1 files changed, 60 insertions, 0 deletions
diff --git a/core/fpdfapi/page/cpdf_expintfunc.cpp b/core/fpdfapi/page/cpdf_expintfunc.cpp
new file mode 100644
index 0000000000..5d1213131b
--- /dev/null
+++ b/core/fpdfapi/page/cpdf_expintfunc.cpp
@@ -0,0 +1,60 @@
+// 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_expintfunc.h"
+
+#include "core/fpdfapi/parser/cpdf_array.h"
+#include "core/fpdfapi/parser/cpdf_dictionary.h"
+#include "core/fxcrt/fx_memory.h"
+
+CPDF_ExpIntFunc::CPDF_ExpIntFunc()
+    : CPDF_Function(Type::kType2ExpotentialInterpolation),
+      m_pBeginValues(nullptr),
+      m_pEndValues(nullptr) {}
+
+CPDF_ExpIntFunc::~CPDF_ExpIntFunc() {
+  FX_Free(m_pBeginValues);
+  FX_Free(m_pEndValues);
+}
+
+bool CPDF_ExpIntFunc::v_Init(CPDF_Object* pObj) {
+  CPDF_Dictionary* pDict = pObj->GetDict();
+  if (!pDict)
+    return false;
+
+  CPDF_Array* pArray0 = pDict->GetArrayFor("C0");
+  if (m_nOutputs == 0) {
+    m_nOutputs = 1;
+    if (pArray0)
+      m_nOutputs = pArray0->GetCount();
+  }
+
+  CPDF_Array* pArray1 = pDict->GetArrayFor("C1");
+  m_pBeginValues = FX_Alloc2D(float, m_nOutputs, 2);
+  m_pEndValues = FX_Alloc2D(float, m_nOutputs, 2);
+  for (uint32_t i = 0; i < m_nOutputs; i++) {
+    m_pBeginValues[i] = pArray0 ? pArray0->GetFloatAt(i) : 0.0f;
+    m_pEndValues[i] = pArray1 ? pArray1->GetFloatAt(i) : 1.0f;
+  }
+
+  m_Exponent = pDict->GetFloatFor("N");
+  m_nOrigOutputs = m_nOutputs;
+  if (m_nOutputs && m_nInputs > INT_MAX / m_nOutputs)
+    return false;
+
+  m_nOutputs *= m_nInputs;
+  return true;
+}
+
+bool CPDF_ExpIntFunc::v_Call(float* inputs, float* results) const {
+  for (uint32_t i = 0; i < m_nInputs; i++)
+    for (uint32_t j = 0; j < m_nOrigOutputs; j++) {
+      results[i * m_nOrigOutputs + j] =
+          m_pBeginValues[j] + FXSYS_pow(inputs[i], m_Exponent) *
+                                  (m_pEndValues[j] - m_pBeginValues[j]);
+    }
+  return true;
+}