libguac  0.9.12-incubating
hash.h
Go to the documentation of this file.
1 /*
2  * Licensed to the Apache Software Foundation (ASF) under one
3  * or more contributor license agreements. See the NOTICE file
4  * distributed with this work for additional information
5  * regarding copyright ownership. The ASF licenses this file
6  * to you under the Apache License, Version 2.0 (the
7  * "License"); you may not use this file except in compliance
8  * with the License. You may obtain a copy of the License at
9  *
10  * http://www.apache.org/licenses/LICENSE-2.0
11  *
12  * Unless required by applicable law or agreed to in writing,
13  * software distributed under the License is distributed on an
14  * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
15  * KIND, either express or implied. See the License for the
16  * specific language governing permissions and limitations
17  * under the License.
18  */
19 
20 
21 #ifndef _GUAC_HASH_H
22 #define _GUAC_HASH_H
23 
31 #include <cairo/cairo.h>
32 
43 unsigned int guac_hash_surface(cairo_surface_t* surface);
44 
56 int guac_surface_cmp(cairo_surface_t* a, cairo_surface_t* b);
57 
58 #endif
59 
int guac_surface_cmp(cairo_surface_t *a, cairo_surface_t *b)
Given two Cairo surfaces, returns zero if the data contained within each is identical, and a positive or negative value if the value of the first is found to be lexically greater or less than the second respectively.
unsigned int guac_hash_surface(cairo_surface_t *surface)
Produces a 24-bit hash value from all pixels of the given surface.