// GL Shading Language version 1.0 Fragment Shader
//  Orion Sky Lawlor, olawlor@acm.org, 2006/08/31 (Public Domain)

// Computes normal lighting, and modulates texture by wood pattern.

// Vertex/fragment shader interface
varying vec4 color; // Material diffuse color
varying vec3 position; // World-space coordinates of object
varying vec3 normal; // Surface normal
varying vec3 cameraDir; // Points toward camera
varying vec2 texCoord; // Texture coordinates

uniform vec4 lightDir; // Points toward light
uniform sampler2D bump, refl; // Textures: bumpmap and diffuse reflectance

// Input: from vertex.txt.  Output: gl_FragColor.
void main(void)
{
	vec3 N=normalize(vec3(texture2D(bump,texCoord))-vec3(0.5)); // Points away from surface
	vec3 L1=normalize(vec3(lightDir)); // Points toward light
	vec3 H=normalize(normalize(cameraDir)+L1);
	
	gl_FragColor=pow(clamp(dot(N,H),0.0,1.0),1000.0)
		+vec4(vec3(
			+0.6*clamp(dot(N,L1),0.0,1.0) // diffuse
			+0.05 // ambient
		),1.0)
		*texture2D(refl,texCoord);  // Scale diffuse+ambient by texture
}