main.cpp Example File

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 #include "openglwindow.h"

 #include <QtGui/QGuiApplication>
 #include <QtGui/QMatrix4x4>
 #include <QtGui/QOpenGLShaderProgram>
 #include <QtGui/QScreen>

 #include <QtCore/qmath.h>

 class TriangleWindow : public OpenGLWindow
 {
 public:
     TriangleWindow();

     void initialize() override;
     void render() override;

 private:
     GLuint m_posAttr;
     GLuint m_colAttr;
     GLuint m_matrixUniform;

     QOpenGLShaderProgram *m_program;
     int m_frame;
 };

 TriangleWindow::TriangleWindow()
     : m_program(0)
     , m_frame(0)
 {
 }

 int main(int argc, char **argv)
 {
     QGuiApplication app(argc, argv);

     QSurfaceFormat format;
     format.setSamples(16);

     TriangleWindow window;
     window.setFormat(format);
     window.resize(640, 480);
     window.show();

     window.setAnimating(true);

     return app.exec();
 }

 static const char *vertexShaderSource =
     "attribute highp vec4 posAttr;\n"
     "attribute lowp vec4 colAttr;\n"
     "varying lowp vec4 col;\n"
     "uniform highp mat4 matrix;\n"
     "void main() {\n"
     "   col = colAttr;\n"
     "   gl_Position = matrix * posAttr;\n"
     "}\n";

 static const char *fragmentShaderSource =
     "varying lowp vec4 col;\n"
     "void main() {\n"
     "   gl_FragColor = col;\n"
     "}\n";

 void TriangleWindow::initialize()
 {
     m_program = new QOpenGLShaderProgram(this);
     m_program->addShaderFromSourceCode(QOpenGLShader::Vertex, vertexShaderSource);
     m_program->addShaderFromSourceCode(QOpenGLShader::Fragment, fragmentShaderSource);
     m_program->link();
     m_posAttr = m_program->attributeLocation("posAttr");
     m_colAttr = m_program->attributeLocation("colAttr");
     m_matrixUniform = m_program->uniformLocation("matrix");
 }

 void TriangleWindow::render()
 {
     const qreal retinaScale = devicePixelRatio();
     glViewport(0, 0, width() * retinaScale, height() * retinaScale);

     glClear(GL_COLOR_BUFFER_BIT);

     m_program->bind();

     QMatrix4x4 matrix;
     matrix.perspective(60.0f, 4.0f/3.0f, 0.1f, 100.0f);
     matrix.translate(0, 0, -2);
     matrix.rotate(100.0f * m_frame / screen()->refreshRate(), 0, 1, 0);

     m_program->setUniformValue(m_matrixUniform, matrix);

     GLfloat vertices[] = {
         0.0f, 0.707f,
         -0.5f, -0.5f,
         0.5f, -0.5f
     };

     GLfloat colors[] = {
         1.0f, 0.0f, 0.0f,
         0.0f, 1.0f, 0.0f,
         0.0f, 0.0f, 1.0f
     };

     glVertexAttribPointer(m_posAttr, 2, GL_FLOAT, GL_FALSE, 0, vertices);
     glVertexAttribPointer(m_colAttr, 3, GL_FLOAT, GL_FALSE, 0, colors);

     glEnableVertexAttribArray(0);
     glEnableVertexAttribArray(1);

     glDrawArrays(GL_TRIANGLES, 0, 3);

     glDisableVertexAttribArray(1);
     glDisableVertexAttribArray(0);

     m_program->release();

     ++m_frame;
 }