请问我怎么在我的bmp控件中旋转我的bmp图像。（旋转90度，180度等）

调用方法：
   bmp_rotate(Image1.Picture.Bitmap, Image2.Picture.Bitmap, RAngle);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));

      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;
*************8
----把一个点绕原点旋转α角度后，新的坐标位置与原坐标位置的
关系是：X=xcosα－ysinα
Y=xsinα＋ycosα
例如要把位图顺时针旋转90度，坐标变换公式为：X=－yY=x----把这一公式用到Image构件上，显示位图的主要问题是Image构
件显示的位图只有一个象限，并且x、y坐标也是互相颠倒的，为了
解决这个问题，必须在Image构件上建立一个新的坐标原点。下面就
举例说明。----1.新建一工程project1,在form1上添加image1、image2、
image3、image4，其Autosize属性设为True,image1用来显示原
图，image2、image3、image4分别用来显示旋转90度、180度和270
度后的图像。双击image1，选定一幅bmp图。----2.添加Button1、Button2、Button3和Button4按钮，其
caption属性分别为"原图"、"旋转90度"、"旋转180度"、
"旋转270度"。----3.编写"旋转90度"按钮的OnClick事件。procedureTForm1.Button2Click(Sender:TObject);
var
i,j:integer;
begin
//确定旋转后位图的大小
image2.Picture.Bitmap.Height:=image1.picture.width;
image2.Picture.Bitmap.Width:=image1.picture.height;
fori:=0toimage1.Heightdo
forj:=0toimage1.Widthdo
image2.canvas.Pixels[(－i＋image1.Height),
j]:=image1.canvas.Pixels[j,i];
end;
----4.编写"旋转180度"按钮的OnClick事件。procedureTForm1.Button3Click(Sender:TObject);
var
i,j:integer;
begin
//确定旋转后位图的大小
image3.Picture.Bitmap.Height:=image1.picture.Height;
image3.Picture.Bitmap.Width:=image1.picture.Width;
fori:=0toimage1.Heightdo
forj:=0toimage1.Widthdo
image3.canvas.Pixels[(image1.Width
－j),(image1.Height－i)]:=image1.canvas.Pixels[j,i];
end;----5.编写"旋转270度"按钮的OnClick事件。代码和步骤3相
似，只需要用image4替换image2，然后用以下的语句替换步骤3for
循环中的原有的语句。image4.canvas.Pixels[i,(image1.Width－j)]:=image1.canvas.Pixels[j,i];procedure Rotate(Bmp,Dst:TFastRGB;cx,cy:Integer;Angle:Extended);
var
cAngle,
sAngle:  Double;
xDiff,
yDiff,
xpr,ypr,
ix,iy,
px,py,
x,y:      Integer;
Tmp:      PFColor;{what means?}
begin
  Angle:=-Angle*Pi/180;
  sAngle:=Sin(Angle);
  cAngle:=Cos(Angle);
  xDiff:=(Dst.Width-Bmp.Width)div 2;
  yDiff:=(Dst.Height-Bmp.Height)div 2;
  Tmp:=Dst.Bits;{what means?}
  for y:=0 to Dst.Height-1 do
  begin
    py:=2*(y-cy)+1;
    for x:=0 to Dst.Width-1 do
    begin
      px:=2*(x-cx)+1;
      xpr:=Round(px*cAngle-py*sAngle);
      ypr:=Round(px*sAngle+py*cAngle);
      ix:=((xpr-1)div 2+cx)-xDiff;
      iy:=((ypr-1)div 2+cy)-yDiff;
      if(ix>-1)and(ix<Bmp.Width)and(iy>-1)and(iy<Bmp.Height)then
      Tmp^:=Bmp.Pixels[iy,ix]; {what means?}
      Inc(Tmp);
    end;
    Tmp:=Pointer(Integer(Tmp)+Dst.Gap); {what means?}
  end;
end;原理：
                    cos(Alpha), sin(Alpha), 0
只需要用源矩阵乘以  -sin(Alpha),cos(Alpha), 0
                    0, 0, 1 如果你发现转过来的图形带有很整齐的花点，解决的办法是反向计算，即从目标求的源点的坐标和像素值。
以上的例子就是这样的。如果真的按下面下矩阵计算每个点，目标区有一些点会是白点(因为有些源点通过计算和四舍五入在目标中凑到一起了)，我以前解决的办法是从目标求的源点的坐标和像素值，不过首先要取到目标区的区域（往往是斜的）。
                    cos(Alpha), sin(Alpha), 0
                    -sin(Alpha),cos(Alpha), 0
                    0, 0, 1 下载我说的控件吗，有现成的例子及DEMO！http://www.crosswinds.net/~khojasteh/delphi-components.htmlTRotateImage v1.21
  This component is a visual component similar to TImage with ability to rotate the image in any arbitrary angle. TRotateImage can be used on Delphi 3, 4, and 5.
调用方法：
   bmp_rotate(Image1.Picture.Bitmap, Image2.Picture.Bitmap, RAngle);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));

      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;
*************8
----把一个点绕原点旋转α角度后，新的坐标位置与原坐标位置的
关系是：X=xcosα－ysinα
Y=xsinα＋ycosα
例如要把位图顺时针旋转90度，坐标变换公式为：X=－yY=x----把这一公式用到Image构件上，显示位图的主要问题是Image构
件显示的位图只有一个象限，并且x、y坐标也是互相颠倒的，为了
解决这个问题，必须在Image构件上建立一个新的坐标原点。下面就
举例说明。----1.新建一工程project1,在form1上添加image1、image2、
image3、image4，其Autosize属性设为True,image1用来显示原
图，image2、image3、image4分别用来显示旋转90度、180度和270
度后的图像。双击image1，选定一幅bmp图。----2.添加Button1、Button2、Button3和Button4按钮，其
caption属性分别为"原图"、"旋转90度"、"旋转180度"、
"旋转270度"。----3.编写"旋转90度"按钮的OnClick事件。procedureTForm1.Button2Click(Sender:TObject);
var
i,j:integer;
begin
//确定旋转后位图的大小
image2.Picture.Bitmap.Height:=image1.picture.width;
image2.Picture.Bitmap.Width:=image1.picture.height;
fori:=0toimage1.Heightdo
forj:=0toimage1.Widthdo
image2.canvas.Pixels[(－i＋image1.Height),
j]:=image1.canvas.Pixels[j,i];
end;
----4.编写"旋转180度"按钮的OnClick事件。procedureTForm1.Button3Click(Sender:TObject);
var
i,j:integer;
begin
//确定旋转后位图的大小
image3.Picture.Bitmap.Height:=image1.picture.Height;
image3.Picture.Bitmap.Width:=image1.picture.Width;
fori:=0toimage1.Heightdo
forj:=0toimage1.Widthdo
image3.canvas.Pixels[(image1.Width
－j),(image1.Height－i)]:=image1.canvas.Pixels[j,i];
end;----5.编写"旋转270度"按钮的OnClick事件。代码和步骤3相
似，只需要用image4替换image2，然后用以下的语句替换步骤3for
循环中的原有的语句。image4.canvas.Pixels[i,(image1.Width－j)]:=image1.canvas.Pixels[j,i];procedure Rotate(Bmp,Dst:TFastRGB;cx,cy:Integer;Angle:Extended);
var
cAngle,
sAngle:  Double;
xDiff,
yDiff,
xpr,ypr,
ix,iy,
px,py,
x,y:      Integer;
Tmp:      PFColor;{what means?}
begin
  Angle:=-Angle*Pi/180;
  sAngle:=Sin(Angle);
  cAngle:=Cos(Angle);
  xDiff:=(Dst.Width-Bmp.Width)div 2;
  yDiff:=(Dst.Height-Bmp.Height)div 2;
  Tmp:=Dst.Bits;{what means?}
  for y:=0 to Dst.Height-1 do
  begin
    py:=2*(y-cy)+1;
    for x:=0 to Dst.Width-1 do
    begin
      px:=2*(x-cx)+1;
      xpr:=Round(px*cAngle-py*sAngle);
      ypr:=Round(px*sAngle+py*cAngle);
      ix:=((xpr-1)div 2+cx)-xDiff;
      iy:=((ypr-1)div 2+cy)-yDiff;
      if(ix>-1)and(ix<Bmp.Width)and(iy>-1)and(iy<Bmp.Height)then
      Tmp^:=Bmp.Pixels[iy,ix]; {what means?}
      Inc(Tmp);
    end;
    Tmp:=Pointer(Integer(Tmp)+Dst.Gap); {what means?}
  end;
end;原理：
                    cos(Alpha), sin(Alpha), 0
只需要用源矩阵乘以  -sin(Alpha),cos(Alpha), 0
                    0, 0, 1 如果你发现转过来的图形带有很整齐的花点，解决的办法是反向计算，即从目标求的源点的坐标和像素值。
以上的例子就是这样的。如果真的按下面下矩阵计算每个点，目标区有一些点会是白点(因为有些源点通过计算和四舍五入在目标中凑到一起了)，我以前解决的办法是从目标求的源点的坐标和像素值，不过首先要取到目标区的区域（往往是斜的）。
                    cos(Alpha), sin(Alpha), 0
                    -sin(Alpha),cos(Alpha), 0
                    0, 0, 1
unit Unit1;interfaceuses
  Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
  ExtCtrls, ImgList, ComCtrls;type
  TDrawingTool = (dtLine, dtRectangle, dtEllipse, dtRoundRect);
  TNode = Record
    rectx1 : integer;
    rectx2 : integer;
    recty1 : integer;
    recty2 : integer;
    name : string;
    pic : tpicture;
    //rect : trect;
  end;  TLine =record
    StartPt,EndPt :TPoint;
  end;  TForm1 = class(TForm)
    ScrollBox1: TScrollBox;
    Image1: TImage;
    TreeView1: TTreeView;
    ImageList1: TImageList;
    procedure Image1MouseDown(Sender: TObject; Button: TMouseButton;
      Shift: TShiftState; X, Y: Integer);
    procedure FormCreate(Sender: TObject);
    procedure Image1MouseUp(Sender: TObject; Button: TMouseButton;
      Shift: TShiftState; X, Y: Integer);
    procedure TreeView1MouseDown(Sender: TObject; Button: TMouseButton;
      Shift: TShiftState; X, Y: Integer);
    procedure FormClose(Sender: TObject; var Action: TCloseAction);
    procedure Image1MouseMove(Sender: TObject; Shift: TShiftState; X,
      Y: Integer);
  private
    { Private declarations }
    pic : tpicture;
    name : string;
    drawing,moving,Lining : Boolean;
    picnode : array of TNode;
    ArrLine :array of TLine;
    nodecount,nodeselectNo : integer;
    LineCount,LineSelectNo :integer;
    origin, movept :TPoint;
    DrawingTool: TDrawingTool;
    procedure DrawShape(TopLeft, BottomRight: TPoint; AMode: TPenMode);
    procedure RefreshImage;
  public
    { Public declarations }
  end;var
  Form1: TForm1;implementation{$R *.DFM}procedure TForm1.RefreshImage;
var i :integer;
beginend;procedure TForm1.Image1MouseDown(Sender: TObject; Button: TMouseButton;
  Shift: TShiftState; X, Y: Integer);
var
  i : integer;
  tmprect : trect;
begin
  if button = mbleft then
  begin
    if drawing then
    begin
      image1.Canvas.Draw(x,y,pic.Graphic);
      setlength(picNode,nodeCount+1);
      picnode[nodecount].rectx1 := x;
      picnode[nodecount].recty1 := y;
      picnode[nodecount].rectx2 := x + pic.Width;
      picnode[nodecount].recty2 := y + pic.Height;
      picnode[nodecount].name := name;
      picnode[nodecount].pic := tpicture.Create;
      picnode[nodecount].pic := pic;
      image1.Canvas.TextOut(picnode[nodecount].rectx1,picnode[nodecount].recty2,picnode[nodecount].name);
      nodecount := nodecount + 1;
      drawing := False;
    end
    else
    begin
      for i := 0 to nodecount do
      begin
        tmprect := rect(picnode[i].rectx1,picnode[i].recty1,picnode[i].rectx2,picnode[i].recty2);
        if ptinrect(tmprect,point(x,y)) then
        begin
          moving := true;
          nodeselectNo := i;
          break;
        end;
      end;
    end;
  end else if Button =mbRight then
  begin
    for i := 0 to nodecount do
    begin
      tmprect := rect(picnode[i].rectx1,picnode[i].recty1,picnode[i].rectx2,picnode[i].recty2);
      if ptinrect(tmprect,point(x,y)) then
      begin
        //moving := true;
        nodeselectNo := i;
        DrawingTool :=dtLine;
        lining :=true;
        Origin :=point(x,y);
        MovePt := Origin;
        break;
      end;
    end;
  end;
end;procedure TForm1.FormCreate(Sender: TObject);
begin
  nodecount := 0;
  LineCount :=0;
  setlength(picnode,30);
  drawing := false;
  moving := false;
  Lining :=false;
end;procedure TForm1.Image1MouseUp(Sender: TObject; Button: TMouseButton;
  Shift: TShiftState; X, Y: Integer);
var
  tmprect : trect;
  i :integer;
  CanLine :Boolean;
begin
  CanLine :=False;
  if button = mbleft then
  begin
    if moving then
    begin
      tmprect := rect(picnode[nodeselectno].rectx1,picnode[nodeselectno].recty1,picnode[nodeselectno].rectx2,picnode[nodeselectno].recty2);
      image1.Canvas.FillRect(tmpRect);
      image1.Canvas.Brush.Color := clWhite;
      image1.Canvas.TextOut(picnode[nodeselectno].rectx1,picnode[nodeselectno].recty2,'                  ');
      image1.Canvas.Draw(x,y,picnode[nodeselectno].pic.Graphic);
      picnode[nodeselectno].rectx1 := x;
      picnode[nodeselectno].recty1 := y;
      picnode[nodeselectno].rectx2 := x + picnode[nodeselectno].pic.Width;
      picnode[nodeselectno].recty2 := y + picnode[nodeselectno].pic.Height;
      image1.Canvas.TextOut(picnode[nodeselectno].rectx1,picnode[nodeselectno].recty2,picnode[nodeselectno].name);
      for i :=0 to Length(ArrLine)-1 do
      begin
        if ptInRect(tmpRect,ArrLine[i].StartPt) then
        begin
          DrawShape(Point(x,y),ArrLine[i].EndPt,PmCopy);
          DrawShape(ArrLine[i].StartPt,ArrLine[i].EndPt,pmNotXor);
          ArrLine[i].StartPt :=Point(x,y);
        end else if  ptInRect(tmpRect,ArrLine[i].EndPt) then
        begin
          DrawShape(ArrLine[i].StartPt,Point(x,y),PmCopy);
          DrawShape(ArrLine[i].StartPt,ArrLine[i].EndPt,pmNotXor);
          ArrLine[i].EndPt :=Point(x,y);
        end;
      end;
      image1.Refresh;
      moving := false;
    end;
  end else if button =mbRight then
  begin
    if lining then
    begin
      for i := 0 to nodecount do
      begin
        tmprect := rect(picnode[i].rectx1,picnode[i].recty1,picnode[i].rectx2,picnode[i].recty2);
        if ptinrect(tmprect,point(x,y)) then
        begin
          CanLine :=True;
          break;
        end;
      end;
      if CanLine then
      begin
        DrawShape(Origin, Point(X, Y), pmCopy);
        inc(LineCount);
        setlength(ArrLine,LineCount);
        ArrLine[LineCount-1].StartPt :=Origin;
        ArrLine[LineCount-1].EndPt :=Point(x,y);
        lining :=false;
      end else
      begin
        DrawShape(Origin,Point(x,y),pmNotXor);
        lining :=false;
      end;
    end;
  end;
end;procedure TForm1.TreeView1MouseDown(Sender: TObject; Button: TMouseButton;
  Shift: TShiftState; X, Y: Integer);
var
  i : integer;
  bmp : tbitmap;
begin
  for i := 0 to Treeview1.Items.Count - 1 do
  begin
    if Treeview1.Items[i].Selected then
    begin
      pic := TPicture.Create;
      bmp :=TBitmap.Create;
      ImageList1.GetBitmap(Treeview1.Items[i].ImageIndex,bmp);
      //SelectIndex := i;
      pic.Assign(bmp);
      Drawing :=True;
      name :=TreeView1.Items[i].Text;
      bmp.Free;
    end;
  end;
end;procedure TForm1.FormClose(Sender: TObject; var Action: TCloseAction);
var
  i : integer;
begin
  pic.Free;
  for i := 0 to nodecount-1 do
    picnode[nodecount].pic.Free;
end;procedure TForm1.Image1MouseMove(Sender: TObject; Shift: TShiftState; X,
  Y: Integer);
begin
  if lining then
  begin
    DrawShape(Origin, MovePt, pmNotXor);
    MovePt := Point(X, Y);
    DrawShape(Origin, MovePt, pmNotXor);
  end;
end;procedure TForm1.DrawShape(TopLeft, BottomRight: TPoint; AMode: TPenMode);
begin
  with Image1.Canvas do
  begin
    Pen.Mode := AMode;
    case DrawingTool of
      dtLine:
        begin
          Image1.Canvas.MoveTo(TopLeft.X, TopLeft.Y);
          Image1.Canvas.LineTo(BottomRight.X, BottomRight.Y);
        end;
      dtRectangle: Image1.Canvas.Rectangle(TopLeft.X, TopLeft.Y, BottomRight.X,
        BottomRight.Y);
      dtEllipse: Image1.Canvas.Ellipse(Topleft.X, TopLeft.Y, BottomRight.X,
        BottomRight.Y);
      dtRoundRect: Image1.Canvas.RoundRect(TopLeft.X, TopLeft.Y, BottomRight.X,
        BottomRight.Y, (TopLeft.X - BottomRight.X) div 2,
        (TopLeft.Y - BottomRight.Y) div 2);
    end;
  end;
end;end.

调试易

请问我怎么在我的bmp控件中旋转我的bmp图像。（旋转90度，180度等）

解决方案 »