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Diffstat (limited to 'examples/opengl/qopenglwindow/main.cpp')
| -rw-r--r-- | examples/opengl/qopenglwindow/main.cpp | 193 |
1 files changed, 193 insertions, 0 deletions
diff --git a/examples/opengl/qopenglwindow/main.cpp b/examples/opengl/qopenglwindow/main.cpp new file mode 100644 index 0000000000..a67bcbb2e3 --- /dev/null +++ b/examples/opengl/qopenglwindow/main.cpp @@ -0,0 +1,193 @@ +/**************************************************************************** +** +** Copyright (C) 2014 Digia Plc and/or its subsidiary(-ies). +** Contact: http://www.qt-project.org/legal +** +** This file is part of the examples of the Qt Toolkit. +** +** $QT_BEGIN_LICENSE:BSD$ +** You may use this file under the terms of the BSD license as follows: +** +** "Redistribution and use in source and binary forms, with or without +** modification, are permitted provided that the following conditions are +** met: +** * Redistributions of source code must retain the above copyright +** notice, this list of conditions and the following disclaimer. +** * Redistributions in binary form must reproduce the above copyright +** notice, this list of conditions and the following disclaimer in +** the documentation and/or other materials provided with the +** distribution. +** * Neither the name of Digia Plc and its Subsidiary(-ies) nor the names +** of its contributors may be used to endorse or promote products derived +** from this software without specific prior written permission. +** +** +** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS +** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT +** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR +** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT +** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, +** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT +** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, +** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY +** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT +** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE +** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE." +** +** $QT_END_LICENSE$ +** +****************************************************************************/ + +#include <QOpenGLWindow> +#include <QScreen> +#include <QPainter> +#include <QGuiApplication> +#include <QMatrix4x4> +#include <QStaticText> +#include <QKeyEvent> + +#include "background_renderer.h" + +static QPainterPath painterPathForTriangle() +{ + static const QPointF bottomLeft(-1.0, -1.0); + static const QPointF top(0.0, 1.0); + static const QPointF bottomRight(1.0, -1.0); + + QPainterPath path(bottomLeft); + path.lineTo(top); + path.lineTo(bottomRight); + path.closeSubpath(); + return path; +} + +class OpenGLWindow : public QOpenGLWindow +{ + Q_OBJECT + +public: + OpenGLWindow(); + +protected: + void paintGL() Q_DECL_OVERRIDE; + void resizeGL(int w, int h) Q_DECL_OVERRIDE; + void keyPressEvent(QKeyEvent *e) Q_DECL_OVERRIDE; + +private: + void setAnimating(bool enabled); + + QMatrix4x4 m_window_normalised_matrix; + QMatrix4x4 m_window_painter_matrix; + QMatrix4x4 m_projection; + QMatrix4x4 m_view; + QMatrix4x4 m_model_triangle; + QMatrix4x4 m_model_text; + QBrush m_brush; + + FragmentToy m_fragment_toy; + QStaticText m_text_layout; + bool m_animate; +}; + +// Use NoPartialUpdate. This means that all the rendering goes directly to +// the window surface, no additional framebuffer object stands in the +// middle. This is fine since we will clear the entire framebuffer on each +// paint. Under the hood this means that the behavior is equivalent to the +// manual makeCurrent - perform OpenGL calls - swapBuffers loop that is +// typical in pure QWindow-based applications. +OpenGLWindow::OpenGLWindow() + : QOpenGLWindow(QOpenGLWindow::NoPartialUpdate) + , m_fragment_toy("background.frag") + , m_text_layout("The triangle and this text is rendered with QPainter") + , m_animate(true) +{ + m_view.lookAt(QVector3D(3,1,1), + QVector3D(0,0,0), + QVector3D(0,1,0)); + + QLinearGradient gradient(QPointF(-1,-1), QPointF(1,1)); + gradient.setColorAt(0, Qt::red); + gradient.setColorAt(1, Qt::green); + + m_brush = QBrush(gradient); + + setAnimating(m_animate); +} + +void OpenGLWindow::paintGL() +{ + m_fragment_toy.draw(size()); + + QPainter p(this); + p.setWorldTransform(m_window_normalised_matrix.toTransform()); + + QMatrix4x4 mvp = m_projection * m_view * m_model_triangle; + p.setTransform(mvp.toTransform(), true); + + p.fillPath(painterPathForTriangle(), m_brush); + + QTransform text_transform = (m_window_painter_matrix * m_view * m_model_text).toTransform(); + p.setTransform(text_transform, false); + p.setPen(QPen(Qt::white)); + m_text_layout.prepare(text_transform); + qreal x = - (m_text_layout.size().width() / 2); + qreal y = 0; + p.drawStaticText(x, y, m_text_layout); + + m_model_triangle.rotate(-1, 0, 1, 0); + m_model_text.rotate(1, 0, 1, 0); +} + +void OpenGLWindow::resizeGL(int w, int h) +{ + m_window_normalised_matrix.setToIdentity(); + m_window_normalised_matrix.translate(w / 2.0, h / 2.0); + m_window_normalised_matrix.scale(w / 2.0, -h / 2.0); + + m_window_painter_matrix.setToIdentity(); + m_window_painter_matrix.translate(w / 2.0, h / 2.0); + + m_text_layout.setTextWidth(std::max(w * 0.2, 80.0)); + + m_projection.setToIdentity(); + m_projection.perspective(45.f, qreal(w) / qreal(h), 0.1f, 100.f); +} + +void OpenGLWindow::keyPressEvent(QKeyEvent *e) +{ + if (e->key() == Qt::Key_P) { // pause + m_animate = !m_animate; + setAnimating(m_animate); + } +} + +void OpenGLWindow::setAnimating(bool enabled) +{ + if (enabled) { + // Animate continuously, throttled by the blocking swapBuffers() call the + // QOpenGLWindow internally executes after each paint. Once that is done + // (frameSwapped signal is emitted), we schedule a new update. This + // obviously assumes that the swap interval (see + // QSurfaceFormat::setSwapInterval()) is non-zero. + connect(this, SIGNAL(frameSwapped()), this, SLOT(update())); + update(); + } else { + disconnect(this, SIGNAL(frameSwapped()), this, SLOT(update())); + } +} + +int main(int argc, char **argv) +{ + QGuiApplication app(argc, argv); + + OpenGLWindow window; + QSurfaceFormat fmt; + fmt.setDepthBufferSize(24); + fmt.setStencilBufferSize(8); + window.setFormat(fmt); + window.show(); + + return app.exec(); +} + +#include "main.moc" |