vertex_shader
	"varying vec3 tangent;
	varying vec3 shadowcoord;
	varying vec3 normal;

	void main()
	{
		gl_Position = ftransform();
		vec2 temp = normalize(gl_Vertex.xz);
		tangent = normalize(gl_NormalMatrix*vec3(temp.x, 0.0, temp.y));
		vec4 eye_pos = gl_ModelViewMatrix*gl_Vertex;
		shadowcoord = vec3(dot(gl_EyePlaneS[3], eye_pos), dot(gl_EyePlaneT[3], eye_pos), dot(gl_EyePlaneR[3], eye_pos));
		normal = normalize(gl_NormalMatrix*gl_Normal);
	}";

fragment_shader
	"uniform sampler2DShadow shadow;
	varying vec3 tangent;
	varying vec3 shadowcoord;
	varying vec3 normal;

	void main()
	{
		float diffuse = max(dot(gl_LightSource[0].position.xyz, normal), 0.0)*(0.6+0.4*abs(dot(gl_LightSource[0].position.xyz, tangent)));
		vec4 color = gl_FrontMaterial.diffuse;
		gl_FragColor = vec4((0.3+diffuse*0.7*shadow2D(shadow, shadowcoord).r)*color.rgb, color.a);
	}";