Added QWindow example in examples/opengl/hellowindow.

(cherry picked from commit 712f5fe0acc7ef73117151cd8206a0d4f5d01428)

1 files changed, 259 insertions, 0 deletions

diff --git a/examples/opengl/hellowindow/hellowindow.cpp b/examples/opengl/hellowindow/hellowindow.cpp
new file mode 100644
index 0000000000..f74d321fd9
--- /dev/null
+++ b/examples/opengl/hellowindow/hellowindow.cpp
@@ -0,0 +1,259 @@
+#include "hellowindow.h"
+
+#include <QWindowContext>
+
+#include <QTimer>
+
+#include <qmath.h>
+
+HelloWindow::HelloWindow()
+    : colorIndex(0)
+{
+    setSurfaceType(OpenGLSurface);
+
+    QWindowFormat format;
+    format.setDepthBufferSize(16);
+    format.setSamples(4);
+
+    setWindowFormat(format);
+
+    setGeometry(QRect(10, 10, 640, 480));
+
+    create();
+
+    initialize();
+
+    QTimer *timer = new QTimer(this);
+    timer->start(10);
+
+    connect(timer, SIGNAL(timeout()), this, SLOT(render()));
+}
+
+void HelloWindow::mousePressEvent(QMouseEvent *)
+{
+    updateColor();
+}
+
+void HelloWindow::updateColor()
+{
+    float colors[][4] =
+    {
+        { 0.4, 1.0, 0.0, 0.0 },
+        { 0.0, 0.4, 1.0, 0.0 }
+    };
+
+    glContext()->makeCurrent();
+
+    program.bind();
+    program.setUniformValue(colorUniform, colors[colorIndex][0], colors[colorIndex][1], colors[colorIndex][2], colors[colorIndex][3]);
+    program.release();
+
+    colorIndex++;
+    if (colorIndex >= sizeof(colors) / sizeof(colors[0]))
+        colorIndex = 0;
+}
+
+void HelloWindow::render()
+{
+    glContext()->makeCurrent();
+
+    glClearColor(0.1f, 0.1f, 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);
+
+    glContext()->swapBuffers();
+
+    m_fAngle += 1.0f;
+}
+
+void HelloWindow::paintQtLogo()
+{
+    program.enableAttributeArray(normalAttr);
+    program.enableAttributeArray(vertexAttr);
+    program.setAttributeArray(vertexAttr, vertices.constData());
+    program.setAttributeArray(normalAttr, normals.constData());
+    glDrawArrays(GL_TRIANGLES, 0, vertices.size());
+    program.disableAttributeArray(normalAttr);
+    program.disableAttributeArray(vertexAttr);
+}
+
+void HelloWindow::initialize()
+{
+    glContext()->makeCurrent();
+
+    glClearColor(0.1f, 0.1f, 0.2f, 1.0f);
+
+    QGLShader *vshader = new QGLShader(QGLShader::Vertex, this);
+    const char *vsrc =
+        "attribute highp vec4 vertex;\n"
+        "attribute mediump vec3 normal;\n"
+        "uniform mediump mat4 matrix;\n"
+        "uniform lowp vec4 sourceColor;\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 = sourceColor.rgb;\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);
+
+    QGLShader *fshader = new QGLShader(QGLShader::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");
+    colorUniform = program.uniformLocation("sourceColor");
+
+    m_fAngle = 0;
+    m_fScale = 1;
+    createGeometry();
+    updateColor();
+}
+
+void HelloWindow::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 qreal Pi = 3.14159f;
+    const int NumSectors = 100;
+
+    for (int i = 0; i < NumSectors; ++i) {
+        qreal angle1 = (i * 2 * Pi) / NumSectors;
+        qreal x5 = 0.30 * qSin(angle1);
+        qreal y5 = 0.30 * qCos(angle1);
+        qreal x6 = 0.20 * qSin(angle1);
+        qreal y6 = 0.20 * qCos(angle1);
+
+        qreal angle2 = ((i + 1) * 2 * Pi) / NumSectors;
+        qreal x7 = 0.20 * qSin(angle2);
+        qreal y7 = 0.20 * qCos(angle2);
+        qreal x8 = 0.30 * qSin(angle2);
+        qreal y8 = 0.30 * qCos(angle2);
+
+        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 HelloWindow::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 HelloWindow::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;
+}