text: /*
   *  GreyscaleLuminanceSource.cpp
   *  zxing
   *
   *  Copyright 2010 ZXing authors All rights reserved.
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *      http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  #include <zxing/common/GreyscaleLuminanceSource.h>
  #include <zxing/common/GreyscaleRotatedLuminanceSource.h>
  #include <zxing/common/IllegalArgumentException.h>
  
  namespace zxing {
  
  GreyscaleLuminanceSource::GreyscaleLuminanceSource(unsigned char* greyData, int dataWidth,
      int dataHeight, int left, int top, int width, int height) : greyData_(greyData),
      dataWidth_(dataWidth), dataHeight_(dataHeight), left_(left), top_(top), width_(width),
      height_(height) {
  
    if (left + width > dataWidth || top + height > dataHeight || top < 0 || left < 0) {
      throw IllegalArgumentException("Crop rectangle does not fit within image data.");
    }
  }
  
  unsigned char* GreyscaleLuminanceSource::getRow(int y, unsigned char* row) {
    if (y < 0 || y >= this->getHeight()) {
      throw IllegalArgumentException("Requested row is outside the image.");
    }
    int width = getWidth();
    // TODO(flyashi): determine if row has enough size.
    if (row == NULL) {
      row = new unsigned char[width_];
    }
    int offset = (y + top_) * dataWidth_ + left_;
    memcpy(row, &greyData_[offset], width);
    return row;
  }
  
  unsigned char* GreyscaleLuminanceSource::getMatrix() {
    int size = width_ * height_;
    unsigned char* result = new unsigned char[size];
    if (left_ == 0 && top_ == 0 && dataWidth_ == width_ && dataHeight_ == height_) {
      memcpy(result, greyData_, size);
    } else {
      for (int row = 0; row < height_; row++) {
        memcpy(result + row * width_, greyData_ + (top_ + row) * dataWidth_ + left_, width_);
      }
    }
    return result;
  }
  
  Ref<LuminanceSource> GreyscaleLuminanceSource::rotateCounterClockwise() {
    // Intentionally flip the left, top, width, and height arguments as needed. dataWidth and
    // dataHeight are always kept unrotated.
    return Ref<LuminanceSource> (new GreyscaleRotatedLuminanceSource(greyData_, dataWidth_,
        dataHeight_, top_, left_, height_, width_));
  }
  
  } /* namespace */
  