File 0001-Use-the-physical-DPI-on-X11-as-logical-DPI... of Package libqt5-qtbase

Overview Repositories Revisions Requests Users Attributes Meta

File 0001-Use-the-physical-DPI-on-X11-as-logical-DPI-by-defaul.patch of Package libqt5-qtbase (Revision 163d7f1c92c9329750a266ad7703f929)

Currently displaying revision 163d7f1c92c9329750a266ad7703f929 , Show latest

From c868fe25f22a62d332279e95dc4b303cb4ef6e29 Mon Sep 17 00:00:00 2001
From: Fabian Vogt <fabian@ritter-vogt.de>
Date: Wed, 5 May 2021 11:42:51 +0200
Subject: [PATCH] Use the physical DPI on X11 as logical DPI by default

If Xft.dpi is not set and QT_USE_PHYSICAL_DPI isn't explicitly set to 0, then
use the physical size of the screen to calculate the logical DPI. Apply some
heuristics to catch invalid EDID values and fall back to 96dpi in such cases.

QTBUG-67928
QTBUG-93454
---
 src/plugins/platforms/xcb/qxcbscreen.cpp | 31 ++++++++++++++++++++----
 src/plugins/platforms/xcb/qxcbscreen.h   |  1 +
 2 files changed, 27 insertions(+), 5 deletions(-)

diff --git a/src/plugins/platforms/xcb/qxcbscreen.cpp b/src/plugins/platforms/xcb/qxcbscreen.cpp
index e637ed827c..566b6f8fd2 100644
--- a/src/plugins/platforms/xcb/qxcbscreen.cpp
+++ b/src/plugins/platforms/xcb/qxcbscreen.cpp
@@ -717,12 +717,18 @@ QDpi QXcbScreen::logicalDpi() const
     if (forcedDpi > 0)
         return QDpi(forcedDpi, forcedDpi);
 
-    // Fall back to physical virtual desktop DPI, but prevent
-    // using DPI values lower than 96. This ensuers that connecting
-    // to e.g. a TV works somewhat predictabilly.
     QDpi virtualDesktopPhysicalDPi = m_virtualDesktop->dpi();
-    return QDpi(std::max(virtualDesktopPhysicalDPi.first, 96.0),
-                std::max(virtualDesktopPhysicalDPi.second, 96.0));
+
+    // By default, X fakes the virtual size to be 96 dpi (+-rounding),
+    // so if it's different the user overwrote it.
+    // Prevent using DPI values lower than 96. This ensuers that connecting
+    // to e.g. a TV works somewhat predictabilly.
+    if (qRound(virtualDesktopPhysicalDPi.first) > 96
+        && qRound(virtualDesktopPhysicalDPi.second) > 96) {
+        return virtualDesktopPhysicalDPi;
+    }
+
+    return QDpi(m_pixelDensity * 96, m_pixelDensity * 96);
 }
 
 QPlatformCursor *QXcbScreen::cursor() const
@@ -788,6 +794,21 @@ void QXcbScreen::updateGeometry(const QRect &geometry, uint8_t rotation)
     if (m_sizeMillimeters.isEmpty())
         m_sizeMillimeters = sizeInMillimeters(geometry.size(), m_virtualDesktop->dpi());
 
+    qreal referenceDpi = physicalSize().width() <= 320 ? 128 : 96;
+
+    m_pixelDensity = qMax(1, qRound(dpi/referenceDpi));
+    if(!qEnvironmentVariableAsBool("QT_USE_PHYSICAL_DPI", true))
+        m_pixelDensity = 1;
+
+    if(m_pixelDensity > 1) {
+        // If we have no physical size or the resolution is untypical, fall back to 1x
+        if (physicalSize().height() <= 0
+            || geometry.height() < 1440
+            || m_pixelDensity > 3) {
+            m_pixelDensity = 1;
+        }
+    }
+
     m_geometry = geometry;
     m_availableGeometry = geometry & m_virtualDesktop->workArea();
     QWindowSystemInterface::handleScreenGeometryChange(QPlatformScreen::screen(), m_geometry, m_availableGeometry);
diff --git a/src/plugins/platforms/xcb/qxcbscreen.h b/src/plugins/platforms/xcb/qxcbscreen.h
index ad2980b55e..b627006b53 100644
--- a/src/plugins/platforms/xcb/qxcbscreen.h
+++ b/src/plugins/platforms/xcb/qxcbscreen.h
@@ -231,6 +231,7 @@ private:
     QXcbCursor *m_cursor;
     qreal m_refreshRate = 60.0;
     QEdidParser m_edid;
+    int m_pixelDensity = 1;
 };
 
 #ifndef QT_NO_DEBUG_STREAM
-- 
2.25.1

Places

File 0001-Use-the-physical-DPI-on-X11-as-logical-DPI-by-defaul.patch of Package libqt5-qtbase (Revision 163d7f1c92c9329750a266ad7703f929)

Places