handle weird semantics of SkRect::intersect() (tdf#131721)
If the two rectangles do not intersect, it only returns false and does
nothing, which is stupid and confusing.
Change-Id: I24de6059807c208c39db4e942ab5624dde788723
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/91471
Tested-by: Jenkins
Reviewed-by: Luboš Luňák <l.lunak@collabora.com>
diff --git a/vcl/skia/gdiimpl.cxx b/vcl/skia/gdiimpl.cxx
index 390bf52..53ccda6 100644
--- a/vcl/skia/gdiimpl.cxx
+++ b/vcl/skia/gdiimpl.cxx
@@ -324,44 +324,50 @@
{
// Make slightly larger, just in case (rounding, antialiasing,...).
mXorExtents.outset(2, 2);
mXorExtents.intersect(SkRect::MakeXYWH(0, 0, mSurface->width(), mSurface->height()));
if (!mXorExtents.intersect(
SkRect::MakeXYWH(0, 0, mSurface->width(), mSurface->height())))
mXorExtents.setEmpty();
}
SAL_INFO("vcl.skia.trace",
"applyxor(" << this << "): "
<< tools::Rectangle(mXorExtents.left(), mXorExtents.top(),
mXorExtents.right(), mXorExtents.bottom()));
// Copy the surface contents to another pixmap.
SkBitmap surfaceBitmap;
// Use unpremultiplied alpha format, so that we do not have to do the conversions to get
// the RGB and back (Skia will do it when converting, but it'll be presumably faster at it).
if (!surfaceBitmap.tryAllocPixels(
mSurface->imageInfo().makeAlphaType(kUnpremul_SkAlphaType)))
abort();
SkPaint paint;
paint.setBlendMode(SkBlendMode::kSrc); // copy as is
SkCanvas canvas(surfaceBitmap);
canvas.drawImageRect(mSurface->makeImageSnapshot(), mXorExtents, mXorExtents, &paint);
// xor to surfaceBitmap
assert(surfaceBitmap.info().alphaType() == kUnpremul_SkAlphaType);
assert(mXorBitmap.info().alphaType() == kUnpremul_SkAlphaType);
assert(surfaceBitmap.bytesPerPixel() == 4);
assert(mXorBitmap.bytesPerPixel() == 4);
for (int y = mXorExtents.top(); y < mXorExtents.bottom(); ++y)
if (!mXorExtents.isEmpty()) // the intersection above may be empty
{
uint8_t* data = static_cast<uint8_t*>(surfaceBitmap.getAddr(mXorExtents.x(), y));
const uint8_t* xordata = static_cast<uint8_t*>(mXorBitmap.getAddr(mXorExtents.x(), y));
for (int x = 0; x < mXorExtents.width(); ++x)
// Copy the surface contents to another pixmap.
SkBitmap surfaceBitmap;
// Use unpremultiplied alpha format, so that we do not have to do the conversions to get
// the RGB and back (Skia will do it when converting, but it'll be presumably faster at it).
if (!surfaceBitmap.tryAllocPixels(
mSurface->imageInfo().makeAlphaType(kUnpremul_SkAlphaType)))
abort();
SkPaint paint;
paint.setBlendMode(SkBlendMode::kSrc); // copy as is
SkCanvas canvas(surfaceBitmap);
canvas.drawImageRect(mSurface->makeImageSnapshot(), mXorExtents, mXorExtents, &paint);
// xor to surfaceBitmap
assert(surfaceBitmap.info().alphaType() == kUnpremul_SkAlphaType);
assert(mXorBitmap.info().alphaType() == kUnpremul_SkAlphaType);
assert(surfaceBitmap.bytesPerPixel() == 4);
assert(mXorBitmap.bytesPerPixel() == 4);
for (int y = mXorExtents.top(); y < mXorExtents.bottom(); ++y)
{
*data++ ^= *xordata++;
*data++ ^= *xordata++;
*data++ ^= *xordata++;
// alpha is not xor-ed
data++;
xordata++;
uint8_t* data = static_cast<uint8_t*>(surfaceBitmap.getAddr(mXorExtents.x(), y));
const uint8_t* xordata
= static_cast<uint8_t*>(mXorBitmap.getAddr(mXorExtents.x(), y));
for (int x = 0; x < mXorExtents.width(); ++x)
{
*data++ ^= *xordata++;
*data++ ^= *xordata++;
*data++ ^= *xordata++;
// alpha is not xor-ed
data++;
xordata++;
}
}
surfaceBitmap.notifyPixelsChanged();
mSurface->getCanvas()->drawBitmapRect(surfaceBitmap, mXorExtents, mXorExtents, &paint);
}
surfaceBitmap.notifyPixelsChanged();
mSurface->getCanvas()->drawBitmapRect(surfaceBitmap, mXorExtents, mXorExtents, &paint);
mXorCanvas.reset();
mXorBitmap.reset();
mXorExtents.setEmpty();
