Merge "[SurfaceFlinger] Fix HDR tone mapping." into pi-dev
diff --git a/services/surfaceflinger/RenderEngine/ProgramCache.cpp b/services/surfaceflinger/RenderEngine/ProgramCache.cpp
index 7a43ea9..6a34981 100644
--- a/services/surfaceflinger/RenderEngine/ProgramCache.cpp
+++ b/services/surfaceflinger/RenderEngine/ProgramCache.cpp
@@ -305,15 +305,24 @@
if (needs.hasToneMapping()) {
fs << R"__SHADER__(
- float ToneMapChannel(const float color) {
+ float CalculateY(const vec3 color) {
+ // BT2020 standard uses the unadjusted KR = 0.2627,
+ // KB = 0.0593 luminance interpretation for RGB conversion.
+ return color.r * 0.262700 + color.g * 0.677998 +
+ color.b * 0.059302;
+ }
+ vec3 ToneMap(const vec3 color) {
const float maxLumi = 10000.0;
const float maxMasteringLumi = 1000.0;
const float maxContentLumi = 1000.0;
const float maxInLumi = min(maxMasteringLumi, maxContentLumi);
const float maxOutLumi = 500.0;
+ // Calculate Y value in XYZ color space.
+ float colorY = CalculateY(color);
+
// convert to nits first
- float nits = color * maxLumi;
+ float nits = colorY * maxLumi;
// clamp to max input luminance
nits = clamp(nits, 0.0, maxInLumi);
@@ -360,12 +369,8 @@
}
// convert back to [0.0, 1.0]
- return nits / maxOutLumi;
- }
-
- vec3 ToneMap(const vec3 color) {
- return vec3(ToneMapChannel(color.r), ToneMapChannel(color.g),
- ToneMapChannel(color.b));
+ float targetY = nits / maxOutLumi;
+ return color * (targetY / max(1e-6, colorY));
}
)__SHADER__";
} else {