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");
}