🚀 go-pugleaf

tvz@zandtwerk.Princeton.EDU () writes:
>Suppose that I want to put a star shape down at 100 or 200 points
>on a page. Which is better, to define a procedure that draws the
>star shape or to define a temporary font with the star shape?
>How much is the difference in terms of performance (memory/speed)?

With these parameters (and assuming that the star is not huge--i.e., that
it's small enough to fit in the font cache) you are much better off using a
font.

The procedure gets executed--all the rendering and rasterization--every
time.  The only thing you really save is in using "bind" to save some
operator lookups, and that's inconsequential compared to the character
rendering time.

With a font, the star character gets converted to a bitmap only once.
That's most of the work.  Then, each time you show the character, the bits
just get blopped into the page bitmap.
-- 
Dick Dunn    rcd@raven.eklektix.com   -or-   raven!rcd    Boulder, Colorado
				Cats!

In article <1992Aug27.070502@eklektix.com> rcd@raven.eklektix.com (Dick Dunn) writes:
>With a font, the star character gets converted to a bitmap only once.
>That's most of the work.  Then, each time you show the character, the bits
>just get blopped into the page bitmap.

One downside of this is if you're rendering to a low resolution device (like
a video screen) you get the same defects for every iteration, and you'll get
regular positioning errors that look like a wave going down the page.

Like everything else, there are a bunch of tradeoffs.
-- 
                                                                `-_-'
                         Have you hugged your wolf today?        'U`

Peter da Silva, Taronga Park BBS, Houston, TX  +1 713 568 0480/1032

In article <DTPIBNI@taronga.com> peter@taronga.com (Peter da Silva) writes:
>In article <1992Aug27.070502@eklektix.com> rcd@raven.eklektix.com (Dick Dunn) writes:
>>With a font, the star character gets converted to a bitmap only once.
>>That's most of the work.  Then, each time you show the character, the bits
>>just get blopped into the page bitmap.
>
>One downside of this is if you're rendering to a low resolution device (like
>a video screen) you get the same defects for every iteration

However, if you don't use a font you get different defects for every
iteration.  Rendering small objects at low resolution requires understanding
device space and how to snap points into it.  If you use a procedure, you
have to do the snapping for each iteration; with a font, you only need to do
it once.  See Chapter 7, "Drawing Small Objects," in "Programming the Display
PostScript System with NeXTstep" for the basic ideas.

__   -paul asente
\/     asente@adobe.com   ...decwrl!adobe!asente   moo-bear@cs.stanford.edu

The most dangerous creation of any society is that man who has
nothing to lose.				-James Baldwin