图像旋转:procedure TfrmColor.bmp_rotate(src,dst: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 //将角度转换为PI值 angle := (angle / 180) * pi; // 计算中心点,你可以修改它 c1x := src.width div 2; c1y := src.height div 2; c2x := dst.width div 2; c2y := dst.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));
var
c1x,c1y,c2x,c2y:integer;
p1x,p1y,p2x,p2y:integer;
radius,n:integer;
alpha:extended;
c0,c1,c2,c3:tcolor;
begin
//将角度转换为PI值
angle := (angle / 180) * pi;
// 计算中心点,你可以修改它
c1x := src.width div 2;
c1y := src.height div 2;
c2x := dst.width div 2;
c2y := dst.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 := src.canvas.pixels[c1x+p1x,c1y+p1y];
c1 := src.canvas.pixels[c1x-p1x,c1y-p1y];
c2 := src.canvas.pixels[c1x+p1y,c1y-p1x];
c3 := src.canvas.pixels[c1x-p1y,c1y+p1x]; dst.canvas.pixels[c2x+p2x,c2y+p2y]:=c0;
dst.canvas.pixels[c2x-p2x,c2y-p2y]:=c1;
dst.canvas.pixels[c2x+p2y,c2y-p2x]:=c2;
dst.canvas.pixels[c2x-p2y,c2y+p2x]:=c3;
end;
application.processmessages
end;
end;