Shader "Hidden/VertexTangentNode"
{
	SubShader
	{
		Pass
		{
			CGPROGRAM
			#pragma vertex vert_img
			#pragma fragment frag
			#include "UnityCG.cginc"

			float4 frag( v2f_img i ) : SV_Target
			{
				float2 tp = 2 * i.uv - 1;
				float tr = sqrt( dot(tp,tp) );
				tr = saturate( tr );
				//if ( tr < 1 ) {
					float2 tuvs;
					float f = ( 1 - sqrt( 1 - tr ) ) / tr;

					float3 tangent = normalize(float3( (1-f)*2, tp.y*0.01, tp.x ));
					return float4((tangent), 1);
				//}
				//else {
				//	return 0;
				//}
			}
			ENDCG
		}
	}
}