forward-add.shader

// ------------------------------------------------------------------
//  Additive forward pass (one light per pass)
struct VertexOutputForwardAdd
{
	float4 pos							: SV_POSITION;
	float4 tex							: TEXCOORD0;
	half3 eyeVec 						: TEXCOORD1;
	half4 tangentToWorldAndLightDir[3]	: TEXCOORD2;	// [3x3:tangentToWorld | 1x3:lightDir]
	LIGHTING_COORDS(5,6)
	UNITY_FOG_COORDS(7)

	// next ones would not fit into SM2.0 limits, but they are always for SM3.0+
#if defined(_PARALLAXMAP)
	half3 viewDirForParallax			: TEXCOORD8;
#endif

	#if PLANE_CLIPPING_ENABLED
		float3 posWorld					: TEXCOORD9;
	#endif
};

VertexOutputForwardAdd vertForwardAdd (VertexInput v)
{
	VertexOutputForwardAdd o;
	UNITY_INITIALIZE_OUTPUT(VertexOutputForwardAdd, o);

	float4 posWorld = mul(_Object2World, v.vertex);
	#if PLANE_CLIPPING_ENABLED
		o.posWorld = posWorld.xyz;
	#endif
	o.pos = mul(UNITY_MATRIX_MVP, v.vertex);
	o.tex = TexCoords(v);
	o.eyeVec = NormalizePerVertexNormal(posWorld.xyz - _WorldSpaceCameraPos);
	float3 normalWorld = UnityObjectToWorldNormal(v.normal);
	#ifdef _TANGENT_TO_WORLD
		float4 tangentWorld = float4(UnityObjectToWorldDir(v.tangent.xyz), v.tangent.w);

		float3x3 tangentToWorld = CreateTangentToWorldPerVertex(normalWorld, tangentWorld.xyz, tangentWorld.w);
		o.tangentToWorldAndLightDir[0].xyz = tangentToWorld[0];
		o.tangentToWorldAndLightDir[1].xyz = tangentToWorld[1];
		o.tangentToWorldAndLightDir[2].xyz = tangentToWorld[2];
	#else
		o.tangentToWorldAndLightDir[0].xyz = 0;
		o.tangentToWorldAndLightDir[1].xyz = 0;
		o.tangentToWorldAndLightDir[2].xyz = normalWorld;
	#endif
	//We need this for shadow receving
	TRANSFER_VERTEX_TO_FRAGMENT(o);

	float3 lightDir = _WorldSpaceLightPos0.xyz - posWorld.xyz * _WorldSpaceLightPos0.w;
	#ifndef USING_DIRECTIONAL_LIGHT
		lightDir = NormalizePerVertexNormal(lightDir);
	#endif
	o.tangentToWorldAndLightDir[0].w = lightDir.x;
	o.tangentToWorldAndLightDir[1].w = lightDir.y;
	o.tangentToWorldAndLightDir[2].w = lightDir.z;

	#ifdef _PARALLAXMAP
		TANGENT_SPACE_ROTATION;
		o.viewDirForParallax = mul (rotation, ObjSpaceViewDir(v.vertex));
	#endif
	
	UNITY_TRANSFER_FOG(o,o.pos);
	return o;
}

half4 fragForwardAdd (VertexOutputForwardAdd i) : SV_Target
{
	FRAGMENT_SETUP_FWDADD(s)
	PLANE_CLIP(s.posWorld)

	UnityLight light = AdditiveLight (s.normalWorld, IN_LIGHTDIR_FWDADD(i), LIGHT_ATTENUATION(i));
	UnityIndirect noIndirect = ZeroIndirect ();

	half4 c = UNITY_BRDF_PBS (s.diffColor, s.specColor, s.oneMinusReflectivity, s.oneMinusRoughness, s.normalWorld, -s.eyeVec, light, noIndirect);
	
	UNITY_APPLY_FOG_COLOR(i.fogCoord, c.rgb, half4(0,0,0,0)); // fog towards black in additive pass
	return OutputForward (c, s.alpha);
}