qtbase-opensource-src/examples/opengl/threadedqopenglwidget/glwidget.cpp

368 lines
11 KiB
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/****************************************************************************
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** Copyright (C) 2016 The Qt Company Ltd.
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** This file is part of the examples of the Qt Toolkit.
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#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;
}