History: CelShading.cg

//
// The maximum number of lights per-object. Decrease this value if you need some extra performance.
//
// If you change this, then you must enter 'CelShading.program' and change the '$numLights'
// variable to match this definition.
#define NUM_LIGHTS 8

float2 calculateSurfaceLighting(
		float3 pos,
		float3 norm,
		
		float4 lightPos,
		float4 lightAtten,
		sampler1D diffuseRamp,
		
		float3 eyePos,
		float shininess,
		sampler1D specRamp )
{
	norm = normalize(norm);
	
	//
	// Calculate light vector and distance
	float3 lightVec = 0;
	if (lightPos.w == 1)
		lightVec = lightPos.xyz - pos;
	else
		lightVec = lightPos.xyz;
	
	float lightDist = length(lightVec);
	lightVec = normalize(lightVec);

	//
	// Calculate the direction in-between the light direction and the camera's direction.
	float3 eyeVec = normalize(eyePos - pos);
	float3 halfDir = normalize(lightVec + eyeVec);
	
	//
	// Calculate luminosity based on light attenuation
	float luminosity = 0;
	if( lightAtten.x > lightDist)
		luminosity = 1.0 / 
			( lightAtten.y + lightAtten.z*lightDist + 
			  lightAtten.w*(lightDist*lightDist) );
	
	//
	// Get diffuse component based on the dot product of the normal and the light direction,
	// multiplied by the luminosity component.
	float diffComponent = max(dot(norm, lightVec), 0)*luminosity;
	
	//
	// Get specular component based on the dot product of the normal and the half-camera-light
	// direction, multiplied by the luminosity component.
	float specComponent = pow(max(dot(norm, halfDir), 0), shininess)*luminosity;
	
	float diffuse = tex1D(diffuseRamp, diffComponent).r;
	float specular = tex1D(specRamp, specComponent).r;

	return float2(diffuse, specular);
}

//
// Vertex program
float4 main_vp(
		float4 iPos			: POSITION,
		float3 iNorm		: NORMAL,
		float2 iUV			: TEXCOORD0,
		out float3 oPos		: TEXCOORD0,
		out float3 oNorm	: TEXCOORD1,
		out float2 oUV		: TEXCOORD3,
		uniform float4x4 worldViewProj ) : POSITION
{
	oPos = iPos.xyz;
	oNorm = iNorm;
	oUV = iUV;
	return mul(worldViewProj, iPos);
}

//
// Color fragment program
float4 main_fp(
		float3 iPos 	: TEXCOORD0,
		float3 iNorm	: TEXCOORD1,
		
		uniform float3 eyePosition,
		
		uniform float4 ambientColor,
		uniform float4 diffuseColor,
		uniform float4 specularColor,
		uniform float4 emissiveColor,
		uniform float shininess,
		
		uniform float3 ambientLight,

		// Light params
		uniform float4 lightDiffuse[NUM_LIGHTS],
		uniform float4 lightSpecular[NUM_LIGHTS],
		uniform float4 lightPosition[NUM_LIGHTS],
		uniform float4 lightAttenuation[NUM_LIGHTS],

		// Texture params
		uniform sampler1D diffuseRamp	: register(s0),
		uniform sampler1D specRamp		: register(s1) ) : COLOR
{
	float4 surfaceColor = float4(ambientLight,1)*ambientColor;
	
	for (char i = 0; i < NUM_LIGHTS; i++)
	{
		if ((length(lightDiffuse[i]) > 0 && length(diffuseColor) > 0)
			|| (length(lightSpecular[i]) > 0 && length(specularColor) > 0))
		{
			float2 surfaceLight = calculateSurfaceLighting(
					iPos, iNorm,
					lightPosition[i], lightAttenuation[i], diffuseRamp,
					eyePosition, shininess, specRamp);
					
			surfaceColor += surfaceLight.x*diffuseColor*lightDiffuse[i]
				+ surfaceLight.y*lightSpecular[i]*specularColor;
		}
	}
	
	return saturate(emissiveColor + surfaceColor);
}

//
// Decal fragment program
float4 mainDecal_fp(
		float3 iPos 	: TEXCOORD0,
		float3 iNorm	: TEXCOORD1,
		float3 iUV		: TEXCOORD3,
		
		uniform float3 eyePosition,
		
		uniform float4 ambientColor,
		uniform float4 diffuseColor,
		uniform float4 specularColor,
		uniform float4 emissiveColor,
		uniform float shininess,
		
		uniform float3 ambientLight,

		// Light params
		uniform float4 lightDiffuse[NUM_LIGHTS],
		uniform float4 lightSpecular[NUM_LIGHTS],
		uniform float4 lightPosition[NUM_LIGHTS],
		uniform float4 lightAttenuation[NUM_LIGHTS],

		// Texture params
		uniform sampler1D diffuseRamp	: register(s0),
		uniform sampler1D specRamp		: register(s1),
		uniform sampler2D decalTex		: register(s2) ) : COLOR
{
	float4 surfaceColor = float4(ambientLight,1)*ambientColor;
	float4 specularSurface = 0;
	float4 texColor = tex2D(decalTex, iUV);
	
	for (char i = 0; i < NUM_LIGHTS; i++)
	{
		if ((length(lightDiffuse[i]) > 0 && length(diffuseColor) > 0 && length(texColor) > 0)
			|| (length(lightSpecular[i]) > 0 && length(specularColor) > 0))
		{
			float2 surfaceLight = calculateSurfaceLighting(
					iPos, iNorm,
					lightPosition[i], lightAttenuation[i], diffuseRamp,
					eyePosition, shininess, specRamp);
					
			surfaceColor += surfaceLight.x*diffuseColor*lightDiffuse[i];
			specularSurface += surfaceLight.y*lightSpecular[i]*specularColor;
		}
	}
	
	return texColor*saturate(emissiveColor + surfaceColor) + specularSurface;
}

//
// Decal + Specular Mapping fragment program
float4 mainDecalSpec_fp(
		float3 iPos 	: TEXCOORD0,
		float3 iNorm	: TEXCOORD1,
		float3 iUV		: TEXCOORD3,
		
		uniform float3 eyePosition,
		
		uniform float4 ambientColor,
		uniform float4 diffuseColor,
		uniform float4 specularColor,
		uniform float4 emissiveColor,
		uniform float shininess,
		
		uniform float3 ambientLight,
		
		// Light params
		uniform float4 lightDiffuse[NUM_LIGHTS],
		uniform float4 lightSpecular[NUM_LIGHTS],
		uniform float4 lightPosition[NUM_LIGHTS],
		uniform float4 lightAttenuation[NUM_LIGHTS],
		
		// Texture params
		uniform sampler1D diffuseRamp	: register(s0),
		uniform sampler1D specRamp		: register(s1),
		
		uniform sampler2D decalTex		: register(s2),
		uniform sampler2D specMap		: register(s3)) : COLOR
{
	float4 surfaceColor = float4(ambientLight,1)*ambientColor;
	float4 specularSurface = 0;
	float4 texColor		= tex2D(decalTex, iUV);
	float4 specMapColor	= tex2D(specMap, iUV);
	
	for (char i = 0; i < NUM_LIGHTS; i++)
	{
		if ((length(lightDiffuse[i]) > 0 && length(diffuseColor) > 0 && length(texColor) > 0)
			|| (length(lightSpecular[i]) > 0 && length(specularColor) > 0 && length(specMapColor) > 0))
		{
			float2 surfaceLight = calculateSurfaceLighting(
					iPos, iNorm,
					lightPosition[i], lightAttenuation[i], diffuseRamp,
					eyePosition, shininess, specRamp);
					
			surfaceColor += surfaceLight.x*diffuseColor*lightDiffuse[i];
			specularSurface += surfaceLight.y*lightSpecular[i]*specularColor;
		}
	}
	
	return texColor*saturate(emissiveColor + surfaceColor) + specMapColor*saturate(specularSurface);
}