Shader "Comic Test" {
    Properties { }

    SubShader {
		Tags { "RenderType"="Opaque" }
		Pass {
			CGPROGRAM
			
				#pragma vertex vert
				#pragma fragment frag
				
				#include "UnityCG.cginc"
				struct v2f {
					float4 pos : POSITION;
					float3 camDir : TEXCOORD1;
				};
				
				v2f vert(appdata_tan v) {
					v2f o;
					
					float4 worldSpacePos = mul(_Object2World, v.vertex);
					
					o.pos = mul(UNITY_MATRIX_MVP, v.vertex);
					
					// calculate binormal
					float3 binormal = cross(v.normal, v.tangent.xyz) * v.tangent.w;
					
					// Setup tangent space matrix.
					float3x3 tspace = float3x3(v.tangent.xyz, binormal, v.normal);
					
					// Calculate view direction
					float3 camDir = normalize((_WorldSpaceCameraPos - worldSpacePos).xyz );
					o.camDir = mul(tspace, camDir);
									
					return o;
				}

				half4 frag(v2f i) : COLOR {
					return float4(i.camDir, 1);
				}
			
			ENDCG
		}
    }
}