#include <acknex.h>

void main () {
	VECTOR cube_min, cube_max;
	VECTOR ray_start, ray_end, ray_dir;
	ENTITY *cube;

	level_load(NULL);
	vec_set(&sky_color, COLOR_WHITE);
	
	cube = ent_create(CUBE_MDL, vector(100, 0, 0), NULL);
	c_setminmax(cube);
	
	// set up ray
	vec_set(&ray_start, vector(100, -32, 0));
	vec_set(&ray_end,   vector(100,  32, 0));
	vec_diff(&ray_dir, &ray_end, &ray_start);
	
	// set up bounding box
	vec_set(&cube_min, &(cube->x));
	vec_add(&cube_min, &(cube->min_x));
	vec_set(&cube_max, &(cube->x));
	vec_add(&cube_max, &(cube->max_x));
	
	while (1) {
		var intersection1, intersection2;
		
		// move ray
		ray_start.z -= time_step;
		if (ray_start.z < (cube_min.z - 10))
			ray_start.z *= -1;
		ray_end.z = ray_start.z;
		
		// intersection test with ray endpoint
		intersection1 = c_intersect(&ray_start, &ray_start, &ray_end, &cube_min, &cube_max, NULL);
		DEBUG_VAR(intersection1, 10);
		
		// intersection test with ray direction vector
		intersection2 = c_intersect(&ray_start, &ray_start, &ray_dir, &cube_min, &cube_max, NULL);
		DEBUG_VAR(intersection2, 50);
		
		if ((intersection1 == -1) || (intersection2 == -1)) {
			draw_text("intersection!", 50, 10, COLOR_BLACK);
		}
		
		// draw ray
		draw_line3d(&ray_start, NULL, 100);
		draw_line3d(&ray_start, COLOR_BLACK, 100);
		draw_line3d(&ray_end, COLOR_BLACK, 100);
		
		wait(1);
	}
}