refactor: Extract camera logic to Camera class

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

src/Camera.cpp

@@ -0,0 +1,111 @@
+#include "Camera.h"
+#include <QApplication>
+#include <QWheelEvent>
+
+Camera::Camera(QObject *parent) : QObject(parent)
+{
+    // Set initial view to an isometric angle on the XY plane
+    m_xRot = 30 * 16;
+    m_yRot = -45 * 16;
+    m_zoom = -20.0f;
+    m_panX = 0.0f;
+    m_panY = 0.0f;
+}
+
+void Camera::processMouseMovement(QMouseEvent* event, const QPoint& lastPos)
+{
+    int dx = event->pos().x() - lastPos.x();
+    int dy = event->pos().y() - lastPos.y();
+
+    if (event->buttons() & Qt::MiddleButton) {
+        if (QApplication::keyboardModifiers() & Qt::ShiftModifier) {
+            // Pan
+            setPanX(m_panX + dx / 100.0f);
+            setPanY(m_panY - dy / 100.0f);
+        } else {
+            // Rotate
+            setXRotation(m_xRot + 8 * dy);
+            setYRotation(m_yRot + 8 * dx);
+        }
+    }
+}
+
+void Camera::processWheel(QWheelEvent* event)
+{
+    QPoint numDegrees = event->angleDelta() / 8;
+    if (!numDegrees.isNull()) {
+        setZoom(m_zoom + numDegrees.y() / 5.0f);
+    }
+}
+
+QMatrix4x4 Camera::modelViewMatrix() const
+{
+    QMatrix4x4 model;
+    model.translate(m_panX, m_panY, m_zoom);
+    model.rotate(m_xRot / 16.0f, 1, 0, 0);
+    model.rotate(m_yRot / 16.0f, 0, 1, 0);
+    return model;
+}
+
+float Camera::xRotation() const { return m_xRot; }
+void Camera::setXRotation(float angle)
+{
+    if (angle != m_xRot) {
+        m_xRot = angle;
+        emit cameraChanged();
+    }
+}
+
+float Camera::yRotation() const { return m_yRot; }
+void Camera::setYRotation(float angle)
+{
+    if (angle != m_yRot) {
+        m_yRot = angle;
+        emit cameraChanged();
+    }
+}
+
+float Camera::zoom() const { return m_zoom; }
+void Camera::setZoom(float value)
+{
+    if (value != m_zoom) {
+        m_zoom = value;
+        emit cameraChanged();
+    }
+}
+
+float Camera::panX() const { return m_panX; }
+void Camera::setPanX(float value)
+{
+    if (value != m_panX) {
+        m_panX = value;
+        emit cameraChanged();
+    }
+}
+
+float Camera::panY() const { return m_panY; }
+void Camera::setPanY(float value)
+{
+    if (value != m_panY) {
+        m_panY = value;
+        emit cameraChanged();
+    }
+}
+
+void Camera::saveState()
+{
+    m_savedXRot = m_xRot;
+    m_savedYRot = m_yRot;
+    m_savedPanX = m_panX;
+    m_savedPanY = m_panY;
+    m_savedZoom = m_zoom;
+}
+
+void Camera::restoreState()
+{
+    setXRotation(m_savedXRot);
+    setYRotation(m_savedYRot);
+    setPanX(m_savedPanX);
+    setPanY(m_savedPanY);
+    setZoom(m_savedZoom);
+}