Setting a 1:1 perspective tells GL to make x=y in units even though the ratio is 1.33:1 in the display. By not doing this rectangle 1 1 would be drawn to match the 4:3 ratio of the window (although the default in GEM is x=y so you have to change it to something other than 1:1 to have this happen).
The test2 patch resets some of the ratios to 1:1 so the perspective corrects that back to fit the window, otherwise the square is taller than it is wide.
Hopefully I didn't make this more confusing.
On 5/13/07, cyrille henry <cyrille.henry@la-kitchen.fr> wrote:
chris clepper a écrit :
> You are wondering why a 1:1 perspective works for a 4:3 window?
>
yes.
cyrille