如何在Java中对角线反射图像

Question

我有以下代码以对角线反映图像：

public void mirrorDiagonal() {
      Pixel[][] pixels = this.getPixels2D();
      Pixel topRightPixel = null;
      Pixel bottomLeftPixel = null;
      int maxLength;
      if (pixels.length < pixels[0].length) { maxLength = pixels.length; }
      else {maxLength = pixels[0].length; }
      for (int row = 0; row < maxLength; row++)
      {
          for (int col = row; col < maxLength; col++)
          {
              topRightPixel = pixels[row][col];
              bottomLeftPixel = pixels[col][row];
              bottomLeftPixel.setColor(topRightPixel.getColor());
          }
      }
  }

但是我把某个地方搞砸了，它从图像的右上角反射到左下方。

我的问题：我还将如何反映其他方式？(更具体地说是从左上角到右下角(

Answer 1

看起来您认为是右上角的像素实际上是左上角。尝试以下内容：

for (int row = 0; row < maxLength; row++) {
    for (int col = maxLength - row - 1; col >= 0; col--) {
        topRightPixel = pixels[row][col];
        bottomLeftPixel = pixels[col][row];
        bottomLeftPixel.setColor(topRightPixel.getColor());
    }
}

Answer 2

为什么要更改颜色？而是可以移动像素对象。另外，如果您定义了3个基本转换，则可以通过不同的方式组合前3个来构建所有其他转换。例如

static void mirrorHor(Pixel[][] pixels) {
  for(int row = 0; row < pixels.length; row++) {
    for(int col = 0; col + col < pixels[row].length - 1; col++) {
      Pixel p = pixels[row][col];
      pixels[row][col] = pixels[row][pixels[row].length - col - 1];
      pixels[row][pixels[row].length - col - 1] = p;
    }
  }
}
static void mirrorVert(Pixel[][] pixels) {
  for(int row = 0; row + row < pixels.length - 1; row++) {
    Pixel[] r = pixels[row];
    pixels[row] = pixels[pixels.length - row - 1];
    pixels[pixels.length - row - 1] = r;
  }
}
static void mirrorTopRightBottomLeft(Pixel[][] pixels) {
  for(int row = 0; row < pixels.length - 1; row++) {
    for(int col = row + 1; col < pixels.length; col++) {
      Pixel p = pixels[row][col];
      pixels[row][col] = pixels[col][row];
      pixels[col][row] = p;
    }
  }
}
static void rotate180(Pixel[][] pixels) {
  mirrorHor(pixels);
  mirrorVert(pixels);
}
static void mirrorTopLeftBottomRight(Pixel[][] pixels) {
  mirrorTopRightBottomLeft(pixels);
  rotate180(pixels);
}
static void rotateLeft90(Pixel[][] pixels) {
  mirrorTopRightBottomLeft(pixels);
  mirrorVert(pixels);
}
static void rotateRight90(Pixel[][] pixels) {
  mirrorTopRightBottomLeft(pixels);
  mirrorHor(pixels);
}