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Diffstat (limited to 'Master/texmf-dist/doc/asymptote/examples/splitpatch.asy')
-rw-r--r-- | Master/texmf-dist/doc/asymptote/examples/splitpatch.asy | 87 |
1 files changed, 87 insertions, 0 deletions
diff --git a/Master/texmf-dist/doc/asymptote/examples/splitpatch.asy b/Master/texmf-dist/doc/asymptote/examples/splitpatch.asy new file mode 100644 index 00000000000..2e9fae66431 --- /dev/null +++ b/Master/texmf-dist/doc/asymptote/examples/splitpatch.asy @@ -0,0 +1,87 @@ +import three; + +size(300); + +// A structure to subdivide two intersecting patches about their intersection. +struct split +{ + surface[] S=sequence(new surface(int i) {return new surface;},1); + surface[] T=sequence(new surface(int i) {return new surface;},1); + + struct tree { + tree[] tree=new tree[2]; + } + // Default subdivision depth. + int n=20; + + // Subdivide p and q to depth n if they overlap. + void write(tree pt, tree qt, triple[][] p, triple[][] q, int depth=n) { + --depth; + triple[][][] Split(triple[][] P)=depth % 2 == 0 ? hsplit : vsplit; + triple[][][] P=Split(p); + triple[][][] Q=Split(q); + + for(int i=0; i < 2; ++i) { + triple[][] Pi=P[i]; + for(int j=0; j < 2; ++j) { + triple[][] Qj=Q[j]; + if(overlap(Pi,Qj)) { + if(!pt.tree.initialized(i)) + pt.tree[i]=new tree; + if(!qt.tree.initialized(j)) + qt.tree[j]=new tree; + if(depth > 0) + write(pt.tree[i],qt.tree[j],Pi,Qj,depth); + } + } + } + } + + // Output the subpatches of p from subdivision. + void read(surface[] S, tree t, triple[][] p, int depth=n) { + --depth; + triple[][][] Split(triple[][] P)=depth % 2 == 0 ? hsplit : vsplit; + triple[][][] P=Split(p); + + for(int i=0; i < 2; ++i) { + if(t.tree.initialized(i)) + read(S,t.tree[i],P[i],depth); + else { + S[0].push(patch(P[i])); + } + } + } + + void operator init(triple[][] p, triple[][] q, int depth=n) { + tree ptrunk,qtrunk; + write(ptrunk,qtrunk,p,q,depth); + read(T,ptrunk,p,depth); + read(S,qtrunk,q,depth); + } +} + +currentprojection=orthographic(0,0,1); + +triple[][] A={ + {(0,0,0),(1,0,0),(1,0,0),(2,0,0)}, + {(0,4/3,0),(2/3,4/3,2),(4/3,4/3,2),(2,4/3,0)}, + {(0,2/3,0),(2/3,2/3,0),(4/3,2/3,0),(2,2/3,0)}, + {(0,2,0),(2/3,2,0),(4/3,2,0),(2,2,0)} +}; + +triple[][] B={ + {(0.5,0,-1),(0.5,1,-1),(0.5,2,-1),(0.5,3,-1)}, + {(0.5,0,0),(0.5,1,0),(0.5,2,0),(0.5,3,0)}, + {(0.5,0,1),(0.5,1,1),(0.5,2,1),(0.5,3,1)}, + {(0.5,0,2),(0.5,1,2),(0.5,2,2),(0.5,3,2)} +}; + +split S=split(B,A); + +defaultrender.merge=true; + +for(int i=0; i < S.S[0].s.length; ++i) + draw(surface(S.S[0].s[i]),Pen(i)); + +for(int i=0; i < S.T[0].s.length; ++i) + draw(surface(S.T[0].s[i]),Pen(i)); |