save camera settings on selection to avoid different result when re-projecting the selection 2d screen points transformation (does not compile because of canvas.h cyclic dependency)

src/canvas.cpp

@@ -2143,6 +2143,48 @@ std::vector<glm::vec2> ui::Canvas::face_to_shape2D(int plane_index)
     return points;
 }
 
+void ui::Canvas::push_camera()
+{
+    m_camera_stack.push(get_camera());
+}
+
+void ui::Canvas::pop_camera()
+{
+    if (!m_camera_stack.empty())
+    {
+        set_camera(m_camera_stack.top());
+        m_camera_stack.pop();
+    }
+}
+
+ui::Canvas::CameraData ui::Canvas::get_camera()
+{
+    CameraData c;
+    c.m_box = m_box;
+    c.m_mv = m_mv;
+    c.m_pan = m_pan;
+    std::copy_n(m_plane_dir, 6, c.m_plane_dir);
+    std::copy_n(m_plane_unproject, 6, c.m_plane_unproject);
+    c.m_proj = m_proj;
+    c.m_vp = m_vp;
+    return c;
+}
+
+void ui::Canvas::set_camera(const ui::Canvas::CameraData& c)
+{
+    m_box = c.m_box;
+    m_mv = c.m_mv;
+    m_pan = c.m_pan;
+    std::copy_n(c.m_plane_dir, 6, m_plane_dir);
+    std::copy_n(c.m_plane_unproject, 6, m_plane_unproject);
+    m_proj = c.m_proj;
+    m_vp = c.m_vp;
+}
+
+void ui::Canvas::reset_camera()
+{
+}
+
 std::vector<vertex_t> ui::Canvas::triangulate_simple(const std::vector<vertex_t>& vertices)
 {
     std::vector<vertex_t> ret;