Median filter pass

For additional denoising
2020-03-10 17:58:23 +01:00
parent 570f36ec28
commit cf324587b2
1 changed files with 64 additions and 0 deletions
@@ -0,0 +1,64 @@
+#include "globals.hlsli"
+#include "ShaderInterop_Postprocess.h"
+
+TEXTURE2D(texture_temporal, float4, TEXSLOT_ONDEMAND0);
+
+RWTEXTURE2D(output, float4, 0);
+
+// A Fast, Small-Radius GPU Median Filter by Morgan McGuire
+// https://casual-effects.com/research/McGuire2008Median/index.html
+
+#define s2(a, b)                            temp = a; a = min(a, b); b = max(temp, b);
+#define t2(a, b)                            s2(v[a], v[b]);
+#define t24(a, b, c, d, e, f, g, h)         t2(a, b); t2(c, d); t2(e, f); t2(g, h); 
+#define t25(a, b, c, d, e, f, g, h, i, j)   t24(a, b, c, d, e, f, g, h); t2(i, j);
+
+[numthreads(POSTPROCESS_BLOCKSIZE, POSTPROCESS_BLOCKSIZE, 1)]
+void main(uint3 DTid : SV_DispatchThreadID)
+{
+    const float2 uv = (DTid.xy + 0.5f) * xPPResolution_rcp;
+    const float depth = texture_depth.SampleLevel(sampler_point_clamp, uv, 0);
+    if (depth == 0.0f) 
+        return;
+    
+    half4 v[25];
+
+    // Add the pixels which make up our window to the pixel array.
+    [unroll]
+    for (int dX = -2; dX <= 2; ++dX)
+    {
+        [unroll]
+        for (int dY = -2; dY <= 2; ++dY)
+        {
+            float2 offset = float2(float(dX), float(dY));
+		    
+            // If a pixel in the window is located at (x+dX, y+dY), put it at index (dX + R)(2R + 1) + (dY + R) of the
+            // pixel array. This will fill the pixel array, with the top left pixel of the window at pixel[0] and the
+            // bottom right pixel of the window at pixel[N-1].
+            v[(dX + 2) * 5 + (dY + 2)] = texture_temporal.SampleLevel(sampler_linear_clamp, uv + offset * xPPResolution_rcp, 0);
+        }
+    }
+    
+    half4 temp;
+    t25(0, 1, 3, 4, 2, 4, 2, 3, 6, 7);
+    t25(5, 7, 5, 6, 9, 7, 1, 7, 1, 4);
+    t25(12, 13, 11, 13, 11, 12, 15, 16, 14, 16);
+    t25(14, 15, 18, 19, 17, 19, 17, 18, 21, 22);
+    t25(20, 22, 20, 21, 23, 24, 2, 5, 3, 6);
+    t25(0, 6, 0, 3, 4, 7, 1, 7, 1, 4);
+    t25(11, 14, 8, 14, 8, 11, 12, 15, 9, 15);
+    t25(9, 12, 13, 16, 10, 16, 10, 13, 20, 23);
+    t25(17, 23, 17, 20, 21, 24, 18, 24, 18, 21);
+    t25(19, 22, 8, 17, 9, 18, 0, 18, 0, 9);
+    t25(10, 19, 1, 19, 1, 10, 11, 20, 2, 20);
+    t25(2, 11, 12, 21, 3, 21, 3, 12, 13, 22);
+    t25(4, 22, 4, 13, 14, 23, 5, 23, 5, 14);
+    t25(15, 24, 6, 24, 6, 15, 7, 16, 7, 19);
+    t25(3, 11, 5, 17, 11, 17, 9, 17, 4, 10);
+    t25(6, 12, 7, 14, 4, 6, 4, 7, 12, 14);
+    t25(10, 14, 6, 7, 10, 12, 6, 10, 6, 17);
+    t25(12, 17, 7, 17, 7, 10, 12, 18, 7, 12);
+    t24(10, 18, 12, 20, 10, 20, 10, 12);
+
+    output[DTid.xy] = v[12];
+}