sizeof (cairo_point_t));
+ if (points != NULL)
+ memcpy (points, strip->points, sizeof (strip->points_embedded));
+ } else {
+ points = _cairo_realloc_ab (strip->points,
+ new_size, sizeof (cairo_trapezoid_t));
+ }
+
+ if (unlikely (points == NULL)) {
+ strip->status = _cairo_error (CAIRO_STATUS_NO_MEMORY);
+ return FALSE;
+ }
+
+ strip->points = points;
+ strip->size_points = new_size;
+ return TRUE;
+}
+
+void
+_cairo_tristrip_add_point (cairo_tristrip_t *strip,
+ const cairo_point_t *p)
+{
+ if (unlikely (strip->num_points == strip->size_points)) {
+ if (unlikely (! _cairo_tristrip_grow (strip)))
+ return;
+ }
+
+ strip->points[strip->num_points++] = *p;
+}
+
+/* Insert degenerate triangles to advance to the given point. The
+ * next point inserted must also be @p. */
+void
+_cairo_tristrip_move_to (cairo_tristrip_t *strip,
+ const cairo_point_t *p)
+{
+ if (strip->num_points == 0)
+ return;
+
+ _cairo_tristrip_add_point (strip, &strip->points[strip->num_points-1]);
+ _cairo_tristrip_add_point (strip, p);
+#if 0
+ /* and one more for luck! (to preserve cw/ccw ordering) */
+ _cairo_tristrip_add_point (strip, p);
+#endif
+}
+
+void
+_cairo_tristrip_translate (cairo_tristrip_t *strip, int x, int y)
+{
+ cairo_fixed_t xoff, yoff;
+ cairo_point_t *p;
+ int i;
+
+ xoff = _cairo_fixed_from_int (x);
+ yoff = _cairo_fixed_from_int (y);
+
+ for (i = 0, p = strip->points; i < strip->num_points; i++, p++) {
+ p->x += xoff;
+ p->y += yoff;
+ }
+}
+
+void
+_cairo_tristrip_extents (const cairo_tristrip_t *strip,
+ cairo_box_t *extents)
+{
+ int i;
+
+ if (strip->num_points == 0) {
+ extents->p1.x = extents->p1.y = 0;
+ extents->p2.x = extents->p2.y = 0;
+ return;
+ }
+
+ extents->p2 = extents->p1 = strip->points[0];
+ for (i = 1; i < strip->num_points; i++) {
+ const cairo_point_t *p = &strip->points[i];
+
+ if (p->x < extents->p1.x)
+ extents->p1.x = p->x;
+ else if (p->x > extents->p2.x)
+ extents->p2.x = p->x;
+
+ if (p->y < extents->p1.y)
+ extents->p1.y = p->y;
+ else if (p->y > extents->p2.y)
+ extents->p2.y = p->y;
+ }
+}