Forward shaded directional light

local s = [[
extern Image normaltex;
extern Image materialtex;
extern Image ramp;
extern Image sramp;
extern vec2 lightvec;

vec4 effect( vec4 color, Image texture, vec2 texture_coords, vec2 screen_coords )
{
	vec4 material = Texel(materialtex, texture_coords);

	float emission = material.g;
	float specintensity = material.r;
	float specpower = material.b;

	vec4 Lcol = vec4(1, 1, 1, 1);
	vec4 tcol = Texel(texture, texture_coords);

	vec3 E = vec3(0, 0, -1);
	vec3 N = 2 * Texel(normaltex, texture_coords).xyz - 1;
	vec3 L = normalize(vec3(lightvec, 100));
	vec3 R = reflect(L, N);
	float NdotL = dot(N, L);
	float EdotR = pow(dot(E, R), specpower*255);

	vec4 diffuse = Lcol * Texel(ramp, vec2(NdotL, 0));
	vec4 specular = Lcol * Texel(sramp, vec2(EdotR, 0)) * specintensity;
	return (diffuse+specular) * tcol + emission * tcol; //Texel(ramp, vec2(dot(normal, l), 0));
}
]]