#include <acknex.h>

void vec2d_rotate ( VECTOR *_v, var angle )
{
	var x = fcos(angle,_v->x) - fsin(angle,_v->y);
	_v->y = fsin(angle,_v->x) + fcos(angle,_v->y);
	_v->x = x;
}

void mouseOnZ0 ( VECTOR *_v )
{
	vec_set ( _v, &mouse_dir3d );
	vec_scale ( _v, -camera->z/_v->z );
	vec_add ( _v, &camera->x );
}

void onMouseLeft ()
{
	VECTOR vStart, vEnd;
	mouseOnZ0 ( &vStart );
	
	while ( mouse_left )
	{
		mouseOnZ0 ( &vEnd );
		
		VECTOR vCenter, vBounds;
		vec_lerp ( &vCenter, &vStart, &vEnd, 0.5 );
		vec_diff ( &vBounds, &vStart, &vCenter );
		vec2d_rotate ( &vBounds, -camera->pan );
		
		VECTOR vP1, vP2;
		vec_set ( &vP1, &vBounds );
		vec_set ( &vP2, vector(vBounds.x,-vBounds.y,-vBounds.z) );
		vec2d_rotate ( &vP1, camera->pan );
		vec2d_rotate ( &vP2, camera->pan );
		
		draw_line3d ( vector ( vCenter.x+vP1.x, vCenter.y+vP1.y, 0), COLOR_RED, 0 );  
		draw_line3d ( vector ( vCenter.x+vP1.x, vCenter.y+vP1.y, 0), COLOR_RED, 100 );  
		draw_line3d ( vector ( vCenter.x+vP2.x, vCenter.y+vP2.y, 0), COLOR_RED, 100 );
		draw_line3d ( vector ( vCenter.x-vP1.x, vCenter.y-vP1.y, 0), COLOR_RED, 100 ); 
		draw_line3d ( vector ( vCenter.x-vP2.x, vCenter.y-vP2.y, 0), COLOR_RED, 100 ); 
		draw_line3d ( vector ( vCenter.x+vP1.x, vCenter.y+vP1.y, 0), COLOR_RED, 100 );
		draw_line3d ( vector ( vCenter.x+vP1.x, vCenter.y+vP1.y, 0), COLOR_RED, 0 );
		
		wait(1);
	}
}

void main ()
{
	video_mode = 10;
	mouse_mode = 4;
	wait(1);
	level_load ( "" );
	camera->tilt = -30;
	camera->pan = 30;
	
	on_mouse_left = onMouseLeft;
	
	while ( !key_esc )
	{
		camera->pan += key_force.x * 10 * time_step;
		vec_for_angle ( &camera->x, &camera->pan );
		vec_scale ( &camera->x, -1000 );
		
		// World space axis
		draw_line3d ( vector(1000,0,0), COLOR_WHITE, 0 );
		draw_line3d ( vector(1000,0,0), COLOR_WHITE, 100 );
		draw_line3d ( vector(-1000,0,0), COLOR_WHITE, 100 );
		draw_line3d ( vector(-1000,0,0), COLOR_WHITE, 0 );
		draw_line3d ( vector(0,1000,0), COLOR_WHITE, 0 );
		draw_line3d ( vector(0,1000,0), COLOR_WHITE, 100 );
		draw_line3d ( vector(0,-1000,0), COLOR_WHITE, 100 );
		draw_line3d ( vector(0,-1000,0), COLOR_WHITE, 0 );
		
		wait(1);
	}
	
	sys_exit ( NULL );
}

VECTOR vCenter, vBounds;
vec_lerp ( &vCenter, &vStart, &vEnd, 0.5 );
vec_diff ( &vBounds, &vStart, &vCenter );

VECTOR vP1, vP2;
vec_set ( &vP1, &vBounds );
vec_set ( &vP2, &vBounds );
vec2d_rotate ( &vP2, -camera->pan );
vP2.y *= -1;
vP2.z *= -1;
vec2d_rotate ( &vP2, camera->pan );