GDI+ 学习记录(25) 变换 - Transform

//比例变化
var
  g: TGPGraphics;
  p: TGPPen;
  rect: TGPRect;
begin
  g := TGPGraphics.Create(Canvas.Handle);
  p := TGPPen.Create(MakeColor(255,255,0,0),0);
  rect := MakeRect(10,10,100,100);

  g.DrawRectangle(p, rect); {原始}

  g.ScaleTransform(2, 0.5); {横向放大、纵向缩小}
  p.SetColor(aclBlue);      {变个颜色看清楚}
  g.DrawRectangle(p, rect); {重绘}
  g.ResetTransform;         {恢复变化, 不然下一个变化将基于现在的状态}

  p.Free;
  g.Free;
end;

var
  g:TGPGraphics;
  p:TGPPen;
  rect:TGPRect;
begin
  g:=TGPGraphics.Create(Canvas.Handle);
  g.Clear(aclWhite);
  p:=TGPPen.Create(aclRed);
  rect:=MakeRect(10,60,100,100);

  g.DrawRectangle(p,rect);
  g.RotateTransform(-28);  //旋转，正值顺时针旋转，负值逆时针旋转
  p.SetColor(aclBlue);

  g.DrawRectangle(p,rect);
  g.ResetTransform;

  p.Free;
  g.Free;
end;

//位置变化(移动)
var
  g:TGPGraphics;
  p:TGPPen;
  rect:TGPRect;
begin
  g:=TGPGraphics.Create(Canvas.Handle);
  g.Clear(aclWhite);
  p:=TGPPen.Create(aclRed,2);
  rect:=MakeRect(10,10,100,100);

  g.DrawRectangle(p,rect);
  g.TranslateTransform(111,66); //移动
  p.SetColor(aclBlue);
  g.DrawRectangle(p,rect);

  p.Free;
  g.Free;
end;