[Freeciv-Dev] Re: (PR#4648) how to do wrapping in map_to_canvas_pos?

["Jason Short" <jdorje@xxxxxxxxxxxxxxxxxxxxx>]

rwetmore@xxxxxxxxxxxx wrote:
> Jason Short wrote:
> 
>>rwetmore@xxxxxxxxxxxx wrote:
> 
> [...]
> 
>>But if you base your calculations off of the center tile this problem 
>>becomes moot.  In fact it fixes another problem as well: in iso view 
>>with unnormalize_map_pos the top and left row of tiles will always be 
>>drawn halfway out of sight, no matter how large the mapview window 
>>becomes.  By using the center tile as origin we guarantee that the set 
>>of positions we draw is always centered on the mapview.
> 
> Maybe, but it is as easy to fix the GUI code to use top-left as it is
> center offsets - I take it back, it is easier to use top-left, as this
> is standard array index looping with no negative offsets that screwup
> DIV scaling and such.

This is complete FUD.  There is no difference in negative offset 
division in the two systems.

> Your claim about things never being drawn right is a GUI code problem
> not unnormalize though. It should be fixed in the GUI code. Hopefully
> you have some ideas from this though.

I have fixed it in the GUI by using map_distance_vector instead of 
unnormalize_map_pos...

jason