added Normal lines mode for perspective aligned lines

engine/canvas.h

@@ -71,7 +71,7 @@ public:
     glm::vec3 m_cam_pos;
     float m_cam_fov = 85;
 
-    enum class kCanvasMode { Draw, Erase, Line, Camera, COUNT };
+    enum class kCanvasMode { Draw, Erase, Line, Camera, Normal, COUNT };
     kCanvasMode m_state{ kCanvasMode::Draw };
     static std::vector<CanvasMode*> modes[];
     std::vector<CanvasMode*>* m_mode;
@@ -106,6 +106,15 @@ public:
     ui::Image thumbnail_generate(int w, int h);
     ui::Image thumbnail_read(std::string data_path);
     void preview_generate();
+    void draw_objects(std::function<void(const glm::mat4& camera, const glm::mat4& proj)>);
+    bool ray_intersect(glm::vec3 ray_origin, glm::vec3 ray_dir, glm::vec3 plane_origin,
+                          glm::vec3 plane_normal, glm::vec3 plane_tangent, glm::vec3 &out_hit);
+    void point_unproject(glm::vec2 loc, glm::vec4 vp, glm::mat4 camera, glm::mat4 proj,
+                         glm::vec3 &out_origin, glm::vec3 &out_dir);
+    bool point_trace(glm::vec2 loc, glm::vec3& ray_origin, glm::vec3& ray_dir,
+                     glm::vec3& hit_pos, glm::vec3& hit_normal, int& out_plane_id);
+    bool point_trace_plane(glm::vec2 loc, glm::vec3& ray_origin, glm::vec3& ray_dir,
+                     glm::vec3& hit_pos, glm::vec3& hit_normal, int plane_id);
 };
 
 class ActionStroke : public Action