From dbf089b9cf3cb12b3e2d20d8e4ca5708d1269782 Mon Sep 17 00:00:00 2001
From: "Kira M. Backes" <kira.backes@nrwsoft.de>
Date: Sat, 19 Oct 2024 03:17:04 +0200
Subject: [PATCH] Fix hue shifting when using SDR Gamma Boost

---
 resource/shaders/HDR/basic_hdr_shader_ps.hlsl | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/resource/shaders/HDR/basic_hdr_shader_ps.hlsl b/resource/shaders/HDR/basic_hdr_shader_ps.hlsl
index 0dc30e7a5..dcaaed8b4 100644
--- a/resource/shaders/HDR/basic_hdr_shader_ps.hlsl
+++ b/resource/shaders/HDR/basic_hdr_shader_ps.hlsl
@@ -461,9 +461,9 @@ main (PS_INPUT input) : SV_TARGET
   {
     if (input.color.y != 1.0f)
     {
-      hdr_color.rgb = sign (hdr_color.rgb) *
-                  pow (abs (hdr_color.rgb),
-                          input.color.yyy);
+      float fLuma = Luminance(hdr_color.rgb);
+      float fLumaWithGamma = sign(fLuma) * pow(abs(fLuma), input.color.y);
+      hdr_color.rgb = hdr_color.rgb * (fLumaWithGamma / fLuma);
     }
   }