Update leenkx/Shaders/std/tonemap.glsl

leenkx/Shaders/std/tonemap.glsl

@@ -1,4 +1,3 @@
-
 vec3 uncharted2Tonemap(const vec3 x) {
 	const float A = 0.15;
 	const float B = 0.50;
@@ -36,3 +35,51 @@ vec3 acesFilm(const vec3 x) {
 vec3 tonemapReinhard(const vec3 color) {
 	return color / (color + vec3(1.0));
 }
+
+// Blender AgX Implementation 
+// Troy Sobotka https://github.com/sobotka/AgX
+
+// AGX Simple
+vec3 tonemapAgXSimple(vec3 x) {
+    const vec3 AgX_A = vec3(0.5, 0.5, 0.5);
+    const vec3 AgX_B = vec3(0.5, 0.5, 0.5);
+    const vec3 AgX_C = vec3(1.0, 1.0, 1.0);
+    const vec3 AgX_D = vec3(0.0, 0.0, 0.0);
+    const vec3 AgX_E = vec3(0.0, 0.0, 0.0);
+    const vec3 AgX_F = vec3(1.0, 1.0, 1.0);
+    
+    return (x * (AgX_A * x + AgX_B)) / (x * (AgX_C * x + AgX_D) + AgX_E) + AgX_F;
+}
+
+// AGX Full Contrast Approx
+vec3 agxDefaultContrastApprox(vec3 x) {
+    vec3 x2 = x * x;
+    vec3 x4 = x2 * x2;
+    return + 15.5     * x4 * x2
+           - 40.14    * x4 * x
+           + 31.96    * x4
+           - 6.868    * x2 * x
+           + 0.4298   * x2
+           + 0.1191   * x
+           - 0.00232;
+}
+// AGX Full Look
+vec3 agxLook(vec3 x, float strength) {
+    const vec3 slope = vec3(1.0);
+    const vec3 power = vec3(1.35);
+    const vec3 sat = vec3(1.4);
+    vec3 lw = vec3(0.2126, 0.7152, 0.0722);
+    float luma = dot(x, lw);
+    return pow(x * slope, power) * sat - (pow(luma * slope, power) * (sat - 1.0));
+}
+
+// AGX Full
+vec3 tonemapAgXFull(vec3 x) {
+    // x *= 2.0 * (1.0/0.8); // Brightness scale to match Blender's default
+    x = clamp(x, 0.0, 65504.0);
+    x = log2(x + 1.0);
+    x = agxDefaultContrastApprox(clamp(x * 0.5 - 10.5, -12.0, 12.0));    
+    x = mix(x, agxLook(x, 0.5), 0.5);
+    x = clamp(x, 0.0, 1.0);
+    return pow(x, vec3(1.0/2.2)); 
+}