wiki:wxGUIDevelopment/MapRendering

Version 2 (modified by wenzeslaus, 7 years ago) (diff)

rashadkm's notes moved from wxGUIAPIproposal

Map rendering

Introduction

  • probably a lot of I/O operations makes current system slow
  • affects both the main GUI and the wx-based d.mon

New Rendering Model

With the help of GRASS Python modules, It easy to pull chunks from raster data as Numpy array. A new rendering model (in-memory) can be added to wxGUI which can directly display a numpy array as wx.Image. This will obviously increase the performance of rendering layers because the overhead of reading and writing data to file (PNG adds a compression during packing and unpacking) can be saved. Also the extent based rendering will allow to read portion of raster image than whole dataset. Also a tile based technique can be added to this which improves the rendering performance further.

Basically this will do what d.rast or generally speaking d.* modules do. I agree adding other modules such as d.legend etc is a massive work. But compared to dealing with large dataset I think its worth it.

This is just a brief of what I have. I can provide further details if anyone is interested.