C / C++ / MFC

void rotateb(Bitmap* image, HDC dc){<br />
	Graphics graphics(dc);<br />
	Bitmap* SrcBitmap1 = image;<br />
	Color mc;<br />
<br />
	int angle=45;        //45° for example <br />
	//Convert degrees to radians <br />
	float radians=(2*3.1416*angle)/360; <br />
<br />
	float cosine=(float)cos(radians); <br />
	float sine=(float)sin(radians); <br />
<br />
	float Point1x=(-SrcBitmap1->GetHeight()*sine); <br />
	float Point1y=(SrcBitmap1->GetHeight()*cosine); <br />
	float Point2x=(SrcBitmap1->GetWidth()*cosine-SrcBitmap1->GetHeight()*sine); <br />
	float Point2y=(SrcBitmap1->GetHeight()*cosine+SrcBitmap1->GetWidth()*sine); <br />
	float Point3x=(SrcBitmap1->GetWidth()*cosine); <br />
	float Point3y=(SrcBitmap1->GetWidth()*sine); <br />
<br />
<br />
	float minx=min(0,min(Point1x,min(Point2x,Point3x))); <br />
	float miny=min(0,min(Point1y,min(Point2y,Point3y))); <br />
	float maxx=max(Point1x,max(Point2x,Point3x)); <br />
	float maxy=max(Point1y,max(Point2y,Point3y)); <br />
<br />
	int DestBitmapWidth=(int)ceil(fabs(maxx)-minx); <br />
	int DestBitmapHeight=(int)ceil(fabs(maxy)-miny);<br />
<br />
	Bitmap* DestBitmap = new Bitmap(DestBitmapWidth, DestBitmapHeight);<br />
<br />
	//----------<br />
	for(int x=0;x<DestBitmapWidth;x++) <br />
	{ <br />
	  for(int y=0;y<DestBitmapHeight;y++) <br />
	  { <br />
		int SrcBitmapx=(int)((x+minx)*cosine+(y+miny)*sine); <br />
		int SrcBitmapy=(int)((y+miny)*cosine-(x+minx)*sine); <br />
		if(SrcBitmapx>=0&&SrcBitmapx<SrcBitmap1->GetWidth() && SrcBitmapy>= 0 && <br />
			 SrcBitmapy<SrcBitmap1->GetHeight()) <br />
		{ <br />
			SrcBitmap1->GetPixel(SrcBitmapx,SrcBitmapy,&mc);<br />
			DestBitmap->SetPixel(x,y,mc);<br />
		} <br />
	  } <br />
	} <br />
<br />
	graphics.DrawImage(DestBitmap,0, 0); <-- this does not <br />
	//graphics.DrawImage(SrcBitmap1,0,0); <-- this displays <br />
}