#version 130

in vec4 worldPosition; //Passed in from the vertex shader
in vec3 normalFromVS;
flat in ivec2 materialFromVS;

out vec4 outputColor;

void main()
{
	// The first byte of our voxel data is the material.
	// We use this to decide how to color the fragment.
	vec4 surfaceColor;
	switch(materialFromVS.x)
	{
	case 1:
		surfaceColor = vec4(1.0, 0.0, 0.0, 1.0);
		break;
	case 2:
		surfaceColor = vec4(0.0, 1.0, 0.0, 1.0);
		break;
	case 3:
		surfaceColor = vec4(0.0, 0.0, 1.0, 1.0);
		break;
	case 4:
		surfaceColor = vec4(1.0, 1.0, 0.0, 1.0);
		break;
	case 5:
		surfaceColor = vec4(1.0, 0.0, 1.0, 1.0);
		break;
	default:
		surfaceColor = vec4(1.0, 1.0, 1.0, 1.0);
		break;
	}
	
	// Quick and dirty lighting, obviously a real implementation
	// should pass light properties as shader parameters, etc.
	vec3 lightDir = vec3(0.0, 0.0, 1.0);
	float diffuse = clamp(dot(lightDir, normalFromVS), 0.0, 1.0);
	diffuse *= 0.7; // Dim the diffuse a bit
	float ambient = 0.3; // Add some ambient
	float lightIntensity = diffuse + ambient; // Compute the final light intensity
	
	outputColor = surfaceColor * lightIntensity; //Compute final rendered color
}