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// Copyright 2016 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_shadingpattern.h"
#include <algorithm>
#include <utility>
#include "core/fpdfapi/page/cpdf_docpagedata.h"
#include "core/fpdfapi/page/cpdf_function.h"
#include "core/fpdfapi/parser/cpdf_array.h"
#include "core/fpdfapi/parser/cpdf_dictionary.h"
#include "core/fpdfapi/parser/cpdf_document.h"
#include "core/fpdfapi/parser/cpdf_object.h"
#include "core/fpdfapi/parser/cpdf_stream.h"
#include "core/fxcrt/check.h"
#include "core/fxcrt/fx_safe_types.h"
#include "core/fxcrt/notreached.h"
namespace {
ShadingType ToShadingType(int type) {
return (type > kInvalidShading && type < kMaxShading)
? static_cast<ShadingType>(type)
: kInvalidShading;
}
} // namespace
CPDF_ShadingPattern::CPDF_ShadingPattern(CPDF_Document* pDoc,
RetainPtr<CPDF_Object> pPatternObj,
bool bShading,
const CFX_Matrix& parentMatrix)
: CPDF_Pattern(pDoc, std::move(pPatternObj), parentMatrix),
m_bShading(bShading) {
DCHECK(document());
if (!bShading)
SetPatternToFormMatrix();
}
CPDF_ShadingPattern::~CPDF_ShadingPattern() = default;
CPDF_ShadingPattern* CPDF_ShadingPattern::AsShadingPattern() {
return this;
}
bool CPDF_ShadingPattern::Load() {
if (m_ShadingType != kInvalidShading)
return true;
RetainPtr<const CPDF_Object> pShadingObj = GetShadingObject();
RetainPtr<const CPDF_Dictionary> pShadingDict =
pShadingObj ? pShadingObj->GetDict() : nullptr;
if (!pShadingDict)
return false;
m_pFunctions.clear();
RetainPtr<const CPDF_Object> pFunc =
pShadingDict->GetDirectObjectFor("Function");
if (pFunc) {
if (const CPDF_Array* pArray = pFunc->AsArray()) {
m_pFunctions.resize(std::min<size_t>(pArray->size(), 4));
for (size_t i = 0; i < m_pFunctions.size(); ++i) {
m_pFunctions[i] = CPDF_Function::Load(pArray->GetDirectObjectAt(i));
}
} else {
m_pFunctions.push_back(CPDF_Function::Load(std::move(pFunc)));
}
}
RetainPtr<const CPDF_Object> pCSObj =
pShadingDict->GetDirectObjectFor("ColorSpace");
if (!pCSObj)
return false;
auto* pDocPageData = CPDF_DocPageData::FromDocument(document());
m_pCS = pDocPageData->GetColorSpace(pCSObj.Get(), nullptr);
// The color space is required and cannot be a Pattern space, according to the
// PDF 1.7 spec, page 305.
if (!m_pCS || m_pCS->GetFamily() == CPDF_ColorSpace::Family::kPattern)
return false;
m_ShadingType = ToShadingType(pShadingDict->GetIntegerFor("ShadingType"));
return Validate();
}
RetainPtr<const CPDF_Object> CPDF_ShadingPattern::GetShadingObject() const {
return m_bShading ? pattern_obj()
: pattern_obj()->GetDict()->GetDirectObjectFor("Shading");
}
bool CPDF_ShadingPattern::Validate() const {
if (m_ShadingType == kInvalidShading)
return false;
// We expect to have a stream if our shading type is a mesh.
if (IsMeshShading() && !ToStream(GetShadingObject()))
return false;
// Validate color space
switch (m_ShadingType) {
case kFunctionBasedShading:
case kAxialShading:
case kRadialShading: {
if (m_pCS->GetFamily() == CPDF_ColorSpace::Family::kIndexed)
return false;
break;
}
case kFreeFormGouraudTriangleMeshShading:
case kLatticeFormGouraudTriangleMeshShading:
case kCoonsPatchMeshShading:
case kTensorProductPatchMeshShading: {
if (!m_pFunctions.empty() &&
m_pCS->GetFamily() == CPDF_ColorSpace::Family::kIndexed) {
return false;
}
break;
}
default: {
NOTREACHED_NORETURN();
}
}
uint32_t nNumColorSpaceComponents = m_pCS->ComponentCount();
switch (m_ShadingType) {
case kFunctionBasedShading: {
// Either one 2-to-N function or N 2-to-1 functions.
return ValidateFunctions(1, 2, nNumColorSpaceComponents) ||
ValidateFunctions(nNumColorSpaceComponents, 2, 1);
}
case kAxialShading:
case kRadialShading: {
// Either one 1-to-N function or N 1-to-1 functions.
return ValidateFunctions(1, 1, nNumColorSpaceComponents) ||
ValidateFunctions(nNumColorSpaceComponents, 1, 1);
}
case kFreeFormGouraudTriangleMeshShading:
case kLatticeFormGouraudTriangleMeshShading:
case kCoonsPatchMeshShading:
case kTensorProductPatchMeshShading: {
// Either no function, one 1-to-N function, or N 1-to-1 functions.
return m_pFunctions.empty() ||
ValidateFunctions(1, 1, nNumColorSpaceComponents) ||
ValidateFunctions(nNumColorSpaceComponents, 1, 1);
}
default:
NOTREACHED_NORETURN();
}
}
bool CPDF_ShadingPattern::ValidateFunctions(
uint32_t nExpectedNumFunctions,
uint32_t nExpectedNumInputs,
uint32_t nExpectedNumOutputs) const {
if (m_pFunctions.size() != nExpectedNumFunctions)
return false;
FX_SAFE_UINT32 nTotalOutputs = 0;
for (const auto& function : m_pFunctions) {
if (!function)
return false;
if (function->InputCount() != nExpectedNumInputs ||
function->OutputCount() != nExpectedNumOutputs) {
return false;
}
nTotalOutputs += function->OutputCount();
}
return nTotalOutputs.IsValid();
}