任意角度图片旋转

韩冰

void S_PicXZ(Graphics::TBitmap *Source,Graphics::TBitmap *NewPic,int angle)// - o. f, M* C8 g- x* [# B7 R) J- n{ if(angle>180)angle=360-angle; if(angle<-180)angle=360+angle;

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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); " k8 ^0 O% L3 \# H7 Hfloat Point2y=(Source->Height*cosine+Source->Width*sine); " P' g9 f1 z3 f4 ]" xfloat Point3x=(Source->Width*cosine); float Point3y=(Source->Width*sine); float minx=min((float)0,min(Point1x,min(Point2x,Point3x))); $ F4 g# v- |/ E7 B: `. lfloat miny=min((float)0,min(Point1y,min(Point2y,Point3y))); ' I5 W5 b( r* |- afloat maxx=max(Point1x,max(Point2x,Point3x)); float maxy=max(Point1y,max(Point2y,Point3y)); : c" N) b) o" |7 L, o" lint DestBitmapWidth,DestBitmapHeight; ! A) E* U* ?6 ]1 c& O# Tif(angle>90&&angle<180) # `! D1 S4 D7 y! K0 Q1 `DestBitmapWidth=(int)ceil(-minx); 5 @5 L8 A6 D/ y6 ]$ felse DestBitmapWidth=(int)ceil(maxx-minx);

if(angle>-180&&angle<-90) 8 O1 ^6 ?" s- _ k0 bDestBitmapHeight=(int)ceil(-miny); 1 p% ^/ t U4 R7 R" y; Telse 7 {# V) c5 i: Y" ?6 sDestBitmapHeight=(int)ceil(maxy-miny);

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NewPic->Height=DestBitmapHeight; 1 C8 u- L; t+ Z3 sNewPic->Width=DestBitmapWidth; for(int x=0;x<DestBitmapWidth;x++) 9 C5 S9 i' }7 L1 K; i{ for(int y=0;y<DestBitmapHeight;y++){ int SrcBitmapx=(int)((x+minx)*cosine+(y+miny)*sine); int SrcBitmapy=(int)((y+miny)*cosine-(x+minx)*sine); ' O$ L* [& H& Nif(SrcBitmapx>=0&&SrcBitmapx<Source->Width&&SrcBitmapy>=0&& ) R! C. M9 [2 ~" U0 Z% m! }SrcBitmapy<Source->Height) { % q1 Q- a2 L9 ]NewPic->Canvas->ixels[x][y]= Source->Canvas->ixels[SrcBitmapx][SrcBitmapy]; . f, q8 S3 A! C! A, o9 d; o- h} E7 ]5 a2 I' \( \# Y8 N* ~} 4 A' f1 v! {! E& q' |4 f} # S7 R+ z2 y4 R! x0 U}