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-rw-r--r--examples/opengl/cube/mainwidget.cpp192
1 files changed, 192 insertions, 0 deletions
diff --git a/examples/opengl/cube/mainwidget.cpp b/examples/opengl/cube/mainwidget.cpp
new file mode 100644
index 0000000000..bead5f79ed
--- /dev/null
+++ b/examples/opengl/cube/mainwidget.cpp
@@ -0,0 +1,192 @@
+#include "mainwidget.h"
+
+#include "geometryengine.h"
+
+#include <QtOpenGL/QGLShaderProgram>
+
+#include <QBasicTimer>
+#include <QMouseEvent>
+
+#include <math.h>
+
+#include <QDebug>
+
+MainWidget::MainWidget(QWidget *parent) :
+ QGLWidget(parent),
+ timer(new QBasicTimer),
+ program(new QGLShaderProgram),
+ geometries(new GeometryEngine)
+{
+}
+
+MainWidget::~MainWidget()
+{
+ delete timer; timer = 0;
+ delete program; program = 0;
+ delete geometries; geometries = 0;
+
+ deleteTexture(texture);
+}
+
+//! [0]
+void MainWidget::mousePressEvent(QMouseEvent *e)
+{
+ // Saving mouse press position
+ mousePressPosition = QVector2D(e->posF());
+}
+
+void MainWidget::mouseReleaseEvent(QMouseEvent *e)
+{
+ // Mouse release position - mouse press position
+ QVector2D diff = QVector2D(e->posF()) - mousePressPosition;
+
+ // Rotation axis is perpendicular to the mouse position difference
+ // vector
+ QVector3D n = QVector3D(diff.y(), diff.x(), 0.0).normalized();
+
+ // Accelerate angular speed relative to the length of the mouse sweep
+ qreal acc = diff.length() / 100.0;
+
+ // Calculate new rotation axis as weighted sum
+ rotationAxis = (rotationAxis * angularSpeed + n * acc).normalized();
+
+ // Increase angular speed
+ angularSpeed += acc;
+}
+//! [0]
+
+//! [1]
+void MainWidget::timerEvent(QTimerEvent *e)
+{
+ Q_UNUSED(e);
+
+ // Decrease angular speed (friction)
+ angularSpeed *= 0.99;
+
+ // Stop rotation when speed goes below threshold
+ if (angularSpeed < 0.01)
+ angularSpeed = 0.0;
+ else {
+ // Update rotation
+ rotation = QQuaternion::fromAxisAndAngle(rotationAxis, angularSpeed) * rotation;
+
+ // Update scene
+ updateGL();
+ }
+}
+//! [1]
+
+void MainWidget::initializeGL()
+{
+ qglClearColor(Qt::black);
+
+ qDebug() << "Initializing shaders...";
+ initShaders();
+
+ qDebug() << "Initializing textures...";
+ initTextures();
+
+//! [2]
+ // Enable depth buffer
+ glEnable(GL_DEPTH_TEST);
+
+ // Enable back face culling
+ glEnable(GL_CULL_FACE);
+//! [2]
+
+ qDebug() << "Initializing geometries...";
+ geometries->init();
+
+ // using QBasicTimer because its faster that QTimer
+ timer->start(12, this);
+}
+
+//! [3]
+void MainWidget::initShaders()
+{
+ // Overriding system locale until shaders are compiled
+ setlocale(LC_NUMERIC, "C");
+
+ // Compiling vertex shader
+ if (!program->addShaderFromSourceFile(QGLShader::Vertex, ":/vshader.glsl"))
+ close();
+
+ // Compiling fragment shader
+ if (!program->addShaderFromSourceFile(QGLShader::Fragment, ":/fshader.glsl"))
+ close();
+
+ // Linking shader pipeline
+ if (!program->link())
+ close();
+
+ // Binding shader pipeline for use
+ if (!program->bind())
+ close();
+
+ // Restore system locale
+ setlocale(LC_ALL, "");
+}
+//! [3]
+
+//! [4]
+void MainWidget::initTextures()
+{
+ // Loading cube.png to texture unit 0
+ glActiveTexture(GL_TEXTURE0);
+ glEnable(GL_TEXTURE_2D);
+ texture = bindTexture(QImage(":/cube.png"));
+
+ // Set nearest filtering mode for texture minification
+ glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
+
+ // Set bilinear filtering mode for texture magnification
+ glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+
+ // Wrap texture coordinates by repeating
+ // f.ex. texture coordinate (1.1, 1.2) is same as (0.1, 0.2)
+ glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
+ glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
+}
+//! [4]
+
+//! [5]
+void MainWidget::resizeGL(int w, int h)
+{
+ // Set OpenGL viewport to cover whole widget
+ glViewport(0, 0, w, h);
+
+ // Calculate aspect ratio
+ qreal aspect = (qreal)w / ((qreal)h?h:1);
+
+ // Set near plane to 3.0, far plane to 7.0, field of view 45 degrees
+ const qreal zNear = 3.0, zFar = 7.0, fov = 45.0;
+
+ // Reset projection
+ projection.setToIdentity();
+
+ // Set perspective projection
+ projection.perspective(fov, aspect, zNear, zFar);
+}
+//! [5]
+
+void MainWidget::paintGL()
+{
+ // Clear color and depth buffer
+ glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+
+//! [6]
+ // Calculate model view transformation
+ QMatrix4x4 matrix;
+ matrix.translate(0.0, 0.0, -5.0);
+ matrix.rotate(rotation);
+
+ // Set modelview-projection matrix
+ program->setUniformValue("mvp_matrix", projection * matrix);
+//! [6]
+
+ // Using texture unit 0 which contains cube.png
+ program->setUniformValue("texture", 0);
+
+ // Draw cube geometry
+ geometries->drawCubeGeometry(program);
+}