summaryrefslogtreecommitdiff
path: root/src/cairo-surface-snapshot.c
diff options
context:
space:
mode:
Diffstat (limited to 'src/cairo-surface-snapshot.c')
-rw-r--r--src/cairo-surface-snapshot.c289
1 files changed, 289 insertions, 0 deletions
diff --git a/src/cairo-surface-snapshot.c b/src/cairo-surface-snapshot.c
new file mode 100644
index 000000000..68bf9054e
--- /dev/null
+++ b/src/cairo-surface-snapshot.c
@@ -0,0 +1,289 @@
+/* cairo - a vector graphics library with display and print output
+ *
+ * Copyright © 2002 University of Southern California
+ * Copyright © 2005 Red Hat, Inc.
+ * Copyright © 2009 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>
+ * Chris Wilson <chris@chris-wilson.co.uk>
+ */
+
+#include "cairoint.h"
+
+#include "cairo-error-private.h"
+#include "cairo-image-surface-private.h"
+#include "cairo-surface-snapshot-inline.h"
+
+static cairo_status_t
+_cairo_surface_snapshot_finish (void *abstract_surface)
+{
+ cairo_surface_snapshot_t *surface = abstract_surface;
+ cairo_status_t status = CAIRO_STATUS_SUCCESS;
+
+ TRACE ((stderr, "%s\n", __FUNCTION__));
+
+ if (surface->clone != NULL) {
+ cairo_surface_finish (surface->clone);
+ status = surface->clone->status;
+
+ cairo_surface_destroy (surface->clone);
+ }
+
+ CAIRO_MUTEX_FINI (surface->mutex);
+
+ return status;
+}
+
+static cairo_status_t
+_cairo_surface_snapshot_flush (void *abstract_surface, unsigned flags)
+{
+ cairo_surface_snapshot_t *surface = abstract_surface;
+ cairo_surface_t *target;
+ cairo_status_t status;
+
+ target = _cairo_surface_snapshot_get_target (&surface->base);
+ status = _cairo_surface_flush (target, flags);
+ cairo_surface_destroy (target);
+
+ return status;
+}
+
+static cairo_surface_t *
+_cairo_surface_snapshot_source (void *abstract_surface,
+ cairo_rectangle_int_t *extents)
+{
+ cairo_surface_snapshot_t *surface = abstract_surface;
+ return _cairo_surface_get_source (surface->target, extents); /* XXX racy */
+}
+
+struct snapshot_extra {
+ cairo_surface_t *target;
+ void *extra;
+};
+
+static cairo_status_t
+_cairo_surface_snapshot_acquire_source_image (void *abstract_surface,
+ cairo_image_surface_t **image_out,
+ void **extra_out)
+{
+ cairo_surface_snapshot_t *surface = abstract_surface;
+ struct snapshot_extra *extra;
+ cairo_status_t status;
+
+ extra = malloc (sizeof (*extra));
+ if (unlikely (extra == NULL))
+ return _cairo_error (CAIRO_STATUS_NO_MEMORY);
+
+ extra->target = _cairo_surface_snapshot_get_target (&surface->base);
+ status = _cairo_surface_acquire_source_image (extra->target, image_out, &extra->extra);
+ if (unlikely (status)) {
+ cairo_surface_destroy (extra->target);
+ free (extra);
+ }
+
+ *extra_out = extra;
+ return status;
+}
+
+static void
+_cairo_surface_snapshot_release_source_image (void *abstract_surface,
+ cairo_image_surface_t *image,
+ void *_extra)
+{
+ struct snapshot_extra *extra = _extra;
+
+ _cairo_surface_release_source_image (extra->target, image, extra->extra);
+ cairo_surface_destroy (extra->target);
+ free (extra);
+}
+
+static cairo_bool_t
+_cairo_surface_snapshot_get_extents (void *abstract_surface,
+ cairo_rectangle_int_t *extents)
+{
+ cairo_surface_snapshot_t *surface = abstract_surface;
+ cairo_surface_t *target;
+ cairo_bool_t bounded;
+
+ target = _cairo_surface_snapshot_get_target (&surface->base);
+ bounded = _cairo_surface_get_extents (target, extents);
+ cairo_surface_destroy (target);
+
+ return bounded;
+}
+
+static const cairo_surface_backend_t _cairo_surface_snapshot_backend = {
+ CAIRO_INTERNAL_SURFACE_TYPE_SNAPSHOT,
+ _cairo_surface_snapshot_finish,
+ NULL,
+
+ NULL, /* create similar */
+ NULL, /* create similar image */
+ NULL, /* map to image */
+ NULL, /* unmap image */
+
+ _cairo_surface_snapshot_source,
+ _cairo_surface_snapshot_acquire_source_image,
+ _cairo_surface_snapshot_release_source_image,
+ NULL, /* snapshot */
+
+ NULL, /* copy_page */
+ NULL, /* show_page */
+
+ _cairo_surface_snapshot_get_extents,
+ NULL, /* get-font-options */
+
+ _cairo_surface_snapshot_flush,
+};
+
+static void
+_cairo_surface_snapshot_copy_on_write (cairo_surface_t *surface)
+{
+ cairo_surface_snapshot_t *snapshot = (cairo_surface_snapshot_t *) surface;
+ cairo_image_surface_t *image;
+ cairo_surface_t *clone;
+ void *extra;
+ cairo_status_t status;
+
+ TRACE ((stderr, "%s: target=%d\n",
+ __FUNCTION__, snapshot->target->unique_id));
+
+ /* We need to make an image copy of the original surface since the
+ * snapshot may exceed the lifetime of the original device, i.e.
+ * when we later need to use the snapshot the data may have already
+ * been lost.
+ */
+
+ CAIRO_MUTEX_LOCK (snapshot->mutex);
+
+ if (snapshot->target->backend->snapshot != NULL) {
+ clone = snapshot->target->backend->snapshot (snapshot->target);
+ if (clone != NULL) {
+ assert (clone->status || ! _cairo_surface_is_snapshot (clone));
+ goto done;
+ }
+ }
+
+ /* XXX copy to a similar surface, leave acquisition till later?
+ * We should probably leave such decisions to the backend in case we
+ * rely upon devices/connections like Xlib.
+ */
+ status = _cairo_surface_acquire_source_image (snapshot->target, &image, &extra);
+ if (unlikely (status)) {
+ snapshot->target = _cairo_surface_create_in_error (status);
+ status = _cairo_surface_set_error (surface, status);
+ goto unlock;
+ }
+ clone = image->base.backend->snapshot (&image->base);
+ _cairo_surface_release_source_image (snapshot->target, image, extra);
+
+done:
+ status = _cairo_surface_set_error (surface, clone->status);
+ snapshot->target = snapshot->clone = clone;
+ snapshot->base.type = clone->type;
+unlock:
+ CAIRO_MUTEX_UNLOCK (snapshot->mutex);
+}
+
+/**
+ * _cairo_surface_snapshot:
+ * @surface: a #cairo_surface_t
+ *
+ * Make an immutable reference to @surface. It is an error to call a
+ * surface-modifying function on the result of this function. The
+ * resulting 'snapshot' is a lazily copied-on-write surface i.e. it
+ * remains a reference to the original surface until that surface is
+ * written to again, at which time a copy is made of the original surface
+ * and the snapshot then points to that instead. Multiple snapshots of the
+ * same unmodified surface point to the same copy.
+ *
+ * The caller owns the return value and should call
+ * cairo_surface_destroy() when finished with it. This function will not
+ * return %NULL, but will return a nil surface instead.
+ *
+ * Return value: The snapshot surface. Note that the return surface
+ * may not necessarily be of the same type as @surface.
+ **/
+cairo_surface_t *
+_cairo_surface_snapshot (cairo_surface_t *surface)
+{
+ cairo_surface_snapshot_t *snapshot;
+ cairo_status_t status;
+
+ TRACE ((stderr, "%s: target=%d\n", __FUNCTION__, surface->unique_id));
+
+ if (unlikely (surface->status))
+ return _cairo_surface_create_in_error (surface->status);
+
+ if (unlikely (surface->finished))
+ return _cairo_surface_create_in_error (_cairo_error (CAIRO_STATUS_SURFACE_FINISHED));
+
+ if (surface->snapshot_of != NULL)
+ return cairo_surface_reference (surface);
+
+ if (_cairo_surface_is_snapshot (surface))
+ return cairo_surface_reference (surface);
+
+ snapshot = (cairo_surface_snapshot_t *)
+ _cairo_surface_has_snapshot (surface, &_cairo_surface_snapshot_backend);
+ if (snapshot != NULL)
+ return cairo_surface_reference (&snapshot->base);
+
+ snapshot = malloc (sizeof (cairo_surface_snapshot_t));
+ if (unlikely (snapshot == NULL))
+ return _cairo_surface_create_in_error (_cairo_error (CAIRO_STATUS_SURFACE_FINISHED));
+
+ _cairo_surface_init (&snapshot->base,
+ &_cairo_surface_snapshot_backend,
+ NULL, /* device */
+ surface->content);
+ snapshot->base.type = surface->type;
+
+ CAIRO_MUTEX_INIT (snapshot->mutex);
+ snapshot->target = surface;
+ snapshot->clone = NULL;
+
+ status = _cairo_surface_copy_mime_data (&snapshot->base, surface);
+ if (unlikely (status)) {
+ cairo_surface_destroy (&snapshot->base);
+ return _cairo_surface_create_in_error (status);
+ }
+
+ snapshot->base.device_transform = surface->device_transform;
+ snapshot->base.device_transform_inverse = surface->device_transform_inverse;
+
+ _cairo_surface_attach_snapshot (surface,
+ &snapshot->base,
+ _cairo_surface_snapshot_copy_on_write);
+
+ return &snapshot->base;
+}