Zero copy preview made optional

src/MainWindow.cpp

@@ -203,6 +203,11 @@ MainWindow::MainWindow(QWidget *parent)
  &settings, &Settings::setIndentWithSpaces);
  connect(&settings, &Settings::darkThemeChanging,
  this, &MainWindow::handleDarkThemeChanging);
+ connect(mUi->actionZeroCopyPreview, &QAction::toggled,
+ [&](bool enabled) {
+ if (mEditorManager.closeAllImageEditors())
+ settings.setZeroCopyPreview(enabled);
+ });
 
  connect(mUi->actionEvalManual, &QAction::triggered,
  this, &MainWindow::updateEvaluationMode);
@@ -322,6 +327,7 @@ void MainWindow::readSettings()
  mUi->actionSyntaxHighlighting->setChecked(settings.syntaxHighlighting());
  mUi->actionDarkTheme->setChecked(settings.darkTheme());
  mUi->actionLineWrapping->setChecked(settings.lineWrap());
+ mUi->actionZeroCopyPreview->setChecked(settings.zeroCopyPreview());
 }
 
 void MainWindow::closeEvent(QCloseEvent *event)

src/MainWindow.ui

@@ -123,6 +123,8 @@
  <addaction name="actionEvalManual"/>
  <addaction name="actionEvalAuto"/>
  <addaction name="actionEvalSteady"/>
+ <addaction name="separator"/>
+ <addaction name="actionZeroCopyPreview"/>
  </widget>
  <addaction name="menuEvaluation"/>
  <addaction name="separator"/>
@@ -539,6 +541,17 @@
  <string>&amp;Dark Theme</string>
  </property>
  </action>
+ <action name="actionZeroCopyPreview">
+ <property name="checkable">
+ <bool>true</bool>
+ </property>
+ <property name="text">
+ <string>&amp;Zero Copy Preview (experimental)</string>
+ </property>
+ <property name="toolTip">
+ <string>Zero Copy Preview</string>
+ </property>
+ </action>
  </widget>
  <resources>
  <include location="resources.qrc"/>

src/Settings.cpp

@@ -2,6 +2,8 @@
 #include <QFontDialog>
 #include <QFontDatabase>
 
+bool gZeroCopyPreview = true;
+
 Settings::Settings(QObject *parent) : QSettings(parent)
 {
  mFont = QFontDatabase::systemFont(QFontDatabase::FixedFont);
@@ -13,6 +15,7 @@ Settings::Settings(QObject *parent) : QSettings(parent)
  setAutoIndentation(value("autoIndentation", "true").toBool());
  setSyntaxHighlighting(value("syntaxHighlighting", "true").toBool());
  setDarkTheme(value("darkTheme", "false").toBool());
+ setZeroCopyPreview(value("zeroCopyPreview", "false").toBool());
 
  auto fontSettings = value("font").toString();
  if (!fontSettings.isEmpty()) {
@@ -31,6 +34,7 @@ Settings::~Settings()
  setValue("syntaxHighlighting", syntaxHighlighting());
  setValue("darkTheme", darkTheme());
  setValue("font", font().toString());
+ setValue("zeroCopyPreview", zeroCopyPreview());
  endGroup();
 }
 
@@ -89,3 +93,15 @@ void Settings::setDarkTheme(bool enabled)
  emit darkThemeChanging(enabled);
  emit darkThemeChanged(enabled);
 }
+
+void Settings::setZeroCopyPreview(bool enabled)
+{
+ gZeroCopyPreview = enabled;
+ gZeroCopyPreview = enabled;
+ emit zeroCopyPreviewChanged(enabled);
+}
+
+bool Settings::zeroCopyPreview() const
+{
+ return gZeroCopyPreview;
+}

src/Settings.h

@@ -26,6 +26,8 @@ class Settings : public QSettings
  bool syntaxHighlighting() const { return mSyntaxHighlighting; }
  void setDarkTheme(bool enabled);
  bool darkTheme() const { return mDarkTheme; }
+ void setZeroCopyPreview(bool enabled);
+ bool zeroCopyPreview() const;
 
 signals:
  void tabSizeChanged(int tabSize);
@@ -36,6 +38,7 @@ class Settings : public QSettings
  void syntaxHighlightingChanged(bool enabled);
  void darkThemeChanging(bool enabled);
  void darkThemeChanged(bool enabled);
+ void zeroCopyPreviewChanged(bool enabled);
 
 private:
  int mTabSize{ 4 };

src/editors/EditorManager.cpp

@@ -314,6 +314,15 @@ bool EditorManager::closeAllEditors()
  return true;
 }
 
+bool EditorManager::closeAllImageEditors()
+{
+ foreach (QDockWidget* dock, mDocks.keys())
+ if (qobject_cast<ImageEditor*>(dock->widget()))
+ if (!closeDock(dock))
+ return false;
+ return true;
+}
+
 void EditorManager::addSourceEditor(SourceEditor *editor)
 {
  mSourceEditors.append(editor);

src/editors/EditorManager.h

@@ -49,6 +49,7 @@ class EditorManager : public DockWindow
  bool reloadEditor();
  bool closeEditor();
  bool closeAllEditors();
+ bool closeAllImageEditors();
 
 signals:
  void editorChanged(const QString &fileName);

src/editors/ImageEditor.cpp

@@ -11,7 +11,9 @@
 #include <QOpenGLShader>
 #include <QOpenGLFunctions_3_3_Core>
 
-class ImageItem : public QGraphicsItem
+extern bool gZeroCopyPreview;
+
+class ZeroCopyItem : public QGraphicsItem
 {
 static constexpr auto vertexShader = R"(
 #version 330
@@ -53,9 +55,9 @@ void main() {
  QOpenGLTexture *mTexture{ };
  QMetaObject::Connection mTextureContextConnection;
  QImage mUploadImage;
+ QRect mBoundingRect;
  GLuint mPreviewTextureId{ };
  bool mPreviewFlipY{ };
- QRect mBoundingRect;
  bool mMagnifyLinear{ };
 
 public:
@@ -192,13 +194,17 @@ ImageEditor::ImageEditor(QString fileName, QWidget *parent)
  mImage.fill(Qt::black);
  setTransformationAnchor(AnchorUnderMouse);
 
- setViewport(new QOpenGLWidget(this));
- setViewportUpdateMode(QGraphicsView::FullViewportUpdate);
+ if (gZeroCopyPreview) {
+ setViewport(new QOpenGLWidget(this));
+ setViewportUpdateMode(QGraphicsView::FullViewportUpdate);
+ }
 
  setScene(new QGraphicsScene(this));
 
- mImageItem = new ImageItem();
- scene()->addItem(mImageItem);
+ if (gZeroCopyPreview) {
+ mZeroCopyItem = new ZeroCopyItem();
+ scene()->addItem(mZeroCopyItem);
+ }
 
  auto color = QColor(Qt::black);
  color.setAlphaF(0.2);
@@ -225,13 +231,15 @@ ImageEditor::ImageEditor(QString fileName, QWidget *parent)
 
 ImageEditor::~ImageEditor() 
 {
- if (auto texture = mImageItem->resetTexture()) {
- auto glWidget = qobject_cast<QOpenGLWidget*>(viewport());
- auto context = glWidget->context();
- auto surface = context->surface();
- if (context->makeCurrent(surface)) {
- delete texture;
- context->doneCurrent();
+ if (mZeroCopyItem) {
+ if (auto texture = mZeroCopyItem->resetTexture()) {
+ auto glWidget = qobject_cast<QOpenGLWidget*>(viewport());
+ auto context = glWidget->context();
+ auto surface = context->surface();
+ if (context->makeCurrent(surface)) {
+ delete texture;
+ context->doneCurrent();
+ }
  }
  }
  delete scene();
@@ -299,8 +307,18 @@ void ImageEditor::replace(QImage image, bool emitDataChanged)
  return;
 
  mImage = image;
- mImageItem->setImage(mImage);
- setBounds(mImageItem->boundingRect().toRect());
+ if (mZeroCopyItem) {
+ mZeroCopyItem->setImage(mImage);
+ setBounds(mZeroCopyItem->boundingRect().toRect());
+ }
+ else {
+ delete mPixmapItem;
+ auto pixmap = QPixmap::fromImage(mImage,
+ Qt::NoOpaqueDetection | Qt::NoFormatConversion);
+ mPixmapItem = new QGraphicsPixmapItem(pixmap);
+ scene()->addItem(mPixmapItem);
+ setBounds(pixmap.rect());
+ }
 
  if (!FileDialog::isEmptyOrUntitled(mFileName))
  setModified(true);
@@ -311,7 +329,8 @@ void ImageEditor::replace(QImage image, bool emitDataChanged)
 
 void ImageEditor::updatePreviewTexture(unsigned int textureId, bool flipY)
 {
- mImageItem->setPreviewTexture(textureId, flipY);
+ if (mZeroCopyItem)
+ mZeroCopyItem->setPreviewTexture(textureId, flipY);
 }
 
 void ImageEditor::setModified(bool modified)
@@ -403,7 +422,8 @@ void ImageEditor::setZoom(int zoom)
  1 << (mZoom));
  updateTransform(scale);
 
- mImageItem->setMagnifyLinear(scale <= 4);
+ if (mZeroCopyItem)
+ mZeroCopyItem->setMagnifyLinear(scale <= 4);
 }
 
 void ImageEditor::updateTransform(double scale)

src/editors/ImageEditor.h

@@ -4,7 +4,7 @@
 #include "IEditor.h"
 #include <QGraphicsView>
 
-class ImageItem;
+class ZeroCopyItem;
 
 class ImageEditor : public QGraphicsView, public IEditor
 {
@@ -13,7 +13,7 @@ class ImageEditor : public QGraphicsView, public IEditor
  static bool load(const QString &fileName, QImage *image);
 
  explicit ImageEditor(QString fileName, QWidget *parent = nullptr);
- ~ImageEditor();
+ ~ImageEditor() override;
 
  QList<QMetaObject::Connection>
  connectEditActions(const EditActions &actions) override;
@@ -55,7 +55,8 @@ class ImageEditor : public QGraphicsView, public IEditor
  int mPanStartY{ };
  QGraphicsPathItem *mInside{ };
  QGraphicsPathItem *mBorder{ };
- ImageItem *mImageItem{ };
+ ZeroCopyItem *mZeroCopyItem{ };
+ QGraphicsPixmapItem *mPixmapItem{ };
 };
 
 #endif // IMAGEEDITOR_H

src/render/RenderSession.cpp

@@ -19,6 +19,8 @@
 #include <QOpenGLVertexArrayObject>
 #include <QOpenGLTimerQuery>
 
+extern bool gZeroCopyPreview;
+
 namespace {
  struct BindingScope
  {
@@ -409,7 +411,7 @@ void RenderSession::executeCommandQueue()
 void RenderSession::downloadModifiedResources()
 {
  for (auto &[itemId, texture] : mCommandQueue->textures)
- if (mItemsChanged || !texture.canUpdatePreview())
+ if (!gZeroCopyPreview || mItemsChanged || !texture.canUpdatePreview())
  mModifiedImages = mModifiedImages.unite(
  texture.getModifiedImages());
 
@@ -453,7 +455,7 @@ void RenderSession::finish()
 
  // keep updating preview texture
  for (auto& [itemId, texture] : mCommandQueue->textures)
- if (!mItemsChanged && texture.canUpdatePreview())
+ if (gZeroCopyPreview && !mItemsChanged && texture.canUpdatePreview())
  if (auto fileItem = castItem<FileItem>(session.findItem(itemId)))
  if (auto editor = editors.getImageEditor(fileItem->fileName))
  editor->updatePreviewTexture(texture.getReadOnlyTextureId(),