GreyscaleLuminanceSource.cpp Example File

 // -*- mode:c++; tab-width:2; indent-tabs-mode:nil; c-basic-offset:2 -*-
 /*
  *  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>

 using zxing::Ref;
 using zxing::ArrayRef;
 using zxing::LuminanceSource;

 namespace zxing {

 GreyscaleLuminanceSource::
 GreyscaleLuminanceSource(ArrayRef<byte> greyData,
                          int dataWidth, int dataHeight,
                          int left, int top,
                          int width, int height)
     : Super(width, height),
       greyData_(greyData),
       dataWidth_(dataWidth), dataHeight_(dataHeight),
       left_(left), top_(top) {

   if (left + width > dataWidth || top + height > dataHeight || top < 0 || left < 0) {
     throw IllegalArgumentException("Crop rectangle does not fit within image data.");
   }
 }

 ArrayRef<byte> GreyscaleLuminanceSource::getRow(int y, ArrayRef<byte> row) const {
   if (y < 0 || y >= this->getHeight()) {
     throw IllegalArgumentException("Requested row is outside the image.");
   }
   int width = getWidth();
   if (!row || row->size() < width) {
     ArrayRef<byte> temp (width);
     row = temp;
   }
   int offset = (y + top_) * dataWidth_ + left_;
   memcpy(&row[0], &greyData_[offset], width);
   return row;
 }

 ArrayRef<byte> GreyscaleLuminanceSource::getMatrix() const {
   if (left_ == 0 && top_ == 0 && dataWidth_ == getWidth() && dataHeight_ == getHeight()) {
     return greyData_;
   } else {
     int size = getWidth() * getHeight();
     ArrayRef<byte> result (size);
     for (int row = 0; row < getHeight(); row++) {
       memcpy(&result[row * getWidth()], &greyData_[(top_ + row) * dataWidth_ + left_], getWidth());
     }
     return result;
   }
 }

 Ref<LuminanceSource> GreyscaleLuminanceSource::rotateCounterClockwise() const {
   // Intentionally flip the left, top, width, and height arguments as
   // needed. dataWidth and dataHeight are always kept unrotated.
   Ref<LuminanceSource> result (
       new GreyscaleRotatedLuminanceSource(greyData_,
                                           dataWidth_, dataHeight_,
                                           top_, left_, getHeight(), getWidth()));
   return result;
 }

 }