guacamole-spice-protocol/libguac/src/palette.c
2012-04-01 21:49:15 -07:00

118 lines
3.6 KiB
C

/* ***** BEGIN LICENSE BLOCK *****
* Version: MPL 1.1/GPL 2.0/LGPL 2.1
*
* 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/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* The Original Code is libguac.
*
* The Initial Developer of the Original Code is
* Michael Jumper.
* Portions created by the Initial Developer are Copyright (C) 2010
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
*
* Alternatively, the contents of this file may be used under the terms of
* either the GNU General Public License Version 2 or later (the "GPL"), or
* the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
* in which case the provisions of the GPL or the LGPL are applicable instead
* of those above. If you wish to allow use of your version of this file only
* under the terms of either the GPL or the LGPL, and not to allow others to
* use your version of this file under the terms of the MPL, indicate your
* decision by deleting the provisions above and replace them with the notice
* and other provisions required by the GPL or the LGPL. If you do not delete
* the provisions above, a recipient may use your version of this file under
* the terms of any one of the MPL, the GPL or the LGPL.
*
* ***** END LICENSE BLOCK ***** */
#include <stdlib.h>
#include <stdio.h>
#include <stdint.h>
#include <string.h>
#include <inttypes.h>
#include <cairo/cairo.h>
#include <sys/types.h>
#include "palette.h"
guac_palette* __guac_create_palette(cairo_surface_t* surface) {
int x, y;
int width = cairo_image_surface_get_width(surface);
int height = cairo_image_surface_get_height(surface);
int stride = cairo_image_surface_get_stride(surface);
unsigned char* data = cairo_image_surface_get_data(surface);
/* Allocate palette */
guac_palette* palette = (guac_palette*) malloc(sizeof(guac_palette));
memset(palette, 0, sizeof(guac_palette));
for (y=0; y<height; y++) {
for (x=0; x<width; x++) {
/* Get pixel color */
int color = ((uint32_t*) data)[x] & 0xFFFFFF;
/* Calculate hash code */
int hash = ((color & 0xFFF000) >> 12) ^ (color & 0xFFF);
guac_palette_entry* entry;
/* Search for open palette entry */
for (;;) {
entry = &(palette->entries[hash]);
/* If we've found a free space, use it */
if (entry->index == 0) {
/* Stop if already at capacity */
if (palette->colors == 256) {
__guac_free_palette(palette);
return NULL;
}
/* Add color to map, done */
entry->index = ++palette->colors;
entry->color = color;
break;
}
/* Otherwise, if already stored here, done */
if (entry->color == color)
break;
/* Otherwise, collision. Move on to another bucket */
hash = (hash+1) & 0xFFF;
}
}
/* Advance to next data row */
data += stride;
}
return palette;
}
void __guac_free_palette(guac_palette* palette) {
free(palette);
}