Bug 106041 – Some SVG filters don't work with tiled drawing

• Component: SVG
• Status: RESOLVED DUPLICATE

[Tim Horton]

I don't know why, but the following examples:

http://srufaculty.sru.edu/david.dailey/svg/Turbulence1.svg
http://srufaculty.sru.edu/david.dailey/svg/later/displace4.svg
http://srufaculty.sru.edu/david.dailey/svg/later/displace7.svg

fail when opened in Safari 6 with tiled drawing on (Mountain Lion, etc.)

<rdar://problem/12951224>

[Dirk Schulze]

I am unsure how WebKit handles tiled drawings if I recover it correctly. But we limit the filter size (the area that get filtered) to WebCore's viewport IIRC. That might or might not be a problem for tiled drawing.

[Simon Fraser (smfr)]

Created attachment 181375 [details]
Testcase

[Simon Fraser (smfr)]

If you resize the window down so that only 1 tile shows, it starts to work. I think some caching is happening when we attempt to draw the filtered element into other tiles where it's clipped out, and that empty version is getting cached.

[Simon Fraser (smfr)]

Turning off the caching in RenderSVGResourceFilter fixes this. So this is about the filtered content being rendered into each tile, but clipped out in some, and a bad version getting cached.

[Simon Fraser (smfr)]

Of course RenderSVGShape::paint() bails at:

    if (!SVGRenderSupport::paintInfoIntersectsRepaintRect(boundingBox, m_localTransform, paintInfo))
        return;

when painting tiles that don't contain the filtered shape.

SVGRenderingContext needs to educated about multiple paint passes of the same rendered into different contexts with different clips.

[Tim Horton]

Confusingly, this seems to have progressed. Will bisect the progression.

[Tim Horton]

Oh, Florin actually explicitly fixed this. Duping.

*** This bug has been marked as a duplicate of bug 106221 ***