[BATIK-888] Bug in SVGFeOffsetElementBridge when using primitiveUnits="objectBoundingBox" -- Wrong Translation

• Type: Bug
• Status: Open
• Resolution: Unresolved
• Affects Version/s: 1.8
• Component/s: GVT Filters
• Environment: Operating System: Windows Vista; Platform: PC
• Assignee: Batik Developer's Mailing list
• Reporter: Eric Amram
• Created: 17/Feb/09 08:36
• Updated: 17/Feb/09 10:17

Description

Hello,

Line 106 of SVGFeOffsetElementBridge states:

float dx = convertNumber(filterElement, SVG_DX_ATTRIBUTE, 0, ctx);
float dy = convertNumber(filterElement, SVG_DY_ATTRIBUTE, 0, ctx);
> AffineTransform at = AffineTransform.getTranslateInstance(dx, dy);

However, this sets an offset filter in userSpace coordinates, not in objectBoundingBox units.

The translation should take into account the object bounding box (as required by spec http://www.w3.org/TR/SVG/filters.html#feOffsetElement),
which is available in
filteredElement.geometryBounds
in this method.

I suggest in case of objectBoundingBox units to rather set:

> AffineTransform at = AffineTransform.getTranslateInstance(
dx * filteredElement.geometryBounds.getWidth() ,
dy * filteredElement.geometryBounds.getHeight() );

Being new to Batik, I don't master all the implications, so decide what's best!

Congrats for Batik, this great piece of work!

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Test case:

Apply the following filter to any <svg>

<defs>
<filter id="CenteringFilter" filterUnits="objectBoundingBox" primitiveUnits="objectBoundingBox" x="-0.5" y="-0.5" width="1.5" height="1.5">
<feOffset in="SourceGraphic" dx="0.5" dy="-0.5" /> <!- FIXME dx & dy !!! -->
</filter>
</defs>

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Note: this works fine with Adove Viewer but not with Batik.