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/render/charposlist.h"
8
9 #include "build/build_config.h"
10 #include "core/fpdfapi/font/cpdf_cidfont.h"
11 #include "core/fpdfapi/font/cpdf_font.h"
12 #include "core/fxge/cfx_substfont.h"
13 #include "core/fxge/text_char_pos.h"
14
GetCharPosList(pdfium::span<const uint32_t> char_codes,pdfium::span<const float> char_pos,CPDF_Font * font,float font_size)15 std::vector<TextCharPos> GetCharPosList(pdfium::span<const uint32_t> char_codes,
16 pdfium::span<const float> char_pos,
17 CPDF_Font* font,
18 float font_size) {
19 std::vector<TextCharPos> results;
20 results.reserve(char_codes.size());
21
22 CPDF_CIDFont* cid_font = font->AsCIDFont();
23 bool is_vertical_writing = cid_font && cid_font->IsVertWriting();
24 bool has_to_unicode = !!font->GetFontDict()->GetStreamFor("ToUnicode");
25 for (size_t i = 0; i < char_codes.size(); ++i) {
26 uint32_t char_code = char_codes[i];
27 if (char_code == static_cast<uint32_t>(-1))
28 continue;
29
30 bool is_vertical_glyph = false;
31 results.emplace_back();
32 TextCharPos& text_char_pos = results.back();
33 if (cid_font)
34 text_char_pos.m_bFontStyle = true;
35 WideString unicode = font->UnicodeFromCharCode(char_code);
36 text_char_pos.m_Unicode = !unicode.IsEmpty() ? unicode[0] : char_code;
37 text_char_pos.m_GlyphIndex =
38 font->GlyphFromCharCode(char_code, &is_vertical_glyph);
39 uint32_t glyph_id = text_char_pos.m_GlyphIndex;
40 #if defined(OS_APPLE)
41 text_char_pos.m_ExtGID = font->GlyphFromCharCodeExt(char_code);
42 glyph_id = text_char_pos.m_ExtGID != static_cast<uint32_t>(-1)
43 ? text_char_pos.m_ExtGID
44 : text_char_pos.m_GlyphIndex;
45 #endif
46 bool is_invalid_glyph = glyph_id == static_cast<uint32_t>(-1);
47 bool is_true_type_zero_glyph = glyph_id == 0 && font->IsTrueTypeFont();
48 bool use_fallback_font = false;
49 if (is_invalid_glyph || is_true_type_zero_glyph) {
50 text_char_pos.m_FallbackFontPosition =
51 font->FallbackFontFromCharcode(char_code);
52 text_char_pos.m_GlyphIndex = font->FallbackGlyphFromCharcode(
53 text_char_pos.m_FallbackFontPosition, char_code);
54 if (is_true_type_zero_glyph &&
55 text_char_pos.m_GlyphIndex == static_cast<uint32_t>(-1)) {
56 // For a TrueType font character, when finding the glyph from the
57 // fallback font fails, switch back to using the original font.
58
59 // When keyword "ToUnicode" exists in the PDF file, it indicates
60 // a "ToUnicode" mapping file is used to convert from CIDs (which
61 // begins at decimal 0) to Unicode code. (See ToUnicode Mapping File
62 // Tutorial - Adobe
63 // https://www.adobe.com/content/dam/acom/en/devnet/acrobat/pdfs/5411.ToUnicode.pdf
64 // and
65 // https://www.freetype.org/freetype2/docs/tutorial/step1.html#section-6)
66 if (has_to_unicode)
67 text_char_pos.m_GlyphIndex = 0;
68 } else {
69 use_fallback_font = true;
70 }
71 }
72 CFX_Font* current_font;
73 if (use_fallback_font) {
74 current_font =
75 font->GetFontFallback(text_char_pos.m_FallbackFontPosition);
76 #if defined(OS_APPLE)
77 text_char_pos.m_ExtGID = text_char_pos.m_GlyphIndex;
78 #endif
79 } else {
80 current_font = font->GetFont();
81 text_char_pos.m_FallbackFontPosition = -1;
82 }
83
84 if (!font->IsEmbedded() && !font->IsCIDFont())
85 text_char_pos.m_FontCharWidth = font->GetCharWidthF(char_code);
86 else
87 text_char_pos.m_FontCharWidth = 0;
88
89 text_char_pos.m_Origin = CFX_PointF(i > 0 ? char_pos[i - 1] : 0, 0);
90 text_char_pos.m_bGlyphAdjust = false;
91
92 float scaling_factor = 1.0f;
93 if (!font->IsEmbedded() && font->HasFontWidths() && !is_vertical_writing &&
94 !current_font->GetSubstFont()->m_bFlagMM) {
95 int pdf_glyph_width = font->GetCharWidthF(char_code);
96 int font_glyph_width =
97 current_font ? current_font->GetGlyphWidth(text_char_pos.m_GlyphIndex)
98 : 0;
99 if (font_glyph_width && pdf_glyph_width > font_glyph_width + 1) {
100 // Move the initial x position by half of the excess (transformed to
101 // text space coordinates).
102 text_char_pos.m_Origin.x +=
103 (pdf_glyph_width - font_glyph_width) * font_size / 2000.0f;
104 } else if (pdf_glyph_width && font_glyph_width &&
105 pdf_glyph_width < font_glyph_width) {
106 scaling_factor = static_cast<float>(pdf_glyph_width) / font_glyph_width;
107 text_char_pos.m_AdjustMatrix[0] = scaling_factor;
108 text_char_pos.m_AdjustMatrix[1] = 0.0f;
109 text_char_pos.m_AdjustMatrix[2] = 0.0f;
110 text_char_pos.m_AdjustMatrix[3] = 1.0f;
111 text_char_pos.m_bGlyphAdjust = true;
112 }
113 }
114 if (!cid_font)
115 continue;
116
117 uint16_t cid = cid_font->CIDFromCharCode(char_code);
118 if (is_vertical_writing) {
119 text_char_pos.m_Origin = CFX_PointF(0, text_char_pos.m_Origin.x);
120
121 CFX_Point16 vertical_origin = cid_font->GetVertOrigin(cid);
122 text_char_pos.m_Origin.x -= font_size * vertical_origin.x / 1000;
123 text_char_pos.m_Origin.y -= font_size * vertical_origin.y / 1000;
124 }
125
126 const uint8_t* cid_transform = cid_font->GetCIDTransform(cid);
127 if (cid_transform && !is_vertical_glyph) {
128 text_char_pos.m_AdjustMatrix[0] =
129 cid_font->CIDTransformToFloat(cid_transform[0]) * scaling_factor;
130 text_char_pos.m_AdjustMatrix[1] =
131 cid_font->CIDTransformToFloat(cid_transform[1]) * scaling_factor;
132 text_char_pos.m_AdjustMatrix[2] =
133 cid_font->CIDTransformToFloat(cid_transform[2]);
134 text_char_pos.m_AdjustMatrix[3] =
135 cid_font->CIDTransformToFloat(cid_transform[3]);
136 text_char_pos.m_Origin.x +=
137 cid_font->CIDTransformToFloat(cid_transform[4]) * font_size;
138 text_char_pos.m_Origin.y +=
139 cid_font->CIDTransformToFloat(cid_transform[5]) * font_size;
140 text_char_pos.m_bGlyphAdjust = true;
141 }
142 }
143
144 return results;
145 }
146