515 lines
11 KiB
C
515 lines
11 KiB
C
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/*
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SDL_image: An example image loading library for use with SDL
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Copyright (C) 1997-2012 Sam Lantinga <slouken@libsdl.org>
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This software is provided 'as-is', without any express or implied
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warranty. In no event will the authors be held liable for any damages
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arising from the use of this software.
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Permission is granted to anyone to use this software for any purpose,
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including commercial applications, and to alter it and redistribute it
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freely, subject to the following restrictions:
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1. The origin of this software must not be misrepresented; you must not
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claim that you wrote the original software. If you use this software
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in a product, an acknowledgment in the product documentation would be
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appreciated but is not required.
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2. Altered source versions must be plainly marked as such, and must not be
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misrepresented as being the original software.
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3. This notice may not be removed or altered from any source distribution.
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*/
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/*
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* XPM (X PixMap) image loader:
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*
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* Supports the XPMv3 format, EXCEPT:
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* - hotspot coordinates are ignored
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* - only colour ('c') colour symbols are used
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* - rgb.txt is not used (for portability), so only RGB colours
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* are recognized (#rrggbb etc) - only a few basic colour names are
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* handled
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*
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* The result is an 8bpp indexed surface if possible, otherwise 32bpp.
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* The colourkey is correctly set if transparency is used.
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*
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* Besides the standard API, also provides
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*
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* SDL_Surface *IMG_ReadXPMFromArray(char **xpm)
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*
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* that reads the image data from an XPM file included in the C source.
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*
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* TODO: include rgb.txt here. The full table (from solaris 2.6) only
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* requires about 13K in binary form.
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*/
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#include <stdlib.h>
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#include <stdio.h>
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#include <string.h>
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#include <ctype.h>
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#include "SDL_image.h"
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#ifdef LOAD_XPM
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/* See if an image is contained in a data source */
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int IMG_isXPM(SDL_RWops *src)
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{
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int start;
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int is_XPM;
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char magic[9];
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if ( !src )
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return 0;
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start = SDL_RWtell(src);
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is_XPM = 0;
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if ( SDL_RWread(src, magic, sizeof(magic), 1) ) {
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if ( memcmp(magic, "/* XPM */", sizeof(magic)) == 0 ) {
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is_XPM = 1;
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}
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}
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SDL_RWseek(src, start, RW_SEEK_SET);
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return(is_XPM);
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}
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/* Hash table to look up colors from pixel strings */
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#define STARTING_HASH_SIZE 256
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struct hash_entry {
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char *key;
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Uint32 color;
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struct hash_entry *next;
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};
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struct color_hash {
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struct hash_entry **table;
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struct hash_entry *entries; /* array of all entries */
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struct hash_entry *next_free;
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int size;
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int maxnum;
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};
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static int hash_key(const char *key, int cpp, int size)
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{
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int hash;
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hash = 0;
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while ( cpp-- > 0 ) {
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hash = hash * 33 + *key++;
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}
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return hash & (size - 1);
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}
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static struct color_hash *create_colorhash(int maxnum)
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{
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int bytes, s;
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struct color_hash *hash;
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/* we know how many entries we need, so we can allocate
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everything here */
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hash = malloc(sizeof *hash);
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if(!hash)
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return NULL;
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/* use power-of-2 sized hash table for decoding speed */
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for(s = STARTING_HASH_SIZE; s < maxnum; s <<= 1)
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;
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hash->size = s;
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hash->maxnum = maxnum;
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bytes = hash->size * sizeof(struct hash_entry **);
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hash->entries = NULL; /* in case malloc fails */
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hash->table = malloc(bytes);
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if(!hash->table)
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return NULL;
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memset(hash->table, 0, bytes);
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hash->entries = malloc(maxnum * sizeof(struct hash_entry));
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if(!hash->entries) {
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free(hash->table);
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return NULL;
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}
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hash->next_free = hash->entries;
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return hash;
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}
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static int add_colorhash(struct color_hash *hash,
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char *key, int cpp, Uint32 color)
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{
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int index = hash_key(key, cpp, hash->size);
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struct hash_entry *e = hash->next_free++;
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e->color = color;
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e->key = key;
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e->next = hash->table[index];
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hash->table[index] = e;
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return 1;
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}
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/* fast lookup that works if cpp == 1 */
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#define QUICK_COLORHASH(hash, key) ((hash)->table[*(Uint8 *)(key)]->color)
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static Uint32 get_colorhash(struct color_hash *hash, const char *key, int cpp)
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{
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struct hash_entry *entry = hash->table[hash_key(key, cpp, hash->size)];
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while(entry) {
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if(memcmp(key, entry->key, cpp) == 0)
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return entry->color;
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entry = entry->next;
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}
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return 0; /* garbage in - garbage out */
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}
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static void free_colorhash(struct color_hash *hash)
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{
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if(hash && hash->table) {
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free(hash->table);
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free(hash->entries);
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free(hash);
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}
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}
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/* portable case-insensitive string comparison */
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static int string_equal(const char *a, const char *b, int n)
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{
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while(*a && *b && n) {
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if(toupper((unsigned char)*a) != toupper((unsigned char)*b))
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return 0;
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a++;
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b++;
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n--;
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}
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return *a == *b;
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}
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#define ARRAYSIZE(a) (int)(sizeof(a) / sizeof((a)[0]))
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/*
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* convert colour spec to RGB (in 0xrrggbb format).
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* return 1 if successful.
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*/
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static int color_to_rgb(char *spec, int speclen, Uint32 *rgb)
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{
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/* poor man's rgb.txt */
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static struct { char *name; Uint32 rgb; } known[] = {
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{"none", 0xffffffff},
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{"black", 0x00000000},
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{"white", 0x00ffffff},
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{"red", 0x00ff0000},
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{"green", 0x0000ff00},
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{"blue", 0x000000ff}
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};
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if(spec[0] == '#') {
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char buf[7];
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switch(speclen) {
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case 4:
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buf[0] = buf[1] = spec[1];
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buf[2] = buf[3] = spec[2];
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buf[4] = buf[5] = spec[3];
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break;
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case 7:
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memcpy(buf, spec + 1, 6);
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break;
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case 13:
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buf[0] = spec[1];
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buf[1] = spec[2];
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buf[2] = spec[5];
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buf[3] = spec[6];
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buf[4] = spec[9];
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buf[5] = spec[10];
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break;
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}
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buf[6] = '\0';
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*rgb = strtol(buf, NULL, 16);
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return 1;
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} else {
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int i;
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for(i = 0; i < ARRAYSIZE(known); i++)
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if(string_equal(known[i].name, spec, speclen)) {
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*rgb = known[i].rgb;
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return 1;
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}
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return 0;
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}
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}
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#ifndef MAX
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#define MAX(a, b) ((a) > (b) ? (a) : (b))
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#endif
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static char *linebuf;
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static int buflen;
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static char *error;
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/*
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* Read next line from the source.
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* If len > 0, it's assumed to be at least len chars (for efficiency).
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* Return NULL and set error upon EOF or parse error.
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*/
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static char *get_next_line(char ***lines, SDL_RWops *src, int len)
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{
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char *linebufnew;
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if(lines) {
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return *(*lines)++;
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} else {
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char c;
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int n;
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do {
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if(SDL_RWread(src, &c, 1, 1) <= 0) {
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error = "Premature end of data";
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return NULL;
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}
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} while(c != '"');
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if(len) {
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len += 4; /* "\",\n\0" */
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if(len > buflen){
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buflen = len;
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linebufnew = realloc(linebuf, buflen);
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if(!linebufnew) {
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free(linebuf);
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error = "Out of memory";
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return NULL;
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}
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linebuf = linebufnew;
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}
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if(SDL_RWread(src, linebuf, len - 1, 1) <= 0) {
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error = "Premature end of data";
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return NULL;
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}
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n = len - 2;
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} else {
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n = 0;
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do {
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if(n >= buflen - 1) {
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if(buflen == 0)
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buflen = 16;
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buflen *= 2;
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linebufnew = realloc(linebuf, buflen);
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if(!linebufnew) {
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free(linebuf);
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error = "Out of memory";
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return NULL;
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}
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linebuf = linebufnew;
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}
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if(SDL_RWread(src, linebuf + n, 1, 1) <= 0) {
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error = "Premature end of data";
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return NULL;
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}
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} while(linebuf[n++] != '"');
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n--;
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}
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linebuf[n] = '\0';
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return linebuf;
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}
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}
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#define SKIPSPACE(p) \
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do { \
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while(isspace((unsigned char)*(p))) \
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++(p); \
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} while(0)
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#define SKIPNONSPACE(p) \
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do { \
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while(!isspace((unsigned char)*(p)) && *p) \
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++(p); \
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} while(0)
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/* read XPM from either array or RWops */
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static SDL_Surface *load_xpm(char **xpm, SDL_RWops *src)
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{
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int start = 0;
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SDL_Surface *image = NULL;
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int index;
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int x, y;
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int w, h, ncolors, cpp;
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int indexed;
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Uint8 *dst;
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struct color_hash *colors = NULL;
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SDL_Color *im_colors = NULL;
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char *keystrings = NULL, *nextkey;
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char *line;
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char ***xpmlines = NULL;
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int pixels_len;
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error = NULL;
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linebuf = NULL;
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buflen = 0;
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if ( src )
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start = SDL_RWtell(src);
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if(xpm)
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xpmlines = &xpm;
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line = get_next_line(xpmlines, src, 0);
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if(!line)
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goto done;
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/*
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* The header string of an XPMv3 image has the format
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*
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* <width> <height> <ncolors> <cpp> [ <hotspot_x> <hotspot_y> ]
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*
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* where the hotspot coords are intended for mouse cursors.
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* Right now we don't use the hotspots but it should be handled
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* one day.
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*/
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if(sscanf(line, "%d %d %d %d", &w, &h, &ncolors, &cpp) != 4
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|| w <= 0 || h <= 0 || ncolors <= 0 || cpp <= 0) {
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error = "Invalid format description";
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goto done;
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}
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keystrings = malloc(ncolors * cpp);
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if(!keystrings) {
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error = "Out of memory";
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goto done;
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}
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nextkey = keystrings;
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/* Create the new surface */
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if(ncolors <= 256) {
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indexed = 1;
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image = SDL_CreateRGBSurface(SDL_SWSURFACE, w, h, 8,
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0, 0, 0, 0);
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im_colors = image->format->palette->colors;
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image->format->palette->ncolors = ncolors;
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} else {
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indexed = 0;
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image = SDL_CreateRGBSurface(SDL_SWSURFACE, w, h, 32,
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0xff0000, 0x00ff00, 0x0000ff, 0);
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}
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if(!image) {
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/* Hmm, some SDL error (out of memory?) */
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goto done;
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}
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/* Read the colors */
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colors = create_colorhash(ncolors);
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if (!colors) {
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error = "Out of memory";
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goto done;
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}
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for(index = 0; index < ncolors; ++index ) {
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char *p;
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line = get_next_line(xpmlines, src, 0);
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if(!line)
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goto done;
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p = line + cpp + 1;
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/* parse a colour definition */
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for(;;) {
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char nametype;
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char *colname;
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Uint32 rgb, pixel;
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SKIPSPACE(p);
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if(!*p) {
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error = "colour parse error";
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goto done;
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}
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nametype = *p;
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SKIPNONSPACE(p);
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SKIPSPACE(p);
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colname = p;
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SKIPNONSPACE(p);
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if(nametype == 's')
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continue; /* skip symbolic colour names */
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if(!color_to_rgb(colname, p - colname, &rgb))
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continue;
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memcpy(nextkey, line, cpp);
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if(indexed) {
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SDL_Color *c = im_colors + index;
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c->r = (Uint8)(rgb >> 16);
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c->g = (Uint8)(rgb >> 8);
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c->b = (Uint8)(rgb);
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pixel = index;
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} else
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pixel = rgb;
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add_colorhash(colors, nextkey, cpp, pixel);
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nextkey += cpp;
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if(rgb == 0xffffffff)
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SDL_SetColorKey(image, SDL_SRCCOLORKEY, pixel);
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break;
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}
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}
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/* Read the pixels */
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pixels_len = w * cpp;
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dst = image->pixels;
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for(y = 0; y < h; y++) {
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line = get_next_line(xpmlines, src, pixels_len);
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if(indexed) {
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/* optimization for some common cases */
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if(cpp == 1)
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for(x = 0; x < w; x++)
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dst[x] = (Uint8)QUICK_COLORHASH(colors,
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line + x);
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else
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for(x = 0; x < w; x++)
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dst[x] = (Uint8)get_colorhash(colors,
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line + x * cpp,
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cpp);
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} else {
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for (x = 0; x < w; x++)
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((Uint32*)dst)[x] = get_colorhash(colors,
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line + x * cpp,
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cpp);
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}
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dst += image->pitch;
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}
|
||
|
|
||
|
done:
|
||
|
if(error) {
|
||
|
if ( src )
|
||
|
SDL_RWseek(src, start, RW_SEEK_SET);
|
||
|
if ( image ) {
|
||
|
SDL_FreeSurface(image);
|
||
|
image = NULL;
|
||
|
}
|
||
|
IMG_SetError(error);
|
||
|
}
|
||
|
free(keystrings);
|
||
|
free_colorhash(colors);
|
||
|
free(linebuf);
|
||
|
return(image);
|
||
|
}
|
||
|
|
||
|
/* Load a XPM type image from an RWops datasource */
|
||
|
SDL_Surface *IMG_LoadXPM_RW(SDL_RWops *src)
|
||
|
{
|
||
|
if ( !src ) {
|
||
|
/* The error message has been set in SDL_RWFromFile */
|
||
|
return NULL;
|
||
|
}
|
||
|
return load_xpm(NULL, src);
|
||
|
}
|
||
|
|
||
|
SDL_Surface *IMG_ReadXPMFromArray(char **xpm)
|
||
|
{
|
||
|
return load_xpm(xpm, NULL);
|
||
|
}
|
||
|
|
||
|
#else /* not LOAD_XPM */
|
||
|
|
||
|
/* See if an image is contained in a data source */
|
||
|
int IMG_isXPM(SDL_RWops *src)
|
||
|
{
|
||
|
return(0);
|
||
|
}
|
||
|
|
||
|
|
||
|
/* Load a XPM type image from an SDL datasource */
|
||
|
SDL_Surface *IMG_LoadXPM_RW(SDL_RWops *src)
|
||
|
{
|
||
|
return(NULL);
|
||
|
}
|
||
|
|
||
|
SDL_Surface *IMG_ReadXPMFromArray(char **xpm)
|
||
|
{
|
||
|
return NULL;
|
||
|
}
|
||
|
#endif /* not LOAD_XPM */
|