Dear Wolfgang,
I’d like to ask you one more.
To make an animation, almost same graphics are drawn repeatedly.
In my code, for example,
The base figure(two circles, line, boundingbox) is fixed and only points are
moved.
But it draws the base figure every time and it is not inefficient.
Is there a way to draw the base figure once, and draw the points only at each
frame?
Thank you.
Best regards,
Dalyoung
\startuseMPgraphic{inversionPoint}{n}
vardef findPointD(expr C, Q, r) =
numeric dist, ang;
pair X, Y;
dist := r**2/sqrt((xpart Q - xpart C)**2 + (ypart Q - ypart C)**2);
ang := angle(Q - C);
Y := C + dir(ang)*dist;
Y
enddef;
numeric radius, now, move;
pair A,B,C,P,Q;
path p,q;
radius := 2cm;
C := origin;
p := fullcircle scaled (2*radius);
z[1] = point 6 of p;
z[2] = point .8 of p;
q := (1.5*z1 - .5*z2) -- (-.5z1 + 1.5*z2);
%q := fullcircle scaled radius shifted (2cm, 1cm);
draw p;
draw q;
% end of base figure
% draw points
move := 0.1;
now := move*\MPvar{n};
P := point now along q;
Q := findPointD(C, P, radius);
drawdot P;
drawdot Q withcolor .625red;
dotlabel.lft(textext("P"),P);
dotlabel.rt(textext("Q"),Q) withcolor .625red;
\stopuseMPgraphic
___________________________________________________________________________________
If your question is of interest to others as well, please add an entry to the
Wiki!
maillist : ntg-context@ntg.nl / http://www.ntg.nl/mailman/listinfo/ntg-context
webpage : http://www.pragma-ade.nl / http://context.aanhet.net
archive : https://bitbucket.org/phg/context-mirror/commits/
wiki : http://contextgarden.net
___________________________________________________________________________________
