[visionegg] Re: Mirroring a viewport?

Thanks! I tried the latter suggestion, and that worked out well. In case
it's useful for anybody, I've attached my code to this email.

On 9/5/07, Andrew Straw <astraw@xxxxxxxxxxx> wrote:
>
> If you're just trying to do a 2D rotation of an image, the easiest thing
> to do is simply to draw the corners of the textured quad in their new
> positions. If you want to draw everything in the viewport flipped, you
> could do something like use the OrthographicProjection class with the
> top and bottom coordinates flipped.
>
> I hope that helped...
>
> Cheers!
> Andrew
>
> Neil Halelamien wrote:
> > This is kind of a basic question, but how do I rotate/flip a viewport's
> > perspective? My OpenGL knowledge is pretty limited so I might be doing
> > something silly, but my attempts so far at using
> > view.parameters.projection.rotate () and
> > view.parameters.projection.stateless_rotate() on a viewport with default
> > parameters have just resulted in making the viewport invisible.
> >
> > On 9/4/07, * Andrew Straw* <astraw@xxxxxxxxxxx
> > <mailto:astraw@xxxxxxxxxxx>> wrote:
> >
> >     Hi Neil,
> >
> >     See the multi_stim.py demo, in particular the put_new_framebuffer()
> >     call.
> >
> >     -Andrew
> >
> >     Neil Halelamien wrote:
> >     > Quick question: What's a straightforward way to mirror the
> >     contents of a
> >     > viewport onto another part of the screen?
> >     >
> >     > -- Neil
> >
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> >
>
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# Includes utility function(s) for drawing mirrored/flipped viewports

try:
   import logging
except ImportError:
   import VisionEgg.py_logging as logging

import VisionEgg
import VisionEgg.Core
import VisionEgg.ParameterTypes as ve_types

def draw_mirrored_viewports(screen, view, flipaxes):
    """flipaxes is a list of (x,y) boolean pairs indicating axes to flip over,
    e.g. flipaxes=[(False,True), (False, False)] would draw flipped over
    y axis as well as without any flip at all.
    Assumption is that original axes in view are 1:1 with pixel coordinates
    """

    for a in flipaxes:
        left = 0
        right = screen.size[0]
        bottom = 0
        top = screen.size[1]
        
        if a[0]:
            left,right = right,left
        if a[1]:
            bottom,top = top,bottom
            
        tmp_proj = VisionEgg.Core.OrthographicProjection(left=left, right=right,
            bottom=bottom, top=top)
        tmp_view = VisionEgg.Core.Viewport(screen=screen, projection=tmp_proj,
            stimuli = view.parameters.stimuli)
        tmp_view.draw()

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