Make the gles3 example more impressive

Add some extra rotations and offsets, to show off the power of
what you can do with a single draw call. Also use QGLWindow instead
of QGLWidget. This improves performance from 23 FPS to 30 FPS on a
4k monitor with integrated Intel graphics.

Change-Id: Iedac1c14cc6057959aa15faaacdf29da91f36ab1
Reviewed-by: Laszlo Agocs <laszlo.agocs@theqtcompany.com>

examples/opengl/hellogles3/glwindow.cpp

@@ -38,7 +38,7 @@
 **
 ****************************************************************************/
 
-#include "glwidget.h"
+#include "glwindow.h"
 #include <QImage>
 #include <QOpenGLTexture>
 #include <QOpenGLShaderProgram>
@@ -49,14 +49,17 @@
 #include <QPropertyAnimation>
 #include <QPauseAnimation>
 #include <QSequentialAnimationGroup>
+#include <QTimer>
 
-GLWidget::GLWidget()
+GLWindow::GLWindow()
     : m_texture(0),
       m_program(0),
       m_vbo(0),
       m_vao(0),
       m_target(0, 0, -1),
-      m_uniformsDirty(true)
+      m_uniformsDirty(true),
+      m_r(0),
+      m_r2(0)
 {
     m_world.setToIdentity();
     m_world.translate(0, 0, -1);
@@ -65,25 +68,34 @@ GLWidget::GLWidget()
     QSequentialAnimationGroup *animGroup = new QSequentialAnimationGroup(this);
     animGroup->setLoopCount(-1);
     QPropertyAnimation *zAnim0 = new QPropertyAnimation(this, QByteArrayLiteral("z"));
-    zAnim0->setStartValue(0.0f);
+    zAnim0->setStartValue(1.5f);
-    zAnim0->setEndValue(1.0f);
+    zAnim0->setEndValue(10.0f);
     zAnim0->setDuration(2000);
     animGroup->addAnimation(zAnim0);
     QPropertyAnimation *zAnim1 = new QPropertyAnimation(this, QByteArrayLiteral("z"));
-    zAnim1->setStartValue(0.0f);
+    zAnim1->setStartValue(10.0f);
-    zAnim1->setEndValue(70.0f);
+    zAnim1->setEndValue(50.0f);
     zAnim1->setDuration(4000);
     zAnim1->setEasingCurve(QEasingCurve::OutElastic);
     animGroup->addAnimation(zAnim1);
     QPropertyAnimation *zAnim2 = new QPropertyAnimation(this, QByteArrayLiteral("z"));
-    zAnim2->setStartValue(70.0f);
+    zAnim2->setStartValue(50.0f);
-    zAnim2->setEndValue(0.0f);
+    zAnim2->setEndValue(1.5f);
     zAnim2->setDuration(2000);
     animGroup->addAnimation(zAnim2);
     animGroup->start();
+
+    QPropertyAnimation* rAnim = new QPropertyAnimation(this, QByteArrayLiteral("r"));
+    rAnim->setStartValue(0.0f);
+    rAnim->setEndValue(360.0f);
+    rAnim->setDuration(2000);
+    rAnim->setLoopCount(-1);
+    rAnim->start();
+
+    QTimer::singleShot(4000, this, SLOT(startSecondStage()));
 }
 
-GLWidget::~GLWidget()
+GLWindow::~GLWindow()
 {
     makeCurrent();
     delete m_texture;
@@ -92,13 +104,37 @@ GLWidget::~GLWidget()
     delete m_vao;
 }
 
-void GLWidget::setZ(float v)
+void GLWindow::startSecondStage()
+{
+    QPropertyAnimation* r2Anim = new QPropertyAnimation(this, QByteArrayLiteral("r2"));
+    r2Anim->setStartValue(0.0f);
+    r2Anim->setEndValue(360.0f);
+    r2Anim->setDuration(20000);
+    r2Anim->setLoopCount(-1);
+    r2Anim->start();
+}
+
+void GLWindow::setZ(float v)
 {
     m_eye.setZ(v);
     m_uniformsDirty = true;
     update();
 }
 
+void GLWindow::setR(float v)
+{
+    m_r = v;
+    m_uniformsDirty = true;
+    update();
+}
+
+void GLWindow::setR2(float v)
+{
+    m_r2 = v;
+    m_uniformsDirty = true;
+    update();
+}
+
 static const char *vertexShaderSource =
     "layout(location = 0) in vec4 vertex;\n"
     "layout(location = 1) in vec3 normal;\n"
@@ -108,11 +144,13 @@ static const char *vertexShaderSource =
     "uniform mat4 projMatrix;\n"
     "uniform mat4 camMatrix;\n"
     "uniform mat4 worldMatrix;\n"
+    "uniform mat4 myMatrix;\n"
     "uniform sampler2D sampler;\n"
     "void main() {\n"
     "   ivec2 pos = ivec2(gl_InstanceID % 32, gl_InstanceID / 32);\n"
-    "   vec2 t = vec2(-16 + pos.x, -18 + pos.y);\n"
+    "   vec2 t = vec2(float(-16 + pos.x) * 0.8, float(-18 + pos.y) * 0.6);\n"
-    "   mat4 wm = mat4(1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, t.x, t.y, 0, 1) * worldMatrix;\n"
+    "   float val = 2.0 * length(texelFetch(sampler, pos, 0).rgb);\n"
+    "   mat4 wm = myMatrix * mat4(1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, t.x, t.y, val, 1) * worldMatrix;\n"
     "   color = texelFetch(sampler, pos, 0).rgb * vec3(0.4, 1.0, 0.0);\n"
     "   vert = vec3(wm * vertex);\n"
     "   vertNormal = mat3(transpose(inverse(wm))) * normal;\n"
@@ -145,7 +183,7 @@ QByteArray versionedShaderCode(const char *src)
     return versionedSrc;
 }
 
-void GLWidget::initializeGL()
+void GLWindow::initializeGL()
 {
     QOpenGLFunctions *f = QOpenGLContext::currentContext()->functions();
 
@@ -171,6 +209,7 @@ void GLWidget::initializeGL()
     m_projMatrixLoc = m_program->uniformLocation("projMatrix");
     m_camMatrixLoc = m_program->uniformLocation("camMatrix");
     m_worldMatrixLoc = m_program->uniformLocation("worldMatrix");
+    m_myMatrixLoc = m_program->uniformLocation("myMatrix");
     m_lightPosLoc = m_program->uniformLocation("lightPos");
 
     // Create a VAO. Not strictly required for ES 3, but it is for plain OpenGL.
@@ -201,14 +240,14 @@ void GLWidget::initializeGL()
     f->glEnable(GL_CULL_FACE);
 }
 
-void GLWidget::resizeGL(int w, int h)
+void GLWindow::resizeGL(int w, int h)
 {
     m_proj.setToIdentity();
     m_proj.perspective(45.0f, GLfloat(w) / h, 0.01f, 100.0f);
     m_uniformsDirty = true;
 }
 
-void GLWidget::paintGL()
+void GLWindow::paintGL()
 {
     // Now use QOpenGLExtraFunctions instead of QOpenGLFunctions as we want to
     // do more than what GL(ES) 2.0 offers.
@@ -226,7 +265,13 @@ void GLWidget::paintGL()
         camera.lookAt(m_eye, m_eye + m_target, QVector3D(0, 1, 0));
         m_program->setUniformValue(m_projMatrixLoc, m_proj);
         m_program->setUniformValue(m_camMatrixLoc, camera);
-        m_program->setUniformValue(m_worldMatrixLoc, m_world);
+        QMatrix4x4 wm = m_world;
+        wm.rotate(m_r, 1, 1, 0);
+        m_program->setUniformValue(m_worldMatrixLoc, wm);
+        QMatrix4x4 mm;
+        mm.setToIdentity();
+        mm.rotate(-m_r2, 1, 0, 0);
+        m_program->setUniformValue(m_myMatrixLoc, mm);
         m_program->setUniformValue(m_lightPosLoc, QVector3D(0, 0, 70));
     }
 

examples/opengl/hellogles3/glwindow.h

@@ -41,7 +41,7 @@
 #ifndef GLWIDGET_H
 #define GLWIDGET_H
 
-#include <QOpenGLWidget>
+#include <QOpenGLWindow>
 #include <QMatrix4x4>
 #include <QVector3D>
 #include "../hellogl2/logo.h"
@@ -51,14 +51,16 @@ class QOpenGLShaderProgram;
 class QOpenGLBuffer;
 class QOpenGLVertexArrayObject;
 
-class GLWidget : public QOpenGLWidget
+class GLWindow : public QOpenGLWindow
 {
     Q_OBJECT
     Q_PROPERTY(float z READ z WRITE setZ)
+    Q_PROPERTY(float r READ r WRITE setR)
+    Q_PROPERTY(float r2 READ r2 WRITE setR2)
 
 public:
-    GLWidget();
+    GLWindow();
-    ~GLWidget();
+    ~GLWindow();
 
     void initializeGL();
     void resizeGL(int w, int h);
@@ -67,6 +69,12 @@ public:
     float z() const { return m_eye.z(); }
     void setZ(float v);
 
+    float r() const { return m_r; }
+    void setR(float v);
+    float r2() const { return m_r2; }
+    void setR2(float v);
+private slots:
+    void startSecondStage();
 private:
     QOpenGLTexture *m_texture;
     QOpenGLShaderProgram *m_program;
@@ -76,12 +84,15 @@ private:
     int m_projMatrixLoc;
     int m_camMatrixLoc;
     int m_worldMatrixLoc;
+    int m_myMatrixLoc;
     int m_lightPosLoc;
     QMatrix4x4 m_proj;
     QMatrix4x4 m_world;
     QVector3D m_eye;
     QVector3D m_target;
     bool m_uniformsDirty;
+    float m_r;
+    float m_r2;
 };
 
 #endif

examples/opengl/hellogles3/hellogles3.pro

@@ -1,14 +1,10 @@
-HEADERS = $$PWD/glwidget.h \
+HEADERS = $$PWD/glwindow.h \
-          $$PWD/mainwindow.h \
           $$PWD/../hellogl2/logo.h
 
-SOURCES = $$PWD/glwidget.cpp \
+SOURCES = $$PWD/glwindow.cpp \
           $$PWD/main.cpp \
-          $$PWD/mainwindow.cpp \
           $$PWD/../hellogl2/logo.cpp
 
-QT += widgets
-
 RESOURCES += hellogles3.qrc
 
 target.path = $$[QT_INSTALL_EXAMPLES]/opengl/hellogles3

examples/opengl/hellogles3/main.cpp

@@ -38,11 +38,11 @@
 **
 ****************************************************************************/
 
-#include <QApplication>
+#include <QGuiApplication>
 #include <QSurfaceFormat>
 #include <QOpenGLContext>
 
-#include "mainwindow.h"
+#include "glwindow.h"
 
 // This example demonstrates easy, cross-platform usage of OpenGL ES 3.0 functions via
 // QOpenGLExtraFunctions in an application that works identically on desktop platforms
@@ -69,10 +69,10 @@ int main(int argc, char *argv[])
 
     QSurfaceFormat::setDefaultFormat(fmt);
 
-    QApplication app(argc, argv);
+    QGuiApplication app(argc, argv);
 
-    MainWindow mainWindow;
+    GLWindow glWindow;
-    mainWindow.showMaximized();
+    glWindow.showMaximized();
 
     return app.exec();
 }

examples/opengl/hellogles3/mainwindow.cpp

@@ -1,58 +0,0 @@
-/****************************************************************************
-**
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
-**
-** This file is part of the examples of the Qt Toolkit.
-**
-** $QT_BEGIN_LICENSE:BSD$
-** 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 "mainwindow.h"
-#include "glwidget.h"
-#include <QApplication>
-#include <QMenuBar>
-#include <QMenu>
-
-MainWindow::MainWindow()
-{
-    QMenuBar *menuBar = new QMenuBar;
-    QMenu *menuWindow = menuBar->addMenu(tr("&File"));
-    QAction *exitAction = new QAction(menuWindow);
-    exitAction->setText(tr("E&xit"));
-    menuWindow->addAction(exitAction);
-    connect(exitAction, SIGNAL(triggered()), qApp, SLOT(quit()));
-    setMenuBar(menuBar);
-
-    setCentralWidget(new GLWidget);
-}

examples/opengl/hellogles3/mainwindow.h

@@ -1,54 +0,0 @@
-/****************************************************************************
-**
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
-**
-** This file is part of the examples of the Qt Toolkit.
-**
-** $QT_BEGIN_LICENSE:BSD$
-** 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."
-**
-** $QT_END_LICENSE$
-**
-****************************************************************************/
-
-#ifndef MAINWINDOW_H
-#define MAINWINDOW_H
-
-#include <QMainWindow>
-
-class MainWindow : public QMainWindow
-{
-    Q_OBJECT
-
-public:
-    MainWindow();
-};
-
-#endif