Rotate a NxN matrix by 90 degrees in place where each pixel in the matrix is 4 bytes.

rotateBitMatrix.ts

/*
  Rotate a NxN matrix by 90 degrees in place where each pixel in the matrix is 4 bytes.
*/

/* example call: 
    rotateMatrix(sanitizeData([
      [1,2,3],
      [8,9,4],
      [7,6,5]
    ]))
*/
function rotateMatrix(m: number[][]): number[][] {
  const size = m.length - 1
  const roundedHalf = Math.ceil((size + 1) / 2)
  for (let r = 0; r < roundedHalf; ++r) {
    for (let c = r; c < roundedHalf; ++c) {
      if (r === c) {
        // Avoid doing XOR on the center cell of an odd sized matrix because that will equal 0.
        if ((m.length % 2 !== 0 )&& (r === roundedHalf - 1)) {
          continue
        }
        verticalSwap(m, r, c)
        verticalSwap(m, size - r, size - c)
        diagonalSwap(m, size - r, c)
      } else {
        diagonalSwap(m, r, c)
        diagonalSwap(m, size - r, size - c)
        horizontalSwap(m, c, r)
      }
    }
  }
  return m
}

function sanitizeData(m: number[][]): number[][] {
  for (let r = 0; r < m.length; ++r) {
    for (let c = 0; c < m.length; ++c) {
      m[r][c] = parseInt(m[r][c].toString(2))
    }
  }
  return m
}

function horizontalSwap(m: number[][], r: number, c: number) {
  const pos1 = {
    row: r,
    col: c
  }
  const pos2 = {
    row: r,
    col: m.length - 1 - c
  }
  bitwiseSwap(m, pos1, pos2)
}

function verticalSwap(m: number[][], r: number, c: number) {
  const pos1 = {
    row: r,
    col: c
  }
  const pos2 = {
    row: m.length - 1 - r,
    col: c
  }
  bitwiseSwap(m, pos1, pos2)
}

function diagonalSwap(m: number[][], r: number, c: number): void {
  const pos1 = {
    row: r,
    col: c
  }
  const pos2 = {
    row: c,
    col: r
  }
  bitwiseSwap(m, pos1, pos2)
}

interface IPosition {
  row: number
  col: number
}

function bitwiseSwap(m: number[][], pos1: IPosition, pos2: IPosition): void {
  m[pos1.row][pos1.col] ^= m[pos2.row][pos2.col]
  m[pos2.row][pos2.col] ^= m[pos1.row][pos1.col]
  m[pos1.row][pos1.col] ^= m[pos2.row][pos2.col]
}