Re: Bug (or misunderstanding) in pattern fill

[Thomas DeWeese]

G. Wade Johnson wrote:

I may have found a problem with pattern filling in Batik. I was working on an example from the O'Reilly "SVG Essentials" book and Batik does not match the description in the book. ASV does match the book.

I don't fully understand what the spec says about the patternUnits and patternContentUnits attributes, but the behavior of this pattern doesn't match anything I can come up with.

   This is very complex, but my (fairly careful) reading of the 
specification says Batik
is right on this one. Basiclly you have to keep in mind that 0,0 in 
Object boundingBoxUnits
is (in this case) really 10,10.  So if you do the substitution you can see:

   <pattern id="tile" x="10" y="10" [...]>
      <path d="M10,10 [...] />
      <path d="M10,10 [...] />
   </pattern>
 

   Since x,y on pattern define a new coordinate system that is used for 
the
replicated content, you really want M0,0.  This is a bit of an odd case
as you are 'mixing' coordinate systems that don't make sense to mix (you 
end up
applying the objectBoundingBox transform twice).  I essentially always 
use viewBox
to establish the inner coodinate system as this almost always makes a 
lot more sense
(at least to me).

My understanding is that the example below should tile with the blocks side by side all over the area of the rect. In reality, each tile is offset by the x,y coordinates of the rectangle.

Otherwise, can somebody tell me what I'm doing wrong?

   I hope I've done so. :)

Thanks,
G. Wade
<?xml version="1.0"?>
<svg xmlns="http://www.w3.org/2000/svg";
    xmlns:xlink="http://www.w3.org/1999/xlink";
    width="300" height="300">
 <defs>
   <pattern id="tile" x="0" y="0" width="0.2" height="0.2"
           patternUnits="objectBoundingBox"
           patternContentUnits="objectBoundingBox">
           <!-- Doesn't display together in Batik -->
            <path d="M0,0 Q.05 .20 .10 .10 T .20 .20"
                    style="stroke: black; fill:none;
stroke-width:0.01;"/>
            <path d="M0,0h0.2v0.2h-0.2z"
                    style="stroke: black; fill:none;
stroke-width:0.005;"/>
   </pattern>
 </defs>
 <rect id="bkg" x="10" y="10" height="280" width="280"
          fill="url(#tile)" stroke="#888" stroke-width="0.5"/>
</svg>
---------------------------------------------------------------------
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]
 





---------------------------------------------------------------------
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]