QImage QFontEngineS60::alphaMapForGlyph(glyph_t glyph)
{
TOpenFontCharMetrics metrics;
const TUint8 *glyphBitmapBytes;
TSize glyphBitmapSize;
getCharacterData(glyph, metrics, glyphBitmapBytes, glyphBitmapSize);
QImage result(glyphBitmapBytes, glyphBitmapSize.iWidth, glyphBitmapSize.iHeight, glyphBitmapSize.iWidth, QImage::Format_Indexed8);
result.setColorTable(grayPalette());
// The above setColorTable() call detached the image data anyway, so why not shape tha data a bit, while we can.
// CFont::GetCharacterData() returns 8-bit data that obviously was 4-bit data before, and converted to 8-bit incorrectly.
// The data values are 0x00, 0x10 ... 0xe0, 0xf0. So, a real opaque 0xff is never reached, which we get punished
// for every time we want to blit this glyph in the raster paint engine.
// "Fix" is to convert all 0xf0 to 0xff. Is fine, quality wise, and I assume faster than correcting all values.
// Blitting is however, evidentially faster now.
const int bpl = result.bytesPerLine();
for (int row = 0; row < result.height(); ++row) {
uchar *scanLine = result.scanLine(row);
for (int column = 0; column < bpl; ++column) {
if (*scanLine == 0xf0)
*scanLine = 0xff;
scanLine++;
}
}
return result;
}
QImage QFontEngineS60::alphaMapForGlyph(glyph_t glyph)
{
// Note: On some Symbian versions (apparently <= Symbian^1), this
// function will return gray values 0x00, 0x10 ... 0xe0, 0xf0 due
// to a bug. The glyphs are nowhere perfectly opaque.
// This has been fixed for Symbian^3.
TOpenFontCharMetrics metrics;
const TUint8 *glyphBitmapBytes;
TSize glyphBitmapSize;
getCharacterData(glyph, metrics, glyphBitmapBytes, glyphBitmapSize);
QImage result(glyphBitmapBytes, glyphBitmapSize.iWidth, glyphBitmapSize.iHeight, glyphBitmapSize.iWidth, QImage::Format_Indexed8);
result.setColorTable(grayPalette());
return result;
}
