+void erb_queue_frame(struct erb_rend *erb);
+void erb_queue_block(struct erb_rend *erb, int x, int y, int width, int height);
+void erb_wait(struct erb_rend *erb);
+
+void erb_primary_ray(struct erb_rend *erb, struct erb_ray *ray, int sample);
+void erb_sample_ray(struct erb_rend *erb, struct erb_ray *ray, float *col);
+