# Re: [pygame] Native PyGame method for automatically scaling inputs to a surface resolution?

```On Tue, 27 Sep 2011 10:42:10 -0400
Christopher Night <cosmologicon@xxxxxxxxx> wrote:

> That's how I understood it... I'm not sure what I said that made it
> sound like I was thinking of a two-way transformation.... Let me try
> rephrasing my question using your notation. Please tell me what the
> following would output (where I have question marks), and tell me if
> you don't understand what I mean by the pseudocode:
>
> >>> init_surface(scale_factor = 0.1)
> >>> r1 = myrect(0, 0, 108, 10)
> >>> r1.left = 4
> >>> fill_rect(r1)
> >>> get_size_bounding_rect()
> ??? x ???

Hi Chris,

probably not very clear. I'm still not sure I got you, but here's a more
articulated example of what I mean, using standard pygame syntax (bar
the ``scale`` parameter):

>>> s1 = pygame.surface.Surface((100,100), scale=0.1)

This will initialise a surface of 10x10 px, "mapping" a 100x100 square.

>>> s1.get_bounding_rect()
<rect(0, 0, 10, 10)>

...because the image is 10x10 pixels.

>>> s2 = pygame.surface.Surface((100,100), scale=0.05)
>>> s2.get_bounding_rect()
<rect(0, 0, 5, 5)>
>>> s1.blit(s2, (20,20))
<rect(2, 2, 5, 5)>

...because the *INPUT* destination is "mapped" on s1, and the blit
method should return its *OUTPUT* in unmapped measures [pixels].

One thing that might have further confused the discussion is that
somewhere in an earlier mail I mentioned "rects". But all I meant was
really just the rects returned by this kind of operations. I was not
thinking to a new class of rects with scaling included.

I'm far from asserting that what above is the best way ever to
implement scaling in PyGame, but this is how I imagined it working. I'm
very open to hear alternative suggestions and feedback, of course! Also: