vcl/source/filter/png/PngImageWriter.cxx | 23 +++++++++++++----------
1 file changed, 13 insertions(+), 10 deletions(-)
New commits:
commit 9b2d13d76d1a41070eea17dc0616895035ef96f6
Author: Noel Grandin <noelgran...@gmail.com>
AuthorDate: Wed Sep 3 20:06:35 2025 +0200
Commit: Noel Grandin <noelgran...@gmail.com>
CommitDate: Wed Sep 3 21:37:13 2025 +0200
fix pngWrite creating alpha for bitmaps without
this manifested on my macos box as a failure in
CppunitTest_sd_png_export_tests
Change-Id: Id12499e0a93872f62bfcd945b11f3aac154a5c63
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/190564
Tested-by: Jenkins
Reviewed-by: Noel Grandin <noel.gran...@collabora.co.uk>
diff --git a/vcl/source/filter/png/PngImageWriter.cxx
b/vcl/source/filter/png/PngImageWriter.cxx
index eb49efb33502..b2ec3a6a80df 100644
--- a/vcl/source/filter/png/PngImageWriter.cxx
+++ b/vcl/source/filter/png/PngImageWriter.cxx
@@ -20,15 +20,16 @@ namespace
{
void combineScanlineChannels(BitmapScopedReadAccess& pAccess, Scanline
pScanline,
std::vector<std::remove_pointer_t<Scanline>>&
pResult,
- sal_uInt32 nBitmapWidth)
+ sal_uInt32 nBitmapWidth, int nChannels)
{
for (sal_uInt32 i = 0; i < nBitmapWidth; ++i)
{
BitmapColor aCol = pAccess->GetPixelFromData(pScanline, i);
- pResult[i * 4] = aCol.GetRed(); // R
- pResult[i * 4 + 1] = aCol.GetGreen(); // G
- pResult[i * 4 + 2] = aCol.GetBlue(); // B
- pResult[i * 4 + 3] = aCol.GetAlpha(); // A
+ pResult[i * nChannels] = aCol.GetRed(); // R
+ pResult[i * nChannels + 1] = aCol.GetGreen(); // G
+ pResult[i * nChannels + 2] = aCol.GetBlue(); // B
+ if (nChannels == 4)
+ pResult[i * 4 + 3] = aCol.GetAlpha(); // A
}
}
}
@@ -216,9 +217,9 @@ static bool pngWrite(SvStream& rStream, const Graphic&
rGraphic, int nCompressio
case ScanlineFormat::N32BitTcBgrx:
{
assert(!aBitmap.HasAlpha());
- colorType = PNG_COLOR_TYPE_RGBA;
+ colorType = PNG_COLOR_TYPE_RGB;
bitDepth = 8;
- png_set_bgr(pPng);
+ bCombineChannels = true;
break;
}
case ScanlineFormat::N32BitTcRgba:
@@ -232,8 +233,9 @@ static bool pngWrite(SvStream& rStream, const Graphic&
rGraphic, int nCompressio
case ScanlineFormat::N32BitTcRgbx:
{
assert(!aBitmap.HasAlpha());
- colorType = PNG_COLOR_TYPE_RGBA;
+ colorType = PNG_COLOR_TYPE_RGB;
bitDepth = 8;
+ bCombineChannels = true;
break;
}
default:
@@ -325,6 +327,7 @@ static bool pngWrite(SvStream& rStream, const Graphic&
rGraphic, int nCompressio
tools::Long nHeight = pAccess->Height();
+ auto nChannels = png_get_channels(pPng, pInfo);
for (int nPass = 0; nPass < nNumberOfPasses; nPass++)
{
for (tools::Long y = 0; y < nHeight; y++)
@@ -336,10 +339,10 @@ static bool pngWrite(SvStream& rStream, const Graphic&
rGraphic, int nCompressio
{
auto nBitmapWidth = pAccess->Width();
// Allocate enough size to fit all channels
- aCombinedChannels.resize(nBitmapWidth *
png_get_channels(pPng, pInfo));
+ aCombinedChannels.resize(nBitmapWidth * nChannels);
// Combine color and alpha channels
combineScanlineChannels(pAccess, pSourcePointer,
aCombinedChannels,
- nBitmapWidth);
+ nBitmapWidth, nChannels);
pFinalPointer = aCombinedChannels.data();
}
png_write_row(pPng, pFinalPointer);
