Dear Otared,
>
> Regarding the way Aditya uses \startuseMPgraphic, it is also very instructive.
> Dalyoung, can you also share the animation example for the foldings ? I am sure we are a few on the list to learn something…
>
1. Here is the working sample of animation using \processMPbuffer which I did before. You can see it using adobe reader.
\startbuffer[UDBasic]
pair A,B,C,D;
pair E, F, G, H;
path p,q;
numeric ang,maxNum;
u:=1in;
A=(.95*TextWidth,u); B=(0,u); C=(0,0); D=(.95*TextWidth,0);
p := A--B--C--D;
q := (TextWidth,1.5u)--(0,1.5u)--(0,-.5u)--(TextWidth,-.5u)--cycle;
z0=(.1u,0);
vardef nextPt (expr M,N) =
if ypart(N) = 0:
H := whatever[N, N + dir(.5*angle(M-N))*u] = whatever[A,B];
else:
H := whatever[N, N + dir(.5*angle(M-N))*u] = whatever[C,D];
fi;
H
enddef;
def grayUD(expr i) =
draw G -- if ypart(B)=ypart(G): B -- C else: C -- B fi --z[i];
filldraw z[i]+2*(G-z[i])*u -- z[i] -- z[i+1] -- z[i+1]+(G-z[i])*u -- cycle withcolor .75white;
draw G -- z[i+1] dashed evenly;
draw z[0] for k=0 upto i: --z[k] endfor dashed evenly;
clip currentpicture to q;
setbounds currentpicture to boundingbox q;
enddef;
def linesUD(expr i) =
draw p;
draw z0 for k=0 upto i+1: --z[k] endfor dashed evenly;
setbounds currentpicture to boundingbox q;
enddef;
\stopbuffer
\startbuffer[UDpts]
ang := 40;
z[1] = whatever[z[0], z[0]+dir(ang)*u] = whatever[A,B];
G := whatever[z[0], z[0]+dir(2*ang)*u] = whatever[A,B];
for k = 2 upto 20:
z[k] = nextPt(z[k-2],z[k-1]);
maxNum := k;
exitif xpart(z[k]) > TextWidth;
endfor;
\stopbuffer
\startbuffer[UD0]
draw p;
setbounds currentpicture to boundingbox q;
\stopbuffer
\startbuffer[UD1]
grayUD(0);
\stopbuffer
\startbuffer[UD11]
linesUD(0);
\stopbuffer
\startbuffer[UD2]
G := z0;
grayUD(1)
\stopbuffer
\startbuffer[UD21]
linesUD(1);
\stopbuffer
\startbuffer[UD3]
G := z1;
grayUD(2);
\stopbuffer
\startbuffer[UD31]
linesUD(2);
\stopbuffer
\startbuffer[UD4]
G := z2;
grayUD(3);
\stopbuffer
\startbuffer[UD41]
linesUD(3);
\stopbuffer
\startbuffer[UD5]
G := z3;
grayUD(4);
\stopbuffer
\startbuffer[UD51]
linesUD(4);
\stopbuffer
\startbuffer[UDFinal]
draw p;
draw z0--z1--z2--z3--z4--z5--z6--z7--z8 dashed evenly;
setbounds currentpicture to boundingbox q;
\stopbuffer
\setupinteraction[state=start]
\usemodule[animation]
\starttext
\startanimation[menu=yes]
{\processMPbuffer[UDBasic,UDpts,UD0]}
{\processMPbuffer[UDBasic,UDpts,UD1]}
{\processMPbuffer[UDBasic,UDpts,UD11]}
{\processMPbuffer[UDBasic,UDpts,UD2]}
{\processMPbuffer[UDBasic,UDpts,UD21]}
{\processMPbuffer[UDBasic,UDpts,UD3]}
{\processMPbuffer[UDBasic,UDpts,UD31]}
{\processMPbuffer[UDBasic,UDpts,UD4]}
{\processMPbuffer[UDBasic,UDpts,UD41]}
{\processMPbuffer[UDBasic,UDpts,UD5]}
{\processMPbuffer[UDBasic,UDpts,UD51]}
{\processMPbuffer[UDBasic,UDpts,UDFinal]}
\stopanimation
\stoptext
Now, I am trying to do the same thing using \startuseMPgraphic, but I don’t the correct result yet.
Using \startuseMPgraphic, and \dorecurse, the code is simpler. But, it seems to me that \startanimation … \stopanimation is not working with \dorecurse{}{} …
It just list all the graphics.
Any hint is welcome.
\startMPinitializations%{UDBasic}
pair A,B,C,D;
pair E, F, G, H;
path p,q;
numeric ang,maxNum;
numeric n; %AM Added
u:=1in;
A=(.95*TextWidth,u); B=(0,u); C=(0,0); D=(.95*TextWidth,0);
p := A--B--C--D;
q := (TextWidth,1.5u)--(0,1.5u)--(0,-.5u)--(TextWidth,-.5u)--cycle;
z0=(.1u,0);
vardef nextPt (expr M,N) =
if ypart(N) = 0:
H := whatever[N, N + dir(.5*angle(M-N))*u] = whatever[A,B];
else:
H := whatever[N, N + dir(.5*angle(M-N))*u] = whatever[C,D];
fi;
H
enddef;
def grayUD(expr i) =
draw G -- if ypart(B)=ypart(G): B -- C else: C -- B fi --z[i];
filldraw z[i]+2*(G-z[i])*u -- z[i] -- z[i+1] -- z[i+1]+(G-z[i])*u -- cycle withcolor .75white;
draw G -- z[i+1] dashed evenly;
draw z[0] for k=0 upto i: --z[k] endfor dashed evenly;
clip currentpicture to q;
enddef;
def linesUD(expr i) =
draw p;
draw z0 for k=0 upto i+1: --z[k] endfor dashed evenly;
% AM: removed. Set in in the main code
% setbounds currentpicture to boundingbox q;
enddef;
ang := 40;
z[1] = whatever[z[0], z[0]+dir(ang)*u] = whatever[A,B];
% AM: Changed next line from G to z[-1]
z[-1] = whatever[z[0], z[0]+dir(2*ang)*u] = whatever[A,B];
for k = 2 upto 20:
z[k] = nextPt(z[k-2],z[k-1]);
maxNum := k;
exitif xpart(z[k]) > TextWidth;
endfor;
\stopMPinitializations
\startuseMPgraphic{foldUD}{num}
numeric n;
n := \MPvar{num}-1;
G := z[n-1];
grayUD(n);
\stopuseMPgraphic
\startuseMPgraphic{dotLines}{num}
numeric n;
n := \MPvar{num}-1;
linesUD(n);
\stopuseMPgraphic
\setupinteraction[state=start]
\usemodule[animation]
\starttext
\startanimation[menu=yes]
\dorecurse{7}
{
{\useMPgraphic{foldUD}{num=\recurselevel}}
{\useMPgraphic{dotLines}{num=\recurselevel}}
}
\stopanimation
\stoptext
Best regards,
Dalyoung