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cpdf_function.cpp
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1// Copyright 2017 The PDFium Authors
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_function.h"
8
9#include <algorithm>
10#include <utility>
11#include <vector>
12
13#include "core/fpdfapi/page/cpdf_expintfunc.h"
14#include "core/fpdfapi/page/cpdf_psfunc.h"
15#include "core/fpdfapi/page/cpdf_sampledfunc.h"
16#include "core/fpdfapi/page/cpdf_stitchfunc.h"
17#include "core/fpdfapi/parser/cpdf_array.h"
18#include "core/fpdfapi/parser/cpdf_dictionary.h"
19#include "core/fpdfapi/parser/cpdf_stream.h"
20#include "core/fpdfapi/parser/fpdf_parser_utility.h"
21#include "core/fxcrt/fx_safe_types.h"
22#include "core/fxcrt/scoped_set_insertion.h"
23#include "core/fxcrt/stl_util.h"
24#include "third_party/base/containers/contains.h"
25
26namespace {
27
28CPDF_Function::Type IntegerToFunctionType(int iType) {
29 switch (iType) {
30 case 0:
31 case 2:
32 case 3:
33 case 4:
34 return static_cast<CPDF_Function::Type>(iType);
35 default:
37 }
38}
39
40} // namespace
41
42// static
43std::unique_ptr<CPDF_Function> CPDF_Function::Load(
44 RetainPtr<const CPDF_Object> pFuncObj) {
45 VisitedSet visited;
46 return Load(std::move(pFuncObj), &visited);
47}
48
49// static
50std::unique_ptr<CPDF_Function> CPDF_Function::Load(
51 RetainPtr<const CPDF_Object> pFuncObj,
52 VisitedSet* pVisited) {
53 if (!pFuncObj)
54 return nullptr;
55
56 if (pdfium::Contains(*pVisited, pFuncObj))
57 return nullptr;
58
59 ScopedSetInsertion<VisitedSet::value_type> insertion(pVisited, pFuncObj);
60
61 int iType = -1;
62 if (const CPDF_Stream* pStream = pFuncObj->AsStream())
63 iType = pStream->GetDict()->GetIntegerFor("FunctionType");
64 else if (const CPDF_Dictionary* pDict = pFuncObj->AsDictionary())
65 iType = pDict->GetIntegerFor("FunctionType");
66
67 std::unique_ptr<CPDF_Function> pFunc;
68 Type type = IntegerToFunctionType(iType);
69 if (type == Type::kType0Sampled)
70 pFunc = std::make_unique<CPDF_SampledFunc>();
72 pFunc = std::make_unique<CPDF_ExpIntFunc>();
73 else if (type == Type::kType3Stitching)
74 pFunc = std::make_unique<CPDF_StitchFunc>();
75 else if (type == Type::kType4PostScript)
76 pFunc = std::make_unique<CPDF_PSFunc>();
77
78 if (!pFunc || !pFunc->Init(pFuncObj, pVisited))
79 return nullptr;
80
81 return pFunc;
82}
83
85
86CPDF_Function::~CPDF_Function() = default;
87
88bool CPDF_Function::Init(const CPDF_Object* pObj, VisitedSet* pVisited) {
89 const CPDF_Stream* pStream = pObj->AsStream();
90 RetainPtr<const CPDF_Dictionary> pDict =
91 pStream ? pStream->GetDict() : pdfium::WrapRetain(pObj->AsDictionary());
92
93 RetainPtr<const CPDF_Array> pDomains = pDict->GetArrayFor("Domain");
94 if (!pDomains)
95 return false;
96
97 m_nInputs = fxcrt::CollectionSize<uint32_t>(*pDomains) / 2;
98 if (m_nInputs == 0)
99 return false;
100
101 size_t nInputs = m_nInputs * 2;
102 m_Domains = ReadArrayElementsToVector(pDomains.Get(), nInputs);
103
104 RetainPtr<const CPDF_Array> pRanges = pDict->GetArrayFor("Range");
105 m_nOutputs = pRanges ? fxcrt::CollectionSize<uint32_t>(*pRanges) / 2 : 0;
106
107 // Ranges are required for type 0 and type 4 functions. A non-zero
108 // |m_nOutputs| here implied Ranges meets the requirements.
109 bool bRangeRequired =
111 if (bRangeRequired && m_nOutputs == 0)
112 return false;
113
114 if (m_nOutputs > 0) {
115 size_t nOutputs = m_nOutputs * 2;
116 m_Ranges = ReadArrayElementsToVector(pRanges.Get(), nOutputs);
117 }
118
119 uint32_t old_outputs = m_nOutputs;
120 if (!v_Init(pObj, pVisited))
121 return false;
122
123 if (!m_Ranges.empty() && m_nOutputs > old_outputs) {
124 FX_SAFE_SIZE_T nOutputs = m_nOutputs;
125 nOutputs *= 2;
126 m_Ranges.resize(nOutputs.ValueOrDie());
127 }
128 return true;
129}
130
132 pdfium::span<const float> inputs,
133 pdfium::span<float> results) const {
134 if (m_nInputs != inputs.size())
135 return absl::nullopt;
136
137 std::vector<float> clamped_inputs(m_nInputs);
138 for (uint32_t i = 0; i < m_nInputs; i++) {
139 float domain1 = m_Domains[i * 2];
140 float domain2 = m_Domains[i * 2 + 1];
141 if (domain1 > domain2)
142 return absl::nullopt;
143
144 clamped_inputs[i] = std::clamp(inputs[i], domain1, domain2);
145 }
146 if (!v_Call(clamped_inputs, results))
147 return absl::nullopt;
148
149 if (m_Ranges.empty())
150 return m_nOutputs;
151
152 for (uint32_t i = 0; i < m_nOutputs; i++) {
153 float range1 = m_Ranges[i * 2];
154 float range2 = m_Ranges[i * 2 + 1];
155 if (range1 > range2)
156 return absl::nullopt;
157
158 results[i] = std::clamp(results[i], range1, range2);
159 }
160 return m_nOutputs;
161}
162
163// See PDF Reference 1.7, page 170.
165 float xmin,
166 float xmax,
167 float ymin,
168 float ymax) const {
169 float divisor = xmax - xmin;
170 return ymin + (divisor ? (x - xmin) * (ymax - ymin) / divisor : 0);
171}
172
173#if defined(PDF_USE_SKIA)
174const CPDF_SampledFunc* CPDF_Function::ToSampledFunc() const {
175 return m_Type == Type::kType0Sampled
176 ? static_cast<const CPDF_SampledFunc*>(this)
177 : nullptr;
178}
179
180const CPDF_ExpIntFunc* CPDF_Function::ToExpIntFunc() const {
181 return m_Type == Type::kType2ExponentialInterpolation
182 ? static_cast<const CPDF_ExpIntFunc*>(this)
183 : nullptr;
184}
185
186const CPDF_StitchFunc* CPDF_Function::ToStitchFunc() const {
187 return m_Type == Type::kType3Stitching
188 ? static_cast<const CPDF_StitchFunc*>(this)
189 : nullptr;
190}
191#endif // defined(PDF_USE_SKIA)
int GetIntegerFor(const ByteString &key) const
uint32_t m_nOutputs
uint32_t m_nInputs
virtual ~CPDF_Function()
bool Init(const CPDF_Object *pObj, VisitedSet *pVisited)
CPDF_Function(Type type)
const Type m_Type
absl::optional< uint32_t > Call(pdfium::span< const float > inputs, pdfium::span< float > results) const
float Interpolate(float x, float xmin, float xmax, float ymin, float ymax) const
RetainPtr< const CPDF_Dictionary > GetDict() const
const CPDF_Stream * AsStream() const