上下翻转Bitmap(快速)

dant

使用内存操作
为某个大坑服务
[pre lang="ruby" line="1"]class Bitmap
  #--------------------------------------------------------------------------
  # ● 传送到内存的API函数
  #--------------------------------------------------------------------------
  RtlMoveMemory_pi = Win32API.new('kernel32', 'RtlMoveMemory', 'pii', 'i')
  Memcpy_ii = Win32API.new('kernel32.dll','RtlMoveMemory','iii','v')
  Malloc = Win32API.new('msvcrt.dll','malloc','i','i')
  Free = Win32API.new('msvcrt.dll','free','i','v')

  #--------------------------------------------------------------------------
  # ● Bitmap地址
  #--------------------------------------------------------------------------
  # [[[bitmap.object_id * 2 + 16] + 8] + 16] == 数据的开头
  def address
    buffer, ad = "rgba", object_id * 2 + 16
    RtlMoveMemory_pi.call(buffer, ad, 4)
    ad = buffer.unpack("L")[0] + 8
    RtlMoveMemory_pi.call(buffer, ad, 4)
    ad = buffer.unpack("L")[0] + 16
    RtlMoveMemory_pi.call(buffer, ad, 4)
    return buffer.unpack("L")[0]
  end
  #--------------------------------------------------------------------------
  # ● 上下翻转
  #--------------------------------------------------------------------------
  def reverse!
    len = width * height * 4
    pBuf = Malloc.call(len)
    lenln = width * 4
    src = address + len - lenln
    dst = pBuf
   
    for i in 0...height
      Memcpy_ii.call(dst,src,lenln)
      src-=lenln
      dst+=lenln
    end
    Memcpy_ii.call(address,pBuf,len)
    Free.call(pBuf)
  end
  
  def reverse
    newBmp=self.clone
    newBmp.reverse!
    return newBmp
  end
end
[/pre]

ky52879

大神，发个全套的吧：上下翻转、左右翻转....

chd114

翻bitmap和图片有区别吗···