uniform sampler2D ntex;
uniform sampler2D dtex;
uniform float spec;
uniform mat4 invproj;
uniform mat4 ViewMatrix;
uniform vec2 screen;

flat in vec3 center;
flat in float energy;
flat in vec3 col;

out vec4 Diffuse;
out vec4 Specular;

vec3 DecodeNormal(vec2 n);

void main() {
	vec2 texc = gl_FragCoord.xy / screen;
	float z = texture(dtex, texc).x;
	vec3 norm = normalize(DecodeNormal(2. * texture(ntex, texc).xy - 1.));

	vec4 xpos = 2.0 * vec4(texc, z, 1.0) - 1.0f;
	xpos = invproj * xpos;
	xpos /= xpos.w;
	vec3 eyedir = normalize(xpos.xyz);

	vec3 diffuse = vec3(0.), specular = vec3(0.);

	vec4 pseudocenter = ViewMatrix * vec4(center.xyz, 1.0);
	pseudocenter /= pseudocenter.w;
	vec3 light_pos = pseudocenter.xyz;
	vec3 light_col = col.xyz;
	float d = distance(light_pos, xpos.xyz);
	float att = energy * 200. / (4. * 3.14 * d * d);
	float spec_att = (energy + 10.) * 200. / (4. * 3.14 * d * d);

	// Light Direction
	vec3 L = normalize(xpos.xyz - light_pos);

	float NdotL = max(0.0, dot(norm, -L));
	diffuse += NdotL * light_col * att;
	// Reflected light dir
	vec3 R = reflect(-L, norm);
	float RdotE = max(0.0, dot(R, eyedir));
	specular += pow(RdotE, spec) * light_col * spec_att;

	Diffuse = vec4(diffuse, 1.);
	Specular = vec4(specular , 1.);
}