1 files changed, 53 insertions, 0 deletions
diff --git a/src/gl.c b/src/gl.c
new file mode 100644
index 0000000..c83ab49
--- /dev/null
+++ b/src/gl.c
@@ -0,0 +1,53 @@
+#include "../include/mgl/gl.h"
+#include <dlfcn.h>
+/*#include <GL/gl.h>*/
+#include <stdio.h>
+
+typedef struct {
+    void **func;
+    const char *name;
+} dlsym_assign;
+
+static void* dlsym_print_fail(void *handle, const char *name) {
+    dlerror();
+    void *sym = dlsym(handle, name);
+    char *err_str = dlerror();
+
+    if(!sym)
+        fprintf(stderr, "dlsym(handle, \"%s\") failed, error: %s\n", name, err_str ? err_str : "(null)");
+
+    return sym;
+}
+
+int mgl_gl_load(mgl_gl *self) {
+    const char *gl_path = "/usr/lib/libOpenGL.so.0";
+    self->handle = dlopen(gl_path, RTLD_LAZY);
+    if(!self->handle) {
+        fprintf(stderr, "dlopen(\"%s\", RTLD_LAZY) failed\n", gl_path);
+        return -1;
+    }
+
+    const dlsym_assign assign[] = {
+        { &self->glViewport, "glViewport" },
+        { &self->glClearColor, "glClearColor" },
+        { &self->glClear, "glClear" },
+        { NULL, NULL }
+    };
+
+    for(int i = 0; assign[i].func; ++i) {
+        *assign[i].func = dlsym_print_fail(self->handle, assign[i].name);
+        if(!assign[i].func) {
+            mgl_gl_unload(self);
+            return -1;
+        }
+    }
+
+    return 0;
+}
+
+void mgl_gl_unload(mgl_gl *self) {
+    if(self->handle) {
+        dlclose(self->handle);
+        self->handle = NULL;
+    }
+}