Java - 从bufferedimage（Heightmap）上的像素获取介于1和0之间的值

Question

我试图在我的游戏中实现Heightmaps，所以现在我已经制作了几种方法，但它们太慢了，而且，高度返回的数字像1.463563298e14！ 如何从高度图上的像素获得介于0和1之间的值？ 这些是我的方法：

public void setupHeights() {
    int pixWidth = heightfile.getWidth();
    int pixHeight = heightfile.getHeight();
    int w = pixWidth;
    int h = pixHeight;
    this.heights = new float[w][h];
    boolean countWidth = true;
    for (int z = 0; z < pixHeight; z++) {
        depth++;
        for (int x = 0; x < pixWidth; x++) {
            if (countWidth)
                width++;
            int height;
            if (whiteHigh) {
                height = 256 - (-1 * heightfile.getRGB(x, z));
            } else {
                height = -1 * heightfile.getRGB(x, z);
            }
            heights[x][z] = height;
            numPoints++;
        }
        countWidth = false;
    }
    System.out.println("Heights have been set up!");
}

@Override
public void update() {
    if (!this.hasWorldObj())
        return;
    if (heightfile!=null) {
        for (Entity e : entities) {
            if (e != null && !(e.posX < pos.getX() || e.posZ < pos.getZ() || e.posX > pos.getX() + 1
                    || e.posZ > pos.getZ() + 1)) {
                {
                    if (heightfile != null) {
                        double localX = Math.abs(pos.getX() - e.posX);
                        double localZ = Math.abs(pos.getZ() - e.posZ);
                        int x = (int) (localX * width);
                        int y = (int) (localZ * depth);
                        e.posY = pos.getY() + getHeight(x, y);
                    }

                }
            } else
                e = null;
        }
    }
}



public float getHeight(float xf, float zf) {
    int x = worldCoordToIndex(xf);
    int z = worldCoordToIndex(zf);
    System.out.println("getting height for: " + x + ", " + z);
    if (x < 0)
        x = 0;
    if (z < 0)
        z = 0;
    if (z >= heights.length) {
        System.out.println("WARN getHeight z index out of bounds: " + z);
        z = heights.length - 1;
    }
    if (x >= heights[z].length) {
        System.out.println("WARN getHeight x index out of bounds: " + x);
        x = heights[z].length - 1;
    }
    System.out.println("Returned height: " + heights[z][x] * heightScale);
    return heights[z][x] * heightScale;

}

private int worldCoordToIndex(float f) {
    return (int) Math.floor(f / widthScale);
}