implement frame buffer fetch extension for iOS, change composition on stroke drawing and commit, add rename layer dialog

engine/canvas.h

@@ -82,6 +82,7 @@ public:
     kCanvasMode m_state{ kCanvasMode::Draw };
     static std::vector<CanvasMode*> modes[];
     std::vector<CanvasMode*>* m_mode = nullptr;
+    kCanvasMode m_current_mode = kCanvasMode::Draw;
     static void set_mode(kCanvasMode mode)
     {
         if (I->m_mode)
@@ -89,6 +90,7 @@ public:
                 m->leave();
         I->m_mode = &modes[(int)mode];
         I->m_state = mode;
+        I->m_current_mode = mode;
     }
 
     std::vector<Layer::Snapshot> m_layers_snapshot;
@@ -126,7 +128,7 @@ public:
     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);
+                     glm::vec3& hit_pos, glm::vec2& fb_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, glm::vec2& hit_fb_pos, int plane_id);
 };