/*******************************************************************************
 *
 * Simple GLSL FX file
 *
 *******************************************************************************/

#pragma language GLSL

// un-tweakables



// structures and shaders /////////////////////

varying vec3 eyeNormal;
varying vec4 eyePos;
varying vec3 eyeView;
varying vec2 texCoord;

void mainVS()
{ 

	//	Must write gl_Position for rasterization to be defined....
	//
	gl_Position = ftransform(); 

	//	Transform to shading space (we are going to shade in eyespace)
	//
	//
	eyeNormal = gl_NormalMatrix * gl_Normal;

	eyeView = -vec3(gl_ModelViewMatrix * gl_Vertex);
}

void mainTexVS()
{ 

	//	Must write gl_Position for rasterization to be defined....
	//
	gl_Position = ftransform(); 

	//	Transform to shading space (we are going to shade in eyespace)
	//
	//
	eyeNormal = gl_NormalMatrix * gl_Normal;

	eyeView = -vec3(gl_ModelViewMatrix * gl_Vertex);
    texCoord = gl_MultiTexCoord0.st;

}

uniform vec3 lightDir = vec3( 0.57735, 0.57735, 0.57735);
uniform vec3 lightColor = vec3( 1.0, 1.0, 1.0);
uniform vec3 diffuseMaterial = vec3( 0.0, 0.0, 0.8);
uniform vec3 ambientLight = vec3( 0.2, 0.2, 0.2);

uniform float shininess = 16.0;

void mainPS()
{
  
  //
  //	Since the EyeNormal is getting interpolated, we
  //	have to first restore it by normalizing it.
  //
  vec3 norm = normalize( eyeNormal );
  vec3 view = normalize(eyeView);
  vec3 refl = normalize( -reflect(view,norm));

  float nDotL = clamp( dot( norm, lightDir), 0.0, 1.0);
  float rDotL = clamp( dot( refl, lightDir), 0.0, 1.0);
  rDotL = (nDotL > 0.0) ? pow( rDotL, shininess) : 0.0;

  vec3 color = lightColor*nDotL*diffuseMaterial + diffuseMaterial*ambientLight + 
               rDotL*lightColor;

  gl_FragColor = vec4( color, 1.0);

}

uniform sampler2D diffuseTexture;

void mainTexPS()
{
  
  //
  //	Since the EyeNormal is getting interpolated, we
  //	have to first restore it by normalizing it.
  //
  vec3 norm = normalize( eyeNormal );
  vec3 view = normalize(eyeView);
  vec3 refl = normalize( -reflect(view,norm));
  vec3 diffuse = texture2D( diffuseTexture, texCoord).rgb;

  float nDotL = clamp( dot( norm, lightDir), 0.0, 1.0);
  float rDotL = clamp( dot( refl, lightDir), 0.0, 1.0);
  rDotL = (nDotL > 0.0) ? pow( rDotL, shininess) : 0.0;

  vec3 color = lightColor*nDotL*diffuse + diffuse*ambientLight + 
               rDotL*lightColor;

  gl_FragColor = vec4( color, 1.0);

}


//////// techniques ////////////////////////////

technique phong
{
	pass p0
	{
		VertexShader = compile vs_2_0 mainVS();
		
		ZEnable = true;
		ZWriteEnable = true;
        ZFunc = LEqual;
		CullMode = Back;

		PixelShader = compile ps_2_0 mainPS();
	}
}

technique texturedPhong
{
	pass p0
	{
		VertexShader = compile vs_2_0 mainTexVS();
		
		ZEnable = true;
		ZWriteEnable = true;
        ZFunc = LEqual;
		CullMode = Back;

		PixelShader = compile ps_2_0 mainTexPS();
	}
}