bool SimpleFontData::containsCharacters(const UChar* characters, int length) const
{
if (m_platformData.isDisabled())
return true;
// FIXME: Microsoft documentation seems to imply that characters can be output using a given font and DC
// merely by testing code page intersection. This seems suspect though. Can't a font only partially
// cover a given code page?
// FIXME: in the case that we failed to get the interface, still use the font.
IMLangFontLinkType* langFontLink = fontCache()->getFontLinkInterface();
if (!langFontLink)
return true;
DWORD fontCodePages = m_platformData.codePages();
if (!fontCodePages)
return false;
DWORD acpCodePages = 0;
langFontLink->CodePageToCodePages(CP_ACP, &acpCodePages);
DWORD actualCodePages;
long numCharactersProcessed;
while (length) {
langFontLink->GetStrCodePages(characters, length, acpCodePages, &actualCodePages, &numCharactersProcessed);
if (actualCodePages && !(actualCodePages & fontCodePages))
return false;
length -= numCharactersProcessed;
characters += numCharactersProcessed;
}
return true;
}
