From 1f5996236040597dd5bbd1a3e8b73c6a0a8514c3 Mon Sep 17 00:00:00 2001
From: Uwe Rathmann <Uwe.Rathmann@tigertal.de>
Date: Sun, 27 Oct 2019 08:11:47 +0100
Subject: [PATCH] devicePixelRatio detection moved to QskTextureRenderer

---
 src/controls/QskSkinlet.cpp      | 25 +++++++++-----------
 src/nodes/QskTextureNode.cpp     | 39 +++-----------------------------
 src/nodes/QskTextureRenderer.cpp | 38 +++++++++++++++++++++++++++++++
 src/nodes/QskTextureRenderer.h   |  3 +++
 4 files changed, 55 insertions(+), 50 deletions(-)

diff --git a/src/controls/QskSkinlet.cpp b/src/controls/QskSkinlet.cpp
index f6f6c1f1..6f27cdf0 100644
--- a/src/controls/QskSkinlet.cpp
+++ b/src/controls/QskSkinlet.cpp
@@ -90,21 +90,18 @@ static inline QSGNode* qskUpdateGraphicNode(
         if ( control->testControlFlag( QskControl::PreferRasterForTextures ) )
             mode = QskTextureRenderer::Raster;
 
-        if ( auto window = control->window() )
-        {
-            /*
-               Aligning the rect according to scene coordinates, so that
-               we don't run into rounding issues downstream, where values
-               will be floored/ceiled ending up with a slightly different
-               aspect ratio.
-             */
-            const QRectF sceneRect(
-                control->mapToScene( r.topLeft() ),
-                r.size() * window->effectiveDevicePixelRatio() );
+        /*
+           Aligning the rect according to scene coordinates, so that
+           we don't run into rounding issues downstream, where values
+           will be floored/ceiled ending up with a slightly different
+           aspect ratio.
+         */
+        const QRectF sceneRect(
+            control->mapToScene( r.topLeft() ),
+            r.size() * QskTextureRenderer::devicePixelRatio() );
 
-            r = qskInnerRect( sceneRect );
-            r.moveTopLeft( control->mapFromScene( r.topLeft() ) );
-        }
+        r = qskInnerRect( sceneRect );
+        r.moveTopLeft( control->mapFromScene( r.topLeft() ) );
     }
 
     graphicNode->setGraphic( graphic, colorFilter, mode, r );
diff --git a/src/nodes/QskTextureNode.cpp b/src/nodes/QskTextureNode.cpp
index 81142dee..4e8f062e 100644
--- a/src/nodes/QskTextureNode.cpp
+++ b/src/nodes/QskTextureNode.cpp
@@ -1,4 +1,5 @@
 #include "QskTextureNode.h"
+#include "QskTextureRenderer.h"
 
 #include <qopenglfunctions.h>
 #include <qsggeometry.h>
@@ -6,41 +7,6 @@
 
 #include <private/qsgnode_p.h>
 
-#if 1
-
-#include <qguiapplication.h>
-#include <qquickwindow.h>
-#include <qscreen.h>
-#include <qsurface.h>
-
-static inline qreal qskDevicePixelRatio()
-{
-    qreal ratio = 1.0;
-
-    const auto context = QOpenGLContext::currentContext();
-
-    if ( context->surface()->surfaceClass() == QSurface::Window )
-    {
-        auto* window = static_cast< QWindow* >( context->surface() );
-
-        if ( auto* quickWindow = qobject_cast< QQuickWindow* >( window ) )
-            ratio = quickWindow->effectiveDevicePixelRatio();
-        else
-            ratio = window->devicePixelRatio();
-    }
-    else
-    {
-        if ( context->screen() )
-            ratio = context->screen()->devicePixelRatio();
-        else
-            ratio = qGuiApp->devicePixelRatio();
-    }
-
-    return ratio;
-}
-
-#endif
-
 namespace
 {
     class MaterialShader final : public QSGMaterialShader
@@ -316,7 +282,8 @@ void QskTextureNode::updateTexture()
         r.setBottom( 0 );
     }
 
-    const qreal ratio = qskDevicePixelRatio();
+    const qreal ratio = QskTextureRenderer::devicePixelRatio();
+
     const QRectF rect( d->rect.x(), d->rect.y(),
         d->rect.width() / ratio, d->rect.height() / ratio );
 
diff --git a/src/nodes/QskTextureRenderer.cpp b/src/nodes/QskTextureRenderer.cpp
index 4978ec53..f0f6471d 100644
--- a/src/nodes/QskTextureRenderer.cpp
+++ b/src/nodes/QskTextureRenderer.cpp
@@ -18,6 +18,11 @@
 #include <qimage.h>
 #include <qpainter.h>
 
+#include <qguiapplication.h>
+#include <qquickwindow.h>
+#include <qscreen.h>
+#include <qsurface.h>
+
 static uint qskCreateTextureOpenGL(
     const QSize& size, QskTextureRenderer::PaintHelper* helper )
 {
@@ -173,3 +178,36 @@ uint QskTextureRenderer::createTextureFromGraphic(
     PaintHelper helper( graphic, colorFilter, aspectRatioMode );
     return createTexture( renderMode, size, &helper );
 }
+
+static inline qreal qskOffscreenBufferRatio( const QOpenGLContext* context )
+{
+    if ( context->screen() )
+        return context->screen()->devicePixelRatio();
+
+    return qGuiApp->devicePixelRatio();
+}
+
+qreal QskTextureRenderer::devicePixelRatio( const QOpenGLContext* context )
+{
+    if ( context == nullptr )
+        context = QOpenGLContext::currentContext();
+
+    qreal ratio = 1.0;
+
+    if ( context->surface()->surfaceClass() == QSurface::Window )
+    {
+        auto* window = static_cast< QWindow* >( context->surface() );
+
+        if ( auto* quickWindow = qobject_cast< QQuickWindow* >( window ) )
+            ratio = quickWindow->effectiveDevicePixelRatio();
+        else
+            ratio = window->devicePixelRatio();
+    }
+    else
+    {
+        ratio = qskOffscreenBufferRatio( context );
+    }
+
+    return ratio;
+}
+
diff --git a/src/nodes/QskTextureRenderer.h b/src/nodes/QskTextureRenderer.h
index 4bd715eb..876ab739 100644
--- a/src/nodes/QskTextureRenderer.h
+++ b/src/nodes/QskTextureRenderer.h
@@ -14,6 +14,7 @@ class QskColorFilter;
 
 class QPainter;
 class QSize;
+class QOpenGLContext;
 
 namespace QskTextureRenderer
 {
@@ -46,6 +47,8 @@ namespace QskTextureRenderer
     QSK_EXPORT uint createTextureFromGraphic(
         RenderMode, const QSize&, const QskGraphic&,
         const QskColorFilter&, Qt::AspectRatioMode );
+
+    QSK_EXPORT qreal devicePixelRatio( const QOpenGLContext* = nullptr );
 }
 
 #endif