No, I need to get off my duff and post some 8^)

-Casey

On Sat, Nov 22, 2008 at 8:45 AM, Jonathan Hartley <[EMAIL PROTECTED]> wrote:
>
> Hey Casey. Py-lepton looks cool. Are there any screenshots of it in
> action? I couldn't spot any on the project page.
>
>
>
> On Nov 20, 9:35 pm, "Casey Duncan" <[EMAIL PROTECTED]> wrote:
>> Here's a recent project I've been working on in python/C for games:
>>
>> http://code.google.com/p/py-lepton/source/browse/trunk/
>>
>> Note there is nothing os x specific about it other than the location
>> of some include and library directories in setup.py because it depends
>> on the OpenGL C API. Everything else is vanilla distutils.
>>
>> -Casey
>>
>> On Thu, Nov 20, 2008 at 2:16 PM, Steve <[EMAIL PROTECTED]> wrote:
>>
>> > On Nov 20, 3:13 pm, "Casey Duncan" <[EMAIL PROTECTED]> wrote:
>> >> Here's one way you could do it:
>>
>> >> Grab a texture from the buffer that is the bounding box of your lasso 
>> >> selection.
>> >> Make a lasso mask that is white only inside the selection
>> >> draw the mask into the stencil buffer
>> >> draw the rectangular texture you grabbed (with the stencil test on)
>> >> into your destination buffer
>>
>> > The stencil buffer is just what I needed. This example makes it very
>> > easy to understand:
>> >http://pseudogreen.org/bzr/pyglet_superbible/ch03/stencil.py
>>
>> > My test code ended up looking like this (graphics lib more or less
>> > wraps some basic pyglet/OpenGL calls):
>> >        pyglet.gl.glClearStencil(0)
>> >        pyglet.gl.glEnable(pyglet.gl.GL_STENCIL_TEST)
>> >        pyglet.gl.glClear(pyglet.gl.GL_STENCIL_BUFFER_BIT)
>> >        pyglet.gl.glStencilFunc(pyglet.gl.GL_NEVER, 0x0, 0x0)
>> >        pyglet.gl.glStencilOp(pyglet.gl.GL_INCR, pyglet.gl.GL_INCR,
>> > pyglet.gl.GL_INCR)
>>
>> >        graphics.set_color(1,1,1,1)
>> >        graphics.draw_rect(self.x1,self.y1,self.x2,self.y2)
>> >        graphics.set_color(0,0,0,1)
>> >        graphics.draw_ellipse(self.x1,self.y1,self.x2,self.y2)
>> >        pyglet.gl.glStencilFunc(pyglet.gl.GL_NOTEQUAL, 0x1, 0x1)
>> >        pyglet.gl.glStencilOp(pyglet.gl.GL_KEEP, pyglet.gl.GL_KEEP,
>> > pyglet.gl.GL_KEEP)
>> >        graphics.set_color(1,1,1,1)
>> >        graphics.draw_image(self.selection, self.x1, self.y1)
>> >        pyglet.gl.glDisable(pyglet.gl.GL_STENCIL_TEST)
>> > That code draws an oval-shaped section of the image self.selection.
>>
>> > On Nov 20, 3:16 pm, "Tristam MacDonald" <[EMAIL PROTECTED]> wrote:
>> >> For a really simple approach, you can use multi-texturing with
>> >> multiplicative blending against a mask texture. This will mask any areas
>> >> where the mask texture is 0, and leave any areas where it is 1, but it may
>> >> not be the most flexible approach.
>> > I couldn't find any useful information about this method with a
>> > rudimentary web search.
>>
>> >> If you are using shaders, you can use a mask texture and a pixel shader to
>> >> render only the unmasked portion of another texture (use the discard
>> >> instruction for masked pixels).
>>
>> >> If you aren't using shaders, you may be able to work something out with 
>> >> the
>> >> stencil buffer, although this wont be as straightforward.
>> > My OpenGL knowledge is scattered and specialized, so I'm not using
>> > shaders. The stencil buffer method was actually very straightforward:
>> > use boilerplate setup code, draw mask, then more boilerplate, then
>> > draw stuff, then more boilerplate.
>>
>> >> C extensions are pretty much identical on OS X to linux, although you do
>> >> need to pass the compiler a few different options. If you need help
>> >> constructing a makefile for a C extension, I have several extension 
>> >> modules
>> >> building cross-platform, so I can probably explain the process.
>> > I tried looking for examples a few days ago but couldn't find anything
>> > more recent than OS X 10.2, which had a much earlier version of
>> > Python. Links to examples would be much appreciated. I'm decent with
>> > C, but have used it primarily for homework assignments, so for now I'm
>> > considering a C extension to be out of the scope of this project.
> >
>

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