/
IMG_xv.c
162 lines (139 loc) · 4.01 KB
2
SDL_image: An example image loading library for use with SDL
3
Copyright (C) 1997-2018 Sam Lantinga <slouken@libsdl.org>
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
This software is provided 'as-is', without any express or implied
warranty. In no event will the authors be held liable for any damages
arising from the use of this software.
Permission is granted to anyone to use this software for any purpose,
including commercial applications, and to alter it and redistribute it
freely, subject to the following restrictions:
1. The origin of this software must not be misrepresented; you must not
claim that you wrote the original software. If you use this software
in a product, an acknowledgment in the product documentation would be
appreciated but is not required.
2. Altered source versions must be plainly marked as such, and must not be
misrepresented as being the original software.
3. This notice may not be removed or altered from any source distribution.
22
/* This is a XV thumbnail image file loading framework */
23
24
25
26
27
28
29
#include "SDL_image.h"
#ifdef LOAD_XV
static int get_line(SDL_RWops *src, char *line, int size)
{
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
while ( size > 0 ) {
if ( SDL_RWread(src, line, 1, 1) <= 0 ) {
return -1;
}
if ( *line == '\r' ) {
continue;
}
if ( *line == '\n' ) {
*line = '\0';
return 0;
}
++line;
--size;
}
/* Out of space for the line */
return -1;
46
47
48
49
}
static int get_header(SDL_RWops *src, int *w, int *h)
{
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
char line[1024];
*w = 0;
*h = 0;
/* Check the header magic */
if ( (get_line(src, line, sizeof(line)) < 0) ||
(SDL_memcmp(line, "P7 332", 6) != 0) ) {
return -1;
}
/* Read the header */
while ( get_line(src, line, sizeof(line)) == 0 ) {
if ( SDL_memcmp(line, "#BUILTIN:", 9) == 0 ) {
/* Builtin image, no data */
break;
}
if ( SDL_memcmp(line, "#END_OF_COMMENTS", 16) == 0 ) {
if ( get_line(src, line, sizeof(line)) == 0 ) {
SDL_sscanf(line, "%d %d", w, h);
if ( *w >= 0 && *h >= 0 ) {
return 0;
}
}
break;
}
}
/* No image data */
return -1;
79
80
81
82
83
}
/* See if an image is contained in a data source */
int IMG_isXV(SDL_RWops *src)
{
84
85
86
87
88
89
90
91
92
93
94
95
96
Sint64 start;
int is_XV;
int w, h;
if ( !src )
return 0;
start = SDL_RWtell(src);
is_XV = 0;
if ( get_header(src, &w, &h) == 0 ) {
is_XV = 1;
}
SDL_RWseek(src, start, RW_SEEK_SET);
return(is_XV);
97
98
99
100
101
}
/* Load a XV thumbnail image from an SDL datasource */
SDL_Surface *IMG_LoadXV_RW(SDL_RWops *src)
{
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
Sint64 start;
const char *error = NULL;
SDL_Surface *surface = NULL;
int w, h;
Uint8 *pixels;
if ( !src ) {
/* The error message has been set in SDL_RWFromFile */
return NULL;
}
start = SDL_RWtell(src);
/* Read the header */
if ( get_header(src, &w, &h) < 0 ) {
error = "Unsupported image format";
goto done;
}
/* Create the 3-3-2 indexed palette surface */
surface = SDL_CreateRGBSurface(SDL_SWSURFACE, w, h, 8, 0xe0, 0x1c, 0x03, 0);
if ( surface == NULL ) {
error = "Out of memory";
goto done;
}
/* Load the image data */
for ( pixels = (Uint8 *)surface->pixels; h > 0; --h ) {
if ( SDL_RWread(src, pixels, w, 1) <= 0 ) {
error = "Couldn't read image data";
goto done;
}
pixels += surface->pitch;
}
135
136
done:
137
138
139
140
141
142
if ( error ) {
SDL_RWseek(src, start, RW_SEEK_SET);
if ( surface ) {
SDL_FreeSurface(surface);
surface = NULL;
}
143
IMG_SetError("%s", error);
144
145
}
return surface;
146
147
148
149
150
151
152
}
#else
/* See if an image is contained in a data source */
int IMG_isXV(SDL_RWops *src)
{
153
return(0);
154
155
156
157
158
}
/* Load a XXX type image from an SDL datasource */
SDL_Surface *IMG_LoadXV_RW(SDL_RWops *src)
{
159
return(NULL);
160
161
162
}
#endif /* LOAD_XV */