A simple rotation of an ellipse by different angle values.

A simple rotation of an ellipse by different angle values. Atomic model by 2-D transformation Code : //#include "winbgim.h" #include <graphics.h> #include <math.h> void Translation(int X,int Y,int Tx,int Ty,int *Xp,int *Yp) { *Xp=X+Tx; *Yp=Y+Ty; } void Scaling(int X,int Y,float Sx,float Sy,int R,int P,int *Xp,int *Yp) { *Xp=(int)(Sx*(X-R)+0.5)+R; *Yp=(int)(Sy*(Y-P)+0.5)+P; } void Rotation(int X,int Y,float S,float C,int R,int P,int *Xp,int *Yp) { int Xx,Yy; Xx=X-R; Yy=Y-P; *Xp=(int)(Xx*C-Yy*S+0.5)+R; *Yp=(int)(Xx*S+Yy*C+0.5)+P; } int main(){ int X[361],Y[361],Xp,Yp,I,J,K,Tx,Ty; float T,C,S,Pi; initwindow(450,450); int i, x, y, color,MaxColors; //srand( seed ); /* Restart random # function */ MaxColors=getmaxcolor()-1; for( i=0 ; i<1500 ; ++i ){ /* Put 5000 pixels on screen */ x = 1 + random( 450 - 1 ); /* Generate a random location */ y = 1 + random( 450 - 1 ); color = random( MaxColors ); putpixel( x, y, color ); } Pi=4*atan(1); for(J=0;J<=360;J++) { T=J*Pi/180; S=sin(T); C=cos(T) ; X[J]=(int)(200.0+150.0*C+0.5); Y[J]=(int)(180.0+100.0*S+0.5); //setcolor(4); setfillstyle(12,1); fillellipse(92,80,4,4); fillellipse(324,200,4,4); } for(J=0;J<9;J++) { setcolor(6+J); T=J*45*Pi/180; S=sin(T); C=cos(T); for(I=0;I<=360;I++) { Rotation(X[I],Y[I],S,C,200,180,&Xp,&Yp); if(I==0) moveto(Xp,Yp); else lineto(Xp,Yp); } setfillstyle(12,1); fillellipse(192,82,4,4); fillellipse(200,281,4,4); } //setfillstyle(13,2); fillellipse(200,180,10,10); getch(); closegraph(); return 0; }