diff options
Diffstat (limited to 'libs/cairo/src/cairo-surface-snapshot.c')
| -rw-r--r-- | libs/cairo/src/cairo-surface-snapshot.c | 220 |
1 files changed, 220 insertions, 0 deletions
diff --git a/libs/cairo/src/cairo-surface-snapshot.c b/libs/cairo/src/cairo-surface-snapshot.c new file mode 100644 index 000000000..030636056 --- /dev/null +++ b/libs/cairo/src/cairo-surface-snapshot.c @@ -0,0 +1,220 @@ +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +#include "cairoint.h" + +#include "cairo-error-private.h" +#include "cairo-surface-snapshot-private.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; + + if (surface->clone != NULL) { + cairo_surface_finish (surface->clone); + status = surface->clone->status; + + cairo_surface_destroy (surface->clone); + } + + return status; +} + +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; + + return _cairo_surface_acquire_source_image (surface->target, image_out, extra_out); +} + +static void +_cairo_surface_snapshot_release_source_image (void *abstract_surface, + cairo_image_surface_t *image, + void *extra) +{ + cairo_surface_snapshot_t *surface = abstract_surface; + + _cairo_surface_release_source_image (surface->target, image, 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; + + return _cairo_surface_get_extents (surface->target, extents); +} + +static const cairo_surface_backend_t _cairo_surface_snapshot_backend = { + CAIRO_INTERNAL_SURFACE_TYPE_SNAPSHOT, + + NULL, /* create similar */ + _cairo_surface_snapshot_finish, + + _cairo_surface_snapshot_acquire_source_image, + _cairo_surface_snapshot_release_source_image, + NULL, NULL, /* acquire, release dest */ + NULL, /* clone similar */ + NULL, /* composite */ + NULL, /* fill rectangles */ + NULL, /* composite trapezoids */ + NULL, /* create span renderer */ + NULL, /* check span renderer */ + NULL, /* copy_page */ + NULL, /* show_page */ + _cairo_surface_snapshot_get_extents, +}; + +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_image_surface_t *clone; + void *extra; + cairo_status_t status; + + /* 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. + */ + + 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); + return; + } + + clone = (cairo_image_surface_t *) + _cairo_image_surface_create_with_pixman_format (NULL, + image->pixman_format, + image->width, + image->height, + 0); + if (likely (clone->base.status == CAIRO_STATUS_SUCCESS)) { + if (clone->stride == image->stride) { + memcpy (clone->data, image->data, image->stride * image->height); + } else { + pixman_image_composite32 (PIXMAN_OP_SRC, + image->pixman_image, NULL, clone->pixman_image, + 0, 0, + 0, 0, + 0, 0, + image->width, image->height); + } + clone->base.is_clear = FALSE; + + snapshot->clone = &clone->base; + } else { + snapshot->clone = &clone->base; + status = _cairo_surface_set_error (surface, clone->base.status); + } + + _cairo_surface_release_source_image (snapshot->target, image, extra); + snapshot->target = snapshot->clone; + snapshot->base.type = snapshot->target->type; +} + +/** + * _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; + + if (unlikely (surface->status)) + return _cairo_surface_create_in_error (surface->status); + + if (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 (surface->backend->snapshot != NULL) { + cairo_surface_t *snap; + + snap = _cairo_surface_has_snapshot (surface, surface->backend); + if (snap != NULL) + return cairo_surface_reference (snap); + + snap = surface->backend->snapshot (surface); + if (snap != NULL) { + if (unlikely (snap->status)) + return snap; + + status = _cairo_surface_copy_mime_data (snap, surface); + if (unlikely (status)) { + cairo_surface_destroy (snap); + return _cairo_surface_create_in_error (status); + } + + snap->device_transform = surface->device_transform; + snap->device_transform_inverse = surface->device_transform_inverse; + + cairo_surface_attach_snapshot (surface, snap, NULL); + + return snap; + } + } + + 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; + + 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; +} |