vertex_shader
	"attribute float offset;
	attribute vec3 direction;
	
	void main()
	{
		vec4 eye_pos = gl_ModelViewMatrix*gl_Vertex;
		vec3 eye_dir = gl_NormalMatrix*direction;
		vec4 offset_dir = normalize(vec4(-eye_dir.y, eye_dir.x, 0.0, 0.0));
		gl_Position = gl_ProjectionMatrix*(eye_pos+offset_dir*offset);
	}";

fragment_shader
	"uniform float fade;
	
	void main()
	{
		gl_FragColor = vec4(30.0, 30.0, 50.0, fade);
	}";

attribute 1 "offset";
attribute 2 "direction";