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/edit/cpdf_pagecontentgenerator.h"
8
9 #include <tuple>
10 #include <utility>
11
12 #include "core/fpdfapi/font/cpdf_font.h"
13 #include "core/fpdfapi/page/cpdf_docpagedata.h"
14 #include "core/fpdfapi/page/cpdf_image.h"
15 #include "core/fpdfapi/page/cpdf_imageobject.h"
16 #include "core/fpdfapi/page/cpdf_page.h"
17 #include "core/fpdfapi/page/cpdf_path.h"
18 #include "core/fpdfapi/page/cpdf_pathobject.h"
19 #include "core/fpdfapi/page/cpdf_textobject.h"
20 #include "core/fpdfapi/parser/cpdf_dictionary.h"
21 #include "core/fpdfapi/parser/cpdf_document.h"
22 #include "core/fpdfapi/parser/cpdf_name.h"
23 #include "core/fpdfapi/parser/cpdf_number.h"
24 #include "core/fpdfapi/parser/cpdf_reference.h"
25 #include "core/fpdfapi/parser/cpdf_stream.h"
26 #include "core/fpdfapi/parser/fpdf_parser_decode.h"
27
28 namespace {
29
operator <<(CFX_ByteTextBuf & ar,const CFX_Matrix & matrix)30 CFX_ByteTextBuf& operator<<(CFX_ByteTextBuf& ar, const CFX_Matrix& matrix) {
31 ar << matrix.a << " " << matrix.b << " " << matrix.c << " " << matrix.d << " "
32 << matrix.e << " " << matrix.f;
33 return ar;
34 }
35
GetColor(const CPDF_Color * pColor,FX_FLOAT * rgb)36 bool GetColor(const CPDF_Color* pColor, FX_FLOAT* rgb) {
37 int intRGB[3];
38 if (!pColor ||
39 pColor->GetColorSpace() != CPDF_ColorSpace::GetStockCS(PDFCS_DEVICERGB) ||
40 !pColor->GetRGB(intRGB[0], intRGB[1], intRGB[2])) {
41 return false;
42 }
43 rgb[0] = intRGB[0] / 255.0f;
44 rgb[1] = intRGB[1] / 255.0f;
45 rgb[2] = intRGB[2] / 255.0f;
46 return true;
47 }
48
49 } // namespace
50
CPDF_PageContentGenerator(CPDF_Page * pPage)51 CPDF_PageContentGenerator::CPDF_PageContentGenerator(CPDF_Page* pPage)
52 : m_pPage(pPage), m_pDocument(m_pPage->m_pDocument) {
53 for (const auto& pObj : *pPage->GetPageObjectList()) {
54 if (pObj)
55 m_pageObjects.push_back(pObj.get());
56 }
57 }
58
~CPDF_PageContentGenerator()59 CPDF_PageContentGenerator::~CPDF_PageContentGenerator() {}
60
GenerateContent()61 void CPDF_PageContentGenerator::GenerateContent() {
62 CFX_ByteTextBuf buf;
63 for (CPDF_PageObject* pPageObj : m_pageObjects) {
64 if (CPDF_ImageObject* pImageObject = pPageObj->AsImage())
65 ProcessImage(&buf, pImageObject);
66 else if (CPDF_PathObject* pPathObj = pPageObj->AsPath())
67 ProcessPath(&buf, pPathObj);
68 else if (CPDF_TextObject* pTextObj = pPageObj->AsText())
69 ProcessText(&buf, pTextObj);
70 }
71 CPDF_Dictionary* pPageDict = m_pPage->m_pFormDict;
72 CPDF_Object* pContent =
73 pPageDict ? pPageDict->GetDirectObjectFor("Contents") : nullptr;
74 if (pContent)
75 pPageDict->RemoveFor("Contents");
76
77 CPDF_Stream* pStream = m_pDocument->NewIndirect<CPDF_Stream>();
78 pStream->SetData(buf.GetBuffer(), buf.GetLength());
79 pPageDict->SetNewFor<CPDF_Reference>("Contents", m_pDocument,
80 pStream->GetObjNum());
81 }
82
RealizeResource(uint32_t dwResourceObjNum,const CFX_ByteString & bsType)83 CFX_ByteString CPDF_PageContentGenerator::RealizeResource(
84 uint32_t dwResourceObjNum,
85 const CFX_ByteString& bsType) {
86 ASSERT(dwResourceObjNum);
87 if (!m_pPage->m_pResources) {
88 m_pPage->m_pResources = m_pDocument->NewIndirect<CPDF_Dictionary>();
89 m_pPage->m_pFormDict->SetNewFor<CPDF_Reference>(
90 "Resources", m_pDocument, m_pPage->m_pResources->GetObjNum());
91 }
92 CPDF_Dictionary* pResList = m_pPage->m_pResources->GetDictFor(bsType);
93 if (!pResList)
94 pResList = m_pPage->m_pResources->SetNewFor<CPDF_Dictionary>(bsType);
95
96 CFX_ByteString name;
97 int idnum = 1;
98 while (1) {
99 name.Format("FX%c%d", bsType[0], idnum);
100 if (!pResList->KeyExist(name)) {
101 break;
102 }
103 idnum++;
104 }
105 pResList->SetNewFor<CPDF_Reference>(name, m_pDocument, dwResourceObjNum);
106 return name;
107 }
108
ProcessImage(CFX_ByteTextBuf * buf,CPDF_ImageObject * pImageObj)109 void CPDF_PageContentGenerator::ProcessImage(CFX_ByteTextBuf* buf,
110 CPDF_ImageObject* pImageObj) {
111 if ((pImageObj->matrix().a == 0 && pImageObj->matrix().b == 0) ||
112 (pImageObj->matrix().c == 0 && pImageObj->matrix().d == 0)) {
113 return;
114 }
115 *buf << "q " << pImageObj->matrix() << " cm ";
116
117 CPDF_Image* pImage = pImageObj->GetImage();
118 if (pImage->IsInline())
119 return;
120
121 CPDF_Stream* pStream = pImage->GetStream();
122 if (!pStream)
123 return;
124
125 bool bWasInline = pStream->IsInline();
126 if (bWasInline)
127 pImage->ConvertStreamToIndirectObject();
128
129 uint32_t dwObjNum = pStream->GetObjNum();
130 CFX_ByteString name = RealizeResource(dwObjNum, "XObject");
131 if (bWasInline)
132 pImageObj->SetUnownedImage(m_pDocument->GetPageData()->GetImage(dwObjNum));
133
134 *buf << "/" << PDF_NameEncode(name) << " Do Q\n";
135 }
136
137 // Processing path with operators from Tables 4.9 and 4.10 of PDF spec 1.7:
138 // "re" appends a rectangle (here, used only if the whole path is a rectangle)
139 // "m" moves current point to the given coordinates
140 // "l" creates a line from current point to the new point
141 // "c" adds a Bezier curve from current to last point, using the two other
142 // points as the Bezier control points
143 // Note: "l", "c" change the current point
144 // "h" closes the subpath (appends a line from current to starting point)
145 // Path painting operators: "S", "n", "B", "f", "B*", "f*", depending on
146 // the filling mode and whether we want stroking the path or not.
147 // "Q" restores the graphics state imposed by the ProcessGraphics method.
ProcessPath(CFX_ByteTextBuf * buf,CPDF_PathObject * pPathObj)148 void CPDF_PageContentGenerator::ProcessPath(CFX_ByteTextBuf* buf,
149 CPDF_PathObject* pPathObj) {
150 ProcessGraphics(buf, pPathObj);
151 auto& pPoints = pPathObj->m_Path.GetPoints();
152 if (pPathObj->m_Path.IsRect()) {
153 CFX_PointF diff = pPoints[2].m_Point - pPoints[0].m_Point;
154 *buf << pPoints[0].m_Point.x << " " << pPoints[0].m_Point.y << " " << diff.x
155 << " " << diff.y << " re";
156 } else {
157 for (size_t i = 0; i < pPoints.size(); i++) {
158 if (i > 0)
159 *buf << " ";
160 *buf << pPoints[i].m_Point.x << " " << pPoints[i].m_Point.y;
161 FXPT_TYPE pointType = pPoints[i].m_Type;
162 if (pointType == FXPT_TYPE::MoveTo) {
163 *buf << " m";
164 } else if (pointType == FXPT_TYPE::LineTo) {
165 *buf << " l";
166 } else if (pointType == FXPT_TYPE::BezierTo) {
167 if (i + 2 >= pPoints.size() ||
168 !pPoints[i].IsTypeAndOpen(FXPT_TYPE::BezierTo) ||
169 !pPoints[i + 1].IsTypeAndOpen(FXPT_TYPE::BezierTo) ||
170 pPoints[i + 2].m_Type != FXPT_TYPE::BezierTo) {
171 // If format is not supported, close the path and paint
172 *buf << " h";
173 break;
174 }
175 *buf << " " << pPoints[i + 1].m_Point.x << " "
176 << pPoints[i + 1].m_Point.y << " " << pPoints[i + 2].m_Point.x
177 << " " << pPoints[i + 2].m_Point.y << " c";
178 i += 2;
179 }
180 if (pPoints[i].m_CloseFigure)
181 *buf << " h";
182 }
183 }
184 if (pPathObj->m_FillType == 0)
185 *buf << (pPathObj->m_bStroke ? " S" : " n");
186 else if (pPathObj->m_FillType == FXFILL_WINDING)
187 *buf << (pPathObj->m_bStroke ? " B" : " f");
188 else if (pPathObj->m_FillType == FXFILL_ALTERNATE)
189 *buf << (pPathObj->m_bStroke ? " B*" : " f*");
190 *buf << " Q\n";
191 }
192
193 // This method supports color operators rg and RGB from Table 4.24 of PDF spec
194 // 1.7. A color will not be set if the colorspace is not DefaultRGB or the RGB
195 // values cannot be obtained. The method also adds an external graphics
196 // dictionary, as described in Section 4.3.4.
197 // "rg" sets the fill color, "RG" sets the stroke color (using DefaultRGB)
198 // "w" sets the stroke line width.
199 // "ca" sets the fill alpha, "CA" sets the stroke alpha.
200 // "q" saves the graphics state, so that the settings can later be reversed
ProcessGraphics(CFX_ByteTextBuf * buf,CPDF_PageObject * pPageObj)201 void CPDF_PageContentGenerator::ProcessGraphics(CFX_ByteTextBuf* buf,
202 CPDF_PageObject* pPageObj) {
203 *buf << "q ";
204 FX_FLOAT fillColor[3];
205 if (GetColor(pPageObj->m_ColorState.GetFillColor(), fillColor)) {
206 *buf << fillColor[0] << " " << fillColor[1] << " " << fillColor[2]
207 << " rg ";
208 }
209 FX_FLOAT strokeColor[3];
210 if (GetColor(pPageObj->m_ColorState.GetStrokeColor(), strokeColor)) {
211 *buf << strokeColor[0] << " " << strokeColor[1] << " " << strokeColor[2]
212 << " RG ";
213 }
214 FX_FLOAT lineWidth = pPageObj->m_GraphState.GetLineWidth();
215 if (lineWidth != 1.0f)
216 *buf << lineWidth << " w ";
217
218 GraphicsData graphD;
219 graphD.fillAlpha = pPageObj->m_GeneralState.GetFillAlpha();
220 graphD.strokeAlpha = pPageObj->m_GeneralState.GetStrokeAlpha();
221 if (graphD.fillAlpha == 1.0f && graphD.strokeAlpha == 1.0f)
222 return;
223
224 CFX_ByteString name;
225 auto it = m_pPage->m_GraphicsMap.find(graphD);
226 if (it != m_pPage->m_GraphicsMap.end()) {
227 name = it->second;
228 } else {
229 auto gsDict = pdfium::MakeUnique<CPDF_Dictionary>();
230 gsDict->SetNewFor<CPDF_Number>("ca", graphD.fillAlpha);
231 gsDict->SetNewFor<CPDF_Number>("CA", graphD.strokeAlpha);
232 CPDF_Object* pDict = m_pDocument->AddIndirectObject(std::move(gsDict));
233 uint32_t dwObjNum = pDict->GetObjNum();
234 name = RealizeResource(dwObjNum, "ExtGState");
235 m_pPage->m_GraphicsMap[graphD] = name;
236 }
237 *buf << "/" << PDF_NameEncode(name) << " gs ";
238 }
239
240 // This method adds text to the buffer, BT begins the text object, ET ends it.
241 // Tm sets the text matrix (allows positioning and transforming text).
242 // Tf sets the font name (from Font in Resources) and font size.
243 // Tj sets the actual text, <####...> is used when specifying charcodes.
ProcessText(CFX_ByteTextBuf * buf,CPDF_TextObject * pTextObj)244 void CPDF_PageContentGenerator::ProcessText(CFX_ByteTextBuf* buf,
245 CPDF_TextObject* pTextObj) {
246 // TODO(npm): Add support for something other than standard type1 fonts.
247 *buf << "BT " << pTextObj->GetTextMatrix() << " Tm ";
248 CPDF_Font* pFont = pTextObj->GetFont();
249 if (!pFont)
250 pFont = CPDF_Font::GetStockFont(m_pDocument, "Helvetica");
251 FontData fontD;
252 fontD.baseFont = pFont->GetBaseFont();
253 auto it = m_pPage->m_FontsMap.find(fontD);
254 CFX_ByteString dictName;
255 if (it != m_pPage->m_FontsMap.end()) {
256 dictName = it->second;
257 } else {
258 auto fontDict = pdfium::MakeUnique<CPDF_Dictionary>();
259 fontDict->SetNewFor<CPDF_Name>("Type", "Font");
260 fontDict->SetNewFor<CPDF_Name>("Subtype", "Type1");
261 fontDict->SetNewFor<CPDF_Name>("BaseFont", fontD.baseFont);
262 CPDF_Object* pDict = m_pDocument->AddIndirectObject(std::move(fontDict));
263 uint32_t dwObjNum = pDict->GetObjNum();
264 dictName = RealizeResource(dwObjNum, "Font");
265 m_pPage->m_FontsMap[fontD] = dictName;
266 }
267 *buf << "/" << PDF_NameEncode(dictName) << " " << pTextObj->GetFontSize()
268 << " Tf ";
269 CFX_ByteString text;
270 for (uint32_t charcode : pTextObj->m_CharCodes) {
271 if (charcode == CPDF_Font::kInvalidCharCode)
272 continue;
273 pFont->AppendChar(text, charcode);
274 }
275 *buf << PDF_EncodeString(text, true) << " Tj ET\n";
276 }
277