The Annoyance Filter.pdf - Fourmilab

98 FLASH TEXT EXTRACTOR ANNOYANCE-FILTER §120
120. Most of the text we’re really interested in will be found in the DefineText tag and its younger
sibling DefineText2. After spitting out the various wobbly green parts, we digest the list of glyphs
composing the text, going back to the font definition to claw them back into civilised language which
we can filter.
〈 Parse Flash DefineText tags 120 〉 ≡
{
#ifdef FLASH_PARSE_DEBUG
unsigned short textID = get16 ( );
cout ≪ "DefineText.␣␣ID␣=␣" ≪ textID ≪ endl ;
#else
get16 ( ); /∗ Ignore textID ∗/
#endif
rect tr ;
getRect (&tr );
matrix tm ;
getMatrix (&tm );
unsigned short textGlyphBits = get8 ( );
unsigned short textAdvanceBits = get8 ( );
int fontId = −1;
map〈unsigned short, vector〈unsigned short〉 ∗〉::iterator fontp = fontMap.end ( );
map〈unsigned short, unsigned short〉::iterator fgcp = fontGlyphCount .end ( );
unsigned int fGlyphs = 0;
fontFlags fFlags = static cast〈fontFlags〉(0);
vector〈unsigned short〉 ∗fontChars = Λ; /∗ Now it’s a matter of parsing the text records ∗/
while (true ) {
unsigned int textRecordType = get8 ( );
if (textRecordType ≡ 0) {
break; /∗ 0 indicates end of text records ∗/
}
if (textRecordType & isTextControl ) {
#ifdef FLASH_PARSE_DEBUG
cout ≪ "Text␣control␣record." ≪ endl ;
#endif
if (textRecordType & textHasFont ) {
fontId = get16 ( );
#ifdef FLASH_PARSE_DEBUG
cout ≪ "␣␣␣␣fontId:␣" ≪ fontId ≪ endl ;
#endif
fgcp = fontGlyphCount .find (fontId );
if (fgcp ≡ fontGlyphCount .end ( )) {
fontp = fontMap.end ( );
if (verbose ) {
cerr ≪ "Flash␣DefineText␣item␣references␣undefined␣font␣ID␣" ≪ fontId ≪
endl ;
}
}
else {
fGlyphs = fgcp ⃗ second ;
fontChars = fontMap.find (fontId ) ⃗ second ;