Add shaders

Sources/Shaders/HiZBuffer.cginc

@@ -0,0 +1,97 @@
+#ifndef __HI_Z__
+#define __HI_Z__
+
+#include "UnityCG.cginc"
+
+struct Input
+{
+    float4 vertex : POSITION;
+    float2 uv : TEXCOORD0;
+};
+
+struct Varyings
+{
+    float4 vertex : SV_POSITION;
+    float2 uv : TEXCOORD0;
+};
+
+Texture2D _MainTex;
+SamplerState sampler_MainTex;
+
+Texture2D _CameraDepthTexture;
+SamplerState sampler_CameraDepthTexture;
+
+float4 _MainTex_TexelSize;
+
+Varyings vertex(in Input input)
+{
+    Varyings output;
+
+    output.vertex = UnityObjectToClipPos(input.vertex.xyz);
+    output.uv = input.uv;
+
+#if UNITY_UV_STARTS_AT_TOP
+    if (_MainTex_TexelSize.y < 0)
+        output.uv.y = 1. - input.uv.y;
+#endif
+
+    return output;
+}
+
+float4 blit(in Varyings input) : SV_Target
+{
+    //return _CameraDepthTexture.Sample(sampler_CameraDepthTexture, input.uv).r;
+	#if UNITY_REVERSED_Z
+		return _CameraDepthTexture.Sample(sampler_CameraDepthTexture, input.uv).r;
+	#else
+		return 1.0 - _CameraDepthTexture.Sample(sampler_CameraDepthTexture, input.uv).r;
+	#endif
+}
+
+// Original code
+float4 reduce_original(in Varyings input) : SV_Target {
+	#if SHADER_API_METAL
+		int2 xy = (int2) (input.uv * (_MainTex_TexelSize.zw - 1.));
+
+		float4 texels[2] = {
+			float4(_MainTex.mips[0][xy].rg, _MainTex.mips[0][xy + int2(1, 0)].rg),
+			float4(_MainTex.mips[0][xy + int2(0, 1)].rg, _MainTex.mips[0][xy + 1].rg)
+		};
+
+		float4 r = float4(texels[0].rb, texels[1].rb);
+		float4 g = float4(texels[0].ga, texels[1].ga);
+	#else
+		float4 r = _MainTex.GatherRed(sampler_MainTex, input.uv);
+		float4 g = _MainTex.GatherGreen(sampler_MainTex, input.uv);
+	#endif
+
+    float minimum = min(min(min(r.x, r.y), r.z), r.w);
+    float maximum = max(max(max(g.x, g.y), g.z), g.w);
+
+    return float4(minimum, maximum, 0., 0.);
+}
+
+// As we do not use maximum
+float4 reduce(in Varyings input) : SV_Target{
+#if SHADER_API_METAL
+	int2 xy = (int2) (input.uv * (_MainTex_TexelSize.zw - 1.));
+
+	float4 texels[2] = {
+		float4(_MainTex.mips[0][xy].rg, _MainTex.mips[0][xy + int2(1, 0)].rg),
+		float4(_MainTex.mips[0][xy + int2(0, 1)].rg, _MainTex.mips[0][xy + 1].rg)
+	};
+
+	float4 r = float4(texels[0].rb, texels[1].rb);
+	//float4 g = float4(texels[0].ga, texels[1].ga);
+#else
+	float4 r = _MainTex.GatherRed(sampler_MainTex, input.uv);
+	//float4 g = _MainTex.GatherGreen(sampler_MainTex, input.uv);
+#endif
+
+	float minimum = min(min(min(r.x, r.y), r.z), r.w);
+	//float maximum = max(max(max(g.x, g.y), g.z), g.w);
+
+	return float4(minimum, 0., 0., 0.);
+}
+
+#endif