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Diffstat (limited to 'src/main/c/simple_graphics.c')
| -rw-r--r-- | src/main/c/simple_graphics.c | 102 |
1 files changed, 102 insertions, 0 deletions
diff --git a/src/main/c/simple_graphics.c b/src/main/c/simple_graphics.c new file mode 100644 index 00000000..40d66ba9 --- /dev/null +++ b/src/main/c/simple_graphics.c @@ -0,0 +1,102 @@ +#define _POSIX_C_SOURCE 200809L +#include "simple_graphics.h" +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <dlfcn.h> +#include <unistd.h> + +#ifdef __CYGWIN__ +#define BACKEND_NAME "simple_minifb.dll" +#define BACKEND_ABI "x86_64_v2_win64" +#else +#define BACKEND_NAME "libsimple_minifb.so" +#define BACKEND_ABI "x86_64_v2_SystemV" +#endif + +// Executable-relative paths work even when launched outside the checkout. +// Working-directory paths also cover test executables and chapter/root shells. +static void *find_backend(void) { + char executable[4096], path[8192]; + ssize_t n=readlink("/proc/self/exe",executable,sizeof(executable)-1); + if (n>0 && n<(ssize_t)sizeof(executable)-1) { + executable[n]=0; + char *slash=strrchr(executable,'/'); + if (slash) { + *slash=0; + const char *relative[]={"/" BACKEND_NAME, + "/../../release/" BACKEND_ABI "/" BACKEND_NAME, + "/../release/" BACKEND_ABI "/" BACKEND_NAME}; + for (unsigned i=0;i<sizeof(relative)/sizeof(*relative);++i) { + snprintf(path,sizeof(path),"%s%s",executable,relative[i]); + void *handle=dlopen(path,RTLD_NOW | RTLD_LOCAL); + if (handle) return handle; + } + } + } + const char *relative[]={"./" BACKEND_NAME, + "./build/release/" BACKEND_ABI "/" BACKEND_NAME, + "./chapter31/build/release/" BACKEND_ABI "/" BACKEND_NAME}; + for (unsigned i=0;i<sizeof(relative)/sizeof(*relative);++i) { + void *handle=dlopen(relative[i],RTLD_NOW | RTLD_LOCAL); + if (handle) return handle; + } + return NULL; +} + +// No MiniFB headers or link dependency in the default runtime. Cygwin's +// dlopen also loads native Windows DLLs; both use the x64 Windows C ABI. +static const struct simple_graphics_api *api; +static void *library; + +static int load_graphics(void) { + // Explicitly disabling graphics also makes headless tests deterministic. + const char *path = getenv("SIMPLE_MINIFB"); + if (path && strcmp(path, "off") == 0) { + fprintf(stderr, "Simple graphics: disabled (SIMPLE_MINIFB=off).\n"); + return -1; + } + if (api) return 0; + int explicit_path=path && *path; + library = explicit_path ? dlopen(path, RTLD_NOW | RTLD_LOCAL) : find_backend(); + if (!library) { + if (explicit_path) + fprintf(stderr, "Simple graphics: cannot load MiniFB backend '%s': %s\n", path, dlerror()); + else + fprintf(stderr, "Simple graphics: MiniFB backend not found beside the executable or in build/release/" + BACKEND_ABI ". Run make graphics, or set SIMPLE_MINIFB to its full path.\n"); + return -1; + } + if (!explicit_path) path="automatically discovered backend"; + const struct simple_graphics_api *(*get_api)(void) = + (const struct simple_graphics_api *(*)(void))dlsym(library, "simple_minifb_api"); + const struct simple_graphics_api *candidate = get_api ? get_api() : NULL; + if (!candidate || candidate->version != SIMPLE_GRAPHICS_VERSION || + !candidate->open || !candidate->present || !candidate->poll || + !candidate->mouse_x || !candidate->mouse_y || !candidate->button || + !candidate->key || !candidate->close || !candidate->wait) { + fprintf(stderr, "Simple graphics: incompatible MiniFB backend '%s'. Rebuild with make graphics.\n", path); + dlclose(library); + library = NULL; + return -1; + } + api = candidate; + // Keep the library loaded until process exit; its window callbacks may + // still be registered. Closing a window releases its native resources. + atexit(api->close); + return 0; +} + +int32_t simple_gfx_open(const char *title, uint32_t width, uint32_t height) { + return load_graphics() ? -1 : api->open(title, width, height); +} +int32_t simple_gfx_present(const uint32_t *pixels, uint32_t count) { + return api ? api->present(pixels, count) : -1; +} +int32_t simple_gfx_poll(int32_t wait) { return api ? api->poll(wait) : -1; } +int32_t simple_gfx_mouse_x(void) { return api ? api->mouse_x() : 0; } +int32_t simple_gfx_mouse_y(void) { return api ? api->mouse_y() : 0; } +int32_t simple_gfx_button(int32_t button) { return api ? api->button(button) : 0; } +int32_t simple_gfx_key(int32_t key) { return api ? api->key(key) : 0; } +int32_t simple_gfx_close(void) { if (api) api->close(); return 0; } +int32_t simple_gfx_wait(int64_t timeout) { return api ? api->wait(timeout) : -1; } |