Shader "Maikel/FX/ClipSpaceShockwave"
{
	Properties
	{
		_MainTex ("Texture", 2D) = "white" {}
		_Amplitude ("Amplitude", Range(0,1)) = 0
	}
	SubShader
	{
		Tags { "RenderType"="Opaque" }
		LOD 100

		Pass
		{
			CGPROGRAM
			#pragma vertex vert
			#pragma fragment frag

			#include "UnityCG.cginc"

			struct appdata
			{
				float4 vertex : POSITION;
				float2 uv : TEXCOORD0;
			};

			struct v2f
			{
				float2 uv : TEXCOORD0;
				float4 vertex : SV_POSITION;


			};

			sampler2D _MainTex;
			float4 	_MainTex_ST;
			float 	_Radius;
			float 	_Amplitude;
			float2 	_ShockwavePos;

			v2f vert (appdata v)
			{
				v2f o;
				o.vertex = v.vertex;
				o.uv = o.vertex * 0.5 + 0.5;

				float2 diff=float2(o.uv.x-_ShockwavePos.x,o.uv.y-_ShockwavePos.y);
				float dist=sqrt(diff.x*diff.x+diff.y*diff.y);
				float2 uv_displaced = float2(o.uv.x,o.uv.y);
				float wavesize=0.2f;
				if (dist>_Radius) {
					if (dist<_Radius+wavesize) {
						float angle=(dist-_Radius)*2*3.141592654/wavesize;
						float cossin=(1-cos(angle))*0.5;
						uv_displaced.x-= cossin*diff.x* _Amplitude/dist;
						uv_displaced.y-= cossin*diff.y* _Amplitude/dist;
					}
				}

				o.uv = uv_displaced;

				return o;
			}

			fixed4 frag (v2f i) : SV_Target
			{
				fixed4 col = tex2D(_MainTex, i.uv);
				return col;
			}
			ENDCG
		}
	}
}