任意角度图片旋转

韩冰

void S_PicXZ(Graphics::TBitmap *Source,Graphics::TBitmap *NewPic,int angle)// 7 f# k# b0 G( ~3 d{ if(angle>180)angle=360-angle; if(angle<-180)angle=360+angle;

float radians=(2*3.1416*angle)/360; * U2 s# | k8 k" i, E5 P# ?& Dfloat cosine=(float)cos(radians); / F2 \% F# x0 K# R0 F* P; Tfloat sine=(float)sin(radians); float Point1x=(-Source->Height*sine); 2 s9 G' I# x; Cfloat Point1y=(Source->Height*cosine); U: n3 I" E2 Qfloat Point2x=(Source->Width*cosine-Source->Height*sine); float Point2y=(Source->Height*cosine+Source->Width*sine); ; [2 T- x3 N6 G' k7 G( q9 g- Xfloat Point3x=(Source->Width*cosine); & G8 a. W6 v$ ]4 A, vfloat Point3y=(Source->Width*sine); 5 C1 @' M- ^" g# D& ifloat minx=min((float)0,min(Point1x,min(Point2x,Point3x))); , r$ b: @% g9 ^, D3 Z& e4 Jfloat miny=min((float)0,min(Point1y,min(Point2y,Point3y))); $ I/ Z( N d9 z& M( ]) h5 ufloat maxx=max(Point1x,max(Point2x,Point3x)); ) Q: e2 B' T, ?8 Xfloat maxy=max(Point1y,max(Point2y,Point3y)); int DestBitmapWidth,DestBitmapHeight; & c- [/ i% q5 `7 S0 |' c7 V( aif(angle>90&&angle<180) DestBitmapWidth=(int)ceil(-minx); 6 ~( U+ n' t5 @( Xelse DestBitmapWidth=(int)ceil(maxx-minx);

if(angle>-180&&angle<-90) DestBitmapHeight=(int)ceil(-miny); 2 w# x. l; y% n4 q* i" J9 T6 B' |8 helse DestBitmapHeight=(int)ceil(maxy-miny);

NewPic->Height=DestBitmapHeight; ( [: p- i( Z( |. P; N+ z8 X$ U' TNewPic->Width=DestBitmapWidth; 5 `2 k. U2 U; L. S- bfor(int x=0;x<DestBitmapWidth;x++) 5 Q) S7 e, Q5 W( p, N2 ~: M$ W/ b{ for(int y=0;y<DestBitmapHeight;y++){ / m) N- M( M. T% T2 q+ r/ }int SrcBitmapx=(int)((x+minx)*cosine+(y+miny)*sine); , U/ U4 \, H# `, ~2 ~) U5 w" |int SrcBitmapy=(int)((y+miny)*cosine-(x+minx)*sine); 0 n5 J& C& Y/ i bif(SrcBitmapx>=0&&SrcBitmapx<Source->Width&&SrcBitmapy>=0&& SrcBitmapy<Source->Height) " o3 N& z$ K; X# L( }& X{ # O6 S" j9 F5 U/ r( _5 fNewPic->Canvas->ixels[x][y]= % @2 q$ k: P7 R% [ W. l/ BSource->Canvas->ixels[SrcBitmapx][SrcBitmapy]; } ' z; _: ?9 z+ |) Y} } }