#version 330

out vec4 outputColor;

in vec3 Position_worldspace;
in vec3 Normal_cameraspace;
in vec3 EyeDirection_cameraspace;
in vec3 LightDirection_cameraspace;

uniform vec3 lightPosition;


void main()
{
	vec3 LightColor = vec3(1,1,1);
	float LightPower = 50.0f;

	vec3 MaterialDiffuseColor = vec3(0.3,0.8,0.3);
	vec3 MaterialAmbientColor = vec3(0.1,0.1,0.1) * MaterialDiffuseColor;
	vec3 MaterialSpecularColor = vec3(0.3,0.3,0.3);

	float distance = length(lightPosition - Position_worldspace);

	vec3 n = normalize(Normal_cameraspace);

	vec3 l = normalize(LightDirection_cameraspace);

	float cosTheta = clamp(dot(n,l),0,1);

	vec3 E = normalize(EyeDirection_cameraspace);

	vec3 R = reflect(-l,n);

	float cosAlpha = clamp(dot(E,R),0,1);

    vec3 color =
		// Ambient : simulates indirect lighting
		MaterialAmbientColor +
		// Diffuse : "color" of the object
		MaterialDiffuseColor * LightColor * LightPower * cosTheta / (distance*distance) +
		// Specular : reflective highlight, like a mirror
		MaterialSpecularColor * LightColor * LightPower * pow(cosAlpha,5) / (distance*distance);

	outputColor = vec4(color, 1.0);
}