From 9ade574b1adc30c762a8988537f0d680d6f9e869 Mon Sep 17 00:00:00 2001
From: Laurent Rineau <laurent.rineau@cgal.org>
Date: Thu, 12 May 2022 12:13:08 +0200
Subject: [PATCH] Add devicePixelRatio() to Camera

---
 GraphicsView/include/CGAL/Qt/camera.h         | 4 +++-
 GraphicsView/include/CGAL/Qt/camera_impl.h    | 3 ++-
 GraphicsView/include/CGAL/Qt/qglviewer_impl.h | 4 ++--
 3 files changed, 7 insertions(+), 4 deletions(-)

diff --git a/GraphicsView/include/CGAL/Qt/camera.h b/GraphicsView/include/CGAL/Qt/camera.h
index bda76bafb05..70f7c8edd8e 100644
--- a/GraphicsView/include/CGAL/Qt/camera.h
+++ b/GraphicsView/include/CGAL/Qt/camera.h
@@ -199,6 +199,7 @@ public:
   CGAL::QGLViewer's window dimensions when the Camera is attached to a CGAL::QGLViewer. See
   also QOpenGLWidget::height() */
   int screenHeight() const { return screenHeight_; }
+  qreal devicePixelRatio() const { return devicePixelRatio_; }
   void getViewport(GLint viewport[4]) const;
   qreal pixelGLRatio(const Vec &position) const;
 
@@ -279,7 +280,7 @@ public Q_SLOTS:
     setScreenWidthAndHeight(int(100.0 * aspect), 100);
   }
 
-  void setScreenWidthAndHeight(int width, int height);
+  void setScreenWidthAndHeight(int width, int height, qreal devicePixelRatio = 1.0);
   /*! Sets the zNearCoefficient() value. */
   void setZNearCoefficient(qreal coef) {
     zNearCoef_ = coef;
@@ -444,6 +445,7 @@ private:
 
   // C a m e r a   p a r a m e t e r s
   int screenWidth_, screenHeight_; // size of the window, in pixels
+  qreal devicePixelRatio_;
   qreal fieldOfView_;              // in radians
   Vec sceneCenter_;
   qreal sceneRadius_; // OpenGL units
diff --git a/GraphicsView/include/CGAL/Qt/camera_impl.h b/GraphicsView/include/CGAL/Qt/camera_impl.h
index 672e5d91c23..a963e13574d 100644
--- a/GraphicsView/include/CGAL/Qt/camera_impl.h
+++ b/GraphicsView/include/CGAL/Qt/camera_impl.h
@@ -160,10 +160,11 @@ frustrum coherence.
 If your Camera is used without a CGAL::QGLViewer (offscreen rendering, shadow maps),
 use setAspectRatio() instead to define the projection matrix. */
 CGAL_INLINE_FUNCTION
-void Camera::setScreenWidthAndHeight(int width, int height) {
+void Camera::setScreenWidthAndHeight(int width, int height, qreal devicePixelRatio) {
   // Prevent negative and zero dimensions that would cause divisions by zero.
   screenWidth_ = width > 0 ? width : 1;
   screenHeight_ = height > 0 ? height : 1;
+  devicePixelRatio_ = devicePixelRatio;
   projectionMatrixIsUpToDate_ = false;
 }
 
diff --git a/GraphicsView/include/CGAL/Qt/qglviewer_impl.h b/GraphicsView/include/CGAL/Qt/qglviewer_impl.h
index 70fdfdd9a15..87c3b4e3a61 100644
--- a/GraphicsView/include/CGAL/Qt/qglviewer_impl.h
+++ b/GraphicsView/include/CGAL/Qt/qglviewer_impl.h
@@ -807,7 +807,7 @@ void CGAL::QGLViewer::setCamera(qglviewer::Camera *const camera) {
 
   camera->setSceneRadius(sceneRadius());
   camera->setSceneCenter(sceneCenter());
-  camera->setScreenWidthAndHeight(width(), height());
+  camera->setScreenWidthAndHeight(width(), height(), devicePixelRatio());
 
   // Disconnect current camera from this viewer.
   disconnect(this->camera()->frame(), SIGNAL(manipulated()), this,
@@ -2369,7 +2369,7 @@ CGAL_INLINE_FUNCTION
 void CGAL::QGLViewer::resizeGL(int width, int height) {
   QOpenGLWidget::resizeGL(width, height);
   glViewport(0, 0, GLint(width), GLint(height));
-  camera()->setScreenWidthAndHeight(this->width(), this->height());
+  camera()->setScreenWidthAndHeight(this->width(), this->height(), this->devicePixelRatio());
 }
 
 //////////////////////////////////////////////////////////////////////////