[OpenJDK 2D-Dev] [9] Review Request: 8059942 Default implementation of DrawImage.renderImageXform() should be improved for d3d/ogl
Jim Graham
james.graham at oracle.com
Tue Nov 11 02:43:33 UTC 2014
On 11/10/14 2:52 PM, Sergey Bylokhov wrote:
> Hi, Jim.
> To simply fill a span in the Region, I'll need to open Region.appendSpan() method,
> but I do not want to do it.
No, that method should remain private. All region objects should be
fully constructed at all times when in the hands of calling code.
> So I need to create my own EdgesSpanIterator, or totally eliminate
this loop and
> return Region object from the TransformHelper directly.
No, all you need is a method:
/**
* (describe edges array - 0,1 are y range, 2N,2N+1 are x ranges, 1 per
y range)
* (dxoff, dyoff are offsets that the edges array values are relative to)
*/
static Region getInstance(int dxoff, int dyoff, int edges[]) {
// copy loop from DrawImage.java here, but use direct manipulation
// of the spans array instead of union operations.
// You should be able to pre-allocate the spans array as well to
// save on growth using appendSpan() et al.
}
That should take only a few minutes to write, then DrawImage simply does:
Region blitclip = Region.getInstance(dx1, dy1, edges);
> Probably some logic can be moved from TransformHelper to the java level
>(at least generation of edges array). Additionally it will be simpler to
> check a performance improvement, because now it is not so obvious
comparing
> to the current percents improvement.
Unfortunately the exact calculations to compute the edges array depend
on a lot of calculations done at the native level. This would be a
major repartitioning of the code...
...jim
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