From 95c6fc5343245001953d7f1aa6450b23c83ab14a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Du=C5=A1an=20Poizl?= <nou.spiro@gmail.com>
Date: Sun, 16 Oct 2022 11:05:15 +0200
Subject: [PATCH] Enable sRGB to gamma correct scaling

---
 imagescrollareagl.cpp | 8 ++++++--
 imagescrollareagl.h   | 1 +
 main.cpp              | 1 +
 3 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/imagescrollareagl.cpp b/imagescrollareagl.cpp
index 63328df..d030ba5 100644
--- a/imagescrollareagl.cpp
+++ b/imagescrollareagl.cpp
@@ -24,8 +24,8 @@ const RawImageType rawImageTypes[] = {
     {QOpenGLTexture::Red, QOpenGLTexture::R8_UNorm, QOpenGLTexture::UInt8, true},
     {QOpenGLTexture::Red, QOpenGLTexture::R16_UNorm, QOpenGLTexture::UInt16, true},
     {QOpenGLTexture::Red, QOpenGLTexture::R32F, QOpenGLTexture::Float32, true},
-    {QOpenGLTexture::RGB, QOpenGLTexture::RGB8_UNorm, QOpenGLTexture::UInt8, false},
-    {QOpenGLTexture::RGBA,QOpenGLTexture::RGB8_UNorm, QOpenGLTexture::UInt8, false},
+    {QOpenGLTexture::RGB, QOpenGLTexture::SRGB8, QOpenGLTexture::UInt8, false},
+    {QOpenGLTexture::RGBA,QOpenGLTexture::SRGB8_Alpha8, QOpenGLTexture::UInt8, false},
     {QOpenGLTexture::RGB, QOpenGLTexture::RGB16_UNorm, QOpenGLTexture::UInt16, false},
     {QOpenGLTexture::RGBA, QOpenGLTexture::RGB16_UNorm, QOpenGLTexture::UInt16, false},
     {QOpenGLTexture::RGB, QOpenGLTexture::RGB32F, QOpenGLTexture::Float32, false}
@@ -79,6 +79,7 @@ ImageWidget::ImageWidget(Database *database, QWidget *parent) : QOpenGLWidget(pa
     });
 
     setMouseTracking(true);
+    setTextureFormat(GL_SRGB8_ALPHA8);
 }
 
 ImageWidget::~ImageWidget()
@@ -110,6 +111,7 @@ void ImageWidget::setImage(std::shared_ptr<RawImage> image, int index)
     m_image->setLevelOfDetailRange(m_superpixel ? 1 : 0, m_image->mipMaxLevel());
     m_image->generateMipMaps();
     m_bwImg = rawImageType.bw;
+    m_srgb = rawImageType.textureFormat == QOpenGLTexture::SRGB8 || rawImageType.textureFormat == QOpenGLTexture::SRGB8_Alpha8;
     update();
 }
 
@@ -288,6 +290,7 @@ void ImageWidget::paintGL()
     }
     else
     {
+        if(m_srgb)f->glEnable(GL_FRAMEBUFFER_SRGB);
         m_vao->bind();
         m_image->bind(0);
         m_program->bind();
@@ -298,6 +301,7 @@ void ImageWidget::paintGL()
         m_program->setUniformValue("bw", m_bwImg);
         m_program->setUniformValue("invert", m_invert);
         f->glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
+        if(m_srgb)f->glDisable(GL_FRAMEBUFFER_SRGB);
     }
 
 }
diff --git a/imagescrollareagl.h b/imagescrollareagl.h
index eada281..b365ade 100644
--- a/imagescrollareagl.h
+++ b/imagescrollareagl.h
@@ -57,6 +57,7 @@ class ImageWidget : public QOpenGLWidget
     bool m_showThumbnails;
     bool m_selecting;
     bool m_sizesDirty;
+    bool m_srgb;
     int m_thumbnailCount;
     QVector<ImageThumb> m_thumnails;
     Database *m_database;
diff --git a/main.cpp b/main.cpp
index 31ea53d..18a0e3c 100644
--- a/main.cpp
+++ b/main.cpp
@@ -15,6 +15,7 @@ int main(int argc, char *argv[])
     format.setMinorVersion(3);
     format.setOption(QSurfaceFormat::DebugContext);
     format.setProfile(QSurfaceFormat::OpenGLContextProfile::CoreProfile);
+    format.setColorSpace(QSurfaceFormat::sRGBColorSpace);
     QSurfaceFormat::setDefaultFormat(format);
 
     QApplication a(argc, argv);