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// Copyright 2017 PDFium Authors. All rights reserved.
// 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 <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 "third_party/base/stl_util.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(
const CPDF_Object* pFuncObj) {
std::set<const CPDF_Object*> visited;
return Load(pFuncObj, &visited);
}
// static
std::unique_ptr<CPDF_Function> CPDF_Function::Load(
const CPDF_Object* pFuncObj,
std::set<const CPDF_Object*>* pVisited) {
if (!pFuncObj)
return nullptr;
if (pdfium::Contains(*pVisited, pFuncObj))
return nullptr;
pdfium::ScopedSetInsertion<const CPDF_Object*> 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,
std::set<const CPDF_Object*>* pVisited) {
const CPDF_Stream* pStream = pObj->AsStream();
const CPDF_Dictionary* pDict =
pStream ? pStream->GetDict() : pObj->AsDictionary();
const CPDF_Array* pDomains = pDict->GetArrayFor("Domain");
if (!pDomains)
return false;
m_nInputs = pDomains->size() / 2;
if (m_nInputs == 0)
return false;
size_t nInputs = m_nInputs * 2;
m_Domains = ReadArrayElementsToVector(pDomains, nInputs);
const CPDF_Array* pRanges = pDict->GetArrayFor("Range");
m_nOutputs = pRanges ? pRanges->size() / 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, 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;
}
bool CPDF_Function::Call(const float* inputs,
uint32_t ninputs,
float* results,
int* nresults) const {
if (m_nInputs != ninputs)
return false;
*nresults = m_nOutputs;
std::vector<float> clamped_inputs(m_nInputs);
for (uint32_t i = 0; i < m_nInputs; i++) {
clamped_inputs[i] =
pdfium::clamp(inputs[i], m_Domains[i * 2], m_Domains[i * 2 + 1]);
}
if (!v_Call(clamped_inputs.data(), results))
return false;
if (m_Ranges.empty())
return true;
for (uint32_t i = 0; i < m_nOutputs; i++) {
results[i] =
pdfium::clamp(results[i], m_Ranges[i * 2], m_Ranges[i * 2 + 1]);
}
return true;
}
// 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);
}
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;
}