1 files changed, 103 insertions, 0 deletions
diff --git a/src/datavis3d/utils/camerahelper.cpp b/src/datavis3d/utils/camerahelper.cpp
new file mode 100644
index 00000000..be71d127
--- /dev/null
+++ b/src/datavis3d/utils/camerahelper.cpp
@@ -0,0 +1,103 @@
+#include "camerahelper_p.h"
+
+#include <QMatrix4x4>
+#include <QVector3D>
+
+QTCOMMERCIALDATAVIS3D_BEGIN_NAMESPACE
+
+// Initial camera position
+QVector3D m_position = QVector3D(0, 0.25, 3);
+QVector3D m_target = QVector3D(0, 0, 0);
+QVector3D m_up = QVector3D(0, 1, 0);
+
+QPoint m_previousMousePos(0, 0);
+
+float m_xRotation = 0;
+float m_yRotation = 0;
+float m_defaultXRotation = 0;
+float m_defaultYRotation = 0;
+
+float m_pi = 3.1415926535897932384626433832795028841971693993751058209749445923078164062862089986280348253421170679f;
+float m_rotationSpeed = 100;
+
+// FUNCTIONS
+void CameraHelper::setRotationSpeed(int speed)
+{
+    // increase for faster rotation
+    m_rotationSpeed = speed;
+}
+
+void CameraHelper::setCameraRotation(QPointF rotation)
+{
+    m_xRotation = rotation.x();
+    m_defaultXRotation = m_xRotation;
+    m_yRotation = rotation.y();
+    m_defaultYRotation = m_yRotation;
+}
+
+void CameraHelper::setDefaultCameraOrientation(QVector3D defaultPosition
+                                               , QVector3D defaultTarget
+                                               , QVector3D defaultUp)
+{
+    m_position = defaultPosition;
+    m_target = defaultTarget;
+    m_up = defaultUp;
+}
+
+QMatrix4x4 CameraHelper::calculateViewMatrix(QPoint mousePos, int zoom, int screenWidth, int screenHeight)
+{
+    QMatrix4x4 viewMatrix;
+
+    // Calculate mouse movement since last frame
+    float mouseMoveX = float(m_previousMousePos.x() - mousePos.x())
+            / (screenWidth / m_rotationSpeed);
+    float mouseMoveY = float(m_previousMousePos.y() - mousePos.y())
+            / (screenHeight / m_rotationSpeed);
+    // Apply to rotations
+    m_xRotation -= mouseMoveX;
+    m_yRotation -= mouseMoveY;
+    // Reset at 360 in x and limit to 0...90 in y
+    if (fabs(m_xRotation) >= 360)
+        m_xRotation = 0;
+    if (m_yRotation >= 90) {
+        m_yRotation = 90;
+    }
+    else if (m_yRotation <= 0) {
+        m_yRotation = 0;
+    }
+
+    // Apply to view matrix
+    viewMatrix.lookAt(
+                m_position                  // Camera is here
+                , m_target                  // and looks here
+                , m_up                      // Head is up (set to 0,-1,0 to look upside-down)
+                );
+    // Apply rotations
+    // Handle x and z rotation when y -angle is other than 0
+    viewMatrix.rotate(m_xRotation, 0, cos(m_yRotation*m_pi/180), sin(m_yRotation*m_pi/180));
+    // y rotation is always "clean"
+    viewMatrix.rotate(m_yRotation, 1.0f, 0, 0);
+    // handle zoom by scaling
+    viewMatrix.scale((float)zoom / 100.0f);
+    //qDebug() << m_xRotation << m_yRotation;
+
+    //qDebug() << "sin(m_yRotation)" << sin(m_yRotation*m_pi/180);
+    //qDebug() << "asin(m_yRotation)" << asin(m_yRotation*m_pi/180);
+    //qDebug() << "cos(m_yRotation)" << cos(m_yRotation*m_pi/180);
+    //qDebug() << "tan(m_yRotation)" << tan(m_yRotation*m_pi/180);
+
+    m_previousMousePos = mousePos;
+    return viewMatrix;
+}
+
+void CameraHelper::updateMousePos(QPoint mousePos)
+{
+    m_previousMousePos = mousePos;
+    // if mouse position is set to (0, 0), reset rotations
+    if (QPoint(0, 0) == mousePos) {
+        m_xRotation = m_defaultXRotation;
+        m_yRotation = m_defaultYRotation;
+    }
+}
+
+QTCOMMERCIALDATAVIS3D_END_NAMESPACE