GreyscaleRotatedLuminanceSource.cpp Example File

 // -*- mode:c++; tab-width:2; indent-tabs-mode:nil; c-basic-offset:2 -*-
 /*
  *  GreyscaleRotatedLuminanceSource.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/GreyscaleRotatedLuminanceSource.h>
 #include <zxing/common/IllegalArgumentException.h>

 using zxing::ArrayRef;

 namespace zxing {

 // Note that dataWidth and dataHeight are not reversed, as we need to
 // be able to traverse the greyData correctly, which does not get
 // rotated.
 GreyscaleRotatedLuminanceSource::
 GreyscaleRotatedLuminanceSource(ArrayRef<byte> greyData,
                                 int dataWidth, int dataHeight,
                                 int left, int top,
                                 int width, int height)
     : Super(width, height),
       greyData_(greyData),
       dataWidth_(dataWidth),
       left_(left), top_(top) {
   // Intentionally comparing to the opposite dimension since we're rotated.
   if (left + width > dataHeight || top + height > dataWidth) {
     throw IllegalArgumentException("Crop rectangle does not fit within image data.");
   }
 }

 // The API asks for rows, but we're rotated, so we return columns.
 ArrayRef<byte>
 GreyscaleRotatedLuminanceSource::getRow(int y, ArrayRef<byte> row) const {
   if (y < 0 || y >= getHeight()) {
     throw IllegalArgumentException("Requested row is outside the image.");
   }
   if (!row || row->size() < getWidth()) {
     row = ArrayRef<byte>(getWidth());
   }
   int offset = (left_ * dataWidth_) + (dataWidth_ - 1 - (y + top_));
   using namespace std;
   if (false) {
     cerr << offset << " = "
          << top_ << " " << left_ << " "
          << getHeight() << " " << getWidth() << " "
          << y << endl;
   }
   for (int x = 0; x < getWidth(); x++) {
     row[x] = greyData_[offset];
     offset += dataWidth_;
   }
   return row;
 }

 ArrayRef<byte> GreyscaleRotatedLuminanceSource::getMatrix() const {
   ArrayRef<byte> result (getWidth() * getHeight());
   for (int y = 0; y < getHeight(); y++) {
     byte* row = &result[y * getWidth()];
     int offset = (left_ * dataWidth_) + (dataWidth_ - 1 - (y + top_));
     for (int x = 0; x < getWidth(); x++) {
       row[x] = greyData_[offset];
       offset += dataWidth_;
     }
   }
   return result;
 }

 }