DiffuseFragment.glsl

// The normal attribute passed in from the vertex shader
in vec3 fragmentNormal;

// The output attribute that will be written to the framebuffer
layout(location = 0) out vec4 fragColour;

// Defines all the light info
struct Lights
{
	vec4 position;
	vec4 diffuse;
};

// Probably meant to be the material colour
uniform vec4 diffuse;

// Pass in the light information from the client
uniform Lights light;

void main()
{
	// Find light normal
	vec3 nrmL = normalize(light.position);

	// Calculate diffuse (lambert reflectance)
	float nDotL = dot(fragmentNormal, nrmL);

	// The final colour is the diffuse(clamped to 0-1 range) multiplied by the light colour and the material colour
	fragColour = diffuse * light.diffuse * max(nDotL, 0.0);
}