FSR: Improve quality of Film Grain and Anti-Aliasing

- New implementation of Film Grain that doesn't suck, so we can turn it up a nod by default. Supports RGB noise and shaping the distribution curve to control noise modulation. The previous implementation was just a placeholder, it was very basic.
- Greatly increased Anti-Aliasing quality in default preset.
- Include license headers to make clear that all my contributions are released on the public domain under the terms of the Unlicense. Anyone can do whatever they want with this.

fsr/fsr.slangp

@@ -10,6 +10,8 @@ filter_linear1 = true
 scale_type1 = source
 scale1 = 1.0
 
-parameters = "FSR_SHARPENING;FSR_FILMGRAIN"
+parameters = "FSR_SHARPENING;FSR_FILMGRAIN;FSR_GRAINCOLOR;FSR_GRAINPDF"
 FSR_SHARPENING = 0.3
-FSR_FILMGRAIN = 0.10
+FSR_FILMGRAIN = 0.3
+FSR_GRAINCOLOR = 1.0
+FSR_GRAINPDF = 0.3

fsr/shaders/fsr-pass0.slang

@@ -1,4 +1,5 @@
 #version 450
+// SPDX-License-Identifier: Unlicense
 #pragma name FSR_EASU
 
 // FSR - [EASU] EDGE ADAPTIVE SPATIAL UPSAMPLING
@@ -40,15 +41,9 @@ layout(set = 0, binding = 2) uniform sampler2D Source;
 #define FSR_EASU_F 1
 AU4 con0, con1, con2, con3;
 
-AF4 FsrEasuRF(AF2 p) {
-    return textureGather(Source, p, 0);
-}
-AF4 FsrEasuGF(AF2 p) {
-    return textureGather(Source, p, 1);
-}
-AF4 FsrEasuBF(AF2 p) {
-    return textureGather(Source, p, 2);
-}
+AF4 FsrEasuRF(AF2 p) { return textureGather(Source, p, 0); }
+AF4 FsrEasuGF(AF2 p) { return textureGather(Source, p, 1); }
+AF4 FsrEasuBF(AF2 p) { return textureGather(Source, p, 2); }
 
 #include "ffx_fsr1.h"
 

fsr/shaders/fsr-pass1.slang

@@ -1,4 +1,5 @@
 #version 450
+// SPDX-License-Identifier: Unlicense
 #pragma name FSR_RCAS
 
 // FSR - [RCAS] ROBUST CONTRAST ADAPTIVE SHARPENING
@@ -8,7 +9,9 @@
 // scale1 = 1.0
 
 #pragma parameter FSR_SHARPENING "FSR RCAS Sharpening Amount (Lower = Sharper)" 0.2 0.0 2.0 0.1
-#pragma parameter FSR_FILMGRAIN "FSR LFGA Film Grain Intensity" 0.10 0.0 1.0 0.02
+#pragma parameter FSR_FILMGRAIN "FSR LFGA Film Grain Intensity" 0.3 0.0 2.0 0.02
+#pragma parameter FSR_GRAINCOLOR "FSR LFGA Film Grain Color: Gray | RGB" 1.0 0.0 1.0 1.0
+#pragma parameter FSR_GRAINPDF "FSR LFGA Grain PDF Curve (0.5 = Triangular, Lower = Gaussian)" 0.3 0.1 0.5 0.05
 
 layout(push_constant) uniform Push {
     vec4 SourceSize;
@@ -17,6 +20,8 @@ layout(push_constant) uniform Push {
     uint FrameCount;
     float FSR_SHARPENING;
     float FSR_FILMGRAIN;
+    float FSR_GRAINCOLOR;
+    float FSR_GRAINPDF;
 } params;
 
 layout(std140, set = 0, binding = 0) uniform UBO {
@@ -45,14 +50,31 @@ layout(set = 0, binding = 2) uniform sampler2D Source;
 #define FSR_RCAS_F 1
 AU4 con0;
 
-AF4 FsrRcasLoadF(ASU2 p) {
-    return AF4(texelFetch(Source, ASU2(p), 0));
-}
-
+AF4 FsrRcasLoadF(ASU2 p) { return AF4(texelFetch(Source, p, 0)); }
 void FsrRcasInputF(inout AF1 r, inout AF1 g, inout AF1 b) {}
 
 #include "ffx_fsr1.h"
 
+// prng: A simple but effective pseudo-random number generator [0;1[
+float prng(vec2 uv, float time) {
+    return fract(sin(dot(uv + fract(time), vec2(12.9898, 78.233))) * 43758.5453);
+}
+
+// pdf: [-0.5;0.5[
+// Removes noise modulation effect by reshaping the uniform/rectangular noise
+// distribution (RPDF) into a Triangular (TPDF) or Gaussian Probability Density
+// Function (GPDF).
+// shape = 1.0: Rectangular
+// shape = 0.5: Triangular
+// shape < 0.5: Gaussian (0.2~0.4)
+float pdf(float noise, float shape) {
+    float orig = noise * 2.0 - 1.0;
+    noise = pow(abs(orig), shape);
+    noise *= sign(orig);
+    noise -= sign(orig);
+    return noise * 0.5;
+}
+
 void main() {
     FsrRcasCon(con0, params.FSR_SHARPENING);
 
@@ -62,8 +84,17 @@ void main() {
 
     // FSR - [LFGA] LINEAR FILM GRAIN APPLICATOR
     if (params.FSR_FILMGRAIN > 0.0) {
-        AF1 noise = fract(10000 * sin(((vTexCoord.x + vTexCoord.y * A_2PI) * params.FrameCount)));
-        FsrLfgaF(Gamma2Color, AF3_(noise - 0.5), params.FSR_FILMGRAIN);
+        if (params.FSR_GRAINCOLOR == 0.0) {
+            float noise = pdf(prng(vTexCoord, params.FrameCount * 0.11), params.FSR_GRAINPDF);
+            FsrLfgaF(Gamma2Color, vec3(noise), params.FSR_FILMGRAIN);
+        } else {
+            vec3 rgbNoise = vec3(
+                pdf(prng(vTexCoord, params.FrameCount * 0.11), params.FSR_GRAINPDF),
+                pdf(prng(vTexCoord, params.FrameCount * 0.13), params.FSR_GRAINPDF),
+                pdf(prng(vTexCoord, params.FrameCount * 0.17), params.FSR_GRAINPDF)
+            );
+            FsrLfgaF(Gamma2Color, rgbNoise, params.FSR_FILMGRAIN);
+        }
     }
 
     FragColor = vec4(Gamma2Color, 1.0);

fsr/smaa+fsr.slangp

@@ -35,7 +35,14 @@ filter_linear5 = true
 scale_type5 = source
 scale5 = 1.0
 
-parameters = "SMAA_EDT;FSR_SHARPENING;FSR_FILMGRAIN"
+parameters = "SMAA_EDT;SMAA_THRESHOLD;SMAA_MAX_SEARCH_STEPS;SMAA_MAX_SEARCH_STEPS_DIAG;SMAA_LOCAL_CONTRAST_ADAPTATION_FACTOR;SMAA_CORNER_ROUNDING;FSR_SHARPENING;FSR_FILMGRAIN;FSR_GRAINCOLOR;FSR_GRAINPDF"
 SMAA_EDT = 1.0
+SMAA_THRESHOLD = 0.05
+SMAA_MAX_SEARCH_STEPS = 40
+SMAA_MAX_SEARCH_STEPS_DIAG = 20
+SMAA_LOCAL_CONTRAST_ADAPTATION_FACTOR = 2.5
+SMAA_CORNER_ROUNDING = 50.0
 FSR_SHARPENING = 0.1
-FSR_FILMGRAIN = 0.12
+FSR_FILMGRAIN = 0.3
+FSR_GRAINCOLOR = 1.0
+FSR_GRAINPDF = 0.3