YuvStamper.h - mozsearch

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/* This Source Code Form is subject to the terms of the Mozilla Public

 * License, v. 2.0. If a copy of the MPL was not distributed with this file,

 * You can obtain one at http://mozilla.org/MPL/2.0/. */

#ifndef YUV_STAMPER_H_

#define YUV_STAMPER_H_

#include <cstdint>

namespace mozilla {

class YuvStamper {

 public:

  bool WriteDigits(uint32_t value);

  template <typename T>

  static bool Write(uint32_t width, uint32_t height, uint32_t stride,

                    unsigned char* pYData, const T& value, uint32_t x = 0,

                    uint32_t y = 0) {

    YuvStamper stamper(pYData, width, height, stride, x, y,

                       (sDigitWidth + sInterDigit) * sPixelSize,

                       (sDigitHeight + sInterLine) * sPixelSize);

    return stamper.WriteDigits(value);

  static bool Encode(uint32_t width, uint32_t height, uint32_t stride,

                     unsigned char* pYData, unsigned char* pMsg, size_t msg_len,

                     uint32_t x = 0, uint32_t y = 0);

  static bool Decode(uint32_t width, uint32_t height, uint32_t stride,

                     unsigned char* pYData, unsigned char* pMsg, size_t msg_len,

                     uint32_t x = 0, uint32_t y = 0);

 private:

  YuvStamper(unsigned char* pYData, uint32_t width, uint32_t height,

             uint32_t stride, uint32_t x, uint32_t y,

             unsigned char symbol_width, unsigned char symbol_height);

  bool WriteDigit(unsigned char digit);

  void WritePixel(unsigned char* data, uint32_t x, uint32_t y);

  uint32_t Capacity();

  bool AdvanceCursor();

  bool WriteBit(bool one);

  bool Write8(unsigned char value);

  bool ReadBit(unsigned char& value);

  bool Read8(unsigned char& bit);

  const static unsigned char sPixelSize = 3;

  const static unsigned char sDigitWidth = 6;

  const static unsigned char sDigitHeight = 7;

  const static unsigned char sInterDigit = 1;

  const static unsigned char sInterLine = 1;

  const static uint32_t sBitSize = 4;

  const static uint32_t sBitThreshold = 60;

  const static unsigned char sYOn = 0x80;

  const static unsigned char sYOff = 0;

  const static unsigned char sLumaThreshold = 96;

  const static unsigned char sLumaMin = 16;

  const static unsigned char sLumaMax = 235;

  unsigned char* pYData;

  uint32_t mStride;

  uint32_t mWidth;

  uint32_t mHeight;

  unsigned char mSymbolWidth;

  unsigned char mSymbolHeight;

  struct Cursor {

    Cursor(uint32_t x, uint32_t y) : x(x), y(y) {}

    uint32_t x;

    uint32_t y;

  } mCursor;

};

}  // namespace mozilla

#endif