waba-spec

[Waba-spec] More on the graphics bug

[Sean L. <se...@cs...>]

I've checked to see what various JVMs do with regard to metrics for 
rects, ovals, arcs, lines, and roundRects.  The spec is a little obtuse, 
but here's what it appears to say:

0. Clips and filled objects go from (x,y) to (x+width-1,y+width-1) 
INCLUSIVE
1. Filled objects go from (x,y) to (x+width,y+width) INCLUSIVE

While practically every JVM is a little buggy with regard to the extents 
of roundrects, ovals, and arcs (!!), EVERY SINGLE JVM is consistent with 
regard to rects.  Unfortunately, Waba is not.  Waba presently implements 
its drawRect() as going from (x,y) to (x+width,y+width) inclusive.  I 
don't know if this was a bug or an intentional decision, but it's not a 
good thing, that's for dang sure.  Unfortunately, most Waba apps assume 
the incorrect measurements, while all portable Java apps assume the 
correct measurements, which means we may be royally screwed here.

I have created some Java code for people to test with.  The code draws a 
"bounds area", and then draws various objects such that they're supposed 
to fit just within the bounds area so that they just touch (but don't 
overwrite) the bounds area lines.  The objects are first drawn and then 
filled.  The filled version is supposed to fit just inside the drawn 
version and not overwrite it.

Waba for the Newton also appears to not handle clips right -- it's off 
by 1 on the top and left.  I don't know if this is a Newton bug or if 
it's a Waba bug (I only have Newtons); could someone run the code on a 
Palm/WinCE box and let me know?

Here's a version that you can compile and run on your JVM and see what 
it does.  I'd be interested in knowing about how Microsoft JVMs draw the 
ovals, arcs, and roundrects, because all I have here are Solaris, MacOS 
9, and MacOS X 10.1.  Send me some screenshots!

Re: [Waba-spec] More on the graphics bug

[Guilherme C. H. <gu...@us...>]

Hi,

      The tests run almost well. Here are the gifs. gta is graphic test in
appletviewer; gtp is gt in palm. The test 6 in palm gave me a pose warning
of writing in data manager structures. The Polygon routine is different
between palm and appletviewer, so thats why the differences. Please let me
know if any of the tests went as expected. The drawArc and fillPie (=
fillarc) algorithms were invented by a catedratic mathematic called
Guilherme Hazan. Eheheh... kidding. I had to create it bc i couldnt find any
one available. If anyone knows a free availabe one, please let me know.

       regards

             guich

Re: [Waba-spec] More on the graphics bug

[Sean L. <se...@cs...>]

Guilherme, if you could provide pictures for GraphicsTestApp.java (just 
run it as "java GraphicsTestApp"), I'd appreciate it.  Plus, you'll be 
able to see what the differences are between Java's correct output and 
the SuperWaba output.

Sean

On Sunday, December 2, 2001, at 06:54 PM, Guilherme C. Hazan wrote:

> Hi,
>
>       The tests run almost well. Here are the gifs. gta is graphic test 
> in
> appletviewer; gtp is gt in palm. The test 6 in palm gave me a pose 
> warning
> of writing in data manager structures. The Polygon routine is different
> between palm and appletviewer, so thats why the differences. Please let 
> me
> know if any of the tests went as expected. The drawArc and fillPie (=
> fillarc) algorithms were invented by a catedratic mathematic called
> Guilherme Hazan. Eheheh... kidding. I had to create it bc i couldnt 
> find any
> one available. If anyone knows a free availabe one, please let me know.
>
>        regards
>
>              guich
>

Re: [Waba-spec] More on the graphics bug

[Sean L. <se...@cs...>]

BTW, you can see the Waba error showing up in Guilherme's draw/fillRect 
pictures (thanks Guilherme). The dark black line should go all the away 
around the gray rect.  That's what it does in the AWT anyway.  But 
instead, in Waba there's a white line on the left and bottom.

Sean