Re: smooth shading & terminal specialities

[Ethan A M. <merritt@u.washington.edu>]

On Monday 08 May 2006 08:16 pm, Daniel J Sebald wrote:
> > be more proper to say
> >   if (!strcmp(term->name,"post") || !strcmp(term->name,"epslatex")
> >      || !strcmp(term->name,"pslatex") ....
> 
> Really?  I thought we're supposed to keep terminal-specific code 
> out of the core and override terminal functions. 

Right. I already pointed out that we had discussed making this
a terminal entry point. But since the only terminal that would
actually use it is post.trm, there wasn't much motion to add the
entry to all terminals.
 
> Well, doing it as an image, one would think that the viewer driver 
> knows to do proper anti-aliasing.  

One would think. 
But there is a known rendering bug in ghostscript's anti-aliasing code.

> >  One recent request (# 1480115) is to add support for an alpha channel.
> 
> Oh yeah, I forgot all about that.
> Am I right that the alpha would be a depth of four, one of the channels
> being 0/nonzero?  

Alpha runs from 0->1 (or 0-255 if it's a 1-byte representation).

> So maybe the syntax should be something like "with rgbaimage",
> or "with argbimage"?

You already wrote code to support in on input -

    binary filetype=avs with rgbimage

AVS files contains 4 bytes per pixel, ARGB.
But right now the Alpha byte is thrown away on input.

Suppose you were to keep the alpha byte in parallel with the
RGB bytes.  A few drivers (gd, svg) can use it directly.
But we'd have to add custom code in order to get most drivers to
handle transparency.

-- 
Ethan A Merritt
Biomolecular Structure Center
University of Washington, Seattle 98195-7742