qzxing/source/zxing/LuminanceSource.cpp

87 lines
2.7 KiB
C++

// -*- mode:c++; tab-width:2; indent-tabs-mode:nil; c-basic-offset:2 -*-
/*
* LuminanceSource.cpp
* zxing
*
* Copyright 2008 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 <sstream>
#include <zxing/LuminanceSource.h>
#include <zxing/InvertedLuminanceSource.h>
#include <zxing/common/IllegalArgumentException.h>
using zxing::Ref;
using zxing::LuminanceSource;
LuminanceSource::LuminanceSource(int width_, int height_) :width(width_), height(height_) {}
LuminanceSource::~LuminanceSource() {}
bool LuminanceSource::isCropSupported() const {
return false;
}
Ref<LuminanceSource> LuminanceSource::crop(int, int, int, int) const {
throw IllegalArgumentException("This luminance source does not support cropping.");
}
bool LuminanceSource::isRotateSupported() const {
return false;
}
Ref<LuminanceSource> LuminanceSource::rotateCounterClockwise() const {
throw IllegalArgumentException("This luminance source does not support rotation.");
}
LuminanceSource::operator std::string() const {
ArrayRef<char> row;
std::ostringstream oss;
for (int y = 0; y < getHeight(); y++) {
row = getRow(y, row);
for (int x = 0; x < getWidth(); x++) {
int luminance = row[x] & 0xFF;
char c;
if (luminance < 0x40) {
c = '#';
} else if (luminance < 0x80) {
c = '+';
} else if (luminance < 0xC0) {
c = '.';
} else {
c = ' ';
}
oss << c;
}
oss << '\n';
}
return oss.str();
}
Ref<LuminanceSource> LuminanceSource::invert() const {
// N.B.: this only works because we use counted objects with the
// count in the object. This is _not_ how things like shared_ptr
// work. They do not allow you to make a smart pointer from a native
// pointer more than once. If we ever switch to (something like)
// shared_ptr's, the luminace source is going to have keep a weak
// pointer to itself from which it can create a strong pointer as
// needed. And, FWIW, that has nasty semantics in the face of
// exceptions during construction.
return Ref<LuminanceSource>
(new InvertedLuminanceSource(Ref<LuminanceSource>(const_cast<LuminanceSource*>(this))));
}