1 files changed, 106 insertions, 0 deletions
diff --git a/core/fxge/cfx_cliprgn.cpp b/core/fxge/cfx_cliprgn.cpp
new file mode 100644
index 0000000000..087c11089a
--- /dev/null
+++ b/core/fxge/cfx_cliprgn.cpp
@@ -0,0 +1,106 @@
+// Copyright 2016 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/fxge/cfx_cliprgn.h"
+
+#include <utility>
+
+#include "core/fxge/dib/cfx_dibitmap.h"
+#include "third_party/base/logging.h"
+
+CFX_ClipRgn::CFX_ClipRgn(int width, int height)
+    : m_Type(RectI), m_Box(0, 0, width, height) {}
+
+CFX_ClipRgn::CFX_ClipRgn(const CFX_ClipRgn& src) {
+  m_Type = src.m_Type;
+  m_Box = src.m_Box;
+  m_Mask = src.m_Mask;
+}
+
+CFX_ClipRgn::~CFX_ClipRgn() {}
+
+void CFX_ClipRgn::Reset(const FX_RECT& rect) {
+  m_Type = RectI;
+  m_Box = rect;
+  m_Mask = nullptr;
+}
+
+void CFX_ClipRgn::IntersectRect(const FX_RECT& rect) {
+  if (m_Type == RectI) {
+    m_Box.Intersect(rect);
+    return;
+  }
+  if (m_Type == MaskF) {
+    IntersectMaskRect(rect, m_Box, m_Mask);
+    return;
+  }
+}
+
+void CFX_ClipRgn::IntersectMaskRect(FX_RECT rect,
+                                    FX_RECT mask_rect,
+                                    const CFX_RetainPtr<CFX_DIBitmap>& pMask) {
+  m_Type = MaskF;
+  m_Box = rect;
+  m_Box.Intersect(mask_rect);
+  if (m_Box.IsEmpty()) {
+    m_Type = RectI;
+    return;
+  }
+  if (m_Box == mask_rect) {
+    m_Mask = pMask;
+    return;
+  }
+  CFX_RetainPtr<CFX_DIBitmap> pOldMask(pMask);
+  m_Mask = pdfium::MakeRetain<CFX_DIBitmap>();
+  m_Mask->Create(m_Box.Width(), m_Box.Height(), FXDIB_8bppMask);
+  for (int row = m_Box.top; row < m_Box.bottom; row++) {
+    uint8_t* dest_scan =
+        m_Mask->GetBuffer() + m_Mask->GetPitch() * (row - m_Box.top);
+    uint8_t* src_scan =
+        pOldMask->GetBuffer() + pOldMask->GetPitch() * (row - mask_rect.top);
+    for (int col = m_Box.left; col < m_Box.right; col++)
+      dest_scan[col - m_Box.left] = src_scan[col - mask_rect.left];
+  }
+}
+
+void CFX_ClipRgn::IntersectMaskF(int left,
+                                 int top,
+                                 const CFX_RetainPtr<CFX_DIBitmap>& pMask) {
+  ASSERT(pMask->GetFormat() == FXDIB_8bppMask);
+  FX_RECT mask_box(left, top, left + pMask->GetWidth(),
+                   top + pMask->GetHeight());
+  if (m_Type == RectI) {
+    IntersectMaskRect(m_Box, mask_box, pMask);
+    return;
+  }
+  if (m_Type == MaskF) {
+    FX_RECT new_box = m_Box;
+    new_box.Intersect(mask_box);
+    if (new_box.IsEmpty()) {
+      m_Type = RectI;
+      m_Mask = nullptr;
+      m_Box = new_box;
+      return;
+    }
+    auto new_dib = pdfium::MakeRetain<CFX_DIBitmap>();
+    new_dib->Create(new_box.Width(), new_box.Height(), FXDIB_8bppMask);
+    for (int row = new_box.top; row < new_box.bottom; row++) {
+      uint8_t* old_scan =
+          m_Mask->GetBuffer() + (row - m_Box.top) * m_Mask->GetPitch();
+      uint8_t* mask_scan = pMask->GetBuffer() + (row - top) * pMask->GetPitch();
+      uint8_t* new_scan =
+          new_dib->GetBuffer() + (row - new_box.top) * new_dib->GetPitch();
+      for (int col = new_box.left; col < new_box.right; col++) {
+        new_scan[col - new_box.left] =
+            old_scan[col - m_Box.left] * mask_scan[col - left] / 255;
+      }
+    }
+    m_Box = new_box;
+    m_Mask = std::move(new_dib);
+    return;
+  }
+  NOTREACHED();
+}