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/page/cpdf_meshstream.h"
8
9 #include "core/fpdfapi/page/cpdf_colorspace.h"
10 #include "core/fpdfapi/page/cpdf_function.h"
11 #include "core/fpdfapi/parser/cpdf_array.h"
12
13 namespace {
14
15 // See PDF Reference 1.7, page 315, table 4.32. (Also table 4.33 and 4.34)
ShouldCheckBPC(ShadingType type)16 bool ShouldCheckBPC(ShadingType type) {
17 switch (type) {
18 case kFreeFormGouraudTriangleMeshShading:
19 case kLatticeFormGouraudTriangleMeshShading:
20 case kCoonsPatchMeshShading:
21 case kTensorProductPatchMeshShading:
22 return true;
23 default:
24 return false;
25 }
26 }
27
28 // Same references as ShouldCheckBPC() above.
IsValidBitsPerComponent(uint32_t x)29 bool IsValidBitsPerComponent(uint32_t x) {
30 switch (x) {
31 case 1:
32 case 2:
33 case 4:
34 case 8:
35 case 12:
36 case 16:
37 return true;
38 default:
39 return false;
40 }
41 }
42
43 // Same references as ShouldCheckBPC() above.
IsValidBitsPerCoordinate(uint32_t x)44 bool IsValidBitsPerCoordinate(uint32_t x) {
45 switch (x) {
46 case 1:
47 case 2:
48 case 4:
49 case 8:
50 case 12:
51 case 16:
52 case 24:
53 case 32:
54 return true;
55 default:
56 return false;
57 }
58 }
59
60 // See PDF Reference 1.7, page 315, table 4.32. (Also table 4.34)
ShouldCheckBitsPerFlag(ShadingType type)61 bool ShouldCheckBitsPerFlag(ShadingType type) {
62 switch (type) {
63 case kFreeFormGouraudTriangleMeshShading:
64 case kCoonsPatchMeshShading:
65 case kTensorProductPatchMeshShading:
66 return true;
67 default:
68 return false;
69 }
70 }
71
72 // Same references as ShouldCheckBitsPerFlag() above.
IsValidBitsPerFlag(uint32_t x)73 bool IsValidBitsPerFlag(uint32_t x) {
74 switch (x) {
75 case 2:
76 case 4:
77 case 8:
78 return true;
79 default:
80 return false;
81 }
82 }
83
84 } // namespace
85
86 CPDF_MeshVertex::CPDF_MeshVertex() = default;
87
88 CPDF_MeshVertex::CPDF_MeshVertex(const CPDF_MeshVertex&) = default;
89
90 CPDF_MeshVertex::~CPDF_MeshVertex() = default;
91
CPDF_MeshStream(ShadingType type,const std::vector<std::unique_ptr<CPDF_Function>> & funcs,CPDF_Stream * pShadingStream,CPDF_ColorSpace * pCS)92 CPDF_MeshStream::CPDF_MeshStream(
93 ShadingType type,
94 const std::vector<std::unique_ptr<CPDF_Function>>& funcs,
95 CPDF_Stream* pShadingStream,
96 CPDF_ColorSpace* pCS)
97 : m_type(type),
98 m_funcs(funcs),
99 m_pShadingStream(pShadingStream),
100 m_pCS(pCS),
101 m_nCoordBits(0),
102 m_nComponentBits(0),
103 m_nFlagBits(0),
104 m_nComponents(0),
105 m_CoordMax(0),
106 m_ComponentMax(0),
107 m_xmin(0),
108 m_xmax(0),
109 m_ymin(0),
110 m_ymax(0),
111 m_pStream(pdfium::MakeRetain<CPDF_StreamAcc>(pShadingStream)) {
112 memset(&m_ColorMin, 0, sizeof(m_ColorMin));
113 memset(&m_ColorMax, 0, sizeof(m_ColorMax));
114 }
115
~CPDF_MeshStream()116 CPDF_MeshStream::~CPDF_MeshStream() {}
117
Load()118 bool CPDF_MeshStream::Load() {
119 m_pStream->LoadAllDataFiltered();
120 m_BitStream = pdfium::MakeUnique<CFX_BitStream>(m_pStream->GetData(),
121 m_pStream->GetSize());
122 CPDF_Dictionary* pDict = m_pShadingStream->GetDict();
123 m_nCoordBits = pDict->GetIntegerFor("BitsPerCoordinate");
124 m_nComponentBits = pDict->GetIntegerFor("BitsPerComponent");
125 if (ShouldCheckBPC(m_type)) {
126 if (!IsValidBitsPerCoordinate(m_nCoordBits))
127 return false;
128 if (!IsValidBitsPerComponent(m_nComponentBits))
129 return false;
130 }
131
132 m_nFlagBits = pDict->GetIntegerFor("BitsPerFlag");
133 if (ShouldCheckBitsPerFlag(m_type) && !IsValidBitsPerFlag(m_nFlagBits))
134 return false;
135
136 uint32_t nComponents = m_pCS->CountComponents();
137 if (nComponents > kMaxComponents)
138 return false;
139
140 m_nComponents = m_funcs.empty() ? nComponents : 1;
141 CPDF_Array* pDecode = pDict->GetArrayFor("Decode");
142 if (!pDecode || pDecode->GetCount() != 4 + m_nComponents * 2)
143 return false;
144
145 m_xmin = pDecode->GetNumberAt(0);
146 m_xmax = pDecode->GetNumberAt(1);
147 m_ymin = pDecode->GetNumberAt(2);
148 m_ymax = pDecode->GetNumberAt(3);
149 for (uint32_t i = 0; i < m_nComponents; ++i) {
150 m_ColorMin[i] = pDecode->GetNumberAt(i * 2 + 4);
151 m_ColorMax[i] = pDecode->GetNumberAt(i * 2 + 5);
152 }
153
154 if (ShouldCheckBPC(m_type)) {
155 m_CoordMax = m_nCoordBits == 32 ? -1 : (1 << m_nCoordBits) - 1;
156 m_ComponentMax = (1 << m_nComponentBits) - 1;
157 }
158 return true;
159 }
160
CanReadFlag() const161 bool CPDF_MeshStream::CanReadFlag() const {
162 return m_BitStream->BitsRemaining() >= m_nFlagBits;
163 }
164
CanReadCoords() const165 bool CPDF_MeshStream::CanReadCoords() const {
166 return m_BitStream->BitsRemaining() / 2 >= m_nCoordBits;
167 }
168
CanReadColor() const169 bool CPDF_MeshStream::CanReadColor() const {
170 return m_BitStream->BitsRemaining() / m_nComponentBits >= m_nComponents;
171 }
172
ReadFlag()173 uint32_t CPDF_MeshStream::ReadFlag() {
174 ASSERT(ShouldCheckBitsPerFlag(m_type));
175 return m_BitStream->GetBits(m_nFlagBits) & 0x03;
176 }
177
ReadCoords()178 CFX_PointF CPDF_MeshStream::ReadCoords() {
179 ASSERT(ShouldCheckBPC(m_type));
180
181 CFX_PointF pos;
182 if (m_nCoordBits == 32) {
183 pos.x = m_xmin + m_BitStream->GetBits(m_nCoordBits) * (m_xmax - m_xmin) /
184 static_cast<double>(m_CoordMax);
185 pos.y = m_ymin + m_BitStream->GetBits(m_nCoordBits) * (m_ymax - m_ymin) /
186 static_cast<double>(m_CoordMax);
187 } else {
188 pos.x = m_xmin +
189 m_BitStream->GetBits(m_nCoordBits) * (m_xmax - m_xmin) / m_CoordMax;
190 pos.y = m_ymin +
191 m_BitStream->GetBits(m_nCoordBits) * (m_ymax - m_ymin) / m_CoordMax;
192 }
193 return pos;
194 }
195
ReadColor()196 std::tuple<float, float, float> CPDF_MeshStream::ReadColor() {
197 ASSERT(ShouldCheckBPC(m_type));
198
199 float color_value[kMaxComponents];
200 for (uint32_t i = 0; i < m_nComponents; ++i) {
201 color_value[i] = m_ColorMin[i] + m_BitStream->GetBits(m_nComponentBits) *
202 (m_ColorMax[i] - m_ColorMin[i]) /
203 m_ComponentMax;
204 }
205
206 float r = 0.0;
207 float g = 0.0;
208 float b = 0.0;
209 if (m_funcs.empty()) {
210 m_pCS->GetRGB(color_value, &r, &g, &b);
211 return std::tuple<float, float, float>(r, g, b);
212 }
213
214 float result[kMaxComponents];
215 memset(result, 0, sizeof(result));
216 int nResults;
217 for (const auto& func : m_funcs) {
218 if (func && func->CountOutputs() <= kMaxComponents)
219 func->Call(color_value, 1, result, &nResults);
220 }
221
222 m_pCS->GetRGB(result, &r, &g, &b);
223 return std::tuple<float, float, float>(r, g, b);
224 }
225
ReadVertex(const CFX_Matrix & pObject2Bitmap,CPDF_MeshVertex * vertex,uint32_t * flag)226 bool CPDF_MeshStream::ReadVertex(const CFX_Matrix& pObject2Bitmap,
227 CPDF_MeshVertex* vertex,
228 uint32_t* flag) {
229 if (!CanReadFlag())
230 return false;
231 *flag = ReadFlag();
232
233 if (!CanReadCoords())
234 return false;
235 vertex->position = pObject2Bitmap.Transform(ReadCoords());
236
237 if (!CanReadColor())
238 return false;
239 std::tie(vertex->r, vertex->g, vertex->b) = ReadColor();
240 m_BitStream->ByteAlign();
241 return true;
242 }
243
ReadVertexRow(const CFX_Matrix & pObject2Bitmap,int count)244 std::vector<CPDF_MeshVertex> CPDF_MeshStream::ReadVertexRow(
245 const CFX_Matrix& pObject2Bitmap,
246 int count) {
247 std::vector<CPDF_MeshVertex> vertices;
248 for (int i = 0; i < count; ++i) {
249 if (m_BitStream->IsEOF() || !CanReadCoords())
250 return std::vector<CPDF_MeshVertex>();
251
252 vertices.push_back(CPDF_MeshVertex());
253 CPDF_MeshVertex& vertex = vertices.back();
254 vertex.position = pObject2Bitmap.Transform(ReadCoords());
255 if (!CanReadColor())
256 return std::vector<CPDF_MeshVertex>();
257
258 std::tie(vertex.r, vertex.g, vertex.b) = ReadColor();
259 m_BitStream->ByteAlign();
260 }
261 return vertices;
262 }
263