Improve image alpha handling in PDF and PS plotters

Fixes: lp:1825276
* https://bugs.launchpad.net/kicad/+bug/1825276
This commit is contained in:
Jon Evans 2019-05-27 12:35:05 -04:00
parent eb4aded5d6
commit 4adf89b40b
2 changed files with 29 additions and 0 deletions

View File

@ -390,6 +390,21 @@ void PDF_PLOTTER::PlotImage( const wxImage & aImage, const wxPoint& aPos,
unsigned char r = aImage.GetRed( x, y ) & 0xFF;
unsigned char g = aImage.GetGreen( x, y ) & 0xFF;
unsigned char b = aImage.GetBlue( x, y ) & 0xFF;
// PDF inline images don't support alpha, so premultiply against white background
if( aImage.HasAlpha() )
{
unsigned char alpha = aImage.GetAlpha( x, y ) & 0xFF;
if( alpha < 0xFF )
{
float a = 1.0 - ( (float) alpha / 255.0 );
r = ( int )( r + ( a * 0xFF ) ) & 0xFF;
g = ( int )( g + ( a * 0xFF ) ) & 0xFF;
b = ( int )( b + ( a * 0xFF ) ) & 0xFF;
}
}
// As usual these days, stdio buffering has to suffeeeeerrrr
if( colorMode )
{

View File

@ -711,6 +711,20 @@ void PS_PLOTTER::PlotImage( const wxImage & aImage, const wxPoint& aPos,
green = aImage.GetGreen( xx, yy) & 0xFF;
blue = aImage.GetBlue( xx, yy) & 0xFF;
// PS doesn't support alpha, so premultiply against white background
if( aImage.HasAlpha() )
{
unsigned char alpha = aImage.GetAlpha( xx, yy ) & 0xFF;
if( alpha < 0xFF )
{
float a = 1.0 - ( (float) alpha / 255.0 );
red = ( int )( red + ( a * 0xFF ) ) & 0xFF;
green = ( int )( green + ( a * 0xFF ) ) & 0xFF;
blue = ( int )( blue + ( a * 0xFF ) ) & 0xFF;
}
}
if( colorMode )
fprintf( outputFile, "%2.2X%2.2X%2.2X", red, green, blue );
else