| /* cairo - a vector graphics library with display and print output |
| * |
| * Copyright © 2005 Red Hat, Inc |
| * |
| * 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 Red Hat, Inc. |
| * |
| * Contributor(s): |
| * Carl Worth <cworth@cworth.org> |
| */ |
| |
| #ifndef CAIRO_PAGINATED_H |
| #define CAIRO_PAGINATED_H |
| |
| #include "cairoint.h" |
| |
| struct _cairo_paginated_surface_backend { |
| /* Optional. Will be called once for each page. |
| * |
| * Note: With respect to the order of drawing operations as seen |
| * by the target, this call will occur before any drawing |
| * operations for the relevant page. However, with respect to the |
| * function calls as made by the user, this call will be *after* |
| * any drawing operations for the page, (that is, it will occur |
| * during the user's call to cairo_show_page or cairo_copy_page). |
| */ |
| cairo_warn cairo_int_status_t |
| (*start_page) (void *surface); |
| |
| /* Required. Will be called twice for each page, once with an |
| * argument of CAIRO_PAGINATED_MODE_ANALYZE and once with |
| * CAIRO_PAGINATED_MODE_RENDER. See more details in the |
| * documentation for _cairo_paginated_surface_create below. |
| */ |
| void |
| (*set_paginated_mode) (void *surface, |
| cairo_paginated_mode_t mode); |
| |
| /* Optional. Specifies the smallest box that encloses all objects |
| * on the page. Will be called at the end of the ANALYZE phase but |
| * before the mode is changed to RENDER. |
| */ |
| cairo_warn cairo_int_status_t |
| (*set_bounding_box) (void *surface, |
| cairo_box_t *bbox); |
| |
| /* Optional. Indicates whether the page requires fallback images. |
| * Will be called at the end of the ANALYZE phase but before the |
| * mode is changed to RENDER. |
| */ |
| cairo_warn cairo_int_status_t |
| (*set_fallback_images_required) (void *surface, |
| cairo_bool_t fallbacks_required); |
| |
| cairo_bool_t |
| (*supports_fine_grained_fallbacks) (void *surface); |
| }; |
| |
| /* A #cairo_paginated_surface_t provides a very convenient wrapper that |
| * is well-suited for doing the analysis common to most surfaces that |
| * have paginated output, (that is, things directed at printers, or |
| * for saving content in files such as PostScript or PDF files). |
| * |
| * To use the paginated surface, you'll first need to create your |
| * 'real' surface using _cairo_surface_init() and the standard |
| * #cairo_surface_backend_t. Then you also call |
| * _cairo_paginated_surface_create which takes its own, much simpler, |
| * #cairo_paginated_surface_backend_t. You are free to return the result |
| * of _cairo_paginated_surface_create() from your public |
| * cairo_<foo>_surface_create(). The paginated backend will be careful |
| * to not let the user see that they really got a "wrapped" |
| * surface. See test-paginated-surface.c for a fairly minimal example |
| * of a paginated-using surface. That should be a reasonable example |
| * to follow. |
| * |
| * What the paginated surface does is first save all drawing |
| * operations for a page into a recording-surface. Then when the user calls |
| * cairo_show_page(), the paginated surface performs the following |
| * sequence of operations (using the backend functions passed to |
| * cairo_paginated_surface_create()): |
| * |
| * 1. Calls start_page() (if not %NULL). At this point, it is appropriate |
| * for the target to emit any page-specific header information into |
| * its output. |
| * |
| * 2. Calls set_paginated_mode() with an argument of %CAIRO_PAGINATED_MODE_ANALYZE |
| * |
| * 3. Replays the recording-surface to the target surface, (with an |
| * analysis surface inserted between which watches the return value |
| * from each operation). This analysis stage is used to decide which |
| * operations will require fallbacks. |
| * |
| * 4. Calls set_bounding_box() to provide the target surface with the |
| * tight bounding box of the page. |
| * |
| * 5. Calls set_paginated_mode() with an argument of %CAIRO_PAGINATED_MODE_RENDER |
| * |
| * 6. Replays a subset of the recording-surface operations to the target surface |
| * |
| * 7. Calls set_paginated_mode() with an argument of %CAIRO_PAGINATED_MODE_FALLBACK |
| * |
| * 8. Replays the remaining operations to an image surface, sets an |
| * appropriate clip on the target, then paints the resulting image |
| * surface to the target. |
| * |
| * So, the target will see drawing operations during three separate |
| * stages, (ANALYZE, RENDER and FALLBACK). During the ANALYZE phase |
| * the target should not actually perform any rendering, (for example, |
| * if performing output to a file, no output should be generated |
| * during this stage). Instead the drawing functions simply need to |
| * return %CAIRO_STATUS_SUCCESS or %CAIRO_INT_STATUS_UNSUPPORTED to |
| * indicate whether rendering would be supported. And it should do |
| * this as quickly as possible. The FALLBACK phase allows the surface |
| * to distinguish fallback images from native rendering in case they |
| * need to be handled as a special case. |
| * |
| * Note: The paginated surface layer assumes that the target surface |
| * is "blank" by default at the beginning of each page, without any |
| * need for an explicit erase operation, (as opposed to an image |
| * surface, for example, which might have uninitialized content |
| * originally). As such, it optimizes away CLEAR operations that |
| * happen at the beginning of each page---the target surface will not |
| * even see these operations. |
| */ |
| cairo_private cairo_surface_t * |
| _cairo_paginated_surface_create (cairo_surface_t *target, |
| cairo_content_t content, |
| const cairo_paginated_surface_backend_t *backend); |
| |
| cairo_private cairo_surface_t * |
| _cairo_paginated_surface_get_target (cairo_surface_t *surface); |
| |
| cairo_private cairo_bool_t |
| _cairo_surface_is_paginated (cairo_surface_t *surface); |
| |
| cairo_private cairo_status_t |
| _cairo_paginated_surface_set_size (cairo_surface_t *surface, |
| int width, |
| int height); |
| |
| #endif /* CAIRO_PAGINATED_H */ |