// Upgrade NOTE: replaced 'mul(UNITY_MATRIX_MVP,*)' with 'UnityObjectToClipPos(*)'

// Upgrade NOTE: replaced 'mul(UNITY_MATRIX_MVP,*)' with 'UnityObjectToClipPos(*)'

// Upgrade NOTE: replaced 'mul(UNITY_MATRIX_MVP,*)' with 'UnityObjectToClipPos(*)'

// Unity built-in shader source. Copyright (c) 2016 Unity Technologies. MIT license (see license.txt)

// Simplified Diffuse shader. Differences from regular Diffuse one:
// - no Main Color
// - fully supports only 1 directional light. Other lights can affect it, but it will be per-vertex/SH.


Shader "Carmen/SDF/Timer"
{
	Properties
	{
		_Tint ("Tint", Color) = (1.0, 1.0, 1.0, 1.0)

		_Crosshairs ("Crosshairs", 2D) = "white" {}
		_CrosshairsThickness ("Thickness", Range(0.0, 1.0)) = 0.5
		
		_WiperProgress ("Wiper Progress", Range(0.0, 1.0)) = 1.0
	}
	SubShader
	{
		Tags { "Queue"="Transparent" "RenderType"="Transparent" "CanUseSpriteAtlas"="True" "ForceNoShadowCasting"="True" }
		LOD 200

		Pass {
			Cull Back
			Lighting Off
			Blend SrcAlpha OneMinusSrcAlpha

			CGPROGRAM
			#include "UnityCG.cginc"
			#pragma target 4.5
			#pragma vertex vert
			#pragma fragment frag

			half4 _Tint;

			UNITY_DECLARE_TEX2D(_Crosshairs);
			half4 _Crosshairs_ST;
			half _CrosshairsThickness;
			half _WiperProgress;

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

			struct V2F
			{
				float4 position : SV_POSITION;
				float2 uv : TEXCOORD0;
			};

			V2F vert(Data v)
			{
				V2F o;

				o.position = UnityObjectToClipPos(v.vertex);
				o.uv = TRANSFORM_TEX(v.uv, _Crosshairs);

				return o;
			}

			fixed4 frag(V2F i) : SV_TARGET
			{
				half crosshairs_sample = UNITY_SAMPLE_TEX2D(_Crosshairs, i.uv).r;
				half crosshairs_halfchange = (abs(ddx(crosshairs_sample)) + abs(ddy(crosshairs_sample))) / 2.0;
				half crosshairs_loweredge = 0.5 - crosshairs_halfchange;
				half crosshairs_upperedge = 0.5 + crosshairs_halfchange;
				half crosshairs = saturate((crosshairs_sample - crosshairs_loweredge) / (crosshairs_upperedge - crosshairs_loweredge));

				half wiper_circlemask_sample = distance(float2(0.5, 0.5), i.uv) * 1.9;
				half wiper_circlemask_halfchange = (abs(ddx(wiper_circlemask_sample)) + abs(ddy(wiper_circlemask_sample))) / 2.0;
				half wiper_circlemask_loweredge = 0.5 - wiper_circlemask_halfchange;
				half wiper_circlemask_upperedge = 0.5 + wiper_circlemask_halfchange;
				half wiper_circlemask = 1.0 - saturate((wiper_circlemask_sample - wiper_circlemask_loweredge) / (wiper_circlemask_upperedge - wiper_circlemask_loweredge));

				half2 wiper_quadrantmask_sample = ceil((i.uv) - half2(0.5, 0.5));
				half wiper_quadrantmask = saturate(1.0 - ceil(wiper_quadrantmask_sample.g - (wiper_quadrantmask_sample.r + wiper_quadrantmask_sample.g / 2.0)));

				half2 uvcentre = i.uv - 0.5;
				half pixelsize = ((1.0 / _ScreenParams.x) + (1.0 / _ScreenParams.y)) / 2.0;
				half wiper = smoothstep(_WiperProgress - pixelsize, _WiperProgress + pixelsize, ((atan2(uvcentre.y, uvcentre.x) / 3.141592) + 1.0) / 1.5075);

				wiper = wiper * wiper_quadrantmask * wiper_circlemask;
				
				return fixed4(_Tint.r, _Tint.g, _Tint.b, saturate(crosshairs + wiper) * _Tint.a);
			}
			ENDCG
		}
	}
	FallBack "Diffuse"
}