qt 6.5.1 original

examples/widgets/painting/deform/CMakeLists.txt

@@ -0,0 +1,102 @@
+# Copyright (C) 2022 The Qt Company Ltd.
+# SPDX-License-Identifier: BSD-3-Clause
+
+cmake_minimum_required(VERSION 3.16)
+project(deform LANGUAGES CXX)
+
+if(NOT DEFINED INSTALL_EXAMPLESDIR)
+    set(INSTALL_EXAMPLESDIR "examples")
+endif()
+
+set(INSTALL_EXAMPLEDIR "${INSTALL_EXAMPLESDIR}/widgets/painting/deform")
+
+find_package(Qt6 REQUIRED COMPONENTS Core Gui Widgets)
+
+qt_standard_project_setup()
+
+qt_add_executable(deform
+    main.cpp
+    pathdeform.cpp pathdeform.h
+)
+
+set_target_properties(deform PROPERTIES
+    WIN32_EXECUTABLE TRUE
+    MACOSX_BUNDLE TRUE
+)
+
+if(NOT TARGET painting_shared::painting_shared)
+    include(../shared/use_lib.cmake)
+endif()
+
+target_link_libraries(deform PRIVATE
+    Qt6::Core
+    Qt6::Gui
+    Qt6::Widgets
+    painting_shared::painting_shared
+)
+
+# Resources:
+set(shared_resource_files
+    "../shared/images/button_normal_cap_left.png"
+    "../shared/images/button_normal_cap_right.png"
+    "../shared/images/button_normal_stretch.png"
+    "../shared/images/button_pressed_cap_left.png"
+    "../shared/images/button_pressed_cap_right.png"
+    "../shared/images/button_pressed_stretch.png"
+    "../shared/images/frame_bottom.png"
+    "../shared/images/frame_bottomleft.png"
+    "../shared/images/frame_bottomright.png"
+    "../shared/images/frame_left.png"
+    "../shared/images/frame_right.png"
+    "../shared/images/frame_top.png"
+    "../shared/images/frame_topleft.png"
+    "../shared/images/frame_topright.png"
+    "../shared/images/groupframe_bottom_left.png"
+    "../shared/images/groupframe_bottom_right.png"
+    "../shared/images/groupframe_bottom_stretch.png"
+    "../shared/images/groupframe_left_stretch.png"
+    "../shared/images/groupframe_right_stretch.png"
+    "../shared/images/groupframe_top_stretch.png"
+    "../shared/images/groupframe_topleft.png"
+    "../shared/images/groupframe_topright.png"
+    "../shared/images/line_dash_dot.png"
+    "../shared/images/line_dash_dot_dot.png"
+    "../shared/images/line_dashed.png"
+    "../shared/images/line_dotted.png"
+    "../shared/images/line_solid.png"
+    "../shared/images/radiobutton-on.png"
+    "../shared/images/radiobutton_off.png"
+    "../shared/images/radiobutton_on.png"
+    "../shared/images/slider_bar.png"
+    "../shared/images/slider_thumb_on.png"
+    "../shared/images/title_cap_left.png"
+    "../shared/images/title_cap_right.png"
+    "../shared/images/title_stretch.png"
+)
+
+qt_add_resources(deform "shared"
+    PREFIX
+        "/res"
+    BASE
+        "../shared"
+    FILES
+        ${shared_resource_files}
+)
+
+set(deform_resource_files
+    "pathdeform.cpp"
+    "pathdeform.html"
+)
+
+qt_add_resources(deform "deform"
+    PREFIX
+        "/res/deform"
+    FILES
+        ${deform_resource_files}
+)
+
+install(TARGETS deform
+    RUNTIME DESTINATION "${INSTALL_EXAMPLEDIR}"
+    BUNDLE DESTINATION "${INSTALL_EXAMPLEDIR}"
+    LIBRARY DESTINATION "${INSTALL_EXAMPLEDIR}"
+)

examples/widgets/painting/deform/deform.pro

@@ -0,0 +1,14 @@
+SOURCES += main.cpp pathdeform.cpp
+HEADERS += pathdeform.h
+
+SHARED_FOLDER = ../shared
+
+include($$SHARED_FOLDER/shared.pri)
+
+RESOURCES += deform.qrc
+
+QT += widgets
+
+# install
+target.path = $$[QT_INSTALL_EXAMPLES]/widgets/painting/deform
+INSTALLS += target

examples/widgets/painting/deform/deform.qrc

@@ -0,0 +1,6 @@
+<!DOCTYPE RCC><RCC version="1.0">
+<qresource prefix="/res/deform">
+   <file>pathdeform.cpp</file>
+   <file>pathdeform.html</file>
+</qresource>
+</RCC>

examples/widgets/painting/deform/main.cpp

@@ -0,0 +1,33 @@
+// Copyright (C) 2016 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
+
+#include "pathdeform.h"
+
+#include <QApplication>
+
+int main(int argc, char **argv)
+{
+    Q_INIT_RESOURCE(deform);
+
+    QApplication app(argc, argv);
+
+    bool smallScreen = QApplication::arguments().contains("-small-screen");
+
+    PathDeformWidget deformWidget(nullptr, smallScreen);
+
+    QStyle *arthurStyle = new ArthurStyle;
+    deformWidget.setStyle(arthurStyle);
+    const QList<QWidget *> widgets = deformWidget.findChildren<QWidget *>();
+    for (QWidget *w : widgets)
+        w->setStyle(arthurStyle);
+
+    if (smallScreen)
+        deformWidget.showFullScreen();
+    else
+        deformWidget.show();
+
+#ifdef QT_KEYPAD_NAVIGATION
+    QApplication::setNavigationMode(Qt::NavigationModeCursorAuto);
+#endif
+    return app.exec();
+}

examples/widgets/painting/deform/pathdeform.cpp

@@ -0,0 +1,596 @@
+// Copyright (C) 2016 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
+
+#include "pathdeform.h"
+
+#include <QGuiApplication>
+#include <QScreen>
+#include <QtDebug>
+#include <QMouseEvent>
+#include <QTimerEvent>
+#include <QLayout>
+#include <QLineEdit>
+#include <QPainter>
+#include <QSlider>
+#include <QLabel>
+#include <qmath.h>
+
+PathDeformControls::PathDeformControls(QWidget *parent,
+                                       PathDeformRenderer* renderer, bool smallScreen)
+      : QWidget(parent)
+{
+    m_renderer = renderer;
+
+    if (smallScreen)
+        layoutForSmallScreen();
+    else
+        layoutForDesktop();
+}
+
+void PathDeformControls::layoutForDesktop()
+{
+    QGroupBox* mainGroup = new QGroupBox(this);
+    mainGroup->setTitle(tr("Controls"));
+
+    QGroupBox *radiusGroup = new QGroupBox(mainGroup);
+    radiusGroup->setTitle(tr("Lens Radius"));
+    QSlider *radiusSlider = new QSlider(Qt::Horizontal, radiusGroup);
+    radiusSlider->setRange(15, 150);
+    radiusSlider->setSizePolicy(QSizePolicy::Preferred, QSizePolicy::Fixed);
+
+    QGroupBox *deformGroup = new QGroupBox(mainGroup);
+    deformGroup->setTitle(tr("Deformation"));
+    QSlider *deformSlider = new QSlider(Qt::Horizontal, deformGroup);
+    deformSlider->setRange(-100, 100);
+    deformSlider->setSizePolicy(QSizePolicy::Preferred, QSizePolicy::Fixed);
+
+    QGroupBox *fontSizeGroup = new QGroupBox(mainGroup);
+    fontSizeGroup->setTitle(tr("Font Size"));
+    QSlider *fontSizeSlider = new QSlider(Qt::Horizontal, fontSizeGroup);
+    fontSizeSlider->setRange(16, 200);
+    fontSizeSlider->setSizePolicy(QSizePolicy::Preferred, QSizePolicy::Fixed);
+
+    QGroupBox *textGroup = new QGroupBox(mainGroup);
+    textGroup->setTitle(tr("Text"));
+    QLineEdit *textInput = new QLineEdit(textGroup);
+
+    QPushButton *animateButton = new QPushButton(mainGroup);
+    animateButton->setText(tr("Animated"));
+    animateButton->setCheckable(true);
+
+    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);
+
+
+    mainGroup->setFixedWidth(180);
+
+    QVBoxLayout *mainGroupLayout = new QVBoxLayout(mainGroup);
+    mainGroupLayout->addWidget(radiusGroup);
+    mainGroupLayout->addWidget(deformGroup);
+    mainGroupLayout->addWidget(fontSizeGroup);
+    mainGroupLayout->addWidget(textGroup);
+    mainGroupLayout->addWidget(animateButton);
+    mainGroupLayout->addStretch(1);
+#if QT_CONFIG(opengl)
+    mainGroupLayout->addWidget(enableOpenGLButton);
+#endif
+    mainGroupLayout->addWidget(showSourceButton);
+    mainGroupLayout->addWidget(whatsThisButton);
+
+    QVBoxLayout *radiusGroupLayout = new QVBoxLayout(radiusGroup);
+    radiusGroupLayout->addWidget(radiusSlider);
+
+    QVBoxLayout *deformGroupLayout = new QVBoxLayout(deformGroup);
+    deformGroupLayout->addWidget(deformSlider);
+
+    QVBoxLayout *fontSizeGroupLayout = new QVBoxLayout(fontSizeGroup);
+    fontSizeGroupLayout->addWidget(fontSizeSlider);
+
+    QVBoxLayout *textGroupLayout = new QVBoxLayout(textGroup);
+    textGroupLayout->addWidget(textInput);
+
+    QVBoxLayout * mainLayout = new QVBoxLayout(this);
+    mainLayout->addWidget(mainGroup);
+    mainLayout->setContentsMargins(QMargins());
+
+    connect(radiusSlider, &QAbstractSlider::valueChanged, m_renderer, &PathDeformRenderer::setRadius);
+    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,
+            whatsThisButton, &QAbstractButton::setChecked);
+    connect(whatsThisButton, &QAbstractButton::clicked, m_renderer, &ArthurFrame::setDescriptionEnabled);
+    connect(showSourceButton, &QAbstractButton::clicked, m_renderer, &ArthurFrame::showSource);
+
+    animateButton->animateClick();
+    deformSlider->setValue(80);
+    fontSizeSlider->setValue(120);
+    radiusSlider->setValue(100);
+    textInput->setText(tr("Qt"));
+}
+
+void PathDeformControls::layoutForSmallScreen()
+{
+    QGroupBox* mainGroup = new QGroupBox(this);
+    mainGroup->setTitle(tr("Controls"));
+
+    QLabel *radiusLabel = new QLabel(mainGroup);
+    radiusLabel->setText(tr("Lens Radius:"));
+    QSlider *radiusSlider = new QSlider(Qt::Horizontal, mainGroup);
+    radiusSlider->setRange(15, 150);
+    radiusSlider->setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Fixed);
+
+    QLabel *deformLabel = new QLabel(mainGroup);
+    deformLabel->setText(tr("Deformation:"));
+    QSlider *deformSlider = new QSlider(Qt::Horizontal, mainGroup);
+    deformSlider->setRange(-100, 100);
+    deformSlider->setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Fixed);
+
+    QLabel *fontSizeLabel = new QLabel(mainGroup);
+    fontSizeLabel->setText(tr("Font Size:"));
+    QSlider *fontSizeSlider = new QSlider(Qt::Horizontal, mainGroup);
+    fontSizeSlider->setRange(16, 200);
+    fontSizeSlider->setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Fixed);
+
+    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);
+
+
+    QGridLayout *mainGroupLayout = new QGridLayout(mainGroup);
+    mainGroupLayout->setContentsMargins(QMargins());
+    mainGroupLayout->addWidget(radiusLabel, 0, 0, Qt::AlignRight);
+    mainGroupLayout->addWidget(radiusSlider, 0, 1);
+    mainGroupLayout->addWidget(deformLabel, 1, 0, Qt::AlignRight);
+    mainGroupLayout->addWidget(deformSlider, 1, 1);
+    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);
+    mainLayout->addStretch(1);
+    mainLayout->addWidget(okButton);
+    mainLayout->addWidget(quitButton);
+
+    connect(quitButton, &QAbstractButton::clicked, this, &PathDeformControls::quitPressed);
+    connect(okButton, &QAbstractButton::clicked, this, &PathDeformControls::okPressed);
+    connect(radiusSlider, &QAbstractSlider::valueChanged, m_renderer, &PathDeformRenderer::setRadius);
+    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);
+    fontSizeSlider->setValue(120);
+
+    QRect screen_size = QGuiApplication::primaryScreen()->geometry();
+    radiusSlider->setValue(qMin(screen_size.width(), screen_size.height())/5);
+
+    m_renderer->setText(tr("Qt"));
+}
+
+PathDeformWidget::PathDeformWidget(QWidget *parent, bool smallScreen)
+    : QWidget(parent)
+{
+    setWindowTitle(tr("Vector Deformation"));
+
+    m_renderer = new PathDeformRenderer(this, smallScreen);
+    m_renderer->setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Expanding);
+
+    // Layouts
+    QHBoxLayout *mainLayout = new QHBoxLayout(this);
+    mainLayout->addWidget(m_renderer);
+
+    m_controls = new PathDeformControls(nullptr, m_renderer, smallScreen);
+    m_controls->setSizePolicy(QSizePolicy::Fixed, QSizePolicy::Minimum);
+
+    if (!smallScreen)
+        mainLayout->addWidget(m_controls);
+
+    m_renderer->loadSourceFile(":res/deform/pathdeform.cpp");
+    m_renderer->loadDescription(":res/deform/pathdeform.html");
+    m_renderer->setDescriptionEnabled(false);
+
+    connect(m_renderer, &PathDeformRenderer::clicked,
+            this, &PathDeformWidget::showControls);
+    connect(m_controls, &PathDeformControls::okPressed,
+            this, &PathDeformWidget::hideControls);
+    connect(m_controls, &PathDeformControls::quitPressed,
+            qApp, &QCoreApplication::quit);
+}
+
+
+void PathDeformWidget::showControls()
+{
+    m_controls->showFullScreen();
+}
+
+void PathDeformWidget::hideControls()
+{
+    m_controls->hide();
+}
+
+void PathDeformWidget::setStyle(QStyle *style)
+{
+    QWidget::setStyle(style);
+    if (!m_controls)
+        return;
+
+    m_controls->setStyle(style);
+
+    const QList<QWidget *> widgets = m_controls->findChildren<QWidget *>();
+    for (QWidget *w : widgets)
+        w->setStyle(style);
+}
+
+static inline QRect circle_bounds(const QPointF &center, qreal radius, qreal compensation)
+{
+    return QRect(qRound(center.x() - radius - compensation),
+                 qRound(center.y() - radius - compensation),
+                 qRound((radius + compensation) * 2),
+                 qRound((radius + compensation) * 2));
+
+}
+
+const int LENS_EXTENT = 10;
+
+PathDeformRenderer::PathDeformRenderer(QWidget *widget, bool smallScreen)
+    : ArthurFrame(widget)
+{
+    m_radius = 100;
+    m_pos = QPointF(m_radius, m_radius);
+    m_direction = QPointF(1, 1);
+    m_fontSize = 24;
+    m_animated = true;
+    m_repaintTimer.start(25, this);
+    m_repaintTracker.start();
+    m_intensity = 100;
+    m_smallScreen = smallScreen;
+
+//     m_fpsTimer.start(1000, this);
+//     m_fpsCounter = 0;
+
+    generateLensPixmap();
+}
+
+void PathDeformRenderer::setText(const QString &text)
+{
+    m_text = text;
+
+    QFont f("times new roman,utopia");
+    f.setStyleStrategy(QFont::ForceOutline);
+    f.setPointSize(m_fontSize);
+    f.setStyleHint(QFont::Times);
+
+    QFontMetrics fm(f);
+
+    m_paths.clear();
+    m_pathBounds = QRect();
+
+    QPointF advance(0, 0);
+
+    bool do_quick = true;
+    for (int i=0; i<text.size(); ++i) {
+        if (text.at(i).unicode() >= 0x4ff && text.at(i).unicode() <= 0x1e00) {
+            do_quick = false;
+            break;
+        }
+    }
+
+    if (do_quick) {
+        for (int i=0; i<text.size(); ++i) {
+            QPainterPath path;
+            path.addText(advance, f, text.mid(i, 1));
+            m_pathBounds |= path.boundingRect();
+            m_paths << path;
+            advance += QPointF(fm.horizontalAdvance(text.mid(i, 1)), 0);
+        }
+    } else {
+        QPainterPath path;
+        path.addText(advance, f, text);
+        m_pathBounds |= path.boundingRect();
+        m_paths << path;
+    }
+
+    for (int i=0; i<m_paths.size(); ++i)
+        m_paths[i] = m_paths[i] * QTransform(1, 0, 0, 1, -m_pathBounds.x(), -m_pathBounds.y());
+
+    update();
+}
+
+
+void PathDeformRenderer::generateLensPixmap()
+{
+    qreal rad = m_radius + LENS_EXTENT;
+
+    QRect bounds = circle_bounds(QPointF(), rad, 0);
+
+    QPainter painter;
+
+    if (preferImage()) {
+        m_lens_image = QImage(bounds.size(), QImage::Format_ARGB32_Premultiplied);
+        m_lens_image.fill(0);
+        painter.begin(&m_lens_image);
+    } else {
+        m_lens_pixmap = QPixmap(bounds.size());
+        m_lens_pixmap.fill(Qt::transparent);
+        painter.begin(&m_lens_pixmap);
+    }
+
+    QRadialGradient gr(rad, rad, rad, 3 * rad / 5, 3 * rad / 5);
+    gr.setColorAt(0.0, QColor(255, 255, 255, 191));
+    gr.setColorAt(0.2, QColor(255, 255, 127, 191));
+    gr.setColorAt(0.9, QColor(150, 150, 200, 63));
+    gr.setColorAt(0.95, QColor(0, 0, 0, 127));
+    gr.setColorAt(1, QColor(0, 0, 0, 0));
+    painter.setRenderHint(QPainter::Antialiasing);
+    painter.setBrush(gr);
+    painter.setPen(Qt::NoPen);
+    painter.drawEllipse(0, 0, bounds.width(), bounds.height());
+}
+
+
+void PathDeformRenderer::setAnimated(bool animated)
+{
+    m_animated = animated;
+
+    if (m_animated) {
+//         m_fpsTimer.start(1000, this);
+//         m_fpsCounter = 0;
+        m_repaintTimer.start(25, this);
+        m_repaintTracker.start();
+    } else {
+//         m_fpsTimer.stop();
+        m_repaintTimer.stop();
+    }
+}
+
+void PathDeformRenderer::timerEvent(QTimerEvent *e)
+{
+
+    if (e->timerId() == m_repaintTimer.timerId()) {
+
+        if (QLineF(QPointF(0,0), m_direction).length() > 1)
+            m_direction *= 0.995;
+        qreal time = m_repaintTracker.restart();
+
+        QRect rectBefore = circle_bounds(m_pos, m_radius, m_fontSize);
+
+        qreal dx = m_direction.x();
+        qreal dy = m_direction.y();
+        if (time > 0) {
+            dx = dx * time * .1;
+            dy = dy * time * .1;
+        }
+
+        m_pos += QPointF(dx, dy);
+
+        if (m_pos.x() - m_radius < 0) {
+            m_direction.setX(-m_direction.x());
+            m_pos.setX(m_radius);
+        } else if (m_pos.x() + m_radius > width()) {
+            m_direction.setX(-m_direction.x());
+            m_pos.setX(width() - m_radius);
+        }
+
+        if (m_pos.y() - m_radius < 0) {
+            m_direction.setY(-m_direction.y());
+            m_pos.setY(m_radius);
+        } else if (m_pos.y() + m_radius > height()) {
+            m_direction.setY(-m_direction.y());
+            m_pos.setY(height() - m_radius);
+        }
+
+#if QT_CONFIG(opengl)
+        if (usesOpenGL()) {
+            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)
+{
+    if (m_showDoc) {
+        setDescriptionEnabled(false);
+        return;
+    }
+    setDescriptionEnabled(false);
+
+    m_repaintTimer.stop();
+    m_offset = QPointF();
+    if (QLineF(m_pos, e->position().toPoint()).length() <= m_radius)
+        m_offset = m_pos - e->position().toPoint();
+
+    m_mousePress = e->position().toPoint();
+
+    // If we're not running in small screen mode, always assume we're dragging
+    m_mouseDrag = !m_smallScreen;
+
+    mouseMoveEvent(e);
+}
+
+void PathDeformRenderer::mouseReleaseEvent(QMouseEvent *e)
+{
+    if (e->buttons() == Qt::NoButton && m_animated) {
+        m_repaintTimer.start(10, this);
+        m_repaintTracker.start();
+    }
+
+    if (!m_mouseDrag && m_smallScreen)
+        emit clicked();
+}
+
+void PathDeformRenderer::mouseMoveEvent(QMouseEvent *e)
+{
+    if (!m_mouseDrag && (QLineF(m_mousePress, e->position().toPoint()).length() > 25.0) )
+        m_mouseDrag = true;
+
+    if (m_mouseDrag) {
+        QRect rectBefore = circle_bounds(m_pos, m_radius, m_fontSize);
+        if (e->type() == QEvent::MouseMove) {
+            QLineF line(m_pos, e->position().toPoint() + m_offset);
+            line.setLength(line.length() * .1);
+            QPointF dir(line.dx(), line.dy());
+            m_direction = (m_direction + dir) / 2;
+        }
+        m_pos = e->position().toPoint() + m_offset;
+#if QT_CONFIG(opengl)
+        if (usesOpenGL()) {
+            update();
+        } else
+#endif
+        {
+            QRect rectAfter = circle_bounds(m_pos, m_radius, m_fontSize);
+            update(rectBefore | rectAfter);
+        }
+    }
+}
+
+QPainterPath PathDeformRenderer::lensDeform(const QPainterPath &source, const QPointF &offset)
+{
+    QPainterPath path;
+    path.addPath(source);
+
+    qreal flip = m_intensity / qreal(100);
+
+    for (int i=0; i<path.elementCount(); ++i) {
+        const QPainterPath::Element &e = path.elementAt(i);
+
+        qreal x = e.x + offset.x();
+        qreal y = e.y + offset.y();
+
+        qreal dx = x - m_pos.x();
+        qreal dy = y - m_pos.y();
+        qreal len = m_radius - qSqrt(dx * dx + dy * dy);
+
+        if (len > 0) {
+            path.setElementPositionAt(i,
+                                      x + flip * dx * len / m_radius,
+                                      y + flip * dy * len / m_radius);
+        } else {
+            path.setElementPositionAt(i, x, y);
+        }
+
+    }
+
+    return path;
+}
+
+void PathDeformRenderer::paint(QPainter *painter)
+{
+    int pad_x = 5;
+    int pad_y = 5;
+
+    int skip_x = qRound(m_pathBounds.width() + pad_x + m_fontSize/2);
+    int skip_y = qRound(m_pathBounds.height() + pad_y);
+
+    painter->setPen(Qt::NoPen);
+    painter->setBrush(Qt::black);
+
+    QRectF clip(painter->clipPath().boundingRect());
+
+    int overlap = pad_x / 2;
+
+    for (int start_y=0; start_y < height(); start_y += skip_y) {
+
+        if (start_y > clip.bottom())
+            break;
+
+        int start_x = -overlap;
+        for (; start_x < width(); start_x += skip_x) {
+
+            if (start_y + skip_y >= clip.top() &&
+                start_x + skip_x >= clip.left() &&
+                start_x <= clip.right()) {
+                for (int i=0; i<m_paths.size(); ++i) {
+                    QPainterPath path = lensDeform(m_paths[i], QPointF(start_x, start_y));
+                    painter->drawPath(path);
+                }
+            }
+        }
+        overlap = skip_x - (start_x - width());
+
+    }
+
+    if (preferImage()) {
+        painter->drawImage(m_pos - QPointF(m_radius + LENS_EXTENT, m_radius + LENS_EXTENT),
+                           m_lens_image);
+    } else {
+        painter->drawPixmap(m_pos - QPointF(m_radius + LENS_EXTENT, m_radius + LENS_EXTENT),
+                            m_lens_pixmap);
+    }
+}
+
+void PathDeformRenderer::setRadius(int radius)
+{
+    qreal max = qMax(m_radius, (qreal)radius);
+    m_radius = radius;
+    generateLensPixmap();
+    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 QT_CONFIG(opengl)
+        if (usesOpenGL()) {
+            update();
+            return;
+        }
+#endif
+        update(circle_bounds(m_pos, m_radius, m_fontSize));
+    }
+}

examples/widgets/painting/deform/pathdeform.h

@@ -0,0 +1,112 @@
+// Copyright (C) 2016 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
+
+#ifndef PATHDEFORM_H
+#define PATHDEFORM_H
+
+#include "arthurwidgets.h"
+
+#include <QBasicTimer>
+#include <QElapsedTimer>
+#include <QPainterPath>
+
+class PathDeformRenderer : public ArthurFrame
+{
+    Q_OBJECT
+    Q_PROPERTY(bool animated READ animated WRITE setAnimated)
+    Q_PROPERTY(int radius READ radius WRITE setRadius)
+    Q_PROPERTY(int fontSize READ fontSize WRITE setFontSize)
+    Q_PROPERTY(int intensity READ intensity WRITE setIntensity)
+    Q_PROPERTY(QString text READ text WRITE setText)
+
+public:
+    explicit PathDeformRenderer(QWidget *widget, bool smallScreen = false);
+
+    void paint(QPainter *painter) override;
+
+    void mousePressEvent(QMouseEvent *e) override;
+    void mouseReleaseEvent(QMouseEvent *e) override;
+    void mouseMoveEvent(QMouseEvent *e) override;
+    void timerEvent(QTimerEvent *e) override;
+
+    QSize sizeHint() const override { return QSize(600, 500); }
+
+    bool animated() const { return m_animated; }
+    int radius() const { return int(m_radius); }
+    int fontSize() const { return m_fontSize; }
+    int intensity() const { return int(m_intensity); }
+    QString text() const { return m_text; }
+
+public slots:
+    void setRadius(int radius);
+    void setFontSize(int fontSize) { m_fontSize = fontSize; setText(m_text); }
+    void setText(const QString &text);
+    void setIntensity(int intensity);
+
+    void setAnimated(bool animated);
+
+signals:
+    void clicked();
+//     void frameRate(double fps);
+
+private:
+    void generateLensPixmap();
+    QPainterPath lensDeform(const QPainterPath &source, const QPointF &offset);
+
+    QBasicTimer m_repaintTimer;
+//     QBasicTimer m_fpsTimer;
+//     int m_fpsCounter;
+    QElapsedTimer m_repaintTracker;
+
+    QList<QPainterPath> m_paths;
+    QList<QPointF> m_advances;
+    QRectF m_pathBounds;
+    QString m_text;
+
+    QPixmap m_lens_pixmap;
+    QImage m_lens_image;
+
+    int m_fontSize;
+    bool m_animated;
+
+    qreal m_intensity;
+    qreal m_radius;
+    QPointF m_pos;
+    QPointF m_offset;
+    QPointF m_direction;
+    QPointF m_mousePress;
+    bool m_mouseDrag;
+    bool m_smallScreen;
+};
+
+class PathDeformControls : public QWidget
+{
+    Q_OBJECT
+public:
+    PathDeformControls(QWidget *parent, PathDeformRenderer* renderer, bool smallScreen);
+signals:
+    void okPressed();
+    void quitPressed();
+private:
+    PathDeformRenderer *m_renderer;
+    void layoutForDesktop();
+    void layoutForSmallScreen();
+};
+
+class PathDeformWidget : public QWidget
+{
+    Q_OBJECT
+public:
+    PathDeformWidget(QWidget *parent, bool smallScreen);
+    void setStyle(QStyle *style);
+
+private:
+    PathDeformRenderer *m_renderer;
+    PathDeformControls *m_controls;
+
+private slots:
+    void showControls();
+    void hideControls();
+};
+
+#endif // PATHDEFORM_H

examples/widgets/painting/deform/pathdeform.html

@@ -0,0 +1,24 @@
+<html>
+<center>
+<h2>Vector deformation</h2>
+</center>
+
+<p>This demo shows how to use advanced vector techniques to draw text 
+using a <code>QPainterPath</code>.</p>
+
+<p>We define a vector deformation field in the shape of a lens and apply
+this to all points in a path. This means that what is rendered on
+screen is not pixel manipulation, but modified vector representations of
+the glyphs themselves. This is visible from the high quality of the
+antialiased edges for the deformed glyphs.</p>
+
+<p>To get a fairly complex path we allow the user to type in text and
+convert the text to paths. This is done using the
+<code>QPainterPath::addText()</code> function.</p>
+
+<p>The lens is drawn using a single call to <code>drawEllipse()</code>, using
+a <code>QRadialGradient</code> to fill it with a specialized color table,
+giving the effect of the Sun's reflection and a drop shadow. The lens
+is cached as a pixmap for better performance.</p>
+
+</html>