VolumetricLighting/Assets/AreaLight/Shaders/AreaLight.shader

Shader "Hidden/AreaLight" {
SubShader {
	Tags { "Queue"="Geometry-1" }

CGINCLUDE
#include "UnityCG.cginc"
#include "UnityPBSLighting.cginc"
#include "UnityDeferredLibrary.cginc"

#define AREA_LIGHT_ENABLE_DIFFUSE 1

#if AREA_LIGHT_SHADOWS
#include "AreaLightShadows.cginc"
#endif
#include "AreaLight.cginc"

sampler2D _CameraGBufferTexture0;
sampler2D _CameraGBufferTexture1;
sampler2D _CameraGBufferTexture2;

void DeferredCalculateLightParams (
	unity_v2f_deferred i,
	out float3 outWorldPos,
	out float2 outUV)
{
	i.ray = i.ray * (_ProjectionParams.z / i.ray.z);
	float2 uv = i.uv.xy / i.uv.w;
	
	// read depth and reconstruct world position
	float depth = SAMPLE_DEPTH_TEXTURE(_CameraDepthTexture, uv);
	depth = Linear01Depth (depth);
	float4 vpos = float4(i.ray * depth,1);
	float3 wpos = mul (unity_CameraToWorld, vpos).xyz;

	outWorldPos = wpos;
	outUV = uv;
}

half4 CalculateLightDeferred (unity_v2f_deferred i)
{
	float3 worldPos;
	float2 uv;
	DeferredCalculateLightParams (i, worldPos, uv);

	half4 gbuffer0 = tex2D (_CameraGBufferTexture0, uv);
	half4 gbuffer1 = tex2D (_CameraGBufferTexture1, uv);
	half4 gbuffer2 = tex2D (_CameraGBufferTexture2, uv);

	half3 baseColor = gbuffer0.rgb;
	half3 specColor = gbuffer1.rgb;
	half oneMinusRoughness = gbuffer1.a;
	half3 normalWorld = gbuffer2.rgb * 2 - 1;
	normalWorld = normalize(normalWorld);
	
	return CalculateLight (worldPos, baseColor, specColor, oneMinusRoughness, normalWorld,
		_LightPos.xyz, _LightColor.xyz).rgbb;
}
ENDCG

// shadows
Pass
{
	Fog { Mode Off }
	ZWrite Off
	Blend One One
	Cull Front
	ZTest Always
	
	CGPROGRAM
	#pragma target 3.0
	#pragma vertex vert_deferred
	#pragma fragment frag
	#pragma exclude_renderers nomrt
	// only one option, so it will always be set and before any includes
	#pragma multi_compile AREA_LIGHT_SHADOWS

	fixed4 frag (unity_v2f_deferred i) : SV_Target
	{
		return CalculateLightDeferred(i);
	}

	ENDCG
}

// no shadows
Pass
{
	Fog { Mode Off }
	ZWrite Off
	Blend One One
	Cull Front
	ZTest Always
	
	CGPROGRAM
	#pragma target 3.0
	#pragma vertex vert_deferred
	#pragma fragment frag
	#pragma exclude_renderers nomrt

	fixed4 frag (unity_v2f_deferred i) : SV_Target
	{
		return CalculateLightDeferred(i);
	}

	ENDCG
}

}
Fallback Off
}