[GEM-dev] automated drawing in gem?

[Alexandre Quessy]

Hi,
I think such a scripting possibility is a must.

Shaders are very - very- nice. They can allow you to modify the
vertices (vertex shader) and textures (fragment shader) you send it.
Furthermore, you can make it compute stuff, such as even physical
simulation, on the GPU. What we need is an extendable way to create
those vertices, and to choose the texture we put on it. By etendable,
I mean that using a lot of [coll], [list] or so, and then [unpack]ing
them is not so scalable. When you have something like 15 parameters on
a sprite (a geo with a texture on it), you need something like a
scripting language to keep track of the states, variables, changes,
and such.

Now, if we call the void gl_lua::render(GemState *state) method of a
gl_lua Gem object, and then call a lua function that draws vertices
with a texture id (according to the GemState object attributes we pass
it, I guess), would the result be drawn in the Gem window ?

I mean using the http://luagl.wikidot.com/ functions. I wonder if
calling those :
"""
gl.Begin("LINES")
gl.Color(1, 1, 0)
gl.Vertex(0, 0)
gl.Vertex(1, 1)
gl.End()
""""
... would work out-of-the-box. Would it ?
If so, that worth it. :)

a


2007/9/16, marius schebella <marius.schebella at gmail.com>:
> alexandre,
> at exactly this minute I was looking at exactly the same stuff, you just
> posted...
> a jit.gl.lua for gem (gl) would be cool. or python, but some scripting
> for gl would be cool. I still did not look into the shader language,
> maybe I will do this now...
> marius.
>
> Alexandre Quessy wrote:
> > Hi!
> > Otherwise, use pix_set, or so. Of course, there could be some kind of
> > QuickDraw-like (tm Apple computer) commands in an object, or an object
> > to which we can send OpenGL-like commands, such as Jitter's
> > http://www.cycling74.com/documentation/jit.gl.sketch ... I might be
> > interested on making one some day. We will see if I get some free
> > time... :)
> >
> > Actually, I am more interested in a Lua wrapper, from which we could
> > use the OpenGL functions which would be rendered in the same render
> > context than Gem's. Would it be easy? ClaudiusMaximus has started a
> > wrapper for Lua, and I wonder if that would be easy to do. Wesley
> > Smith has done the jit.gl.lua external ( see
> > http://www.cycling74.com/twiki/bin/view/Share/WesleySmith ) which
> > extends really well Jitter. It is not free (neither is Jitter), but it
> > is a proof that adding some script language to a dataflow software
> > makes things way easier when trying to make complex animations !!
> > Calling OpenGL functions in text is nice, you know ! Way faster than
> > using pd messages.
> >
> > See : http://luagl.wikidot.com/
> >
> > a
> >
> >
>
>


-- 
Alexandre Quessy
http://alexandre.quessy.net
http://www.puredata.info/Members/aalex