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improve docs for tag_scope()

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Adrian Mariano 2024-11-03 08:06:28 -05:00
parent 400f3efa97
commit da261588b7
1 changed files with 61 additions and 8 deletions
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@ -1252,13 +1252,66 @@ module default_tag(tag,do_tag=true)
// Creates a tag scope with locally altered tag names to avoid tag name conflict with other code. // Creates a tag scope with locally altered tag names to avoid tag name conflict with other code.
// This is necessary when writing modules because the module's caller might happen to use the same tags. // This is necessary when writing modules because the module's caller might happen to use the same tags.
// Note that if you directly set the `$tag` variable then tag scoping will not work correctly. // Note that if you directly set the `$tag` variable then tag scoping will not work correctly.
// Usually you will want to use tag_scope in the first child of {{attachable()}} to isolate the geometry
// of your attachable object. If you put it **outside** the {{attachable()}} call, then it will
// set a scope that also applies to the children passed to your attachable object.
// Side Effects: // Side Effects:
// `$tag_prefix` is set to the value of `scope=` if given, otherwise is set to a random string. // `$tag_prefix` is set to the value of `scope=` if given, otherwise is set to a random string.
// Example: In this example the ring module uses "remove" tags which will conflict with use of the same tags by the parent. // Example(3D,NoAxes): In this example, tag_scope() is required for things to work correctly.
// module ring(r,h,w=1,anchor,spin,orient) // module myring(){
// attachable(anchor=CENTER, spin=0, d=60, l=60) {
// tag_scope()
// diff()
// cyl(d=60, l=60){
// tag("remove")
// color_this("lightblue")
// cyl(d=30, l=61);
// }
// children();
// }
// }
// diff()
// myring()
// color_this("green") cyl(d=20, l=61)
// tag("remove") color_this("yellow") cyl(d=10, l=65);
// Example(3D,NoAxes): Without tag_scope() we get this result
// module myring(){
// attachable(anchor=CENTER, spin=0, d=60, l=60) {
// diff()
// cyl(d=60, l=60){
// tag("remove")
// color_this("lightblue")
// cyl(d=30, l=61);
// }
// children();
// }
// }
// diff()
// myring()
// color_this("green") cyl(d=20, l=61)
// tag("remove") color_this("yellow") cyl(d=10, l=65);
// Example(3D,NoAxes): If the tag_scope() is outside the attachable() call then something different goes wrong:
// module myring(){
// tag_scope()
// attachable(anchor=CENTER, spin=0, d=60, l=60) {
// diff()
// cyl(d=60, l=60){
// tag("remove")
// color_this("lightblue")
// cyl(d=30, l=61);
// }
// children();
// }
// }
// diff()
// myring()
// color_this("green") cyl(d=20, l=61)
// tag("remove") color_this("yellow") cyl(d=10, l=65);
// Example: In this example the myring module uses "remove" tags which will conflict with use of the same tags elsewhere in a diff() operation, even without a parent-child relationship. Without the tag_scope() the result is a solid cylinder.
// module myring(r,h,w=1,anchor,spin,orient)
// { // {
// tag_scope("ringscope")
// attachable(anchor,spin,orient,r=r,h=h){ // attachable(anchor,spin,orient,r=r,h=h){
// tag_scope("myringscope")
// diff() // diff()
// cyl(r=r,h=h) // cyl(r=r,h=h)
// tag("remove") cyl(r=r-w,h=h+1); // tag("remove") cyl(r=r-w,h=h+1);
@ -1267,14 +1320,14 @@ module default_tag(tag,do_tag=true)
// } // }
// // Calling the module using "remove" tags // // Calling the module using "remove" tags
// // will conflict with internal tag use in // // will conflict with internal tag use in
// // the ring module. // // the myring module.
// $fn=32; // $fn=32;
// diff(){ // diff(){
// ring(10,7,w=4); // myring(10,7,w=4);
// tag("remove")ring(8,8); // tag("remove")myring(8,8);
// tag("remove")diff("rem"){ // tag("remove")diff("rem"){
// ring(9.5,8,w=1); // myring(9.5,8,w=1);
// tag("rem")ring(9.5,8,w=.3); // tag("rem")myring(9.5,8,w=.3);
// } // }
// } // }
module tag_scope(scope){ module tag_scope(scope){