Re: GnomeCanvasText behavioural change

[Keith Packard <keithp keithp com>]

On Mon, 2001-12-10 at 10:24, ERDI Gergo wrote:

> I'll never understand why one would want to scale text by rendering it
> into a bitmap and scaling that.
> What should be done is rendering it anti-aliased, at a _very large_ size, 
> into a greyscale pixbuf, and then translating that. Or maybe render the
> text with size = requested_size * zoom_factor

I suggest that you should probably always use FreeType to rasterize the
glyphs as this will avoid any pixelized edges.  It also uses an analytic 
algorithm to compute pixel coverage which generates reasonable AA results
much faster than supersampling and filtering.

The question then is whether you want to scale the fonts before or after 
hinting the glyphs -- if you scale beforehand, you'll get the best looking 
glyphs at any particular size.  If you scale afterwards, you'll get glyphs 
that look the same at any particular zoom factor, but which will 
invariably have fuzzy edges.

Xft lets you do either; it provides a pixel size and a separate affine 
transformation matrix.

Keith Packard        XFree86 Core Team        Compaq Cambridge Research Lab