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Fix wxBitmap conversion to wxImage with/without a mask

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Note that QImage is in premultiplied format if it has alpha, so we
need to unpremultiply it when converting to wxImage
This commit is contained in:
ali kettab 2023-09-13 19:48:01 +01:00
parent c1f91177df
commit 36679cf896
1 changed files with 67 additions and 8 deletions
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75
src/qt/bitmap.cpp
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@ -56,15 +56,17 @@ static wxImage ConvertImage( QImage qtImage )
{
QRgb colour = line[x];
if (hasAlpha)
{
colour = qUnpremultiply(colour);
alpha[0] = qAlpha(colour);
alpha++;
}
data[0] = qRed(colour);
data[1] = qGreen(colour);
data[2] = qBlue(colour);
if (hasAlpha)
{
alpha[0] = qAlpha(colour);
alpha++;
}
data += 3;
}
}
@ -293,10 +295,67 @@ int wxBitmap::GetDepth() const
#if wxUSE_IMAGE
wxImage wxBitmap::ConvertToImage() const
{
QPixmap pixmap(M_PIXDATA);
wxImage image;
wxCHECK_MSG(IsOk(), image, "invalid bitmap");
image = ConvertImage(M_PIXDATA.toImage());
// now handle the mask, if we have any
if ( M_MASK && M_MASK->GetHandle() )
pixmap.setMask(*M_MASK->GetHandle());
return ConvertImage(pixmap.toImage());
{
// we hard code the mask colour for now but we could also make an
// effort (and waste time) to choose a colour not present in the
// image already to avoid having to fudge the pixels below --
// whether it's worth to do it is unclear however
static const int MASK_RED = 1;
static const int MASK_GREEN = 2;
static const int MASK_BLUE = 3;
static const int MASK_BLUE_REPLACEMENT = 2;
wxBitmap bmpMask(M_MASK->GetBitmap());
wxMonoPixelData dataMask(bmpMask);
const int h = dataMask.GetHeight();
const int w = dataMask.GetWidth();
unsigned char* data = image.GetData();
wxMonoPixelData::Iterator rowStart(dataMask);
for ( int y = 0; y < h; ++y )
{
// traverse one mask line
wxMonoPixelData::Iterator p = rowStart;
for ( int x = 0; x < w; ++x )
{
// should this pixel be transparent?
if ( p.Pixel() )
{
// no, check that it isn't transparent by accident
if ( (data[0] == MASK_RED) &&
(data[1] == MASK_GREEN) &&
(data[2] == MASK_BLUE) )
{
// we have to fudge the colour a bit to prevent
// this pixel from appearing transparent
data[2] = MASK_BLUE_REPLACEMENT;
}
data += 3;
}
else // yes, transparent pixel
{
*data++ = MASK_RED;
*data++ = MASK_GREEN;
*data++ = MASK_BLUE;
}
++p;
}
rowStart.OffsetY(dataMask, 1);
}
image.SetMaskColour(MASK_RED, MASK_GREEN, MASK_BLUE);
}
return image;
}
#endif // wxUSE_IMAGE