任意角度图片旋转

【 tulaoshi.com - 编程语言 】

void S_PicXZ(Graphics::TBitmap *Source,Graphics::TBitmap *NewPic,int angle)//
{
if(angle180)angle=360-angle;
if(angle-180)angle=360+angle;
float radians=(2*3.1416*angle)/360;
float cosine=(float)cos(radians);
float sine=(float)sin(radians);
float Point1x=(-Source-Height*sine);
float Point1y=(Source-Height*cosine);
float Point2x=(Source-Width*cosine-Source-Height*sine);
float Point2y=(Source-Height*cosine+Source-Width*sine);
float Point3x=(Source-Width*cosine);
float Point3y=(Source-Width*sine);
float minx=min((float)0,min(Point1x,min(Point2x,Point3x)));
float miny=min((float)0,min(Point1y,min(Point2y,Point3y)));
float maxx=max(Point1x,max(Point2x,Point3x));
float maxy=max(Point1y,max(Point2y,Point3y));
int DestBitmapWidth,DestBitmapHeight;
if(angle90&&angle180)
　DestBitmapWidth=(int)ceil(-minx);
else
　DestBitmapWidth=(int)ceil(maxx-minx);
if(angle-180&&angle-90)
　DestBitmapHeight=(int)ceil(-miny);
else
　DestBitmapHeight=(int)ceil(maxy-miny);
NewPic-Height=DestBitmapHeight;
NewPic-Width=DestBitmapWidth;
for(int x=0;xDestBitmapWidth;x++)
　{
　for(int y=0;yDestBitmapHeight;y++)
　　{
　　int SrcBitmapx=(int)((x+minx)*cosine+(y+miny)*sine);
　　int SrcBitmapy=(int)((y+miny)*cosine-(x+minx)*sine);
　　if(SrcBitmapx=0&&SrcBitmapxSource-Width&&SrcBitmapy=0&&
　　SrcBitmapySource-Height)
　　　{
　　　NewPic-Canvas-Pixels[x][y]=Source-Canvas-Pixels[SrcBitmapx][SrcBitmapy];
　　　}
　　}
　}
}