1 files changed, 91 insertions, 0 deletions
diff --git a/core/fpdfapi/page/cpdf_stitchfunc.cpp b/core/fpdfapi/page/cpdf_stitchfunc.cpp
new file mode 100644
index 0000000000..336c74bf5c
--- /dev/null
+++ b/core/fpdfapi/page/cpdf_stitchfunc.cpp
@@ -0,0 +1,91 @@
+// 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_stitchfunc.h"
+
+#include <utility>
+
+#include "core/fpdfapi/parser/cpdf_array.h"
+#include "core/fpdfapi/parser/cpdf_dictionary.h"
+#include "core/fxcrt/fx_memory.h"
+
+CPDF_StitchFunc::CPDF_StitchFunc()
+    : CPDF_Function(Type::kType3Stitching),
+      m_pBounds(nullptr),
+      m_pEncode(nullptr) {}
+
+CPDF_StitchFunc::~CPDF_StitchFunc() {
+  FX_Free(m_pBounds);
+  FX_Free(m_pEncode);
+}
+
+bool CPDF_StitchFunc::v_Init(CPDF_Object* pObj) {
+  CPDF_Dictionary* pDict = pObj->GetDict();
+  if (!pDict) {
+    return false;
+  }
+  if (m_nInputs != kRequiredNumInputs) {
+    return false;
+  }
+  CPDF_Array* pArray = pDict->GetArrayFor("Functions");
+  if (!pArray) {
+    return false;
+  }
+  uint32_t nSubs = pArray->GetCount();
+  if (nSubs == 0)
+    return false;
+  m_nOutputs = 0;
+  for (uint32_t i = 0; i < nSubs; i++) {
+    CPDF_Object* pSub = pArray->GetDirectObjectAt(i);
+    if (pSub == pObj)
+      return false;
+    std::unique_ptr<CPDF_Function> pFunc(CPDF_Function::Load(pSub));
+    if (!pFunc)
+      return false;
+    // Check that the input dimensionality is 1, and that all output
+    // dimensionalities are the same.
+    if (pFunc->CountInputs() != kRequiredNumInputs)
+      return false;
+    if (pFunc->CountOutputs() != m_nOutputs) {
+      if (m_nOutputs)
+        return false;
+
+      m_nOutputs = pFunc->CountOutputs();
+    }
+
+    m_pSubFunctions.push_back(std::move(pFunc));
+  }
+  m_pBounds = FX_Alloc(float, nSubs + 1);
+  m_pBounds[0] = m_pDomains[0];
+  pArray = pDict->GetArrayFor("Bounds");
+  if (!pArray)
+    return false;
+  for (uint32_t i = 0; i < nSubs - 1; i++)
+    m_pBounds[i + 1] = pArray->GetFloatAt(i);
+  m_pBounds[nSubs] = m_pDomains[1];
+  m_pEncode = FX_Alloc2D(float, nSubs, 2);
+  pArray = pDict->GetArrayFor("Encode");
+  if (!pArray)
+    return false;
+
+  for (uint32_t i = 0; i < nSubs * 2; i++)
+    m_pEncode[i] = pArray->GetFloatAt(i);
+  return true;
+}
+
+bool CPDF_StitchFunc::v_Call(float* inputs, float* outputs) const {
+  float input = inputs[0];
+  size_t i;
+  for (i = 0; i < m_pSubFunctions.size() - 1; i++) {
+    if (input < m_pBounds[i + 1])
+      break;
+  }
+  input = Interpolate(input, m_pBounds[i], m_pBounds[i + 1], m_pEncode[i * 2],
+                      m_pEncode[i * 2 + 1]);
+  int nresults;
+  m_pSubFunctions[i]->Call(&input, kRequiredNumInputs, outputs, &nresults);
+  return true;
+}