commit dcd3b5a52b343aa82933ba27be3396f46ee465ee
author Luboš Luňák <l.lunak@collabora.com> Fri Dec 13 12:20:43 2019 +0100
committer Luboš Luňák <l.lunak@collabora.com> Fri Dec 13 14:13:42 2019 +0100
tree e11f6da048b1f1478e8a25c6f28688535609128a
parent fe8ca52b1265e5da0e1ef645f364296cf9ee8b12

use SkCanvas::clipPath() as the real solution

SkCanvas::clipRegion() is buggy and may be removed in future
(https://bugs.chromium.org/p/skia/issues/detail?id=9580).

Change-Id: I7070d3616e579ec8ce795f6a4bdef66b1ca1c493
Reviewed-on: https://gerrit.libreoffice.org/85102
Tested-by: Jenkins
Reviewed-by: Luboš Luňák <l.lunak@collabora.com>

vcl/skia/gdiimpl.cxx

diff --git a/vcl/skia/gdiimpl.cxx b/vcl/skia/gdiimpl.cxx
index 532f819..25980de 100644
--- a/vcl/skia/gdiimpl.cxx
+++ b/vcl/skia/gdiimpl.cxx
@@ -343,40 +343,6 @@ void SkiaSalGraphicsImpl::checkSurface()
    }
}

static SkIRect toSkIRect(const tools::Rectangle& rectangle)
{
    return SkIRect::MakeXYWH(rectangle.Left(), rectangle.Top(), rectangle.GetWidth(),
                             rectangle.GetHeight());
}

static SkRegion toSkRegion(const vcl::Region& region)
{
    if (region.IsEmpty())
        return SkRegion();
    if (region.IsRectangle())
        return SkRegion(toSkIRect(region.GetBoundRect()));
    // Prefer rectangles to polygons (simpler and also see the addPolygonToPath() comment).
    if (region.getRegionBand())
    {
        SkRegion skRegion;
        RectangleVector rectangles;
        region.GetRegionRectangles(rectangles);
        for (const tools::Rectangle& rect : rectangles)
            skRegion.op(toSkIRect(rect), SkRegion::kUnion_Op);
        return skRegion;
    }
    else
    {
        assert(region.HasPolyPolygonOrB2DPolyPolygon());
        SkPath path;
        addPolyPolygonToPath(region.GetAsB2DPolyPolygon(), path);
        path.setFillType(SkPathFillType::kEvenOdd);
        SkRegion skRegion;
        skRegion.setPath(path, SkRegion(path.getBounds().roundOut()));
        return skRegion;
    }
}

bool SkiaSalGraphicsImpl::setClipRegion(const vcl::Region& region)
{
    if (mClipRegion == region)
@@ -393,34 +359,23 @@ bool SkiaSalGraphicsImpl::setClipRegion(const vcl::Region& region)
    assert(canvas->getSaveCount() == 2); // = there is just one save()
    canvas->restore();
    canvas->save();
#if 1
    // TODO
    // SkCanvas::clipRegion() is buggy with Vulkan, use SkCanvas::clipPath().
    // https://bugs.chromium.org/p/skia/issues/detail?id=9580
    // This is further complicated by rectangle->polygon area conversions
    // being problematic (see addPolygonToPath() comment), so handle rectangles
    // first before resorting to polygons.
    SkPath path;
    // Handle polygons last, since rectangle->polygon area conversions
    // are problematic (see addPolygonToPath() comment).
    if (region.getRegionBand())
    {
        RectangleVector rectangles;
        region.GetRegionRectangles(rectangles);
        SkPath path;
        for (const tools::Rectangle& rectangle : rectangles)
            path.addRect(SkRect::MakeXYWH(rectangle.getX(), rectangle.getY(), rectangle.GetWidth(),
                                          rectangle.GetHeight()));
        path.setFillType(SkPathFillType::kEvenOdd);
        canvas->clipPath(path);
    }
    else if (!region.IsEmpty() && !region.IsRectangle())
    else if (!region.IsEmpty())
    {
        SkPath path;
        addPolyPolygonToPath(region.GetAsB2DPolyPolygon(), path);
        path.setFillType(SkPathFillType::kEvenOdd);
        canvas->clipPath(path);
    }
    else
#endif
        canvas->clipRegion(toSkRegion(region));
    path.setFillType(SkPathFillType::kEvenOdd);
    canvas->clipPath(path);
    return true;
}