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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/fxge/fx_freetype.h"
12 #include "third_party/base/numerics/safe_math.h"
13 
CPDF_SimpleFont()14 CPDF_SimpleFont::CPDF_SimpleFont() : m_BaseEncoding(PDFFONT_ENCODING_BUILTIN) {
15   memset(m_CharWidth, 0xff, sizeof(m_CharWidth));
16   memset(m_GlyphIndex, 0xff, sizeof(m_GlyphIndex));
17   memset(m_ExtGID, 0xff, sizeof(m_ExtGID));
18   for (size_t i = 0; i < FX_ArraySize(m_CharBBox); ++i)
19     m_CharBBox[i] = FX_RECT(-1, -1, -1, -1);
20 }
21 
~CPDF_SimpleFont()22 CPDF_SimpleFont::~CPDF_SimpleFont() {}
23 
GlyphFromCharCode(uint32_t charcode,bool * pVertGlyph)24 int CPDF_SimpleFont::GlyphFromCharCode(uint32_t charcode, bool* pVertGlyph) {
25   if (pVertGlyph)
26     *pVertGlyph = false;
27 
28   if (charcode > 0xff)
29     return -1;
30 
31   int index = m_GlyphIndex[charcode];
32   if (index == 0xffff || (index == 0 && IsTrueTypeFont()))
33     return -1;
34 
35   return index;
36 }
37 
LoadCharMetrics(int charcode)38 void CPDF_SimpleFont::LoadCharMetrics(int charcode) {
39   if (!m_Font.GetFace())
40     return;
41 
42   if (charcode < 0 || charcode > 0xff) {
43     return;
44   }
45   int glyph_index = m_GlyphIndex[charcode];
46   if (glyph_index == 0xffff) {
47     if (!m_pFontFile && charcode != 32) {
48       LoadCharMetrics(32);
49       m_CharBBox[charcode] = m_CharBBox[32];
50       if (m_bUseFontWidth) {
51         m_CharWidth[charcode] = m_CharWidth[32];
52       }
53     }
54     return;
55   }
56   FXFT_Face face = m_Font.GetFace();
57   int err = FXFT_Load_Glyph(
58       face, glyph_index,
59       FXFT_LOAD_NO_SCALE | FXFT_LOAD_IGNORE_GLOBAL_ADVANCE_WIDTH);
60   if (err)
61     return;
62 
63   int iHoriBearingX = FXFT_Get_Glyph_HoriBearingX(face);
64   int iHoriBearingY = FXFT_Get_Glyph_HoriBearingY(face);
65   m_CharBBox[charcode] =
66       FX_RECT(TT2PDF(iHoriBearingX, face), TT2PDF(iHoriBearingY, face),
67               TT2PDF(iHoriBearingX + FXFT_Get_Glyph_Width(face), face),
68               TT2PDF(iHoriBearingY - FXFT_Get_Glyph_Height(face), face));
69 
70   if (m_bUseFontWidth) {
71     int TT_Width = TT2PDF(FXFT_Get_Glyph_HoriAdvance(face), face);
72     if (m_CharWidth[charcode] == 0xffff) {
73       m_CharWidth[charcode] = TT_Width;
74     } else if (TT_Width && !IsEmbedded()) {
75       m_CharBBox[charcode].right =
76           m_CharBBox[charcode].right * m_CharWidth[charcode] / TT_Width;
77       m_CharBBox[charcode].left =
78           m_CharBBox[charcode].left * m_CharWidth[charcode] / TT_Width;
79     }
80   }
81 }
82 
GetCharWidthF(uint32_t charcode)83 int CPDF_SimpleFont::GetCharWidthF(uint32_t charcode) {
84   if (charcode > 0xff)
85     charcode = 0;
86 
87   if (m_CharWidth[charcode] == 0xffff) {
88     LoadCharMetrics(charcode);
89     if (m_CharWidth[charcode] == 0xffff) {
90       m_CharWidth[charcode] = 0;
91     }
92   }
93   return m_CharWidth[charcode];
94 }
95 
GetCharBBox(uint32_t charcode)96 FX_RECT CPDF_SimpleFont::GetCharBBox(uint32_t charcode) {
97   if (charcode > 0xff)
98     charcode = 0;
99 
100   if (m_CharBBox[charcode].left == -1)
101     LoadCharMetrics(charcode);
102 
103   return m_CharBBox[charcode];
104 }
105 
LoadCommon()106 bool CPDF_SimpleFont::LoadCommon() {
107   CPDF_Dictionary* pFontDesc = m_pFontDict->GetDictFor("FontDescriptor");
108   if (pFontDesc) {
109     LoadFontDescriptor(pFontDesc);
110   }
111   CPDF_Array* pWidthArray = m_pFontDict->GetArrayFor("Widths");
112   m_bUseFontWidth = !pWidthArray;
113   if (pWidthArray) {
114     if (pFontDesc && pFontDesc->KeyExist("MissingWidth")) {
115       int MissingWidth = pFontDesc->GetIntegerFor("MissingWidth");
116       for (int i = 0; i < 256; i++) {
117         m_CharWidth[i] = MissingWidth;
118       }
119     }
120     size_t width_start = m_pFontDict->GetIntegerFor("FirstChar", 0);
121     size_t width_end = m_pFontDict->GetIntegerFor("LastChar", 0);
122     if (width_start <= 255) {
123       if (width_end == 0 || width_end >= width_start + pWidthArray->GetCount())
124         width_end = width_start + pWidthArray->GetCount() - 1;
125       if (width_end > 255)
126         width_end = 255;
127       for (size_t i = width_start; i <= width_end; i++)
128         m_CharWidth[i] = pWidthArray->GetIntegerAt(i - width_start);
129     }
130   }
131   if (m_pFontFile) {
132     if (m_BaseFont.GetLength() > 8 && m_BaseFont[7] == '+')
133       m_BaseFont = m_BaseFont.Right(m_BaseFont.GetLength() - 8);
134   } else {
135     LoadSubstFont();
136   }
137   if (!FontStyleIsSymbolic(m_Flags))
138     m_BaseEncoding = PDFFONT_ENCODING_STANDARD;
139   CPDF_Object* pEncoding = m_pFontDict->GetDirectObjectFor("Encoding");
140   LoadPDFEncoding(pEncoding, m_BaseEncoding, &m_CharNames, !!m_pFontFile,
141                   m_Font.IsTTFont());
142   LoadGlyphMap();
143   m_CharNames.clear();
144   if (!m_Font.GetFace())
145     return true;
146 
147   if (FontStyleIsAllCaps(m_Flags)) {
148     unsigned char kLowercases[][2] = {{'a', 'z'}, {0xe0, 0xf6}, {0xf8, 0xfd}};
149     for (size_t range = 0; range < FX_ArraySize(kLowercases); ++range) {
150       const auto& lower = kLowercases[range];
151       for (int i = lower[0]; i <= lower[1]; ++i) {
152         if (m_GlyphIndex[i] != 0xffff && m_pFontFile)
153           continue;
154 
155         int j = i - 32;
156         m_GlyphIndex[i] = m_GlyphIndex[j];
157         if (m_CharWidth[j]) {
158           m_CharWidth[i] = m_CharWidth[j];
159           m_CharBBox[i] = m_CharBBox[j];
160         }
161       }
162     }
163   }
164   CheckFontMetrics();
165   return true;
166 }
167 
LoadSubstFont()168 void CPDF_SimpleFont::LoadSubstFont() {
169   if (!m_bUseFontWidth && !FontStyleIsFixedPitch(m_Flags)) {
170     int width = 0, i;
171     for (i = 0; i < 256; i++) {
172       if (m_CharWidth[i] == 0 || m_CharWidth[i] == 0xffff)
173         continue;
174 
175       if (width == 0)
176         width = m_CharWidth[i];
177       else if (width != m_CharWidth[i])
178         break;
179     }
180     if (i == 256 && width)
181       m_Flags |= FXFONT_FIXED_PITCH;
182   }
183   pdfium::base::CheckedNumeric<int> safeStemV(m_StemV);
184   if (m_StemV < 140)
185     safeStemV *= 5;
186   else
187     safeStemV = safeStemV * 4 + 140;
188   m_Font.LoadSubst(m_BaseFont, IsTrueTypeFont(), m_Flags,
189                    safeStemV.ValueOrDefault(FXFONT_FW_NORMAL), m_ItalicAngle, 0,
190                    false);
191 }
192 
IsUnicodeCompatible() const193 bool CPDF_SimpleFont::IsUnicodeCompatible() const {
194   return m_BaseEncoding != PDFFONT_ENCODING_BUILTIN &&
195          m_BaseEncoding != PDFFONT_ENCODING_ADOBE_SYMBOL &&
196          m_BaseEncoding != PDFFONT_ENCODING_ZAPFDINGBATS;
197 }
198 
UnicodeFromCharCode(uint32_t charcode) const199 WideString CPDF_SimpleFont::UnicodeFromCharCode(uint32_t charcode) const {
200   WideString unicode = CPDF_Font::UnicodeFromCharCode(charcode);
201   if (!unicode.IsEmpty())
202     return unicode;
203   wchar_t ret = m_Encoding.UnicodeFromCharCode((uint8_t)charcode);
204   if (ret == 0)
205     return WideString();
206   return ret;
207 }
208 
CharCodeFromUnicode(wchar_t unicode) const209 uint32_t CPDF_SimpleFont::CharCodeFromUnicode(wchar_t unicode) const {
210   uint32_t ret = CPDF_Font::CharCodeFromUnicode(unicode);
211   if (ret)
212     return ret;
213   return m_Encoding.CharCodeFromUnicode(unicode);
214 }
215 
HasFontWidths() const216 bool CPDF_SimpleFont::HasFontWidths() const {
217   return !m_bUseFontWidth;
218 }
219