159 lines
4.7 KiB
C++
159 lines
4.7 KiB
C++
// Copyright (C) 2016 The Qt Company Ltd.
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// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
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#include "squircle.h"
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#include <QtQuick/qquickwindow.h>
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#include <QOpenGLShaderProgram>
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#include <QOpenGLContext>
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#include <QtCore/QRunnable>
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//! [7]
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Squircle::Squircle()
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: m_t(0)
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, m_renderer(nullptr)
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{
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connect(this, &QQuickItem::windowChanged, this, &Squircle::handleWindowChanged);
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}
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//! [7]
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//! [8]
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void Squircle::setT(qreal t)
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{
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if (t == m_t)
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return;
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m_t = t;
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emit tChanged();
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if (window())
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window()->update();
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}
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//! [8]
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//! [1]
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void Squircle::handleWindowChanged(QQuickWindow *win)
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{
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if (win) {
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connect(win, &QQuickWindow::beforeSynchronizing, this, &Squircle::sync, Qt::DirectConnection);
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connect(win, &QQuickWindow::sceneGraphInvalidated, this, &Squircle::cleanup, Qt::DirectConnection);
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//! [1]
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//! [3]
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// Ensure we start with cleared to black. The squircle's blend mode relies on this.
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win->setColor(Qt::black);
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}
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}
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//! [3]
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//! [6]
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void Squircle::cleanup()
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{
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delete m_renderer;
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m_renderer = nullptr;
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}
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class CleanupJob : public QRunnable
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{
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public:
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CleanupJob(SquircleRenderer *renderer) : m_renderer(renderer) { }
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void run() override { delete m_renderer; }
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private:
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SquircleRenderer *m_renderer;
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};
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void Squircle::releaseResources()
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{
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window()->scheduleRenderJob(new CleanupJob(m_renderer), QQuickWindow::BeforeSynchronizingStage);
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m_renderer = nullptr;
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}
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SquircleRenderer::~SquircleRenderer()
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{
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delete m_program;
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}
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//! [6]
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//! [9]
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void Squircle::sync()
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{
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if (!m_renderer) {
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m_renderer = new SquircleRenderer();
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connect(window(), &QQuickWindow::beforeRendering, m_renderer, &SquircleRenderer::init, Qt::DirectConnection);
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connect(window(), &QQuickWindow::beforeRenderPassRecording, m_renderer, &SquircleRenderer::paint, Qt::DirectConnection);
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}
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m_renderer->setViewportSize(window()->size() * window()->devicePixelRatio());
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m_renderer->setT(m_t);
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m_renderer->setWindow(window());
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}
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//! [9]
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//! [4]
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void SquircleRenderer::init()
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{
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if (!m_program) {
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QSGRendererInterface *rif = m_window->rendererInterface();
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Q_ASSERT(rif->graphicsApi() == QSGRendererInterface::OpenGL);
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initializeOpenGLFunctions();
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const float values[] = { -1, -1, 1, -1, -1, 1, 1, 1 };
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m_vbo.create();
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m_vbo.bind();
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m_vbo.allocate(values, sizeof(values));
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glEnableVertexAttribArray(0);
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glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, 2 * sizeof(GLfloat), nullptr);
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m_program = new QOpenGLShaderProgram();
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m_program->addCacheableShaderFromSourceCode(QOpenGLShader::Vertex,
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"attribute highp vec4 vertices;"
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"varying highp vec2 coords;"
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"void main() {"
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" gl_Position = vertices;"
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" coords = vertices.xy;"
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"}");
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m_program->addCacheableShaderFromSourceCode(QOpenGLShader::Fragment,
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"uniform lowp float t;"
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"varying highp vec2 coords;"
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"void main() {"
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" lowp float i = 1. - (pow(abs(coords.x), 4.) + pow(abs(coords.y), 4.));"
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" i = smoothstep(t - 0.8, t + 0.8, i);"
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" i = floor(i * 20.) / 20.;"
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" gl_FragColor = vec4(coords * .5 + .5, i, i);"
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"}");
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m_program->bindAttributeLocation("vertices", 0);
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m_program->link();
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}
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}
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//! [4] //! [5]
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void SquircleRenderer::paint()
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{
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// Play nice with the RHI. Not strictly needed when the scenegraph uses
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// OpenGL directly.
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m_window->beginExternalCommands();
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m_vbo.bind();
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m_program->bind();
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m_program->setUniformValue("t", (float)m_t);
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glEnableVertexAttribArray(0);
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glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, 2 * sizeof(GLfloat), nullptr);
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glViewport(0, 0, m_viewportSize.width(), m_viewportSize.height());
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glDisable(GL_DEPTH_TEST);
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glEnable(GL_BLEND);
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glBlendFunc(GL_SRC_ALPHA, GL_ONE);
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glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
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glDisableVertexAttribArray(0);
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m_program->release();
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m_window->endExternalCommands();
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}
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//! [5]
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