implement selection mask with lasso tool

engine/node_image.h

@@ -9,6 +9,7 @@ public:
     static ui::Plane m_plane;
     static Sampler m_sampler;
     bool m_use_atlas = false;
+    bool m_use_mipmaps = false;
     glm::vec4 m_region;
     glm::vec2 m_off;
     glm::vec2 m_sz;