[Freeciv-Dev] (PR#1180) canvas_to_map_pos() off by one

["a-l@xxxxxxx" <a-l@xxxxxxx>]

1 year+ old issue.

In isometric mode, this operation still decreases tile_x by 1:

{
  map_to_canvas_pos(&canvas_x, &canvas_y, tile_x, tile_y);
  canvas_to_map_pos(&tile_x, &tile_y, canvas_x, canvas_y);
}

I work around the problem like this:

{
  map_to_canvas_pos(&canvas_x, &canvas_y, tile_x, tile_y);
  canvas_x += NORMAL_TILE_WIDTH / 2;
  canvas_to_map_pos(&tile_x, &tile_y, canvas_x, canvas_y);
}


Arnstein