blob: ddce719410d2f2b44d817c5bf6dfda1049df3515 [file] [log] [blame]
// 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_stitchfunc.h"
#include <utility>
#include "core/fpdfapi/parser/cpdf_array.h"
#include "core/fpdfapi/parser/cpdf_dictionary.h"
#include "core/fpdfapi/parser/fpdf_parser_utility.h"
#include "core/fxcrt/fx_safe_types.h"
#include "core/fxcrt/stl_util.h"
namespace {
constexpr uint32_t kRequiredNumInputs = 1;
} // namespace
CPDF_StitchFunc::CPDF_StitchFunc() : CPDF_Function(Type::kType3Stitching) {}
CPDF_StitchFunc::~CPDF_StitchFunc() = default;
bool CPDF_StitchFunc::v_Init(const CPDF_Object* pObj, VisitedSet* pVisited) {
if (m_nInputs != kRequiredNumInputs)
return false;
CHECK(pObj->IsDictionary() || pObj->IsStream());
RetainPtr<const CPDF_Dictionary> pDict = pObj->GetDict();
RetainPtr<const CPDF_Array> pFunctionsArray = pDict->GetArrayFor("Functions");
if (!pFunctionsArray)
return false;
RetainPtr<const CPDF_Array> pBoundsArray = pDict->GetArrayFor("Bounds");
if (!pBoundsArray)
return false;
RetainPtr<const CPDF_Array> pEncodeArray = pDict->GetArrayFor("Encode");
if (!pEncodeArray)
return false;
const uint32_t nSubs = fxcrt::CollectionSize<uint32_t>(*pFunctionsArray);
if (nSubs == 0)
return false;
// Check array sizes. The checks are slightly relaxed to allow the "Bounds"
// and "Encode" arrays to have more than the required number of elements.
{
if (pBoundsArray->size() < nSubs - 1)
return false;
FX_SAFE_UINT32 nExpectedEncodeSize = nSubs;
nExpectedEncodeSize *= 2;
if (!nExpectedEncodeSize.IsValid())
return false;
if (pEncodeArray->size() < nExpectedEncodeSize.ValueOrDie())
return false;
}
// Check sub-functions.
{
std::optional<uint32_t> nOutputs;
for (uint32_t i = 0; i < nSubs; ++i) {
RetainPtr<const CPDF_Object> pSub = pFunctionsArray->GetDirectObjectAt(i);
if (pSub == pObj)
return false;
std::unique_ptr<CPDF_Function> pFunc =
CPDF_Function::Load(std::move(pSub), pVisited);
if (!pFunc)
return false;
// Check that the input dimensionality is 1, and that all output
// dimensionalities are the same.
if (pFunc->InputCount() != kRequiredNumInputs) {
return false;
}
uint32_t nFuncOutputs = pFunc->OutputCount();
if (nFuncOutputs == 0)
return false;
if (nOutputs.has_value()) {
if (nOutputs != nFuncOutputs)
return false;
} else {
nOutputs = nFuncOutputs;
}
m_pSubFunctions.push_back(std::move(pFunc));
}
m_nOutputs = nOutputs.value();
}
m_bounds.reserve(nSubs + 1);
m_bounds.push_back(m_Domains[0]);
for (uint32_t i = 0; i < nSubs - 1; i++)
m_bounds.push_back(pBoundsArray->GetFloatAt(i));
m_bounds.push_back(m_Domains[1]);
m_encode = ReadArrayElementsToVector(pEncodeArray.Get(), nSubs * 2);
return true;
}
bool CPDF_StitchFunc::v_Call(pdfium::span<const float> inputs,
pdfium::span<float> results) const {
float input = inputs[0];
size_t i;
for (i = 0; i + 1 < m_pSubFunctions.size(); i++) {
if (input < m_bounds[i + 1])
break;
}
input = Interpolate(input, m_bounds[i], m_bounds[i + 1], m_encode[i * 2],
m_encode[i * 2 + 1]);
return m_pSubFunctions[i]
->Call(pdfium::span_from_ref(input), results)
.has_value();
}