Screen space coord Unlit/Transparent Color Gradient shader

UnlitTransparentColorGradient.shader

Shader "Unlit/Transparent Color Gradient" {
	Properties{
		_MainTex("Base (RGB) Trans (A)", 2D) = "white" { }
		_Color("Color1", Color) = (1.000000,1.000000,1.000000,1.000000)
		_Color2("Color2", Color) = (1.000000,1.000000,1.000000,1.000000)
	}
	
		SubShader{
			LOD 100
			Tags{ "QUEUE" = "Transparent" "IGNOREPROJECTOR" = "true" "RenderType" = "Transparent" }
			Pass{
			Tags{ "QUEUE" = "Transparent" "IGNOREPROJECTOR" = "true" "RenderType" = "Transparent" }
			Blend SrcAlpha OneMinusSrcAlpha
		
			CGPROGRAM
			#pragma vertex vert
			#pragma fragment frag
			#pragma target 2.0
			#include "UnityCG.cginc"
			#pragma multi_compile_fog
			#define USING_FOG (defined(FOG_LINEAR) || defined(FOG_EXP) || defined(FOG_EXP2))

			// uniforms
			float4 _MainTex_ST;

			// vertex shader input data
			struct appdata {
				float3 pos : POSITION;
				float3 uv0 : TEXCOORD0;
			};

			// vertex-to-fragment interpolators
			struct v2f {
				fixed4 color : COLOR0;
				float2 uv0 : TEXCOORD0;
				#if USING_FOG
					fixed fog : TEXCOORD1;
				#endif
				float4 pos : SV_POSITION;
				float4 screenPos: TEXCOORD2;
			};

			// vertex shader
			v2f vert(appdata IN) {
				v2f o;
				half4 color = half4(0,0,0,1.1);
				float3 eyePos = mul(UNITY_MATRIX_MV, float4(IN.pos,1)).xyz;
				half3 viewDir = 0.0;
				o.color = saturate(color);
				// compute texture coordinates
				o.uv0 = IN.uv0.xy * _MainTex_ST.xy + _MainTex_ST.zw;
				// fog
				#if USING_FOG
					float fogCoord = length(eyePos.xyz); // radial fog distance
					UNITY_CALC_FOG_FACTOR(fogCoord);
					o.fog = saturate(unityFogFactor);
				#endif
				// transform position
				o.pos = UnityObjectToClipPos(IN.pos);
				o.screenPos = ComputeScreenPos(o.pos);
				return o;
			}

			// textures
			sampler2D _MainTex;
			fixed4 _Color;
			fixed4 _Color2;

			// fragment shader
			fixed4 frag(v2f IN) : SV_Target{
				fixed4 col;
				fixed4 tex, tmp0, tmp1, tmp2;
				// SetTexture #0
				tex = tex2D(_MainTex, IN.uv0.xy);

				float2 screenPosition = (IN.screenPos.xy / IN.screenPos.w);

				//float2 screenUV = IN.screenPos.xy / IN.screenPos.w;
				fixed4 color = lerp(_Color, _Color2, screenPosition.x);

				col.rgb = tex * color;
				col.a = tex.a * color.a;
				// fog
				#if USING_FOG
					col.rgb = lerp(unity_FogColor.rgb, col.rgb, IN.fog);
				#endif
				return col;
			}

			// texenvs
			//! TexEnv0: 01010102 01050106 [_MainTex] [_Color]
			ENDCG
		}
	}
}