Forward diff method

forward.cpp

     //forward differencing method for rendering curve points
     int t=20;
     double space=0.05;
     double fx,fy,f1x,f2x,f3x,f1y,f2y,f3y;
     fx=ansMat[3][0];
     fy=ansMat[3][1];

     f1x= ansMat[0][0]*pow(space,3)+ ansMat[1][0]*pow(space,2)+ansMat[2][0]*space;
     f2x=6*ansMat[0][0]*pow(space,3)+ 2*ansMat[1][0]*pow(space,2);
     f3x=6*ansMat[0][0]*pow(space,3);

     f1y= ansMat[0][1]*pow(space,3)+ ansMat[1][1]*pow(space,2)+ansMat[2][1]*space;
     f2y=6*ansMat[0][1]*pow(space,3)+ 2*ansMat[1][1]*pow(space,2);
     f3y=6*ansMat[0][1]*pow(space,3);

     pointsOn[midx].x = (double)fx;
     pointsOn[midx].y = (double)fy;
     midx++;

     for(int i=0; i<t; i++){
        fx+=f1x;
        f1x+=f2x;
        f2x+=f3x;

        fy+=f1y;
        f1y+=f2y;
        f2y+=f3y;
        pointsOn[midx].x = (double)fx;
        pointsOn[midx].y = (double)fy;
        midx++;

     }