nuclear@0: #include <stdlib.h>
nuclear@0: #include <string.h>
nuclear@0: #include "sgl.h"
nuclear@0: 
nuclear@0: struct cbnode {
nuclear@0: 	void (*func[SGL_NUM_CALLBACKS])();
nuclear@0: 	struct cbnode *next;
nuclear@0: };
nuclear@0: 
nuclear@0: struct cbnode first_cbnode;
nuclear@0: struct cbnode *cb = &first_cbnode;
nuclear@0: 
nuclear@0: int sgl_push_callbacks(void)
nuclear@0: {
nuclear@0: 	struct cbnode *node;
nuclear@0: 
nuclear@0: 	if(!(node = malloc(sizeof *node))) {
nuclear@0: 		return -1;
nuclear@0: 	}
nuclear@0: 	node->next = cb;
nuclear@0: 	cb = node;
nuclear@0: 	sgl_clear_callbacks();
nuclear@0: 	return 0;
nuclear@0: }
nuclear@0: 
nuclear@0: int sgl_pop_callbacks(void)
nuclear@0: {
nuclear@0: 	struct cbnode *node;
nuclear@0: 
nuclear@0: 	if(!cb->next) {
nuclear@0: 		return -1;
nuclear@0: 	}
nuclear@0: 
nuclear@0: 	node = cb;
nuclear@0: 	cb = cb->next;
nuclear@0: 	free(node);
nuclear@0: 	return 0;
nuclear@0: }
nuclear@0: 
nuclear@0: void sgl_clear_callbacks(void)
nuclear@0: {
nuclear@0: 	memset(cb->func, 0, sizeof cb->func);
nuclear@0: }
nuclear@0: 
nuclear@0: void (*sgl_callback(int idx, void (*func)()))()
nuclear@0: {
nuclear@0: 	void (*prev)() = cb->func[idx];
nuclear@0: 	cb->func[idx] = func;
nuclear@0: 	return prev;
nuclear@0: }