From 0ec1884b243bfb0b5b97c988f45a8aa89e132574 Mon Sep 17 00:00:00 2001
From: Allan Sandfeld Jensen <allan.jensen@qt.io>
Date: Wed, 2 Jun 2021 18:04:15 +0200
Subject: [PATCH] Disable text gamma-correction when painting on linear color
 space

We currently only support full gamma corrected painting by using linear
color space images, the text logic however did its own gamma correction
on top of that.

Change-Id: I4ef41745f4bc1c3a5815426abbcee6968987e70d
Reviewed-by: Eirik Aavitsland <eirik.aavitsland@qt.io>
---
 src/gui/painting/qpaintengine_raster.cpp | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/gui/painting/qpaintengine_raster.cpp b/src/gui/painting/qpaintengine_raster.cpp
index 5b58c32c5fb..5ac1f748e5b 100644
--- a/src/gui/painting/qpaintengine_raster.cpp
+++ b/src/gui/painting/qpaintengine_raster.cpp
@@ -2596,6 +2596,8 @@ void QRasterPaintEngine::alphaPenBlt(const void* src, int bpl, int depth, int rx
         return;
 
     QRasterBuffer *rb = d->rasterBuffer.data();
+    if (rb->colorSpace.transferFunction() == QColorSpace::TransferFunction::Linear)
+        useGammaCorrection = false;
 
     const QRect rect(rx, ry, w, h);
     const QClipData *clip = d->clip();