using System;
using System.Collections;
using System.Text;
/*
* Copyright 2007 ZXing authors
*
* 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.
*/
namespace com.google.zxing.common
{
/// <summary>
/// <p>Represents a 2D matrix of bits. In function arguments below, and throughout the common
/// module, x is the column position, and y is the row position. The ordering is always x, y.
/// The origin is at the top-left.</p>
///
/// <p>Internally the bits are represented in a 1-D array of 32-bit ints. However, each row begins
/// with a new int. This is done intentionally so that we can copy out a row into a BitArray very
/// efficiently.</p>
///
/// <p>The ordering of bits is row-major. Within each int, the least significant bits are used first,
/// meaning they represent lower x values. This is compatible with BitArray's implementation.</p>
///
/// @author Sean Owen
/// @author dswitkin@google.com (Daniel Switkin)
/// </summary>
public sealed class BitMatrix
{
private readonly int width;
private readonly int height;
private readonly int rowSize;
private readonly int[] bits;
// A helper to construct a square matrix.
public BitMatrix(int dimension) : this(dimension, dimension)
{
}
public BitMatrix(int width, int height)
{
if (width < 1 || height < 1)
{
throw new System.ArgumentException("Both dimensions must be greater than 0");
}
this.width = width;
this.height = height;
this.rowSize = (width + 31) >> 5;
bits = new int[rowSize * height];
}
/// <summary>
/// <p>Gets the requested bit, where true means black.</p>
/// </summary>
/// <param name="x"> The horizontal component (i.e. which column) </param>
/// <param name="y"> The vertical component (i.e. which row) </param>
/// <returns> value of given bit in matrix </returns>
public bool get(int x, int y)
{
int offset = y * rowSize + (x >> 5);
return (((int)((uint)bits[offset] >> (x & 0x1f))) & 1) != 0;
}
/// <summary>
/// <p>Sets the given bit to true.</p>
/// </summary>
/// <param name="x"> The horizontal component (i.e. which column) </param>
/// <param name="y"> The vertical component (i.e. which row) </param>
public void set(int x, int y)
{
int offset = y * rowSize + (x >> 5);
bits[offset] |= 1 << (x & 0x1f);
}
/// <summary>
/// <p>Flips the given bit.</p>
/// </summary>
/// <param name="x"> The horizontal component (i.e. which column) </param>
/// <param name="y"> The vertical component (i.e. which row) </param>
public void flip(int x, int y)
{
int offset = y * rowSize + (x >> 5);
bits[offset] ^= 1 << (x & 0x1f);
}
/// <summary>
/// Clears all bits (sets to false).
/// </summary>
public void clear()
{
int max = bits.Length;
for (int i = 0; i < max; i++)
{
bits[i] = 0;
}
}
/// <summary>
/// <p>Sets a square region of the bit matrix to true.</p>
/// </summary>
/// <param name="left"> The horizontal position to begin at (inclusive) </param>
/// <param name="top"> The vertical position to begin at (inclusive) </param>
/// <param name="width"> The width of the region </param>
/// <param name="height"> The height of the region </param>
public void setRegion(int left, int top, int width, int height)
{
if (top < 0 || left < 0)
{
throw new System.ArgumentException("Left and top must be nonnegative");
}
if (height < 1 || width < 1)
{
throw new System.ArgumentException("Height and width must be at least 1");
}
int right = left + width;
int bottom = top + height;
if (bottom > this.height || right > this.width)
{
throw new System.ArgumentException("The region must fit inside the matrix");
}
for (int y = top; y < bottom; y++)
{
int offset = y * rowSize;
for (int x = left; x < right; x++)
{
bits[offset + (x >> 5)] |= 1 << (x & 0x1f);
}
}
}
/// <summary>
/// A fast method to retrieve one row of data from the matrix as a BitArray.
/// </summary>
/// <param name="y"> The row to retrieve </param>
/// <param name="row"> An optional caller-allocated BitArray, will be allocated if null or too small </param>
/// <returns> The resulting BitArray - this reference should always be used even when passing
/// your own row </returns>
public BitArray getRow(int y, BitArray row)
{
if (row == null || row.Size < width)
{
row = new BitArray(width);
}
int offset = y * rowSize;
for (int x = 0; x < rowSize; x++)
{
row.setBulk(x << 5, bits[offset + x]);
}
return row;
}
/// <param name="y"> row to set </param>
/// <param name="row"> <seealso cref="BitArray"/> to copy from </param>
public void setRow(int y, BitArray row)
{
Array.Copy(row.BitArrayBits, 0, bits, y * rowSize, rowSize);
}
/// <summary>
/// This is useful in detecting the enclosing rectangle of a 'pure' barcode.
/// </summary>
/// <returns> {left,top,width,height} enclosing rectangle of all 1 bits, or null if it is all white </returns>
public int[] EnclosingRectangle
{
get
{
int left = this.width;
int top = this.height;
int right = -1;
int bottom = -1;
for (int y = 0; y < this.height; y++)
{
for (int x32 = 0; x32 < rowSize; x32++)
{
int theBits = bits[y * rowSize + x32];
if (theBits != 0)
{
if (y < top)
{
top = y;
}
if (y > bottom)
{
bottom = y;
}
if (x32 * 32 < left)
{
int bit = 0;
while ((theBits << (31 - bit)) == 0)
{
bit++;
}
if ((x32 * 32 + bit) < left)
{
left = x32 * 32 + bit;
}
}
if (x32 * 32 + 31 > right)
{
int bit = 31;
while (((int)((uint)theBits >> bit)) == 0)
{
bit--;
}
if ((x32 * 32 + bit) > right)
{
right = x32 * 32 + bit;
}
}
}
}
}
int width = right - left;
int height = bottom - top;
if (width < 0 || height < 0)
{
return null;
}
return new int[] {left, top, width, height};
}
}
/// <summary>
/// This is useful in detecting a corner of a 'pure' barcode.
/// </summary>
/// <returns> {x,y} coordinate of top-left-most 1 bit, or null if it is all white </returns>
public int[] TopLeftOnBit
{
get
{
int bitsOffset = 0;
while (bitsOffset < bits.Length && bits[bitsOffset] == 0)
{
bitsOffset++;
}
if (bitsOffset == bits.Length)
{
return null;
}
int y = bitsOffset / rowSize;
int x = (bitsOffset % rowSize) << 5;
int theBits = bits[bitsOffset];
int bit = 0;
while ((theBits << (31 - bit)) == 0)
{
bit++;
}
x += bit;
return new int[] {x, y};
}
}
public int[] BottomRightOnBit
{
get
{
int bitsOffset = bits.Length - 1;
while (bitsOffset >= 0 && bits[bitsOffset] == 0)
{
bitsOffset--;
}
if (bitsOffset < 0)
{
return null;
}
int y = bitsOffset / rowSize;
int x = (bitsOffset % rowSize) << 5;
int theBits = bits[bitsOffset];
int bit = 31;
while (((int)((uint)theBits >> bit)) == 0)
{
bit--;
}
x += bit;
return new int[] {x, y};
}
}
/// <returns> The width of the matrix </returns>
public int Width
{
get
{
return width;
}
}
/// <returns> The height of the matrix </returns>
public int Height
{
get
{
return height;
}
}
public override bool Equals(object o)
{
if (!(o is BitMatrix))
{
return false;
}
BitMatrix other = (BitMatrix) o;
if (width != other.width || height != other.height || rowSize != other.rowSize || bits.Length != other.bits.Length)
{
return false;
}
for (int i = 0; i < bits.Length; i++)
{
if (bits[i] != other.bits[i])
{
return false;
}
}
return true;
}
public override int GetHashCode()
{
int hash = width;
hash = 31 * hash + width;
hash = 31 * hash + height;
hash = 31 * hash + rowSize;
foreach (int bit in bits)
{
hash = 31 * hash + bit;
}
return hash;
}
public override string ToString()
{
StringBuilder result = new StringBuilder(height * (width + 1));
for (int y = 0; y < height; y++)
{
for (int x = 0; x < width; x++)
{
result.Append(get(x, y) ? "X " : " ");
}
result.Append('\n');
}
return result.ToString();
}
}
}