Re: Simplified processing of image and rgbimage plots

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

On Sunday 19 November 2006 09:11 pm, Daniel J Sebald wrote:
> Ethan A Merritt wrote:
> 
> > We could do better.
> > 
> > PostScript supports the specification of a general transformation
> > matrix.  Rather than using individual filled_polygons
> > to draw a rgbimage in 3D, we could simply include a projection of
> > the 3x3 rotation matrix.
> 
> > I believe that PDF and SVG also benefit from this approach, but
> > I have not investigated fully.
> 
> But does the PDF library support translation matrices?

Yes. Exactly the same as PostScript:

void PDF_concat(PDF *p, double a, double b, double c, double d, double e, double f)
  Concatenate a matrix to the current transformation matrix.
  a, b, c, d, e, f Elements of a transformation matrix. 
  The six values make up a matrix in the same way as in PostScript and PDF 
  (see references). In order to avoid degenerate transformations, 
  a*d must not be equal to b*c.



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