Fixed scaling bug on a HiDPI display.

src/core/CameraInfo.cpp

@@ -6,7 +6,8 @@ namespace core
 {
 
 CameraInfo::CameraInfo()
-    : mScreenSize()
+    : mDevicePixelRatio(1.0)
+    , mScreenSize()
     , mImageSize()
     , mCenter()
     , mLeftTopPos()
@@ -15,8 +16,10 @@ CameraInfo::CameraInfo()
 {
 }
 
-void CameraInfo::reset(const QSize& aScreenSize, const QSize& aImageSize, const QPoint& aLeftTopPos)
+void CameraInfo::reset(const QSize& aScreenSize, double aDpr,
+                       const QSize& aImageSize, const QPoint& aLeftTopPos)
 {
+    mDevicePixelRatio = aDpr;
     mScreenSize = aScreenSize;
     mImageSize = aImageSize;
     mScale = 1.0f;
@@ -25,6 +28,11 @@ void CameraInfo::reset(const QSize& aScreenSize, const QSize& aImageSize, const
     mCenter = mLeftTopPos + centerOffset();
 }
 
+void CameraInfo::setDevicePixelRatio(double aRatio)
+{
+    mDevicePixelRatio = aRatio;
+}
+
 void CameraInfo::setLeftTopPos(const QVector2D& aPos)
 {
     mLeftTopPos = aPos;

src/core/CameraInfo.h

@@ -17,8 +17,10 @@ class CameraInfo
 public:
     CameraInfo();
 
-    void reset(const QSize& aScreenSize, const QSize& aImageSize, const QPoint& aLeftTopPos);
+    void reset(const QSize& aScreenSize, double aDpr,
+               const QSize& aImageSize, const QPoint& aLeftTopPos);
 
+    void setDevicePixelRatio(double aRatio);
     inline void setScreenWidth(int aWidth) { mScreenSize.setWidth(aWidth); }
     inline void setScreenHeight(int aHeight) { mScreenSize.setHeight(aHeight); }
     inline void setScreenSize(const QSize& aSize) { mScreenSize = aSize; }
@@ -28,9 +30,11 @@ class CameraInfo
     void setScale(float aScale);
     void setRotate(float aRadian);
 
+    inline double devicePixelRatio() const { return mDevicePixelRatio; }
     inline int screenWidth() const { return mScreenSize.width(); }
     inline int screenHeight() const { return mScreenSize.height(); }
     inline QSize screenSize() const { return mScreenSize; }
+    inline QSize deviceScreenSize() const { return mScreenSize * mDevicePixelRatio; }
     QVector2D screenCenter() const;
 
     inline QSize imageSize() const { return mImageSize; }
@@ -69,6 +73,7 @@ class CameraInfo
         return 0.5f * QVector2D(mImageSize.width(), mImageSize.height());
     }
 
+    double mDevicePixelRatio;
     QSize mScreenSize;
     QSize mImageSize;
     QVector2D mCenter;

src/core/LayerNode.cpp

@@ -248,7 +248,7 @@ void LayerNode::renderClipper(
         shader.setAttributeArray("inTexCoord", mCurrentMesh->texCoords(), mCurrentMesh->vertexCount());
 
         shader.setUniformValue("uViewMatrix", viewMatrix);
-        shader.setUniformValue("uScreenSize", QSizeF(aInfo.camera.screenSize()));
+        shader.setUniformValue("uScreenSize", QSizeF(aInfo.camera.deviceScreenSize()));
         shader.setUniformValue("uImageSize", QSizeF(textureSize));
         shader.setUniformValue("uTexCoordOffset", texCoordOffset);
         shader.setUniformValue("uColor", color);
@@ -388,7 +388,7 @@ void LayerNode::renderShape(
         shader.setAttributeArray("inTexCoord", mCurrentMesh->texCoords(), mCurrentMesh->vertexCount());
 
         shader.setUniformValue("uViewMatrix", viewMatrix);
-        shader.setUniformValue("uScreenSize", QSizeF(aInfo.camera.screenSize()));
+        shader.setUniformValue("uScreenSize", QSizeF(aInfo.camera.deviceScreenSize()));
         shader.setUniformValue("uImageSize", QSizeF(textureSize));
         shader.setUniformValue("uTexCoordOffset", texCoordOffset);
         shader.setUniformValue("uColor", color);

src/ctrl/Exporter.cpp

@@ -568,7 +568,7 @@ bool Exporter::update()
 
     // render
     core::RenderInfo renderInfo;
-    renderInfo.camera.reset(originSize, originSize, QPoint());
+    renderInfo.camera.reset(originSize, 1.0, originSize, QPoint());
     renderInfo.time = timeInfo;
     renderInfo.framebuffer = mFramebuffers.front()->handle();
     renderInfo.dest = mFramebuffers.front()->texture();

src/gui/Main.cpp

@@ -102,6 +102,7 @@ int entryPoint(int argc, char *argv[])
     // create qt application
     QApplication app(argc, argv);
     XC_DEBUG_REPORT() << "exe path =" << app.applicationFilePath();
+    app.setAttribute(Qt::AA_UseHighDpiPixmaps);
 
     // application path
 #if defined(Q_OS_MAC)

src/gui/MainDisplayWidget.cpp

@@ -1,6 +1,7 @@
 #include <functional>
 #include <QMouseEvent>
 #include <QOpenGLFunctions>
+#include <QGuiApplication>
 #include "XC.h"
 #include "util/Finally.h"
 #include "gl/Util.h"
@@ -40,6 +41,7 @@ MainDisplayWidget::MainDisplayWidget(ViaPoint& aViaPoint, QWidget* aParent)
     , mCanvasMover()
     , mMovingCanvasByTool(false)
     , mMovingCanvasByKey(false)
+    , mDevicePixelRatio(1.0)
 {
 #ifdef USE_GL_CORE_PROFILE
     // setup opengl format
@@ -134,6 +136,7 @@ void MainDisplayWidget::setProject(core::Project* aProject)
     {
         mProject = aProject->pointee();
         mRenderInfo = &(static_cast<ProjectHook*>(mProject->hook())->renderInfo());
+        mRenderInfo->camera.setDevicePixelRatio(this->devicePixelRatioF());
         mRenderInfo->camera.setScreenSize(this->size());
         mRenderInfo->camera.setImageSize(mProject->attribute().imageSize());
         mCanvasMover.setCamera(&(mRenderInfo->camera));
@@ -221,16 +224,18 @@ void MainDisplayWidget::initializeGL()
     mDefaultVAO->bind(); // keep binding
 #endif
 
+    mDevicePixelRatio = this->devicePixelRatioF();
+
     // create framebuffer for display
-    mFramebuffer.reset(new QOpenGLFramebufferObject(this->size()));
+    mFramebuffer.reset(new QOpenGLFramebufferObject(deviceSize()));
 
     // create clipping buffer
     mClippingFrame.reset(new core::ClippingFrame());
-    mClippingFrame->resize(this->size());
+    mClippingFrame->resize(deviceSize());
 
     // create texturizer for destination colors of the framebuffer
     mDestinationTexturizer.reset(new core::DestinationTexturizer());
-    mDestinationTexturizer->resize(this->size());
+    mDestinationTexturizer->resize(deviceSize());
 
     // create texture drawer for copying framebuffer to display
     mTextureDrawer.reset(new gl::EasyTextureDrawer());
@@ -262,7 +267,7 @@ void MainDisplayWidget::paintGL()
     }
 
     // setup
-    gl::Util::setViewportAsActualPixels(this->size());
+    gl::Util::setViewportAsActualPixels(deviceSize());
     gl::Util::clearColorBuffer(0.25f, 0.25f, 0.25f, 1.0f);
     gl::Util::resetRenderState();
     GL_CHECK_ERROR();
@@ -342,25 +347,29 @@ void MainDisplayWidget::paintEvent(QPaintEvent* aEvent)
 
 void MainDisplayWidget::resizeGL(int w, int h)
 {
-    const QSize newSize(w, h);
+    // currrent device pixel ratio (Attention that it is variable.)
+    mDevicePixelRatio = this->devicePixelRatioF();
+    const QSize devSize(mDevicePixelRatio * w, mDevicePixelRatio * h); // device pixel size
+    const QSize absSize(w, h); // abstract pixel size
 
     if (mRenderInfo)
     {
-        mRenderInfo->camera.setScreenSize(newSize);
+        mRenderInfo->camera.setDevicePixelRatio(mDevicePixelRatio);
+        mRenderInfo->camera.setScreenSize(absSize);
         mCanvasMover.onScreenResized();
     }
     mFramebuffer.reset();
-    mFramebuffer.reset(new QOpenGLFramebufferObject(w, h));
+    mFramebuffer.reset(new QOpenGLFramebufferObject(devSize.width(), devSize.height()));
 
     mClippingFrame.reset();
     mClippingFrame.reset(new core::ClippingFrame());
-    mClippingFrame->resize(newSize);
+    mClippingFrame->resize(devSize);
 
-    mDestinationTexturizer->resize(newSize);
+    mDestinationTexturizer->resize(devSize);
 
     if (mProjectTabBar)
     {
-        mProjectTabBar->updateTabPosition(newSize);
+        mProjectTabBar->updateTabPosition(absSize);
     }
     GL_CHECK_ERROR();
 }

src/gui/MainDisplayWidget.h

@@ -73,6 +73,7 @@ class MainDisplayWidget : public QOpenGLWidget
     virtual void tabletEvent(QTabletEvent* event);
 
     void updateCursor();
+    QSize deviceSize() const { return this->size() * mDevicePixelRatio; }
 
     ViaPoint& mViaPoint;
     gl::DeviceInfo mGLDeviceInfo;
@@ -95,6 +96,7 @@ class MainDisplayWidget : public QOpenGLWidget
     CanvasMover mCanvasMover;
     bool mMovingCanvasByTool;
     bool mMovingCanvasByKey;
+    double mDevicePixelRatio;
 };
 
 } // namespace gui