保持比例图像缩放简易算法

public struct PicSize
{
  public int Width;
  public int Height;
}
public static PicSize AdjustSize(int spcWidth, int spcHeight, int orgWidth, int orgHeight)
{
  PicSize size = new PicSize();
  // 原始宽高在指定宽高范围内，不作任何处理
  if (orgWidth <= spcWidth && orgHeight <= spcHeight)
  {
    size.Width = orgWidth;
    size.Height = orgHeight;
  }
  else
  {
    // 取得比例系数
    float w = orgWidth / (float)spcWidth;
    float h = orgHeight / (float)spcHeight;
    // 宽度比大于高度比
    if (w > h)
    {
      size.Width = spcWidth;
      size.Height = (int)(w >= 1 ? Math.Round(orgHeight / w) : Math.Round(orgHeight * w));
    }
    // 宽度比小于高度比
    else if (w < h)
    {
      size.Height = spcHeight;
      size.Width = (int)(h >= 1 ? Math.Round(orgWidth / h) : Math.Round(orgWidth * h));
    }
    // 宽度比等于高度比
    else
    {
      size.Width = spcWidth;
      size.Height = spcHeight;
    }
  }
  return size;
}