add history to guides

src/canvas_modes.h

@@ -3,6 +3,7 @@
 #include "shape.h"
 #include "brush.h"
 #include "texture.h"
+#include "action.h"
 #include <poly2tri.h>
 
 enum class kCanvasMode 
@@ -106,6 +107,7 @@ public:
     virtual void leave(kCanvasMode next) override;
 };
 
+struct ray_t { glm::vec3 o, d; };
 class CanvasModeGrid : public CanvasMode
 {
     LineSegment m_line;
@@ -113,15 +115,30 @@ class CanvasModeGrid : public CanvasMode
     glm::vec3 dir;
     int m_plane_id;
     bool m_dragging = false;
-    struct ray_t { glm::vec3 o, d; };
-    std::vector<ray_t> m_lines;
+    bool m_added = false;
+    std::unique_ptr<class ActionModeGrid> m_action;
 public:
+    bool m_highlight = false;
+    int m_selected_index;
+    std::vector<ray_t> m_lines;
     virtual void on_MouseEvent(MouseEvent* me, glm::vec2& loc) override;
+    virtual void on_KeyEvent(KeyEvent* ke) override;
     virtual void on_Draw(const glm::mat4& ortho, const glm::mat4& proj, const glm::mat4& camera) override;
     virtual void init() override;
     void commit();
     void clear();
 };
+struct ActionModeGrid : public Action
+{
+    CanvasModeGrid* m_mode;
+    bool m_highlight;
+    int m_selected_index;
+    std::vector<ray_t> m_lines;
+    virtual void run() override { }
+    virtual Action* get_redo() override;
+    virtual void undo() override;
+    virtual size_t memory() override { return 0; }
+};
 
 class CanvasModeCamera : public CanvasMode
 {