cube to equirect conversion using shader, save latlong to file

engine/canvas.h

@@ -59,7 +59,10 @@ public:
     Sampler m_sampler_bg;
     glm::vec2 m_cam_rot;
     float m_cam_fov = 85;
-    
+
+    GLuint cube_id;
+    RTT m_latlong;
+
     std::vector<Layer::Snapshot> m_layers_snapshot;
 
     bool create(int width, int height);