1 // Copyright 2016 PDFium Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4 
5 // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
6 
7 #include "core/fpdfapi/font/cpdf_simplefont.h"
8 
9 #include "core/fpdfapi/parser/cpdf_array.h"
10 #include "core/fpdfapi/parser/cpdf_dictionary.h"
11 #include "core/fpdfapi/parser/cpdf_name.h"
12 #include "core/fxge/fx_font.h"
13 #include "core/fxge/fx_freetype.h"
14 #include "third_party/base/numerics/safe_math.h"
15 #include "third_party/base/stl_util.h"
16 
17 namespace {
18 
GetPredefinedEncoding(const ByteString & value,int * basemap)19 void GetPredefinedEncoding(const ByteString& value, int* basemap) {
20   if (value == "WinAnsiEncoding")
21     *basemap = PDFFONT_ENCODING_WINANSI;
22   else if (value == "MacRomanEncoding")
23     *basemap = PDFFONT_ENCODING_MACROMAN;
24   else if (value == "MacExpertEncoding")
25     *basemap = PDFFONT_ENCODING_MACEXPERT;
26   else if (value == "PDFDocEncoding")
27     *basemap = PDFFONT_ENCODING_PDFDOC;
28 }
29 
30 }  // namespace
31 
CPDF_SimpleFont(CPDF_Document * pDocument,CPDF_Dictionary * pFontDict)32 CPDF_SimpleFont::CPDF_SimpleFont(CPDF_Document* pDocument,
33                                  CPDF_Dictionary* pFontDict)
34     : CPDF_Font(pDocument, pFontDict) {
35   memset(m_CharWidth, 0xff, sizeof(m_CharWidth));
36   memset(m_GlyphIndex, 0xff, sizeof(m_GlyphIndex));
37   for (size_t i = 0; i < pdfium::size(m_CharBBox); ++i)
38     m_CharBBox[i] = FX_RECT(-1, -1, -1, -1);
39 }
40 
41 CPDF_SimpleFont::~CPDF_SimpleFont() = default;
42 
GlyphFromCharCode(uint32_t charcode,bool * pVertGlyph)43 int CPDF_SimpleFont::GlyphFromCharCode(uint32_t charcode, bool* pVertGlyph) {
44   if (pVertGlyph)
45     *pVertGlyph = false;
46 
47   if (charcode > 0xff)
48     return -1;
49 
50   int index = m_GlyphIndex[charcode];
51   if (index == 0xffff)
52     return -1;
53 
54   return index;
55 }
56 
LoadCharMetrics(int charcode)57 void CPDF_SimpleFont::LoadCharMetrics(int charcode) {
58   if (!m_Font.GetFaceRec())
59     return;
60 
61   if (charcode < 0 || charcode > 0xff) {
62     return;
63   }
64   int glyph_index = m_GlyphIndex[charcode];
65   if (glyph_index == 0xffff) {
66     if (!m_pFontFile && charcode != 32) {
67       LoadCharMetrics(32);
68       m_CharBBox[charcode] = m_CharBBox[32];
69       if (m_bUseFontWidth) {
70         m_CharWidth[charcode] = m_CharWidth[32];
71       }
72     }
73     return;
74   }
75   FXFT_FaceRec* face = m_Font.GetFaceRec();
76   int err =
77       FT_Load_Glyph(face, glyph_index,
78                     FT_LOAD_NO_SCALE | FT_LOAD_IGNORE_GLOBAL_ADVANCE_WIDTH);
79   if (err)
80     return;
81 
82   int iHoriBearingX = FXFT_Get_Glyph_HoriBearingX(face);
83   int iHoriBearingY = FXFT_Get_Glyph_HoriBearingY(face);
84   m_CharBBox[charcode] =
85       FX_RECT(TT2PDF(iHoriBearingX, face), TT2PDF(iHoriBearingY, face),
86               TT2PDF(iHoriBearingX + FXFT_Get_Glyph_Width(face), face),
87               TT2PDF(iHoriBearingY - FXFT_Get_Glyph_Height(face), face));
88 
89   if (m_bUseFontWidth) {
90     int TT_Width = TT2PDF(FXFT_Get_Glyph_HoriAdvance(face), face);
91     if (m_CharWidth[charcode] == 0xffff) {
92       m_CharWidth[charcode] = TT_Width;
93     } else if (TT_Width && !IsEmbedded()) {
94       m_CharBBox[charcode].right =
95           m_CharBBox[charcode].right * m_CharWidth[charcode] / TT_Width;
96       m_CharBBox[charcode].left =
97           m_CharBBox[charcode].left * m_CharWidth[charcode] / TT_Width;
98     }
99   }
100 }
101 
LoadPDFEncoding(bool bEmbedded,bool bTrueType)102 void CPDF_SimpleFont::LoadPDFEncoding(bool bEmbedded, bool bTrueType) {
103   const CPDF_Object* pEncoding = m_pFontDict->GetDirectObjectFor("Encoding");
104   if (!pEncoding) {
105     if (m_BaseFontName == "Symbol") {
106       m_BaseEncoding = bTrueType ? PDFFONT_ENCODING_MS_SYMBOL
107                                  : PDFFONT_ENCODING_ADOBE_SYMBOL;
108     } else if (!bEmbedded && m_BaseEncoding == PDFFONT_ENCODING_BUILTIN) {
109       m_BaseEncoding = PDFFONT_ENCODING_WINANSI;
110     }
111     return;
112   }
113   if (pEncoding->IsName()) {
114     if (m_BaseEncoding == PDFFONT_ENCODING_ADOBE_SYMBOL ||
115         m_BaseEncoding == PDFFONT_ENCODING_ZAPFDINGBATS) {
116       return;
117     }
118     if (FontStyleIsSymbolic(m_Flags) && m_BaseFontName == "Symbol") {
119       if (!bTrueType)
120         m_BaseEncoding = PDFFONT_ENCODING_ADOBE_SYMBOL;
121       return;
122     }
123     ByteString bsEncoding = pEncoding->GetString();
124     if (bsEncoding.Compare("MacExpertEncoding") == 0) {
125       bsEncoding = "WinAnsiEncoding";
126     }
127     GetPredefinedEncoding(bsEncoding, &m_BaseEncoding);
128     return;
129   }
130 
131   const CPDF_Dictionary* pDict = pEncoding->AsDictionary();
132   if (!pDict)
133     return;
134 
135   if (m_BaseEncoding != PDFFONT_ENCODING_ADOBE_SYMBOL &&
136       m_BaseEncoding != PDFFONT_ENCODING_ZAPFDINGBATS) {
137     ByteString bsEncoding = pDict->GetStringFor("BaseEncoding");
138     if (bTrueType && bsEncoding.Compare("MacExpertEncoding") == 0)
139       bsEncoding = "WinAnsiEncoding";
140     GetPredefinedEncoding(bsEncoding, &m_BaseEncoding);
141   }
142   if ((!bEmbedded || bTrueType) && m_BaseEncoding == PDFFONT_ENCODING_BUILTIN)
143     m_BaseEncoding = PDFFONT_ENCODING_STANDARD;
144 
145   const CPDF_Array* pDiffs = pDict->GetArrayFor("Differences");
146   if (!pDiffs)
147     return;
148 
149   m_CharNames.resize(256);
150   uint32_t cur_code = 0;
151   for (uint32_t i = 0; i < pDiffs->size(); i++) {
152     const CPDF_Object* pElement = pDiffs->GetDirectObjectAt(i);
153     if (!pElement)
154       continue;
155 
156     const CPDF_Name* pName = pElement->AsName();
157     if (pName) {
158       if (cur_code < 256)
159         m_CharNames[cur_code] = pName->GetString();
160       cur_code++;
161     } else {
162       cur_code = pElement->GetInteger();
163     }
164   }
165 }
166 
GetCharWidthF(uint32_t charcode)167 int CPDF_SimpleFont::GetCharWidthF(uint32_t charcode) {
168   if (charcode > 0xff)
169     charcode = 0;
170 
171   if (m_CharWidth[charcode] == 0xffff) {
172     LoadCharMetrics(charcode);
173     if (m_CharWidth[charcode] == 0xffff) {
174       m_CharWidth[charcode] = 0;
175     }
176   }
177   return m_CharWidth[charcode];
178 }
179 
GetCharBBox(uint32_t charcode)180 FX_RECT CPDF_SimpleFont::GetCharBBox(uint32_t charcode) {
181   if (charcode > 0xff)
182     charcode = 0;
183 
184   if (m_CharBBox[charcode].left == -1)
185     LoadCharMetrics(charcode);
186 
187   return m_CharBBox[charcode];
188 }
189 
LoadCommon()190 bool CPDF_SimpleFont::LoadCommon() {
191   const CPDF_Dictionary* pFontDesc = m_pFontDict->GetDictFor("FontDescriptor");
192   if (pFontDesc) {
193     LoadFontDescriptor(pFontDesc);
194   }
195   const CPDF_Array* pWidthArray = m_pFontDict->GetArrayFor("Widths");
196   m_bUseFontWidth = !pWidthArray;
197   if (pWidthArray) {
198     if (pFontDesc && pFontDesc->KeyExist("MissingWidth")) {
199       int MissingWidth = pFontDesc->GetIntegerFor("MissingWidth");
200       for (int i = 0; i < 256; i++) {
201         m_CharWidth[i] = MissingWidth;
202       }
203     }
204     size_t width_start = m_pFontDict->GetIntegerFor("FirstChar", 0);
205     size_t width_end = m_pFontDict->GetIntegerFor("LastChar", 0);
206     if (width_start <= 255) {
207       if (width_end == 0 || width_end >= width_start + pWidthArray->size())
208         width_end = width_start + pWidthArray->size() - 1;
209       if (width_end > 255)
210         width_end = 255;
211       for (size_t i = width_start; i <= width_end; i++)
212         m_CharWidth[i] = pWidthArray->GetIntegerAt(i - width_start);
213     }
214   }
215   if (m_pFontFile) {
216     if (m_BaseFontName.GetLength() > 8 && m_BaseFontName[7] == '+')
217       m_BaseFontName = m_BaseFontName.Last(m_BaseFontName.GetLength() - 8);
218   } else {
219     LoadSubstFont();
220   }
221   if (!FontStyleIsSymbolic(m_Flags))
222     m_BaseEncoding = PDFFONT_ENCODING_STANDARD;
223   LoadPDFEncoding(!!m_pFontFile, m_Font.IsTTFont());
224   LoadGlyphMap();
225   m_CharNames.clear();
226   if (!m_Font.GetFaceRec())
227     return true;
228 
229   if (FontStyleIsAllCaps(m_Flags)) {
230     static const unsigned char kLowercases[][2] = {
231         {'a', 'z'}, {0xe0, 0xf6}, {0xf8, 0xfd}};
232     for (size_t range = 0; range < pdfium::size(kLowercases); ++range) {
233       const auto& lower = kLowercases[range];
234       for (int i = lower[0]; i <= lower[1]; ++i) {
235         if (m_GlyphIndex[i] != 0xffff && m_pFontFile)
236           continue;
237 
238         int j = i - 32;
239         m_GlyphIndex[i] = m_GlyphIndex[j];
240         if (m_CharWidth[j]) {
241           m_CharWidth[i] = m_CharWidth[j];
242           m_CharBBox[i] = m_CharBBox[j];
243         }
244       }
245     }
246   }
247   CheckFontMetrics();
248   return true;
249 }
250 
LoadSubstFont()251 void CPDF_SimpleFont::LoadSubstFont() {
252   if (!m_bUseFontWidth && !FontStyleIsFixedPitch(m_Flags)) {
253     int width = 0, i;
254     for (i = 0; i < 256; i++) {
255       if (m_CharWidth[i] == 0 || m_CharWidth[i] == 0xffff)
256         continue;
257 
258       if (width == 0)
259         width = m_CharWidth[i];
260       else if (width != m_CharWidth[i])
261         break;
262     }
263     if (i == 256 && width)
264       m_Flags |= FXFONT_FIXED_PITCH;
265   }
266   m_Font.LoadSubst(m_BaseFontName, IsTrueTypeFont(), m_Flags, GetFontWeight(),
267                    m_ItalicAngle, 0, false);
268 }
269 
IsUnicodeCompatible() const270 bool CPDF_SimpleFont::IsUnicodeCompatible() const {
271   return m_BaseEncoding != PDFFONT_ENCODING_BUILTIN &&
272          m_BaseEncoding != PDFFONT_ENCODING_ADOBE_SYMBOL &&
273          m_BaseEncoding != PDFFONT_ENCODING_ZAPFDINGBATS;
274 }
275 
UnicodeFromCharCode(uint32_t charcode) const276 WideString CPDF_SimpleFont::UnicodeFromCharCode(uint32_t charcode) const {
277   WideString unicode = CPDF_Font::UnicodeFromCharCode(charcode);
278   if (!unicode.IsEmpty())
279     return unicode;
280   wchar_t ret = m_Encoding.UnicodeFromCharCode((uint8_t)charcode);
281   if (ret == 0)
282     return WideString();
283   return ret;
284 }
285 
CharCodeFromUnicode(wchar_t unicode) const286 uint32_t CPDF_SimpleFont::CharCodeFromUnicode(wchar_t unicode) const {
287   uint32_t ret = CPDF_Font::CharCodeFromUnicode(unicode);
288   if (ret)
289     return ret;
290   return m_Encoding.CharCodeFromUnicode(unicode);
291 }
292 
HasFontWidths() const293 bool CPDF_SimpleFont::HasFontWidths() const {
294   return !m_bUseFontWidth;
295 }
296