refactor: Extract camera logic to Camera class

Co-authored-by: aider (gemini/gemini-2.5-pro) <aider@aider.chat>

src/Camera.h

@@ -0,0 +1,64 @@
+#ifndef CAMERA_H
+#define CAMERA_H
+
+#include <QObject>
+#include <QMatrix4x4>
+#include <QPoint>
+#include <QMouseEvent>
+#include <QWheelEvent>
+
+class Camera : public QObject
+{
+    Q_OBJECT
+    Q_PROPERTY(float xRotation READ xRotation WRITE setXRotation)
+    Q_PROPERTY(float yRotation READ yRotation WRITE setYRotation)
+    Q_PROPERTY(float zoom READ zoom WRITE setZoom)
+    Q_PROPERTY(float panX READ panX WRITE setPanX)
+    Q_PROPERTY(float panY READ panY WRITE setPanY)
+
+public:
+    explicit Camera(QObject *parent = nullptr);
+
+    void processMouseMovement(QMouseEvent* event, const QPoint& lastPos);
+    void processWheel(QWheelEvent* event);
+
+    QMatrix4x4 modelViewMatrix() const;
+
+    float xRotation() const;
+    void setXRotation(float angle);
+    float yRotation() const;
+    void setYRotation(float angle);
+    float zoom() const;
+    void setZoom(float value);
+    float panX() const;
+    void setPanX(float value);
+    float panY() const;
+    void setPanY(float value);
+
+    void saveState();
+    void restoreState();
+
+    float savedXRot() const { return m_savedXRot; }
+    float savedYRot() const { return m_savedYRot; }
+    float savedZoom() const { return m_savedZoom; }
+    float savedPanX() const { return m_savedPanX; }
+    float savedPanY() const { return m_savedPanY; }
+
+signals:
+    void cameraChanged();
+
+private:
+    float m_xRot;
+    float m_yRot;
+    float m_zoom;
+    float m_panX;
+    float m_panY;
+
+    float m_savedXRot = 0;
+    float m_savedYRot = 0;
+    float m_savedZoom = -5.0f;
+    float m_savedPanX = 0;
+    float m_savedPanY = 0;
+};
+
+#endif // CAMERA_H