Examples: remove OpenGL code paths from painting examples

The extra code for using the OpenGL paint engine is significant enough
to be distracting from what the examples are supposed to show. If we
want to show how to use QPainter on an OpenGL widget, then we can make
dedicated and documented examples for that, in the OpenGL category. And
we have such examples in the Qt OpenGL module anyway.

As is, the examples feel more like manual tests of the OpenGL paint
engine; if we need more coverage there, then we can add it there.

Change-Id: I7b56ea6d08c02cd0a1050ab03991656a0538498d
Reviewed-by: Laszlo Agocs <laszlo.agocs@qt.io>
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Eirik Aavitsland <eirik.aavitsland@qt.io>

examples/widgets/painting/CMakeLists.txt

@@ -4,7 +4,7 @@
 qt_internal_add_example(basicdrawing)
 qt_internal_add_example(concentriccircles)
 qt_internal_add_example(affine)
-# qt_internal_add_example(composition) # FIXME: Seems buggy wrt. usesOpenGL function
+qt_internal_add_example(composition)
 qt_internal_add_example(deform)
 qt_internal_add_example(gradients)
 qt_internal_add_example(pathstroke)

examples/widgets/painting/affine/xform.cpp

@@ -777,12 +777,6 @@ XFormWidget::XFormWidget(QWidget *parent)
 
     QPushButton *showSourceButton = new QPushButton(mainGroup);
     showSourceButton->setText(tr("Show Source"));
-#if QT_CONFIG(opengl)
-    QPushButton *enableOpenGLButton = new QPushButton(mainGroup);
-    enableOpenGLButton->setText(tr("Use OpenGL"));
-    enableOpenGLButton->setCheckable(true);
-    enableOpenGLButton->setChecked(view->usesOpenGL());
-#endif
     QPushButton *whatsThisButton = new QPushButton(mainGroup);
     whatsThisButton->setText(tr("What's This?"));
     whatsThisButton->setCheckable(true);
@@ -812,9 +806,6 @@ XFormWidget::XFormWidget(QWidget *parent)
     mainGroupLayout->addWidget(resetButton);
     mainGroupLayout->addWidget(animateButton);
     mainGroupLayout->addWidget(showSourceButton);
-#if QT_CONFIG(opengl)
-    mainGroupLayout->addWidget(enableOpenGLButton);
-#endif
     mainGroupLayout->addWidget(whatsThisButton);
 
     mainGroup->setLayout(mainGroupLayout);
@@ -852,9 +843,6 @@ XFormWidget::XFormWidget(QWidget *parent)
     connect(view, &XFormView::descriptionEnabledChanged, view->hoverPoints(), &HoverPoints::setDisabled);
     connect(view, &XFormView::descriptionEnabledChanged, whatsThisButton, &QPushButton::setChecked);
     connect(showSourceButton, &QPushButton::clicked, view, &XFormView::showSource);
-#if QT_CONFIG(opengl)
-    connect(enableOpenGLButton, &QPushButton::clicked, view, &XFormView::enableOpenGL);
-#endif
     view->loadSourceFile(":res/affine/xform.cpp");
     view->loadDescription(":res/affine/xform.html");
 

examples/widgets/painting/composition/composition.cpp

@@ -10,11 +10,6 @@
 #include <QMouseEvent>
 #include <qmath.h>
 
-#if QT_CONFIG(opengl)
-#include <QOpenGLFunctions>
-#include <QOpenGLWindow>
-#endif
-
 const int animationInterval = 15; // update every 16 ms = ~60FPS
 
 CompositionWidget::CompositionWidget(QWidget *parent)
@@ -94,12 +89,6 @@ CompositionWidget::CompositionWidget(QWidget *parent)
 
     QPushButton *showSourceButton = new QPushButton(mainGroup);
     showSourceButton->setText(tr("Show Source"));
-#if QT_CONFIG(opengl)
-    QPushButton *enableOpenGLButton = new QPushButton(mainGroup);
-    enableOpenGLButton->setText(tr("Use OpenGL"));
-    enableOpenGLButton->setCheckable(true);
-    enableOpenGLButton->setChecked(view->usesOpenGL());
-#endif
     QPushButton *whatsThisButton = new QPushButton(mainGroup);
     whatsThisButton->setText(tr("What's This?"));
     whatsThisButton->setCheckable(true);
@@ -121,9 +110,6 @@ CompositionWidget::CompositionWidget(QWidget *parent)
     mainGroupLayout->addWidget(animateButton);
     mainGroupLayout->addWidget(whatsThisButton);
     mainGroupLayout->addWidget(showSourceButton);
-#if QT_CONFIG(opengl)
-    mainGroupLayout->addWidget(enableOpenGLButton);
-#endif
 
     QGridLayout *modesLayout = new QGridLayout(modesGroup);
     modesLayout->addWidget(rbClear, 0, 0);
@@ -165,9 +151,6 @@ CompositionWidget::CompositionWidget(QWidget *parent)
     connect(whatsThisButton, &QAbstractButton::clicked, view, &ArthurFrame::setDescriptionEnabled);
     connect(view, &ArthurFrame::descriptionEnabledChanged, whatsThisButton, &QAbstractButton::setChecked);
     connect(showSourceButton, &QAbstractButton::clicked, view, &ArthurFrame::showSource);
-#if QT_CONFIG(opengl)
-    connect(enableOpenGLButton, &QAbstractButton::clicked, view, &ArthurFrame::enableOpenGL);
-#endif
     connect(animateButton, &QAbstractButton::toggled, view, &CompositionRenderer::setAnimationEnabled);
 
     circleColorSlider->setValue(270);
@@ -217,10 +200,6 @@ CompositionRenderer::CompositionRenderer(QWidget *parent)
     m_circle_pos = QPoint(200, 100);
 
     setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Expanding);
-#if QT_CONFIG(opengl)
-    m_pbuffer_size = 1024;
-    m_base_tex = 0;
-#endif
 }
 
 CompositionRenderer::~CompositionRenderer()
@@ -313,89 +292,25 @@ void CompositionRenderer::drawSource(QPainter &p)
 
 void CompositionRenderer::paint(QPainter *painter)
 {
-#if QT_CONFIG(opengl)
+    if (m_buffer.size() != size()) {
-    if (usesOpenGL() && glWindow()->isValid()) {
+        m_buffer = QImage(size(), QImage::Format_ARGB32_Premultiplied);
-        auto *funcs = QOpenGLContext::currentContext()->functions();
+        m_base_buffer = QImage(size(), QImage::Format_ARGB32_Premultiplied);
 
-        if (!m_blitter.isCreated())
+        m_base_buffer.fill(0);
-            m_blitter.create();
 
-        int new_pbuf_size = m_pbuffer_size;
+        QPainter p(&m_base_buffer);
-        while (size().width() > new_pbuf_size || size().height() > new_pbuf_size)
-            new_pbuf_size *= 2;
 
-        while (size().width() < new_pbuf_size/2 && size().height() < new_pbuf_size/2)
+        drawBase(p);
-            new_pbuf_size /= 2;
-
-        if (!m_fbo || new_pbuf_size != m_pbuffer_size) {
-            m_fbo.reset(new QFboPaintDevice(QSize(new_pbuf_size, new_pbuf_size), false, false));
-            m_pbuffer_size = new_pbuf_size;
-        }
-
-        if (size() != m_previous_size) {
-            m_previous_size = size();
-            QPainter p(m_fbo.get());
-            p.setCompositionMode(QPainter::CompositionMode_Source);
-            p.fillRect(QRect(QPoint(0, 0), size()), Qt::transparent);
-            p.setCompositionMode(QPainter::CompositionMode_SourceOver);
-            drawBase(p);
-            p.end();
-            if (m_base_tex)
-                funcs->glDeleteTextures(1, &m_base_tex);
-            m_base_tex = m_fbo->takeTexture();
-        }
-
-        painter->beginNativePainting();
-        uint compositingTex;
-        {
-            QPainter p(m_fbo.get());
-            p.beginNativePainting();
-            m_blitter.bind();
-            const QRect targetRect(QPoint(0, 0), m_fbo->size());
-            const QMatrix4x4 target = QOpenGLTextureBlitter::targetTransform(targetRect, QRect(QPoint(0, 0), m_fbo->size()));
-            m_blitter.blit(m_base_tex, target, QOpenGLTextureBlitter::OriginBottomLeft);
-            m_blitter.release();
-            p.endNativePainting();
-            drawSource(p);
-            p.end();
-            compositingTex = m_fbo->texture();
-        }
-        painter->endNativePainting();
-
-        painter->beginNativePainting();
-        funcs->glEnable(GL_BLEND);
-        funcs->glBlendEquation(GL_FUNC_ADD);
-        funcs->glBlendFunc(GL_ONE, GL_ONE_MINUS_SRC_ALPHA);
-        m_blitter.bind();
-        const QRect targetRect(QPoint(0, 0), m_fbo->size());
-        const QMatrix4x4 target = QOpenGLTextureBlitter::targetTransform(targetRect, QRect(QPoint(0, 0), size()));
-        m_blitter.blit(compositingTex, target, QOpenGLTextureBlitter::OriginBottomLeft);
-        m_blitter.release();
-        painter->endNativePainting();
-    } else
-#endif
-    {
-        // using a QImage
-        if (m_buffer.size() != size()) {
-            m_buffer = QImage(size(), QImage::Format_ARGB32_Premultiplied);
-            m_base_buffer = QImage(size(), QImage::Format_ARGB32_Premultiplied);
-
-            m_base_buffer.fill(0);
-
-            QPainter p(&m_base_buffer);
-
-            drawBase(p);
-        }
-
-        memcpy(m_buffer.bits(), m_base_buffer.bits(), m_buffer.sizeInBytes());
-
-        {
-            QPainter p(&m_buffer);
-            drawSource(p);
-        }
-
-        painter->drawImage(0, 0, m_buffer);
     }
+
+    memcpy(m_buffer.bits(), m_base_buffer.bits(), m_buffer.sizeInBytes());
+
+    {
+        QPainter p(&m_buffer);
+        drawSource(p);
+    }
+
+    painter->drawImage(0, 0, m_buffer);
 }
 
 void CompositionRenderer::mousePressEvent(QMouseEvent *e)
@@ -443,12 +358,6 @@ void CompositionRenderer::setCirclePos(const QPointF &pos)
     const QRect oldRect = rectangle_around(m_circle_pos).toAlignedRect();
     m_circle_pos = pos;
     const QRect newRect = rectangle_around(m_circle_pos).toAlignedRect();
-#if QT_CONFIG(opengl)
-    if (usesOpenGL()) {
-        update();
-        return;
-    }
-#endif
     update(oldRect | newRect);
 }
 

examples/widgets/painting/composition/composition.h

@@ -6,11 +6,6 @@
 
 #include "arthurwidgets.h"
 
-#if QT_CONFIG(opengl)
-#include "fbopaintdevice.h"
-#include <QOpenGLTextureBlitter>
-#endif
-
 #include <QPainter>
 #include <QEvent>
 
@@ -143,14 +138,6 @@ private:
     ObjectType m_current_object;
     bool m_animation_enabled;
     int m_animationTimer;
-
-#if QT_CONFIG(opengl)
-    std::unique_ptr<QFboPaintDevice> m_fbo;
-    int m_pbuffer_size; // width==height==size of pbuffer
-    uint m_base_tex;
-    QSize m_previous_size;
-    QOpenGLTextureBlitter m_blitter;
-#endif
 };
 
 #endif // COMPOSITION_H

examples/widgets/painting/deform/pathdeform.cpp

@@ -61,13 +61,6 @@ void PathDeformControls::layoutForDesktop()
     QPushButton *showSourceButton = new QPushButton(mainGroup);
     showSourceButton->setText(tr("Show Source"));
 
-#if QT_CONFIG(opengl)
-    QPushButton *enableOpenGLButton = new QPushButton(mainGroup);
-    enableOpenGLButton->setText(tr("Use OpenGL"));
-    enableOpenGLButton->setCheckable(true);
-    enableOpenGLButton->setChecked(m_renderer->usesOpenGL());
-#endif
-
     QPushButton *whatsThisButton = new QPushButton(mainGroup);
     whatsThisButton->setText(tr("What's This?"));
     whatsThisButton->setCheckable(true);
@@ -82,9 +75,6 @@ void PathDeformControls::layoutForDesktop()
     mainGroupLayout->addWidget(textGroup);
     mainGroupLayout->addWidget(animateButton);
     mainGroupLayout->addStretch(1);
-#if QT_CONFIG(opengl)
-    mainGroupLayout->addWidget(enableOpenGLButton);
-#endif
     mainGroupLayout->addWidget(showSourceButton);
     mainGroupLayout->addWidget(whatsThisButton);
 
@@ -108,9 +98,6 @@ void PathDeformControls::layoutForDesktop()
     connect(deformSlider, &QAbstractSlider::valueChanged, m_renderer, &PathDeformRenderer::setIntensity);
     connect(fontSizeSlider, &QAbstractSlider::valueChanged, m_renderer, &PathDeformRenderer::setFontSize);
     connect(animateButton, &QAbstractButton::clicked, m_renderer, &PathDeformRenderer::setAnimated);
-#if QT_CONFIG(opengl)
-    connect(enableOpenGLButton, &QAbstractButton::clicked, m_renderer, &ArthurFrame::enableOpenGL);
-#endif
 
     connect(textInput, &QLineEdit::textChanged, m_renderer, &PathDeformRenderer::setText);
     connect(m_renderer, &ArthurFrame::descriptionEnabledChanged,
@@ -151,13 +138,6 @@ void PathDeformControls::layoutForSmallScreen()
     QPushButton *animateButton = new QPushButton(tr("Animated"), mainGroup);
     animateButton->setCheckable(true);
 
-#if QT_CONFIG(opengl)
-    QPushButton *enableOpenGLButton = new QPushButton(mainGroup);
-    enableOpenGLButton->setText(tr("Use OpenGL"));
-    enableOpenGLButton->setCheckable(mainGroup);
-    enableOpenGLButton->setChecked(m_renderer->usesOpenGL());
-#endif
-
     QPushButton *quitButton = new QPushButton(tr("Quit"), mainGroup);
     QPushButton *okButton = new QPushButton(tr("OK"), mainGroup);
 
@@ -171,9 +151,6 @@ void PathDeformControls::layoutForSmallScreen()
     mainGroupLayout->addWidget(fontSizeLabel, 2, 0, Qt::AlignRight);
     mainGroupLayout->addWidget(fontSizeSlider, 2, 1);
     mainGroupLayout->addWidget(animateButton, 3,0, 1,2);
-#if QT_CONFIG(opengl)
-    mainGroupLayout->addWidget(enableOpenGLButton, 4,0, 1,2);
-#endif
 
     QVBoxLayout *mainLayout = new QVBoxLayout(this);
     mainLayout->addWidget(mainGroup);
@@ -187,10 +164,6 @@ void PathDeformControls::layoutForSmallScreen()
     connect(deformSlider, &QAbstractSlider::valueChanged, m_renderer, &PathDeformRenderer::setIntensity);
     connect(fontSizeSlider, &QAbstractSlider::valueChanged, m_renderer, &PathDeformRenderer::setFontSize);
     connect(animateButton, &QAbstractButton::clicked, m_renderer, &PathDeformRenderer::setAnimated);
-#if QT_CONFIG(opengl)
-    connect(enableOpenGLButton, &QAbstractButton::clicked, m_renderer, &ArthurFrame::enableOpenGL);
-#endif
-
 
     animateButton->animateClick();
     deformSlider->setValue(80);
@@ -380,7 +353,6 @@ void PathDeformRenderer::setAnimated(bool animated)
 
 void PathDeformRenderer::timerEvent(QTimerEvent *e)
 {
-
     if (e->timerId() == m_repaintTimer.timerId()) {
 
         if (QLineF(QPointF(0,0), m_direction).length() > 1)
@@ -414,22 +386,9 @@ void PathDeformRenderer::timerEvent(QTimerEvent *e)
             m_pos.setY(height() - m_radius);
         }
 
-#if QT_CONFIG(opengl)
+        QRect rectAfter = circle_bounds(m_pos, m_radius, m_fontSize);
-        if (usesOpenGL()) {
+        update(rectAfter | rectBefore);
-            update();
-        } else
-#endif
-        {
-            QRect rectAfter = circle_bounds(m_pos, m_radius, m_fontSize);
-            update(rectAfter | rectBefore);
-        }
     }
-//     else if (e->timerId() == m_fpsTimer.timerId()) {
-//         printf("fps: %d\n", m_fpsCounter);
-//         emit frameRate(m_fpsCounter);
-//         m_fpsCounter = 0;
-
-//     }
 }
 
 void PathDeformRenderer::mousePressEvent(QMouseEvent *e)
@@ -478,15 +437,8 @@ void PathDeformRenderer::mouseMoveEvent(QMouseEvent *e)
             m_direction = (m_direction + dir) / 2;
         }
         m_pos = e->position().toPoint() + m_offset;
-#if QT_CONFIG(opengl)
+        QRect rectAfter = circle_bounds(m_pos, m_radius, m_fontSize);
-        if (usesOpenGL()) {
+        update(rectBefore | rectAfter);
-            update();
-        } else
-#endif
-        {
-            QRect rectAfter = circle_bounds(m_pos, m_radius, m_fontSize);
-            update(rectBefore | rectAfter);
-        }
     }
 }
 
@@ -570,27 +522,13 @@ void PathDeformRenderer::setRadius(int radius)
     qreal max = qMax(m_radius, (qreal)radius);
     m_radius = radius;
     generateLensPixmap();
-    if (!m_animated || m_radius < max) {
+    if (!m_animated || m_radius < max)
-#if QT_CONFIG(opengl)
-        if (usesOpenGL()){
-            update();
-            return;
-        }
-#endif
         update(circle_bounds(m_pos, max, m_fontSize));
-    }
 }
 
 void PathDeformRenderer::setIntensity(int intensity)
 {
     m_intensity = intensity;
-    if (!m_animated) {
+    if (!m_animated)
-#if QT_CONFIG(opengl)
-        if (usesOpenGL()) {
-            update();
-            return;
-        }
-#endif
         update(circle_bounds(m_pos, m_radius, m_fontSize));
-    }
 }

examples/widgets/painting/gradients/gradients.cpp

@@ -273,12 +273,6 @@ GradientWidget::GradientWidget(QWidget *parent)
 
     QPushButton *showSourceButton = new QPushButton(mainGroup);
     showSourceButton->setText(tr("Show Source"));
-#if QT_CONFIG(opengl)
-    QPushButton *enableOpenGLButton = new QPushButton(mainGroup);
-    enableOpenGLButton->setText(tr("Use OpenGL"));
-    enableOpenGLButton->setCheckable(true);
-    enableOpenGLButton->setChecked(m_renderer->usesOpenGL());
-#endif
     QPushButton *whatsThisButton = new QPushButton(mainGroup);
     whatsThisButton->setText(tr("What's This?"));
     whatsThisButton->setCheckable(true);
@@ -292,9 +286,6 @@ GradientWidget::GradientWidget(QWidget *parent)
     mainGroupLayout->addWidget(defaultsGroup);
     mainGroupLayout->addStretch(1);
     mainGroupLayout->addWidget(showSourceButton);
-#if QT_CONFIG(opengl)
-    mainGroupLayout->addWidget(enableOpenGLButton);
-#endif
     mainGroupLayout->addWidget(whatsThisButton);
 
     QVBoxLayout *editorGroupLayout = new QVBoxLayout(editorGroup);
@@ -370,11 +361,6 @@ GradientWidget::GradientWidget(QWidget *parent)
 
     connect(showSourceButton, &QPushButton::clicked,
             m_renderer, &GradientRenderer::showSource);
-#if QT_CONFIG(opengl)
-    connect(enableOpenGLButton, QOverload<bool>::of(&QPushButton::clicked),
-            m_renderer, &ArthurFrame::enableOpenGL);
-#endif
-
     connect(whatsThisButton, QOverload<bool>::of(&QPushButton::clicked),
             m_renderer, &ArthurFrame::setDescriptionEnabled);
     connect(whatsThisButton, QOverload<bool>::of(&QPushButton::clicked),

examples/widgets/painting/pathstroke/pathstroke.cpp

@@ -177,12 +177,6 @@ void PathStrokeControls::layoutForDesktop()
 
     QPushButton *showSourceButton = new QPushButton(mainGroup);
     showSourceButton->setText(tr("Show Source"));
-#if QT_CONFIG(opengl)
-    QPushButton *enableOpenGLButton = new QPushButton(mainGroup);
-    enableOpenGLButton->setText(tr("Use OpenGL"));
-    enableOpenGLButton->setCheckable(true);
-    enableOpenGLButton->setChecked(m_renderer->usesOpenGL());
-#endif
     QPushButton *whatsThisButton = new QPushButton(mainGroup);
     whatsThisButton->setText(tr("What's This?"));
     whatsThisButton->setCheckable(true);
@@ -206,9 +200,6 @@ void PathStrokeControls::layoutForDesktop()
     mainGroupLayout->addWidget(animated);
     mainGroupLayout->addStretch(1);
     mainGroupLayout->addWidget(showSourceButton);
-#if QT_CONFIG(opengl)
-    mainGroupLayout->addWidget(enableOpenGLButton);
-#endif
     mainGroupLayout->addWidget(whatsThisButton);
 
 
@@ -221,10 +212,6 @@ void PathStrokeControls::layoutForDesktop()
 
     connect(showSourceButton, &QAbstractButton::clicked,
             m_renderer, &ArthurFrame::showSource);
-#if QT_CONFIG(opengl)
-    connect(enableOpenGLButton, &QAbstractButton::clicked,
-            m_renderer, &ArthurFrame::enableOpenGL);
-#endif
     connect(whatsThisButton, &QAbstractButton::clicked,
             m_renderer, &ArthurFrame::setDescriptionEnabled);
     connect(m_renderer, &ArthurFrame::descriptionEnabledChanged,
@@ -259,13 +246,6 @@ void PathStrokeControls::layoutForSmallScreens()
     penWidth->setSizePolicy(QSizePolicy::Preferred, QSizePolicy::Fixed);
     penWidth->setRange(0, 500);
 
-#if QT_CONFIG(opengl)
-    QPushButton *enableOpenGLButton = new QPushButton(this);
-    enableOpenGLButton->setText(tr("Use OpenGL"));
-    enableOpenGLButton->setCheckable(true);
-    enableOpenGLButton->setChecked(m_renderer->usesOpenGL());
-#endif
-
     // Layouts:
     QHBoxLayout *penWidthLayout = new QHBoxLayout;
     penWidthLayout->addWidget(penWidthLabel, 0, Qt::AlignRight);
@@ -274,9 +254,6 @@ void PathStrokeControls::layoutForSmallScreens()
     QVBoxLayout *leftLayout = new QVBoxLayout;
     leftLayout->addWidget(m_capGroup);
     leftLayout->addWidget(m_joinGroup);
-#if QT_CONFIG(opengl)
-    leftLayout->addWidget(enableOpenGLButton);
-#endif
     leftLayout->addLayout(penWidthLayout);
 
     QVBoxLayout *rightLayout = new QVBoxLayout;
@@ -297,10 +274,6 @@ void PathStrokeControls::layoutForSmallScreens()
     mainLayout->addWidget(quitBtn, 2, 1, Qt::AlignHCenter | Qt::AlignTop);
     mainLayout->addWidget(okBtn, 2, 2, Qt::AlignHCenter | Qt::AlignTop);
 
-#if QT_CONFIG(opengl)
-    connect(enableOpenGLButton, &QAbstractButton::clicked, m_renderer, &ArthurFrame::enableOpenGL);
-#endif
-
     connect(penWidth, &QAbstractSlider::valueChanged, m_renderer, &PathStrokeRenderer::setPenWidth);
     connect(quitBtn, &QAbstractButton::clicked, this, &PathStrokeControls::emitQuitSignal);
     connect(okBtn, &QAbstractButton::clicked, this, &PathStrokeControls::emitOkSignal);

examples/widgets/painting/shared/CMakeLists.txt

@@ -15,15 +15,3 @@ set_target_properties(painting_shared PROPERTIES UNITY_BUILD OFF)
 
 target_link_libraries(painting_shared PUBLIC Qt6::Widgets)
 target_include_directories(painting_shared PUBLIC "${CMAKE_CURRENT_SOURCE_DIR}")
-
-## Scopes:
-#####################################################################
-
-if (TARGET Qt6::OpenGL OR QT_FEATURE_opengles2)
-    target_compile_definitions(painting_shared PRIVATE QT_OPENGL_SUPPORT)
-    target_link_libraries(painting_shared PUBLIC
-        Qt6::OpenGL
-    )
-    qt6_wrap_cpp(moc_files_gl fbopaintdevice.h) # no automoc for OBJECT libs
-    target_sources(painting_shared PRIVATE fbopaintdevice.cpp fbopaintdevice.h ${moc_files_gl})
-endif()

examples/widgets/painting/shared/arthurwidgets.cpp

@@ -14,11 +14,6 @@
 #include <QBoxLayout>
 #include <QRegularExpression>
 #include <QOffscreenSurface>
-#include <QOpenGLContext>
-#if QT_CONFIG(opengl)
-#include <QtOpenGL/QOpenGLPaintDevice>
-#include <QtOpenGL/QOpenGLWindow>
-#endif
 
 extern QPixmap cached(const QString &img);
 
@@ -34,61 +29,13 @@ ArthurFrame::ArthurFrame(QWidget *parent)
     pt.end();
 }
 
-
-#if QT_CONFIG(opengl)
-void ArthurFrame::enableOpenGL(bool use_opengl)
-{
-    if (m_use_opengl == use_opengl)
-        return;
-
-    m_use_opengl = use_opengl;
-
-    if (!m_glWindow && use_opengl) {
-        createGlWindow();
-        QApplication::postEvent(this, new QResizeEvent(size(), size()));
-    }
-
-    if (use_opengl) {
-        m_glWidget->show();
-    } else {
-        if (m_glWidget)
-            m_glWidget->hide();
-    }
-
-    update();
-}
-
-void ArthurFrame::createGlWindow()
-{
-    Q_ASSERT(m_use_opengl);
-
-    m_glWindow = new QOpenGLWindow();
-    QSurfaceFormat f = QSurfaceFormat::defaultFormat();
-    f.setSamples(4);
-    f.setAlphaBufferSize(8);
-    f.setStencilBufferSize(8);
-    m_glWindow->setFormat(f);
-    m_glWindow->setFlags(Qt::WindowTransparentForInput);
-    m_glWindow->resize(width(), height());
-    m_glWidget = QWidget::createWindowContainer(m_glWindow, this);
-    // create() must be called after createWindowContainer() otherwise
-    // an incorrect offsetting of the position will occur.
-    m_glWindow->create();
-}
-#endif
-
-
 void ArthurFrame::paintEvent(QPaintEvent *e)
 {
     static QImage *static_image = nullptr;
 
     QPainter painter;
 
-    if (preferImage()
+    if (preferImage()) {
-#if QT_CONFIG(opengl)
-        && !m_use_opengl
-#endif
-        ) {
         if (!static_image || static_image->size() != size()) {
             delete static_image;
             static_image = new QImage(size(), QImage::Format_RGB32);
@@ -103,18 +50,7 @@ void ArthurFrame::paintEvent(QPaintEvent *e)
         painter.fillRect(0, height() - o, o, o, bg);
         painter.fillRect(width() - o, height() - o, o, o, bg);
     } else {
-#if QT_CONFIG(opengl)
-        if (m_use_opengl && m_glWindow->isValid()) {
-            m_glWindow->makeCurrent();
-
-            painter.begin(m_glWindow);
-            painter.fillRect(QRectF(0, 0, m_glWindow->width(), m_glWindow->height()), palette().color(backgroundRole()));
-        } else {
-            painter.begin(this);
-        }
-#else
         painter.begin(this);
-#endif
     }
 
     painter.setClipRect(e->rect());
@@ -158,27 +94,15 @@ void ArthurFrame::paintEvent(QPaintEvent *e)
     painter.setBrush(Qt::NoBrush);
     painter.drawPath(clipPath);
 
-    if (preferImage()
+    if (preferImage()) {
-#if QT_CONFIG(opengl)
-        && !m_use_opengl
-#endif
-        ) {
         painter.end();
         painter.begin(this);
         painter.drawImage(e->rect(), *static_image, e->rect());
     }
-#if QT_CONFIG(opengl)
-    if (m_use_opengl)
-        m_glWindow->update();
-#endif
 }
 
 void ArthurFrame::resizeEvent(QResizeEvent *e)
 {
-#if QT_CONFIG(opengl)
-    if (m_glWidget)
-        m_glWidget->setGeometry(0, 0, e->size().width(), e->size().height());
-#endif
     QWidget::resizeEvent(e);
 }
 

examples/widgets/painting/shared/arthurwidgets.h

@@ -9,7 +9,6 @@
 #include <QPushButton>
 #include <QGroupBox>
 
-QT_FORWARD_DECLARE_CLASS(QOpenGLWindow)
 QT_FORWARD_DECLARE_CLASS(QTextDocument)
 QT_FORWARD_DECLARE_CLASS(QTextEdit)
 QT_FORWARD_DECLARE_CLASS(QVBoxLayout)
@@ -30,20 +29,12 @@ public:
     void loadSourceFile(const QString &fileName);
 
     bool preferImage() const { return m_preferImage; }
-#if QT_CONFIG(opengl)
-    QOpenGLWindow *glWindow() const { return m_glWindow; }
-#endif
 
 public slots:
     void setPreferImage(bool pi) { m_preferImage = pi; }
     void setDescriptionEnabled(bool enabled);
     void showSource();
 
-#if QT_CONFIG(opengl)
-    void enableOpenGL(bool use_opengl);
-    bool usesOpenGL() { return m_use_opengl; }
-#endif
-
 signals:
     void descriptionEnabledChanged(bool);
 
@@ -51,12 +42,6 @@ protected:
     void paintEvent(QPaintEvent *) override;
     void resizeEvent(QResizeEvent *) override;
 
-#if QT_CONFIG(opengl)
-    virtual void createGlWindow();
-    QOpenGLWindow *m_glWindow = nullptr;
-    QWidget *m_glWidget = nullptr;
-    bool m_use_opengl = false;
-#endif
     QPixmap m_tile;
 
     bool m_showDoc = false;

examples/widgets/painting/shared/fbopaintdevice.cpp

@@ -1,75 +0,0 @@
-// Copyright (C) 2018 The Qt Company Ltd.
-// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
-
-#include "fbopaintdevice.h"
-
-#include <QOffscreenSurface>
-#include <QOpenGLFunctions>
-
-QFboPaintDevice::QFboPaintDevice(const QSize &size, bool flipped, bool clearOnInit,
-                                 QOpenGLFramebufferObject::Attachment attachment)
-        : QOpenGLPaintDevice(size)
-{
-    QOpenGLFramebufferObjectFormat format;
-    format.setAttachment(attachment);
-    format.setSamples(4);
-    m_framebufferObject = new QOpenGLFramebufferObject(size, format);
-    QOffscreenSurface *surface = new QOffscreenSurface();
-    surface->create();
-    m_surface = surface;
-    setPaintFlipped(flipped);
-    if (clearOnInit) {
-        m_framebufferObject->bind();
-
-        context()->functions()->glClearColor(0, 0, 0, 0);
-        context()->functions()->glClear(GL_COLOR_BUFFER_BIT);
-    }
-    m_resolvedFbo = new QOpenGLFramebufferObject(m_framebufferObject->size(), m_framebufferObject->attachment());
-}
-
-QFboPaintDevice::~QFboPaintDevice()
-{
-    delete m_framebufferObject;
-    delete m_resolvedFbo;
-    delete m_surface;
-}
-
-void QFboPaintDevice::ensureActiveTarget()
-{
-    if (QOpenGLContext::currentContext() != context())
-        context()->makeCurrent(m_surface);
-
-    m_framebufferObject->bind();
-}
-
-GLuint QFboPaintDevice::texture()
-{
-    m_resolvedFbo->bind(); // to get the backing texture recreated if it was taken (in takeTexture) previously
-    QOpenGLFramebufferObject::blitFramebuffer(m_resolvedFbo, m_framebufferObject);
-    return m_resolvedFbo->texture();
-}
-
-GLuint QFboPaintDevice::takeTexture()
-{
-    m_resolvedFbo->bind(); // to get the backing texture recreated if it was taken (in takeTexture) previously
-    // We have multisamples so we can't just forward takeTexture(), have to resolve first.
-    QOpenGLFramebufferObject::blitFramebuffer(m_resolvedFbo, m_framebufferObject);
-    return m_resolvedFbo->takeTexture();
-}
-
-QImage QFboPaintDevice::toImage() const
-{
-    QOpenGLContext *currentContext = QOpenGLContext::currentContext();
-    QSurface *currentSurface = currentContext ? currentContext->surface() : nullptr;
-
-    context()->makeCurrent(m_surface);
-
-    QImage image = m_framebufferObject->toImage(!paintFlipped());
-
-    if (currentContext)
-        currentContext->makeCurrent(currentSurface);
-    else
-        context()->doneCurrent();
-
-    return image;
-}

examples/widgets/painting/shared/fbopaintdevice.h

@@ -1,46 +0,0 @@
-// Copyright (C) 2018 The Qt Company Ltd.
-// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
-
-#ifndef QFBOPAINTDEVICE_H
-#define QFBOPAINTDEVICE_H
-
-#ifndef QT_NO_OPENGL
-
-#include <QImage>
-#include <QOpenGLFramebufferObject>
-#include <QOpenGLPaintDevice>
-#include <QSurface>
-
-class QFboPaintDevice : public QOpenGLPaintDevice {
-public:
-    QFboPaintDevice(const QSize &size, bool flipped = false, bool clearOnInit = true,
-        QOpenGLFramebufferObject::Attachment = QOpenGLFramebufferObject::CombinedDepthStencil);
-    ~QFboPaintDevice();
-
-    // QOpenGLPaintDevice:
-    void ensureActiveTarget() override;
-
-    bool isValid() const { return m_framebufferObject->isValid(); }
-    GLuint handle() const { return m_framebufferObject->handle(); }
-    GLuint texture();
-    GLuint takeTexture();
-    QImage toImage() const;
-
-    bool bind() { return m_framebufferObject->bind(); }
-    bool release() { return m_framebufferObject->release(); }
-    QSize size() const { return m_framebufferObject->size(); }
-
-    QOpenGLFramebufferObject* framebufferObject() { return m_framebufferObject; }
-    const QOpenGLFramebufferObject* framebufferObject() const { return m_framebufferObject; }
-
-    static bool isSupported() { return QOpenGLFramebufferObject::hasOpenGLFramebufferObjects(); }
-
-private:
-    QOpenGLFramebufferObject *m_framebufferObject;
-    QOpenGLFramebufferObject *m_resolvedFbo;
-    QSurface *m_surface;
-};
-
-#endif // QT_NO_OPENGL
-
-#endif // QFBOPAINTDEVICE_H

examples/widgets/painting/shared/hoverpoints.cpp

@@ -6,10 +6,6 @@
 
 #include <algorithm>
 
-#if QT_CONFIG(opengl)
-#include <QtOpenGL/QOpenGLWindow>
-#endif
-
 HoverPoints::HoverPoints(QWidget *widget, PointShape shape)
     : QObject(widget),
       m_widget(widget),
@@ -230,17 +226,7 @@ bool HoverPoints::eventFilter(QObject *object, QEvent *event)
 void HoverPoints::paintPoints()
 {
     QPainter p;
-#if QT_CONFIG(opengl)
-    ArthurFrame *af = qobject_cast<ArthurFrame *>(m_widget);
-    if (af && af->usesOpenGL() && af->glWindow()->isValid()) {
-        af->glWindow()->makeCurrent();
-        p.begin(af->glWindow());
-    } else {
-        p.begin(m_widget);
-    }
-#else
     p.begin(m_widget);
-#endif
 
     p.setRenderHint(QPainter::Antialiasing);
 

examples/widgets/painting/shared/shared.pri

@@ -1,11 +1,5 @@
 INCLUDEPATH += $$PWD
 
-qtConfig(opengl) {
-    QT += opengl
-    SOURCES += $$PWD/fbopaintdevice.cpp
-    HEADERS += $$PWD/fbopaintdevice.h
-}
-
 SOURCES += \
     $$PWD/arthurstyle.cpp\
     $$PWD/arthurwidgets.cpp \

examples/widgets/painting/shared/use_lib.cmake

@@ -9,8 +9,4 @@ if(NOT TARGET Qt::Widgets)
     find_package(Qt6 REQUIRED COMPONENTS Widgets)
 endif()
 
-if(NOT TARGET Qt::OpenGL)
-    find_package(Qt6 OPTIONAL_COMPONENTS OpenGL)
-endif()
-
 add_subdirectory("${CMAKE_CURRENT_LIST_DIR}" painting_shared)