qt-everywhere-src-5.15.1/qtbase/examples/opengl/threadedqopenglwidget/glwidget.cpp - orbit - Git at Google

 /****************************************************************************
 **
 ** Copyright (C) 2016 The Qt Company Ltd.
 ** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the examples of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
 ** Commercial License Usage
 ** Licensees holding valid commercial Qt licenses may use this file in
 ** accordance with the commercial license agreement provided with the
 ** Software or, alternatively, in accordance with the terms contained in
 ** a written agreement between you and The Qt Company. For licensing terms
 ** and conditions see https://www.qt.io/terms-conditions. For further
 ** information use the contact form at https://www.qt.io/contact-us.
 **
 ** BSD License Usage
 ** Alternatively, 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 The Qt Company Ltd 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 "glwidget.h"
 #include <qmath.h>
 #include <QGuiApplication>

 GLWidget::GLWidget(QWidget *parent)
     : QOpenGLWidget(parent)
 {
     setMinimumSize(300, 250);

     connect(this, &QOpenGLWidget::aboutToCompose, this, &GLWidget::onAboutToCompose);
     connect(this, &QOpenGLWidget::frameSwapped, this, &GLWidget::onFrameSwapped);
     connect(this, &QOpenGLWidget::aboutToResize, this, &GLWidget::onAboutToResize);
     connect(this, &QOpenGLWidget::resized, this, &GLWidget::onResized);

     m_thread = new QThread;
     m_renderer = new Renderer(this);
     m_renderer->moveToThread(m_thread);
     connect(m_thread, &QThread::finished, m_renderer, &QObject::deleteLater);

     connect(this, &GLWidget::renderRequested, m_renderer, &Renderer::render);
     connect(m_renderer, &Renderer::contextWanted, this, &GLWidget::grabContext);

     m_thread->start();
 }

 GLWidget::~GLWidget()
 {
     m_renderer->prepareExit();
     m_thread->quit();
     m_thread->wait();
     delete m_thread;
 }

 void GLWidget::onAboutToCompose()
 {
     // We are on the gui thread here. Composition is about to
     // begin. Wait until the render thread finishes.
     m_renderer->lockRenderer();
 }

 void GLWidget::onFrameSwapped()
 {
     m_renderer->unlockRenderer();
     // Assuming a blocking swap, our animation is driven purely by the
     // vsync in this example.
     emit renderRequested();
 }

 void GLWidget::onAboutToResize()
 {
     m_renderer->lockRenderer();
 }

 void GLWidget::onResized()
 {
     m_renderer->unlockRenderer();
 }

 void GLWidget::grabContext()
 {
     m_renderer->lockRenderer();
     QMutexLocker lock(m_renderer->grabMutex());
     context()->moveToThread(m_thread);
     m_renderer->grabCond()->wakeAll();
     m_renderer->unlockRenderer();
 }

 Renderer::Renderer(GLWidget *w) : m_glwidget(w) {}

 void Renderer::paintQtLogo()
 {
     vbo.bind();
     program.setAttributeBuffer(vertexAttr, GL_FLOAT, 0, 3);
     program.setAttributeBuffer(normalAttr, GL_FLOAT, vertices.count() * 3 * sizeof(GLfloat), 3);
     vbo.release();

     program.enableAttributeArray(vertexAttr);
     program.enableAttributeArray(normalAttr);

     glDrawArrays(GL_TRIANGLES, 0, vertices.size());

     program.disableAttributeArray(normalAttr);
     program.disableAttributeArray(vertexAttr);
 }

 // Some OpenGL implementations have serious issues with compiling and linking
 // shaders on multiple threads concurrently. Avoid this.
 Q_GLOBAL_STATIC(QMutex, initMutex)

 void Renderer::render()
 {
     if (m_exiting)
         return;

     QOpenGLContext *ctx = m_glwidget->context();
     if (!ctx) // QOpenGLWidget not yet initialized
         return;

     // Grab the context.
     m_grabMutex.lock();
     emit contextWanted();
     m_grabCond.wait(&m_grabMutex);
     QMutexLocker lock(&m_renderMutex);
     m_grabMutex.unlock();

     if (m_exiting)
         return;

     Q_ASSERT(ctx->thread() == QThread::currentThread());

     // Make the context (and an offscreen surface) current for this thread. The
     // QOpenGLWidget's fbo is bound in the context.
     m_glwidget->makeCurrent();

     if (!m_inited) {
         m_inited = true;
         initializeOpenGLFunctions();

         QMutexLocker initLock(initMutex());
         QOpenGLShader *vshader = new QOpenGLShader(QOpenGLShader::Vertex, this);
         const char *vsrc =
             "attribute highp vec4 vertex;\n"
             "attribute mediump vec3 normal;\n"
             "uniform mediump mat4 matrix;\n"
             "varying mediump vec4 color;\n"
             "void main(void)\n"
             "{\n"
             "    vec3 toLight = normalize(vec3(0.0, 0.3, 1.0));\n"
             "    float angle = max(dot(normal, toLight), 0.0);\n"
             "    vec3 col = vec3(0.40, 1.0, 0.0);\n"
             "    color = vec4(col * 0.2 + col * 0.8 * angle, 1.0);\n"
             "    color = clamp(color, 0.0, 1.0);\n"
             "    gl_Position = matrix * vertex;\n"
             "}\n";
         vshader->compileSourceCode(vsrc);

         QOpenGLShader *fshader = new QOpenGLShader(QOpenGLShader::Fragment, this);
         const char *fsrc =
             "varying mediump vec4 color;\n"
             "void main(void)\n"
             "{\n"
             "    gl_FragColor = color;\n"
             "}\n";
         fshader->compileSourceCode(fsrc);

         program.addShader(vshader);
         program.addShader(fshader);
         program.link();

         vertexAttr = program.attributeLocation("vertex");
         normalAttr = program.attributeLocation("normal");
         matrixUniform = program.uniformLocation("matrix");

         m_fAngle = 0;
         m_fScale = 1;
         createGeometry();

         vbo.create();
         vbo.bind();
         const int verticesSize = vertices.count() * 3 * sizeof(GLfloat);
         vbo.allocate(verticesSize * 2);
         vbo.write(0, vertices.constData(), verticesSize);
         vbo.write(verticesSize, normals.constData(), verticesSize);

         m_elapsed.start();
     }

     //qDebug("%p elapsed %lld", QThread::currentThread(), m_elapsed.restart());

     glClearColor(0.1f, 0.2f, 0.2f, 1.0f);
     glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

     glFrontFace(GL_CW);
     glCullFace(GL_FRONT);
     glEnable(GL_CULL_FACE);
     glEnable(GL_DEPTH_TEST);

     QMatrix4x4 modelview;
     modelview.rotate(m_fAngle, 0.0f, 1.0f, 0.0f);
     modelview.rotate(m_fAngle, 1.0f, 0.0f, 0.0f);
     modelview.rotate(m_fAngle, 0.0f, 0.0f, 1.0f);
     modelview.scale(m_fScale);
     modelview.translate(0.0f, -0.2f, 0.0f);

     program.bind();
     program.setUniformValue(matrixUniform, modelview);
     paintQtLogo();
     program.release();

     glDisable(GL_DEPTH_TEST);
     glDisable(GL_CULL_FACE);

     m_fAngle += 1.0f;

     // Make no context current on this thread and move the QOpenGLWidget's
     // context back to the gui thread.
     m_glwidget->doneCurrent();
     ctx->moveToThread(qGuiApp->thread());

     // Schedule composition. Note that this will use QueuedConnection, meaning
     // that update() will be invoked on the gui thread.
     QMetaObject::invokeMethod(m_glwidget, "update");
 }

 void Renderer::createGeometry()
 {
     vertices.clear();
     normals.clear();

     qreal x1 = +0.06f;
     qreal y1 = -0.14f;
     qreal x2 = +0.14f;
     qreal y2 = -0.06f;
     qreal x3 = +0.08f;
     qreal y3 = +0.00f;
     qreal x4 = +0.30f;
     qreal y4 = +0.22f;

     quad(x1, y1, x2, y2, y2, x2, y1, x1);
     quad(x3, y3, x4, y4, y4, x4, y3, x3);

     extrude(x1, y1, x2, y2);
     extrude(x2, y2, y2, x2);
     extrude(y2, x2, y1, x1);
     extrude(y1, x1, x1, y1);
     extrude(x3, y3, x4, y4);
     extrude(x4, y4, y4, x4);
     extrude(y4, x4, y3, x3);

     const int NumSectors = 100;
     const qreal sectorAngle = 2 * qreal(M_PI) / NumSectors;

     for (int i = 0; i < NumSectors; ++i) {
         qreal angle = i * sectorAngle;
         qreal x5 = 0.30 * sin(angle);
         qreal y5 = 0.30 * cos(angle);
         qreal x6 = 0.20 * sin(angle);
         qreal y6 = 0.20 * cos(angle);

         angle += sectorAngle;
         qreal x7 = 0.20 * sin(angle);
         qreal y7 = 0.20 * cos(angle);
         qreal x8 = 0.30 * sin(angle);
         qreal y8 = 0.30 * cos(angle);

         quad(x5, y5, x6, y6, x7, y7, x8, y8);

         extrude(x6, y6, x7, y7);
         extrude(x8, y8, x5, y5);
     }

     for (int i = 0;i < vertices.size();i++)
         vertices[i] *= 2.0f;
 }

 void Renderer::quad(qreal x1, qreal y1, qreal x2, qreal y2, qreal x3, qreal y3, qreal x4, qreal y4)
 {
     vertices << QVector3D(x1, y1, -0.05f);
     vertices << QVector3D(x2, y2, -0.05f);
     vertices << QVector3D(x4, y4, -0.05f);

     vertices << QVector3D(x3, y3, -0.05f);
     vertices << QVector3D(x4, y4, -0.05f);
     vertices << QVector3D(x2, y2, -0.05f);

     QVector3D n = QVector3D::normal
         (QVector3D(x2 - x1, y2 - y1, 0.0f), QVector3D(x4 - x1, y4 - y1, 0.0f));

     normals << n;
     normals << n;
     normals << n;

     normals << n;
     normals << n;
     normals << n;

     vertices << QVector3D(x4, y4, 0.05f);
     vertices << QVector3D(x2, y2, 0.05f);
     vertices << QVector3D(x1, y1, 0.05f);

     vertices << QVector3D(x2, y2, 0.05f);
     vertices << QVector3D(x4, y4, 0.05f);
     vertices << QVector3D(x3, y3, 0.05f);

     n = QVector3D::normal
         (QVector3D(x2 - x4, y2 - y4, 0.0f), QVector3D(x1 - x4, y1 - y4, 0.0f));

     normals << n;
     normals << n;
     normals << n;

     normals << n;
     normals << n;
     normals << n;
 }

 void Renderer::extrude(qreal x1, qreal y1, qreal x2, qreal y2)
 {
     vertices << QVector3D(x1, y1, +0.05f);
     vertices << QVector3D(x2, y2, +0.05f);
     vertices << QVector3D(x1, y1, -0.05f);

     vertices << QVector3D(x2, y2, -0.05f);
     vertices << QVector3D(x1, y1, -0.05f);
     vertices << QVector3D(x2, y2, +0.05f);

     QVector3D n = QVector3D::normal
         (QVector3D(x2 - x1, y2 - y1, 0.0f), QVector3D(0.0f, 0.0f, -0.1f));

     normals << n;
     normals << n;
     normals << n;

     normals << n;
     normals << n;
     normals << n;
 }
	/****************************************************************************
	**
	** Copyright (C) 2016 The Qt Company Ltd.
	** Contact: https://www.qt.io/licensing/
	**
	** This file is part of the examples of the Qt Toolkit.
	**
	** $QT_BEGIN_LICENSE:BSD$
	** Commercial License Usage
	** Licensees holding valid commercial Qt licenses may use this file in
	** accordance with the commercial license agreement provided with the
	** Software or, alternatively, in accordance with the terms contained in
	** a written agreement between you and The Qt Company. For licensing terms
	** and conditions see https://www.qt.io/terms-conditions. For further
	** information use the contact form at https://www.qt.io/contact-us.
	**
	** BSD License Usage
	** Alternatively, 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 The Qt Company Ltd 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 "glwidget.h"
	#include <qmath.h>
	#include <QGuiApplication>

	GLWidget::GLWidget(QWidget *parent)
	: QOpenGLWidget(parent)
	{
	setMinimumSize(300, 250);

	connect(this, &QOpenGLWidget::aboutToCompose, this, &GLWidget::onAboutToCompose);
	connect(this, &QOpenGLWidget::frameSwapped, this, &GLWidget::onFrameSwapped);
	connect(this, &QOpenGLWidget::aboutToResize, this, &GLWidget::onAboutToResize);
	connect(this, &QOpenGLWidget::resized, this, &GLWidget::onResized);

	m_thread = new QThread;
	m_renderer = new Renderer(this);
	m_renderer->moveToThread(m_thread);
	connect(m_thread, &QThread::finished, m_renderer, &QObject::deleteLater);

	connect(this, &GLWidget::renderRequested, m_renderer, &Renderer::render);
	connect(m_renderer, &Renderer::contextWanted, this, &GLWidget::grabContext);

	m_thread->start();
	}

	GLWidget::~GLWidget()
	{
	m_renderer->prepareExit();
	m_thread->quit();
	m_thread->wait();
	delete m_thread;
	}

	void GLWidget::onAboutToCompose()
	{
	// We are on the gui thread here. Composition is about to
	// begin. Wait until the render thread finishes.
	m_renderer->lockRenderer();
	}

	void GLWidget::onFrameSwapped()
	{
	m_renderer->unlockRenderer();
	// Assuming a blocking swap, our animation is driven purely by the
	// vsync in this example.
	emit renderRequested();
	}

	void GLWidget::onAboutToResize()
	{
	m_renderer->lockRenderer();
	}

	void GLWidget::onResized()
	{
	m_renderer->unlockRenderer();
	}

	void GLWidget::grabContext()
	{
	m_renderer->lockRenderer();
	QMutexLocker lock(m_renderer->grabMutex());
	context()->moveToThread(m_thread);
	m_renderer->grabCond()->wakeAll();
	m_renderer->unlockRenderer();
	}

	Renderer::Renderer(GLWidget *w) : m_glwidget(w) {}

	void Renderer::paintQtLogo()
	{
	vbo.bind();
	program.setAttributeBuffer(vertexAttr, GL_FLOAT, 0, 3);
	program.setAttributeBuffer(normalAttr, GL_FLOAT, vertices.count() * 3 * sizeof(GLfloat), 3);
	vbo.release();

	program.enableAttributeArray(vertexAttr);
	program.enableAttributeArray(normalAttr);

	glDrawArrays(GL_TRIANGLES, 0, vertices.size());

	program.disableAttributeArray(normalAttr);
	program.disableAttributeArray(vertexAttr);
	}

	// Some OpenGL implementations have serious issues with compiling and linking
	// shaders on multiple threads concurrently. Avoid this.
	Q_GLOBAL_STATIC(QMutex, initMutex)

	void Renderer::render()
	{
	if (m_exiting)
	return;

	QOpenGLContext *ctx = m_glwidget->context();
	if (!ctx) // QOpenGLWidget not yet initialized
	return;

	// Grab the context.
	m_grabMutex.lock();
	emit contextWanted();
	m_grabCond.wait(&m_grabMutex);
	QMutexLocker lock(&m_renderMutex);
	m_grabMutex.unlock();

	if (m_exiting)
	return;

	Q_ASSERT(ctx->thread() == QThread::currentThread());

	// Make the context (and an offscreen surface) current for this thread. The
	// QOpenGLWidget's fbo is bound in the context.
	m_glwidget->makeCurrent();

	if (!m_inited) {
	m_inited = true;
	initializeOpenGLFunctions();

	QMutexLocker initLock(initMutex());
	QOpenGLShader *vshader = new QOpenGLShader(QOpenGLShader::Vertex, this);
	const char *vsrc =
	"attribute highp vec4 vertex;\n"
	"attribute mediump vec3 normal;\n"
	"uniform mediump mat4 matrix;\n"
	"varying mediump vec4 color;\n"
	"void main(void)\n"
	"{\n"
	" vec3 toLight = normalize(vec3(0.0, 0.3, 1.0));\n"
	" float angle = max(dot(normal, toLight), 0.0);\n"
	" vec3 col = vec3(0.40, 1.0, 0.0);\n"
	" color = vec4(col * 0.2 + col * 0.8 * angle, 1.0);\n"
	" color = clamp(color, 0.0, 1.0);\n"
	" gl_Position = matrix * vertex;\n"
	"}\n";
	vshader->compileSourceCode(vsrc);

	QOpenGLShader *fshader = new QOpenGLShader(QOpenGLShader::Fragment, this);
	const char *fsrc =
	"varying mediump vec4 color;\n"
	"void main(void)\n"
	"{\n"
	" gl_FragColor = color;\n"
	"}\n";
	fshader->compileSourceCode(fsrc);

	program.addShader(vshader);
	program.addShader(fshader);
	program.link();

	vertexAttr = program.attributeLocation("vertex");
	normalAttr = program.attributeLocation("normal");
	matrixUniform = program.uniformLocation("matrix");

	m_fAngle = 0;
	m_fScale = 1;
	createGeometry();

	vbo.create();
	vbo.bind();
	const int verticesSize = vertices.count() * 3 * sizeof(GLfloat);
	vbo.allocate(verticesSize * 2);
	vbo.write(0, vertices.constData(), verticesSize);
	vbo.write(verticesSize, normals.constData(), verticesSize);

	m_elapsed.start();
	}

	//qDebug("%p elapsed %lld", QThread::currentThread(), m_elapsed.restart());

	glClearColor(0.1f, 0.2f, 0.2f, 1.0f);
	glClear(GL_COLOR_BUFFER_BIT \| GL_DEPTH_BUFFER_BIT);

	glFrontFace(GL_CW);
	glCullFace(GL_FRONT);
	glEnable(GL_CULL_FACE);
	glEnable(GL_DEPTH_TEST);

	QMatrix4x4 modelview;
	modelview.rotate(m_fAngle, 0.0f, 1.0f, 0.0f);
	modelview.rotate(m_fAngle, 1.0f, 0.0f, 0.0f);
	modelview.rotate(m_fAngle, 0.0f, 0.0f, 1.0f);
	modelview.scale(m_fScale);
	modelview.translate(0.0f, -0.2f, 0.0f);

	program.bind();
	program.setUniformValue(matrixUniform, modelview);
	paintQtLogo();
	program.release();

	glDisable(GL_DEPTH_TEST);
	glDisable(GL_CULL_FACE);

	m_fAngle += 1.0f;

	// Make no context current on this thread and move the QOpenGLWidget's
	// context back to the gui thread.
	m_glwidget->doneCurrent();
	ctx->moveToThread(qGuiApp->thread());

	// Schedule composition. Note that this will use QueuedConnection, meaning
	// that update() will be invoked on the gui thread.
	QMetaObject::invokeMethod(m_glwidget, "update");
	}

	void Renderer::createGeometry()
	{
	vertices.clear();
	normals.clear();

	qreal x1 = +0.06f;
	qreal y1 = -0.14f;
	qreal x2 = +0.14f;
	qreal y2 = -0.06f;
	qreal x3 = +0.08f;
	qreal y3 = +0.00f;
	qreal x4 = +0.30f;
	qreal y4 = +0.22f;

	quad(x1, y1, x2, y2, y2, x2, y1, x1);
	quad(x3, y3, x4, y4, y4, x4, y3, x3);

	extrude(x1, y1, x2, y2);
	extrude(x2, y2, y2, x2);
	extrude(y2, x2, y1, x1);
	extrude(y1, x1, x1, y1);
	extrude(x3, y3, x4, y4);
	extrude(x4, y4, y4, x4);
	extrude(y4, x4, y3, x3);

	const int NumSectors = 100;
	const qreal sectorAngle = 2 * qreal(M_PI) / NumSectors;

	for (int i = 0; i < NumSectors; ++i) {
	qreal angle = i * sectorAngle;
	qreal x5 = 0.30 * sin(angle);
	qreal y5 = 0.30 * cos(angle);
	qreal x6 = 0.20 * sin(angle);
	qreal y6 = 0.20 * cos(angle);

	angle += sectorAngle;
	qreal x7 = 0.20 * sin(angle);
	qreal y7 = 0.20 * cos(angle);
	qreal x8 = 0.30 * sin(angle);
	qreal y8 = 0.30 * cos(angle);

	quad(x5, y5, x6, y6, x7, y7, x8, y8);

	extrude(x6, y6, x7, y7);
	extrude(x8, y8, x5, y5);
	}

	for (int i = 0;i < vertices.size();i++)
	vertices[i] *= 2.0f;
	}

	void Renderer::quad(qreal x1, qreal y1, qreal x2, qreal y2, qreal x3, qreal y3, qreal x4, qreal y4)
	{
	vertices << QVector3D(x1, y1, -0.05f);
	vertices << QVector3D(x2, y2, -0.05f);
	vertices << QVector3D(x4, y4, -0.05f);

	vertices << QVector3D(x3, y3, -0.05f);
	vertices << QVector3D(x4, y4, -0.05f);
	vertices << QVector3D(x2, y2, -0.05f);

	QVector3D n = QVector3D::normal
	(QVector3D(x2 - x1, y2 - y1, 0.0f), QVector3D(x4 - x1, y4 - y1, 0.0f));

	normals << n;
	normals << n;
	normals << n;

	normals << n;
	normals << n;
	normals << n;

	vertices << QVector3D(x4, y4, 0.05f);
	vertices << QVector3D(x2, y2, 0.05f);
	vertices << QVector3D(x1, y1, 0.05f);

	vertices << QVector3D(x2, y2, 0.05f);
	vertices << QVector3D(x4, y4, 0.05f);
	vertices << QVector3D(x3, y3, 0.05f);

	n = QVector3D::normal
	(QVector3D(x2 - x4, y2 - y4, 0.0f), QVector3D(x1 - x4, y1 - y4, 0.0f));

	normals << n;
	normals << n;
	normals << n;

	normals << n;
	normals << n;
	normals << n;
	}

	void Renderer::extrude(qreal x1, qreal y1, qreal x2, qreal y2)
	{
	vertices << QVector3D(x1, y1, +0.05f);
	vertices << QVector3D(x2, y2, +0.05f);
	vertices << QVector3D(x1, y1, -0.05f);

	vertices << QVector3D(x2, y2, -0.05f);
	vertices << QVector3D(x1, y1, -0.05f);
	vertices << QVector3D(x2, y2, +0.05f);

	QVector3D n = QVector3D::normal
	(QVector3D(x2 - x1, y2 - y1, 0.0f), QVector3D(0.0f, 0.0f, -0.1f));

	normals << n;
	normals << n;
	normals << n;

	normals << n;
	normals << n;
	normals << n;
	}