| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (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.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, |
| * software distributed under the License is distributed on an |
| * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
| * KIND, either express or implied. See the License for the |
| * specific language governing permissions and limitations |
| * under the License. |
| */ |
| |
| #include "config.h" |
| |
| #include "palette.h" |
| |
| #include <cairo/cairo.h> |
| |
| #include <stdint.h> |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <string.h> |
| |
| guac_palette* guac_palette_alloc(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) { |
| |
| png_color* c; |
| |
| /* Stop if already at capacity */ |
| if (palette->size == 256) { |
| guac_palette_free(palette); |
| return NULL; |
| } |
| |
| /* Store in palette */ |
| c = &(palette->colors[palette->size]); |
| c->blue = (color ) & 0xFF; |
| c->green = (color >> 8 ) & 0xFF; |
| c->red = (color >> 16) & 0xFF; |
| |
| /* Add color to map */ |
| entry->index = ++palette->size; |
| 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; |
| |
| } |
| |
| int guac_palette_find(guac_palette* palette, int color) { |
| |
| /* Calculate hash code */ |
| int hash = ((color & 0xFFF000) >> 12) ^ (color & 0xFFF); |
| |
| guac_palette_entry* entry; |
| |
| /* Search for palette entry */ |
| for (;;) { |
| |
| entry = &(palette->entries[hash]); |
| |
| /* If we've found a free space, color not stored. */ |
| if (entry->index == 0) |
| return -1; |
| |
| /* Otherwise, if color indeed stored here, done */ |
| if (entry->color == color) |
| return entry->index - 1; |
| |
| /* Otherwise, collision. Move on to another bucket */ |
| hash = (hash+1) & 0xFFF; |
| |
| } |
| |
| } |
| |
| void guac_palette_free(guac_palette* palette) { |
| free(palette); |
| } |
| |