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/* imagediff - Compare two images
*
* Copyright © 2004 Richard D. Worth
* Copyright © 2006 Red Hat, Inc.
*
* Permission to use, copy, modify, distribute, and sell this software
* and its documentation for any purpose is hereby granted without
* fee, provided that the above copyright notice appear in all copies
* and that both that copyright notice and this permission notice
* appear in supporting documentation, and that the name of the authors
* not be used in advertising or publicity pertaining to distribution
* of the software without specific, written prior permission.
* The authors make no representations about the suitability of this
* software for any purpose. It is provided "as is" without express
* or implied warranty.
*
* THE AUTHORS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
* INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN
* NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
* CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS
* OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
* NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
* CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*
* Authors: Richard D. Worth <richard@theworths.org>
* Carl Worth <cworth@cworth.org>
*/
#ifndef BUFFER_DIFF_H
#define BUFFER_DIFF_H
#include "cairo-test.h"
typedef struct _buffer_diff_result {
unsigned int pixels_changed;
unsigned int max_diff;
} buffer_diff_result_t;
/* Compares two image buffers ignoring the alpha channel.
*
* Provides number of pixels changed and maximum single-channel
* difference in result.
*
* Also fills in a "diff" buffer intended to visually show where the
* images differ.
*/
void
buffer_diff_noalpha (const unsigned char *buf_a,
const unsigned char *buf_b,
unsigned char *buf_diff,
int width,
int height,
int stride,
buffer_diff_result_t *result);
/* The central algorithm to compare two images, and return the differences
* in the surface_diff.
*
* Provides number of pixels changed and maximum single-channel
* difference in result.
*/
cairo_status_t
image_diff (const cairo_test_context_t *ctx,
cairo_surface_t *surface_a,
cairo_surface_t *surface_b,
cairo_surface_t *surface_diff,
buffer_diff_result_t *result);
cairo_bool_t
image_diff_is_failure (const buffer_diff_result_t *result,
unsigned int tolerance);
#endif