Atlas - testdlopennote.c
Home / ext / SDL / test
Lines: 1 | Size: 1977 bytes
[Download] [Show on GitHub] [Search similar files] [Raw] [Raw (proxy)] 
[FILE BEGIN]
1#include <SDL3/SDL.h>
2#include <SDL3/SDL_main.h>
3
4#ifdef SDL_PLATFORM_WINDOWS
5#define PNG_SHARED_LIBRARY "libpng16-16.dll"
6#elif defined(SDL_PLATFORM_APPLE)
7#define PNG_SHARED_LIBRARY "libpng16.16.dylib"
8#else
9#define PNG_SHARED_LIBRARY "libpng16.so.16"
10#endif
11
12SDL_ELF_NOTE_DLOPEN(
13    "png",
14    "Support for loading PNG images using libpng",
15    SDL_ELF_NOTE_DLOPEN_PRIORITY_RECOMMENDED,
16    PNG_SHARED_LIBRARY
17)
18
19typedef int png_sig_cmp_fn(const unsigned char *sig, size_t start, size_t num_to_check);
20
21static struct {
22    SDL_SharedObject *library;
23    png_sig_cmp_fn *png_sig_cmp;
24} libpng16;
25
26static bool libpng_init(void)
27{
28    libpng16.library = SDL_LoadObject(PNG_SHARED_LIBRARY);
29    if (!libpng16.library) {
30        SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Failed to load libpng library \"" PNG_SHARED_LIBRARY "\"");
31        return false;
32    }
33    libpng16.png_sig_cmp = (png_sig_cmp_fn *)SDL_LoadFunction(libpng16.library, "png_sig_cmp");
34    return libpng16.png_sig_cmp != NULL;
35}
36
37static void libpng_quit(void)
38{
39    SDL_UnloadObject(libpng16.library);
40    SDL_zero(libpng16);
41}
42
43static bool is_png(const char *path)
44{
45    unsigned char header[8];
46    size_t count;
47    bool result;
48    SDL_IOStream *io = SDL_IOFromFile(path, "rb");
49    if (io == NULL) {
50        return false;
51    }
52    count = SDL_ReadIO(io, header, sizeof(header));
53    result = libpng16.png_sig_cmp(header, 0, count) == 0;
54    SDL_CloseIO(io);
55    return result;
56}
57
58int main(int argc, char *argv[])
59{
60    int i;
61
62    /* Enable standard application logging */
63    SDL_SetLogPriority(SDL_LOG_CATEGORY_APPLICATION, SDL_LOG_PRIORITY_INFO);
64
65    if (argc < 2) {
66        SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Usage: %s IMAGE [IMAGE [IMAGE ... ]]", argv[0]);
67        return 1;
68    }
69    if (!libpng_init()) {
70        return 1;
71    }
72    for (i = 1; i < argc; i++) {
73        SDL_Log("\"%s\" is a png: %s", argv[i], is_png(argv[i]) ? "YES" : "NO");
74    }
75    libpng_quit();
76    return 0;
77}
78
[FILE END]
(C) 2025 0x4248
(C) 2025 4248 Media and 4248 Systems, All part of 0x4248
See LICENCE files for more information. Not all files are by 0x4248 always check Licencing.