java - 在 Java 中使用 for 循环重复线条/条纹

Question

我想在图像上绘制黑白条纹，在图像顶部水平和垂直地每 20 列切换一次，同时保持在图像边界内。到目前为止，我可以获得一个带有 1 像素宽垂直条纹的黑色正方形。我尝试过通过切换东西来至少在水平线上获得细长的白色条纹，但它仍然是垂直的。

public void zebraStripes() {

    Image img = ImageViewer.getImage();

    double numPixelsWide = img.getWidth();
    int numPixelsHigh = img.getHeight();


    Color c = Color.WHITE;
    Color b = Color.BLACK;


    double i = numPixelsWide;
    if (i % 20 == 0) {

        for (int x = 0; x < numPixelsHigh; x++) {
            for (int y = 0; y < i; y++) {
                img.setPixelColor(y, x, b);
                }

            for (int z = 19; z < i; z = z + 20) {
                    img.setPixelColor(z, x, c);
            }
        }
    }
}

// paint black and white stripes (left to right) on the image, switching
// every 20th row
public void jailBird() {

    Image img = ImageViewer.getImage();

    double numPixelsWide = img.getWidth();
    double numPixelsHigh = img.getHeight();

    Color c = Color.WHITE;
    Color b = Color.BLACK;

    double i = numPixelsHigh;
    if (i % 20 == 0) {

        for (int x = 0; x < numPixelsHigh; x++) {
            for (int y = 0; y < i; y++) {
                img.setPixelColor(y, x, b);
                }

            for (int z = 19; z < i; z = z + 20) {
                    img.setPixelColor(z, x, c);
            }
                }
            }
        }

}

如何使白色条纹的宽度和水平均为 20 像素？

Answer 1

未经测试!希望它能让你继续前进。

    // paint a 20 pixels wide horizontal line for every 40 pixels
    for (int y = 0; y < numPixelsHigh; y += 40) {
        // paint a stripe
        for (int ys = y; ys < y + 20; ys++) {
            for (int x = 0; x < numPixelsWide; x++) {
                img.setPixelColor(x, ys, Color.BLACK);
            }
        }
    }