Shader "Enviro/Particles/WeatherParticlesAdditive" {
Properties {
	_TintColor ("Tint Color", Color) = (0.5,0.5,0.5,0.5)
	_MainTex ("Particle Texture", 2D) = "white" {}
	_InvFade ("Soft Particles Factor", Range(0.01,3.0)) = 1.0
	_lightIntensity ("Light Intensity", Range(0.0,1.0)) = 1.0
}

Category {
	Tags{ "Queue" = "Transparent" "IgnoreProjector" = "True" "RenderType" = "Transparent" "PreviewType" = "Plane" }
		Blend One OneMinusSrcColor
		ColorMask RGB
		Cull Off Lighting Off ZWrite Off

	SubShader {
		Pass {
		
			CGPROGRAM
			#pragma vertex vert
			#pragma fragment frag
			#pragma target 3.0
			#pragma multi_compile_particles
			#pragma multi_compile_fog
			#pragma exclude_renderers gles 

			#include "UnityCG.cginc"
			#include "../../Resources/Shaders/Core/EnviroFogCore.cginc"

			sampler2D _MainTex;
			fixed4 _TintColor;
			float4 _EnviroLighting;
			float _lightIntensity;
			float _InvFade;

			struct appdata_t {
				float4 vertex : POSITION;
				fixed4 color : COLOR;
				float2 texcoord : TEXCOORD0;
				UNITY_VERTEX_INPUT_INSTANCE_ID
			};

			struct v2f {
				float4 vertex : SV_POSITION;
				fixed4 color : COLOR;
				float2 texcoord : TEXCOORD0;
				UNITY_FOG_COORDS(1)
				float4 projPos : TEXCOORD2;
				float3 posWorld : TEXCOORD3;
				UNITY_VERTEX_OUTPUT_STEREO
			};
			
			float4 _MainTex_ST;

			v2f vert (appdata_t v)
			{
				v2f o;
				UNITY_SETUP_INSTANCE_ID(v);
				UNITY_INITIALIZE_VERTEX_OUTPUT_STEREO(o);
				o.vertex = UnityObjectToClipPos(v.vertex);
				o.posWorld = mul(unity_ObjectToWorld, v.vertex);
				o.projPos = ComputeScreenPos (o.vertex);
				COMPUTE_EYEDEPTH(o.projPos.z);
				o.color = v.color;
				o.texcoord = TRANSFORM_TEX(v.texcoord,_MainTex);
				UNITY_TRANSFER_FOG(o,o.vertex);
				return o;
			}

			UNITY_DECLARE_DEPTH_TEXTURE(_CameraDepthTexture);
			//float _InvFade;
			
			fixed4 frag (v2f i) : SV_Target
			{
				float sceneZ = LinearEyeDepth(SAMPLE_DEPTH_TEXTURE_PROJ(_CameraDepthTexture, UNITY_PROJ_COORD(i.projPos)));

#ifdef SOFTPARTICLES_ON
				float partZ = i.projPos.z;
				float fade = saturate(_InvFade * (sceneZ - partZ));
				i.color.a *= fade;
#endif

				half4 col = i.color * tex2D(_MainTex, i.texcoord);
				col.rgb *= _EnviroLighting * 1.5;
				col.rgb *= col.a;
				
				UNITY_APPLY_FOG_COLOR(i.fogCoord, col, fixed4(0, 0, 0, 0)); // fog towards black due to our blend mode

																			//half linear01Depth = LinearEyeDepth(i.projPos.z);
				float4 fog = TransparentFog(col, i.posWorld, i.projPos.xy, sceneZ);
				fog.rgb *= col.rgb;
				return fog;
			}  
			ENDCG 
		}
	}	
} 
}