added camera pan for parallax and improved line drawing with preview line

engine/canvas.h

@@ -39,6 +39,7 @@ class Canvas
     Plane m_plane_brush;
     BrushMesh m_mesh;
     bool m_dirty = false;
+    bool m_commit_delayed = false;
 public:
     static Canvas* I;
     bool m_alpha_lock = false;
@@ -67,9 +68,10 @@ public:
     Sampler m_sampler_bg;
     Sampler m_sampler_mask;
     glm::vec2 m_cam_rot;
+    glm::vec3 m_cam_pos;
     float m_cam_fov = 85;
 
-    enum class kCanvasMode { Draw, Erase, Line, Camera };
+    enum class kCanvasMode { Draw, Erase, Line, Camera, COUNT };
     kCanvasMode m_state{ kCanvasMode::Draw };
     static std::vector<CanvasMode*> modes[];
     std::vector<CanvasMode*>* m_mode;