Re: [pygame] subsurfaces outside of their parents

[Kris Schnee <kschnee@xxxxxxxxxx>]

Forest Darling wrote:
> I want a subsurface to be the size/location that you ask it, even if
> it overlaps/is outside of the parent surface. Any pixels that are
> outside of the surface would be "dummy" pixels and any drawing to them
> would be ignored. The idea is to be able to draw to a surface (0,
> 0)through(10, 10) and on the parent surface have it be drawing (-5,
> -5)through(5, 5), and only (5, 5) --> (10, 10), which is (0, 0)
> through(5, 5) on the parent surface, would actually be drawing to
> non-dummy pixels. This might be really hackish though because what
> then if you were to blit this subsurface to another surface, with its
> dummy pixels? what would the dummy pixels show up as? I guess it
> simply wouldn't copy them... as if you had asked it to blit a smaller
> rect. I am mostly thinking about drawing aspect though...

I'm not sure why you'd want to do this, but maybe you could create a 
class that contains a surface and an offset marker, which affects where 
it's blitted onto its parent surface. So, make it whatever size you 
want, and when you call its Blit() function, it just blits onto the 
parent surface, harmlessly ignoring anything outside its own surface. I 
don't think the "harmlessly ignoring" part requires any special code; 
I've been messing with sprites that can get drawn outside the display 
surface.

(Why does the concept of "putting subsurfaces outside of their parents" 
sound like something a preacher would denounce as against God's will?)

Kris