Delphi位图任意角度旋转

      2020-08-02 12:26      HTML5

  核心提示://*********************************************************** //功能:任意角度旋转 //参数:Srcbmp:源位图 DestBmp:目标...

//***********************************************************
//功能:任意角度旋转
//参数:Srcbmp:源位图 DestBmp:目标位图 ;angle旋转角度
//返回值:无
class procedure TGraphicUtil.Rotate(Srcbmp, DestBmp: Tbitmap;
angle: extended);
var
c1x, c1y, c2x, c2y: integer;
p1x, p1y, p2x, p2y: integer;
radius, n: integer;
alpha: extended;
c0, c1, c2, c3: tcolor;
begin
if SrcBmp.Width > SrcBmp.Height then
begin
DestBmp.width := SrcBmp.Width;
DestBmp.height := SrcBmp.Width;
end
else
DestBmp.Width := SrcBmp.Height;
DestBmp.Height := SrcBmp.Height;
//将角度转换为PI值
angle := (angle / 180) * pi;
// 计算中心点,你可以修改它
c1x := SrcBmp.width div 2;
c1y := SrcBmp.height div 2;
c2x := DestBmp.width div 2;
c2y := DestBmp.height div 2;
// 步骤数值number
if c2x < c2y then
n := c2y
else
n := c2x;
dec(n, 1);
// 开始旋转
for p2x := 0 to n do
begin
for p2y := 0 to n do
begin
if p2x = 0 then
alpha := pi / 2
else
alpha := arctan2(p2y, p2x);
radius := round(sqrt((p2x * p2x) + (p2y * p2y)));
p1x := round(radius * cos(angle + alpha));
p1y := round(radius * sin(angle + alpha));

c0 := SrcBmp.canvas.pixels[c1x + p1x, c1y + p1y];
c1 := SrcBmp.canvas.pixels[c1x - p1x, c1y - p1y];
c2 := SrcBmp.canvas.pixels[c1x + p1y, c1y - p1x];
c3 := SrcBmp.canvas.pixels[c1x - p1y, c1y + p1x];

DestBmp.Canvas.pixels[c2x + p2x, c2y + p2y] := c0;
DestBmp.canvas.pixels[c2x - p2x, c2y - p2y] := c1;
DestBmp.canvas.pixels[c2x + p2y, c2y - p2x] := c2;
DestBmp.canvas.pixels[c2x - p2y, c2y + p2x] := c3;
end;
application.processmessages
end;

end;