rtx: add reinhard tonemapping

ref_vk/shaders/denoiser.comp

@@ -31,6 +31,14 @@ vec3 aces_tonemap(vec3 color){
 	return clamp(m2 * (a / b), 0.0, 1.0);
 }
 
+vec3 reinhard(vec3 color){
+	return color / (color + 1.0);
+}
+
+vec3 reinhard02(vec3 c, vec3 Cwhite2) {
+	return c * (1. + c / Cwhite2) / (1. + c);
+}
+
 float normpdf2(in float x2, in float sigma) { return 0.39894*exp(-0.5*x2/(sigma*sigma))/sigma; }
 float normpdf(in float x, in float sigma) { return normpdf2(x*x, sigma); }
 
@@ -122,7 +130,8 @@ void main() {
 	// TODO: should be dynamic based on previous frames brightness
 	colour *= 4.;
 
-	colour = aces_tonemap(colour);
+	//colour = aces_tonemap(colour);
+	colour = reinhard02(colour, vec3(400.));
 
 	imageStore(dest, pix, vec4(colour, 0.));
 	//imageStore(dest, pix, imageLoad(src_diffuse_gi, pix));