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// Copyright 2017 The PDFium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
// Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
#include "core/fpdfapi/page/cpdf_function.h"
#include <algorithm>
#include <utility>
#include <vector>
#include "core/fpdfapi/page/cpdf_expintfunc.h"
#include "core/fpdfapi/page/cpdf_psfunc.h"
#include "core/fpdfapi/page/cpdf_sampledfunc.h"
#include "core/fpdfapi/page/cpdf_stitchfunc.h"
#include "core/fpdfapi/parser/cpdf_array.h"
#include "core/fpdfapi/parser/cpdf_dictionary.h"
#include "core/fpdfapi/parser/cpdf_stream.h"
#include "core/fpdfapi/parser/fpdf_parser_utility.h"
#include "core/fxcrt/fx_safe_types.h"
#include "core/fxcrt/scoped_set_insertion.h"
#include "core/fxcrt/stl_util.h"
#include "third_party/base/containers/contains.h"
namespace {
CPDF_Function::Type IntegerToFunctionType(int iType) {
switch (iType) {
case 0:
case 2:
case 3:
case 4:
return static_cast<CPDF_Function::Type>(iType);
default:
return CPDF_Function::Type::kTypeInvalid;
}
}
} // namespace
// static
std::unique_ptr<CPDF_Function> CPDF_Function::Load(
RetainPtr<const CPDF_Object> pFuncObj) {
VisitedSet visited;
return Load(std::move(pFuncObj), &visited);
}
// static
std::unique_ptr<CPDF_Function> CPDF_Function::Load(
RetainPtr<const CPDF_Object> pFuncObj,
VisitedSet* pVisited) {
if (!pFuncObj)
return nullptr;
if (pdfium::Contains(*pVisited, pFuncObj))
return nullptr;
ScopedSetInsertion<VisitedSet::value_type> insertion(pVisited, pFuncObj);
int iType = -1;
if (const CPDF_Stream* pStream = pFuncObj->AsStream())
iType = pStream->GetDict()->GetIntegerFor("FunctionType");
else if (const CPDF_Dictionary* pDict = pFuncObj->AsDictionary())
iType = pDict->GetIntegerFor("FunctionType");
std::unique_ptr<CPDF_Function> pFunc;
Type type = IntegerToFunctionType(iType);
if (type == Type::kType0Sampled)
pFunc = std::make_unique<CPDF_SampledFunc>();
else if (type == Type::kType2ExponentialInterpolation)
pFunc = std::make_unique<CPDF_ExpIntFunc>();
else if (type == Type::kType3Stitching)
pFunc = std::make_unique<CPDF_StitchFunc>();
else if (type == Type::kType4PostScript)
pFunc = std::make_unique<CPDF_PSFunc>();
if (!pFunc || !pFunc->Init(pFuncObj, pVisited))
return nullptr;
return pFunc;
}
CPDF_Function::CPDF_Function(Type type) : m_Type(type) {}
CPDF_Function::~CPDF_Function() = default;
bool CPDF_Function::Init(const CPDF_Object* pObj, VisitedSet* pVisited) {
const CPDF_Stream* pStream = pObj->AsStream();
RetainPtr<const CPDF_Dictionary> pDict =
pStream ? pStream->GetDict() : pdfium::WrapRetain(pObj->AsDictionary());
RetainPtr<const CPDF_Array> pDomains = pDict->GetArrayFor("Domain");
if (!pDomains)
return false;
m_nInputs = fxcrt::CollectionSize<uint32_t>(*pDomains) / 2;
if (m_nInputs == 0)
return false;
size_t nInputs = m_nInputs * 2;
m_Domains = ReadArrayElementsToVector(pDomains.Get(), nInputs);
RetainPtr<const CPDF_Array> pRanges = pDict->GetArrayFor("Range");
m_nOutputs = pRanges ? fxcrt::CollectionSize<uint32_t>(*pRanges) / 2 : 0;
// Ranges are required for type 0 and type 4 functions. A non-zero
// |m_nOutputs| here implied Ranges meets the requirements.
bool bRangeRequired =
m_Type == Type::kType0Sampled || m_Type == Type::kType4PostScript;
if (bRangeRequired && m_nOutputs == 0)
return false;
if (m_nOutputs > 0) {
size_t nOutputs = m_nOutputs * 2;
m_Ranges = ReadArrayElementsToVector(pRanges.Get(), nOutputs);
}
uint32_t old_outputs = m_nOutputs;
if (!v_Init(pObj, pVisited))
return false;
if (!m_Ranges.empty() && m_nOutputs > old_outputs) {
FX_SAFE_SIZE_T nOutputs = m_nOutputs;
nOutputs *= 2;
m_Ranges.resize(nOutputs.ValueOrDie());
}
return true;
}
absl::optional<uint32_t> CPDF_Function::Call(
pdfium::span<const float> inputs,
pdfium::span<float> results) const {
if (m_nInputs != inputs.size())
return absl::nullopt;
std::vector<float> clamped_inputs(m_nInputs);
for (uint32_t i = 0; i < m_nInputs; i++) {
float domain1 = m_Domains[i * 2];
float domain2 = m_Domains[i * 2 + 1];
if (domain1 > domain2)
return absl::nullopt;
clamped_inputs[i] = std::clamp(inputs[i], domain1, domain2);
}
if (!v_Call(clamped_inputs, results))
return absl::nullopt;
if (m_Ranges.empty())
return m_nOutputs;
for (uint32_t i = 0; i < m_nOutputs; i++) {
float range1 = m_Ranges[i * 2];
float range2 = m_Ranges[i * 2 + 1];
if (range1 > range2)
return absl::nullopt;
results[i] = std::clamp(results[i], range1, range2);
}
return m_nOutputs;
}
// See PDF Reference 1.7, page 170.
float CPDF_Function::Interpolate(float x,
float xmin,
float xmax,
float ymin,
float ymax) const {
float divisor = xmax - xmin;
return ymin + (divisor ? (x - xmin) * (ymax - ymin) / divisor : 0);
}
#if defined(_SKIA_SUPPORT_)
const CPDF_SampledFunc* CPDF_Function::ToSampledFunc() const {
return m_Type == Type::kType0Sampled
? static_cast<const CPDF_SampledFunc*>(this)
: nullptr;
}
const CPDF_ExpIntFunc* CPDF_Function::ToExpIntFunc() const {
return m_Type == Type::kType2ExponentialInterpolation
? static_cast<const CPDF_ExpIntFunc*>(this)
: nullptr;
}
const CPDF_StitchFunc* CPDF_Function::ToStitchFunc() const {
return m_Type == Type::kType3Stitching
? static_cast<const CPDF_StitchFunc*>(this)
: nullptr;
}
#endif // defined(_SKIA_SUPPORT_)