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/* 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 

 *      Chris Wilson 

 */

#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;

}