Revert postscript code removal.

core/fxcodec/codec/fx_codec_fax.cpp

 // Copyright 2014 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 <algorithm>
 #include <memory>
 #include <vector>
 
 #include "core/fxcodec/codec/codec_int.h"
 #include "core/fxcodec/fx_codec.h"
+#include "core/fxcrt/fx_memory.h"
 #include "third_party/base/ptr_util.h"
 
 namespace {
 
 const uint8_t OneLeadPos[256] = {
     8, 7, 6, 6, 5, 5, 5, 5, 4, 4, 4, 4, 4, 4, 4, 4, 3, 3, 3, 3, 3, 3, 3, 3,
     3, 3, 3, 3, 3, 3, 3, 3, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
     2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 1, 1, 1, 1, 1, 1, 1, 1,
     1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
     1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
@@ skipping 14 matching lines @@
     1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
     1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
     2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
     2, 2, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3,
     4, 4, 4, 4, 4, 4, 4, 4, 5, 5, 5, 5, 6, 6, 7, 8,
 };
 
 // Limit of image dimension, an arbitrary large number.
 const int kMaxImageDimension = 0x01FFFF;
 
-int FindBit(const std::vector<uint8_t>& data_buf,
-            int max_pos,
-            int start_pos,
-            int bit) {
+int FindBit(const uint8_t* data_buf, int max_pos, int start_pos, int bit) {

[dsinclair, 2017/01/05 17:13:43]

This one's a bit weird. Why do we change from a vector to a raw pointer?

[rbpotter, 2017/01/05 22:58:18]

The encoder needs to call this function on rows of the source data. The source
data is represented as a raw pointer in order to avoid copying it and to easily
step through the rows. Previously the only caller called it on the reference
buffer for the decoder, which is a vector whose data gets rewritten on each
iteration. The other option would be to create a vector to pass in here and copy
the source data rows to it each iteration. Let me know if you think this would
be better.

   ASSERT(start_pos >= 0);
   if (start_pos >= max_pos)
     return max_pos;
 
   const uint8_t* leading_pos = bit ? OneLeadPos : ZeroLeadPos;
   if (start_pos % 8) {
     uint8_t data = data_buf[start_pos / 8];
     if (bit)
       data &= 0xff >> (start_pos % 8);
     else
@@ skipping 20 matching lines @@
 }
 
 void FaxG4FindB1B2(const std::vector<uint8_t>& ref_buf,
                    int columns,
                    int a0,
                    bool a0color,
                    int* b1,
                    int* b2) {
   uint8_t first_bit =
       (a0 < 0) ? 1 : ((ref_buf[a0 / 8] & (1 << (7 - a0 % 8))) != 0);
-  *b1 = FindBit(ref_buf, columns, a0 + 1, !first_bit);
+  *b1 = FindBit(ref_buf.data(), columns, a0 + 1, !first_bit);
   if (*b1 >= columns) {
     *b1 = *b2 = columns;
     return;
   }
   if (first_bit == !a0color) {
-    *b1 = FindBit(ref_buf, columns, *b1 + 1, first_bit);
+    *b1 = FindBit(ref_buf.data(), columns, *b1 + 1, first_bit);
     first_bit = !first_bit;
   }
   if (*b1 >= columns) {
     *b1 = *b2 = columns;
     return;
   }
-  *b2 = FindBit(ref_buf, columns, *b1 + 1, first_bit);
+  *b2 = FindBit(ref_buf.data(), columns, *b1 + 1, first_bit);
 }
 
 void FaxFillBits(uint8_t* dest_buf, int columns, int startpos, int endpos) {
   startpos = std::max(startpos, 0);
   endpos = std::min(std::max(endpos, 0), columns);
   if (startpos >= endpos)
     return;
 
   int first_byte = startpos / 8;
   int last_byte = (endpos - 1) / 8;
@@ skipping 487 matching lines @@
 
   // Reject unreasonable large input.
   if (actual_width > kMaxImageDimension || actual_height > kMaxImageDimension)
     return nullptr;
 
   uint32_t pitch = (static_cast<uint32_t>(actual_width) + 31) / 32 * 4;
   return pdfium::MakeUnique<CCodec_FaxDecoder>(
       src_buf, src_size, actual_width, actual_height, pitch, K, EndOfLine,
       EncodedByteAlign, BlackIs1);
 }
+
+#if _FX_OS_ == _FX_WIN32_DESKTOP_ || _FX_OS_ == _FX_WIN64_DESKTOP_
+namespace {
+const uint8_t BlackRunTerminator[128] = {
+    0x37, 10, 0x02, 3,  0x03, 2,  0x02, 2,  0x03, 3,  0x03, 4,  0x02, 4,
+    0x03, 5,  0x05, 6,  0x04, 6,  0x04, 7,  0x05, 7,  0x07, 7,  0x04, 8,
+    0x07, 8,  0x18, 9,  0x17, 10, 0x18, 10, 0x08, 10, 0x67, 11, 0x68, 11,
+    0x6c, 11, 0x37, 11, 0x28, 11, 0x17, 11, 0x18, 11, 0xca, 12, 0xcb, 12,
+    0xcc, 12, 0xcd, 12, 0x68, 12, 0x69, 12, 0x6a, 12, 0x6b, 12, 0xd2, 12,
+    0xd3, 12, 0xd4, 12, 0xd5, 12, 0xd6, 12, 0xd7, 12, 0x6c, 12, 0x6d, 12,
+    0xda, 12, 0xdb, 12, 0x54, 12, 0x55, 12, 0x56, 12, 0x57, 12, 0x64, 12,
+    0x65, 12, 0x52, 12, 0x53, 12, 0x24, 12, 0x37, 12, 0x38, 12, 0x27, 12,
+    0x28, 12, 0x58, 12, 0x59, 12, 0x2b, 12, 0x2c, 12, 0x5a, 12, 0x66, 12,
+    0x67, 12,
+};
+
+const uint8_t BlackRunMarkup[80] = {
+    0x0f, 10, 0xc8, 12, 0xc9, 12, 0x5b, 12, 0x33, 12, 0x34, 12, 0x35, 12,
+    0x6c, 13, 0x6d, 13, 0x4a, 13, 0x4b, 13, 0x4c, 13, 0x4d, 13, 0x72, 13,
+    0x73, 13, 0x74, 13, 0x75, 13, 0x76, 13, 0x77, 13, 0x52, 13, 0x53, 13,
+    0x54, 13, 0x55, 13, 0x5a, 13, 0x5b, 13, 0x64, 13, 0x65, 13, 0x08, 11,
+    0x0c, 11, 0x0d, 11, 0x12, 12, 0x13, 12, 0x14, 12, 0x15, 12, 0x16, 12,
+    0x17, 12, 0x1c, 12, 0x1d, 12, 0x1e, 12, 0x1f, 12,
+};
+
+const uint8_t WhiteRunTerminator[128] = {
+    0x35, 8, 0x07, 6, 0x07, 4, 0x08, 4, 0x0B, 4, 0x0C, 4, 0x0E, 4, 0x0F, 4,
+    0x13, 5, 0x14, 5, 0x07, 5, 0x08, 5, 0x08, 6, 0x03, 6, 0x34, 6, 0x35, 6,
+    0x2a, 6, 0x2B, 6, 0x27, 7, 0x0c, 7, 0x08, 7, 0x17, 7, 0x03, 7, 0x04, 7,
+    0x28, 7, 0x2B, 7, 0x13, 7, 0x24, 7, 0x18, 7, 0x02, 8, 0x03, 8, 0x1a, 8,
+    0x1b, 8, 0x12, 8, 0x13, 8, 0x14, 8, 0x15, 8, 0x16, 8, 0x17, 8, 0x28, 8,
+    0x29, 8, 0x2a, 8, 0x2b, 8, 0x2c, 8, 0x2d, 8, 0x04, 8, 0x05, 8, 0x0a, 8,
+    0x0b, 8, 0x52, 8, 0x53, 8, 0x54, 8, 0x55, 8, 0x24, 8, 0x25, 8, 0x58, 8,
+    0x59, 8, 0x5a, 8, 0x5b, 8, 0x4a, 8, 0x4b, 8, 0x32, 8, 0x33, 8, 0x34, 8,
+};
+
+const uint8_t WhiteRunMarkup[80] = {
+    0x1b, 5,  0x12, 5,  0x17, 6,  0x37, 7,  0x36, 8,  0x37, 8,  0x64, 8,
+    0x65, 8,  0x68, 8,  0x67, 8,  0xcc, 9,  0xcd, 9,  0xd2, 9,  0xd3, 9,
+    0xd4, 9,  0xd5, 9,  0xd6, 9,  0xd7, 9,  0xd8, 9,  0xd9, 9,  0xda, 9,
+    0xdb, 9,  0x98, 9,  0x99, 9,  0x9a, 9,  0x18, 6,  0x9b, 9,  0x08, 11,
+    0x0c, 11, 0x0d, 11, 0x12, 12, 0x13, 12, 0x14, 12, 0x15, 12, 0x16, 12,
+    0x17, 12, 0x1c, 12, 0x1d, 12, 0x1e, 12, 0x1f, 12,
+};
+
+void AddBitStream(uint8_t* dest_buf, int& dest_bitpos, int data, int bitlen) {
+  for (int i = bitlen - 1; i >= 0; i--) {
+    if (data & (1 << i)) {
+      dest_buf[dest_bitpos / 8] |= 1 << (7 - dest_bitpos % 8);
+    }
+    dest_bitpos++;
+  }
+}
+
+void FaxEncodeRun(uint8_t* dest_buf, int& dest_bitpos, int run, bool bWhite) {
+  while (run >= 2560) {
+    AddBitStream(dest_buf, dest_bitpos, 0x1f, 12);
+    run -= 2560;
+  }
+  if (run >= 64) {
+    int markup = run - run % 64;
+    const uint8_t* p = bWhite ? WhiteRunMarkup : BlackRunMarkup;
+    p += (markup / 64 - 1) * 2;
+    AddBitStream(dest_buf, dest_bitpos, *p, p[1]);
+  }
+  run %= 64;
+  const uint8_t* p = bWhite ? WhiteRunTerminator : BlackRunTerminator;
+  p += run * 2;
+  AddBitStream(dest_buf, dest_bitpos, *p, p[1]);
+}
+
+void FaxEncode2DLine(uint8_t* dest_buf,
+                     int& dest_bitpos,
+                     const uint8_t* src_buf,
+                     const std::vector<uint8_t>& ref_buf,
+                     int cols) {
+  int a0 = -1;
+  bool a0color = true;
+  while (1) {
+    int a1 = FindBit(src_buf, cols, a0 + 1, !a0color);
+    int b1;
+    int b2;
+    FaxG4FindB1B2(ref_buf, cols, a0, a0color, &b1, &b2);
+    if (b2 < a1) {
+      dest_bitpos += 3;
+      dest_buf[dest_bitpos / 8] |= 1 << (7 - dest_bitpos % 8);
+      dest_bitpos++;
+      a0 = b2;
+    } else if (a1 - b1 <= 3 && b1 - a1 <= 3) {
+      int delta = a1 - b1;
+      switch (delta) {
+        case 0:
+          dest_buf[dest_bitpos / 8] |= 1 << (7 - dest_bitpos % 8);
+          break;
+        case 1:
+        case 2:
+        case 3:
+          dest_bitpos += delta == 1 ? 1 : delta + 2;
+          dest_buf[dest_bitpos / 8] |= 1 << (7 - dest_bitpos % 8);
+          dest_bitpos++;
+          dest_buf[dest_bitpos / 8] |= 1 << (7 - dest_bitpos % 8);
+          break;
+        case -1:
+        case -2:
+        case -3:
+          dest_bitpos += delta == -1 ? 1 : -delta + 2;
+          dest_buf[dest_bitpos / 8] |= 1 << (7 - dest_bitpos % 8);
+          dest_bitpos++;
+          break;
+      }
+      dest_bitpos++;
+      a0 = a1;
+      a0color = !a0color;
+    } else {
+      int a2 = FindBit(src_buf, cols, a1 + 1, a0color);
+      dest_bitpos++;
+      dest_bitpos++;
+      dest_buf[dest_bitpos / 8] |= 1 << (7 - dest_bitpos % 8);
+      dest_bitpos++;
+      if (a0 < 0) {
+        a0 = 0;
+      }
+      FaxEncodeRun(dest_buf, dest_bitpos, a1 - a0, a0color);
+      FaxEncodeRun(dest_buf, dest_bitpos, a2 - a1, !a0color);
+      a0 = a2;
+    }
+    if (a0 >= cols) {
+      return;
+    }
+  }
+}
+
+class CCodec_FaxEncoder {
+ public:
+  CCodec_FaxEncoder(const uint8_t* src_buf, int width, int height, int pitch);
+  ~CCodec_FaxEncoder();
+  void Encode(std::unique_ptr<uint8_t, FxFreeDeleter>& dest_buf,
+              uint32_t& dest_size);
+
+ private:
+  CFX_BinaryBuf m_DestBuf;
+  std::vector<uint8_t> m_RefLine;
+  uint8_t* m_pLineBuf;
+  const int m_Cols;
+  const int m_Rows;
+  const int m_Pitch;
+  const uint8_t* m_pSrcBuf;
+};
+
+CCodec_FaxEncoder::CCodec_FaxEncoder(const uint8_t* src_buf,
+                                     int width,
+                                     int height,
+                                     int pitch)
+    : m_Cols(width), m_Rows(height), m_Pitch(pitch), m_pSrcBuf(src_buf) {
+  m_RefLine.resize(m_Pitch);
+  FXSYS_memset(m_RefLine.data(), 0xff, m_Pitch);
+  m_pLineBuf = FX_Alloc2D(uint8_t, m_Pitch, 8);
+  m_DestBuf.EstimateSize(0, 10240);
+}
+
+CCodec_FaxEncoder::~CCodec_FaxEncoder() {
+  FX_Free(m_pLineBuf);
+}
+
+void CCodec_FaxEncoder::Encode(
+    std::unique_ptr<uint8_t, FxFreeDeleter>& dest_buf,
+    uint32_t& dest_size) {
+  int dest_bitpos = 0;
+  uint8_t last_byte = 0;
+  for (int i = 0; i < m_Rows; i++) {
+    const uint8_t* scan_line = m_pSrcBuf + i * m_Pitch;
+    FXSYS_memset(m_pLineBuf, 0, m_Pitch * 8);
+    m_pLineBuf[0] = last_byte;
+    FaxEncode2DLine(m_pLineBuf, dest_bitpos, scan_line, m_RefLine, m_Cols);
+    m_DestBuf.AppendBlock(m_pLineBuf, dest_bitpos / 8);
+    last_byte = m_pLineBuf[dest_bitpos / 8];
+    dest_bitpos %= 8;
+    FXSYS_memcpy(m_RefLine.data(), scan_line, m_Pitch);
+  }
+  if (dest_bitpos) {
+    m_DestBuf.AppendByte(last_byte);
+  }
+  dest_size = m_DestBuf.GetSize();
+  dest_buf = m_DestBuf.DetachBuffer();
+}
+
+}  // namespace
+
+void CCodec_FaxModule::FaxEncode(
+    const uint8_t* src_buf,
+    int width,
+    int height,
+    int pitch,
+    std::unique_ptr<uint8_t, FxFreeDeleter>& dest_buf,
+    uint32_t& dest_size) {
+  CCodec_FaxEncoder encoder(src_buf, width, height, pitch);
+  encoder.Encode(dest_buf, dest_size);
+}
+
+#endif