Fixed ram_horn example, slight refactor on to_mesh

README.md

@@ -2,15 +2,15 @@
 
 ## Highest priority:
 
-- See `ram_horn_*` and `curve_horn_*` TODOs: these are both solved by
+- Clean up my 'parent vertex mapping' thingy, *and* come up with
-  some sort of parent-vertex-mapping layer.  The only other way around
+  meaningful terms to discuss it.
-  this that I need is to require that rule functions exist in
+- Do transforms compose in the *reverse* of automata_scratch? This
-  explictly separate forms.
+  appears to be the case.
-- Consider trampolining `to_mesh`.  My call stack seems needlessly
-  deep in spots.  Can I make tail-recursive?
 
 ## Important but less critical:
 
+- Consider trampolining `to_mesh`.  My call stack seems needlessly
+  deep in spots.  Can I make tail-recursive?
 - Grep for all TODOs in code, really.
 - Look at everything in README.md in automata_scratch.
 - Implement some of the tougher examples from the above too, e.g. the

src/examples.rs

@@ -119,11 +119,11 @@ fn cube_thing_rule() -> RuleStep {
 // Conversion from Python & automata_scratch
 fn ram_horn_start() -> RuleStep {
     let opening_xform = |i| {
-        (geometry::Translation3::new(0.0, 0.0, -1.0).to_homogeneous() *
+        ((geometry::Rotation3::from_axis_angle(
-         Matrix4::new_scaling(0.5) *
+            &nalgebra::Vector3::z_axis(), i).to_homogeneous()) *
          geometry::Translation3::new(0.25, 0.25, 1.0).to_homogeneous() *
-         geometry::Rotation3::from_axis_angle(
+         Matrix4::new_scaling(0.5) *
-             &nalgebra::Vector3::z_axis(), i).to_homogeneous())
+         geometry::Translation3::new(0.0, 0.0, -1.0).to_homogeneous())
     };
     RuleStep {
         geom: OpenMesh {
@@ -171,19 +171,21 @@ fn ram_horn_start() -> RuleStep {
         },
         final_geom: prim::empty_mesh(),
         children: vec![
-            (Rule::Recurse(ram_horn), opening_xform(0.0), vec![0,4,8,7]),
+            (Rule::Recurse(ram_horn), opening_xform(0.0), vec![5,2,6,8]),
-            (Rule::Recurse(ram_horn), opening_xform(std::f32::consts::FRAC_PI_2), vec![1,5,8,4]),
+            (Rule::Recurse(ram_horn), opening_xform(std::f32::consts::FRAC_PI_2), vec![4,1,5,8]),
-            (Rule::Recurse(ram_horn), opening_xform(std::f32::consts::FRAC_PI_2*2.0), vec![2,6,8,5]),
+            (Rule::Recurse(ram_horn), opening_xform(std::f32::consts::FRAC_PI_2*2.0), vec![7,0,4,8]),
-            (Rule::Recurse(ram_horn), opening_xform(std::f32::consts::FRAC_PI_2*3.0), vec![3,7,8,6]),
+            (Rule::Recurse(ram_horn), opening_xform(std::f32::consts::FRAC_PI_2*3.0), vec![6,3,7,8]),
+            // TODO: These vertex mappings appear to be right.
+            // Understand *why* they are right.
         ],
     }
 }
 
 fn ram_horn() -> RuleStep {
     let v = Unit::new_normalize(Vector3::new(-1.0, 0.0, 1.0));
-    let incr: Mat4 = Matrix4::new_scaling(0.9) *
+    let incr: Mat4 = geometry::Translation3::new(0.0, 0.0, 0.8).to_homogeneous() *
         geometry::Rotation3::from_axis_angle(&v, 0.3).to_homogeneous() *
-        geometry::Translation3::new(0.0, 0.0, 0.8).to_homogeneous();
+        Matrix4::new_scaling(0.9);
     let seed = vec![
         vertex(-0.5, -0.5, 1.0),
         vertex(-0.5,  0.5, 1.0),
@@ -202,10 +204,6 @@ fn ram_horn() -> RuleStep {
             Tag::Parent(3), Tag::Parent(2), Tag::Body(3),
             Tag::Body(0), Tag::Parent(3), Tag::Body(3),
             Tag::Parent(0), Tag::Parent(3), Tag::Body(0),
-            // TODO: These are correct once the recursion is already
-            // going - but they are wrong at the start!  Note how I'm
-            // never using the 'midpoint' vertex from the parent,
-            // Tag::Parent(8).
         ],
     };
     let final_geom = OpenMesh {
@@ -238,6 +236,8 @@ pub fn main() {
     };
 
     run_test(Rule::Recurse(cube_thing_rule), 3, "cube_thing");
+    // this can't work on its own because the resultant OpenMesh still
+    // has parent references:
     //run_test(Rule::Recurse(curve_horn_thing_rule), 100, "curve_horn_thing");
     run_test(Rule::Recurse(curve_horn_start), 100, "curve_horn2");
     run_test(Rule::Recurse(ram_horn_start), 200, "ram_horn");

src/openmesh.rs

@@ -84,7 +84,8 @@ impl OpenMesh {
         stl_io::write_stl(writer, triangles.iter())
     }
 
-    pub fn connect(&self, others: &Vec<(OpenMesh, Vec<usize>)>) -> OpenMesh {
+    pub fn connect(&self, others: &Vec<(OpenMesh, &Vec<usize>)>) -> OpenMesh {
+        // TODO: Clean up Vec<usize> stuff
 
         // Copy body vertices & faces:
         let mut verts: Vec<Vertex> = self.verts.clone();

src/rule.rs

@@ -26,6 +26,9 @@ pub struct RuleStep {
     // Child rules, paired with the transform that will be applied to
     // all of their geometry and parent vertex mappings
     pub children: Vec<(Rule, Mat4, Vec<usize>)>,
+    // TODO: Clean this up, perhaps change the tuple to something
+    // saner.
+    // TODO: Also, document & rename this more clearly.
 }
 
 impl Rule {
@@ -57,21 +60,23 @@ impl Rule {
         match self {
             Rule::Recurse(f) => {
                 let rs: RuleStep = f();
+                // TODO: This logic is more or less right, but it
+                // could perhaps use some un-tupling or something.
 
-                // Get sub-geometry (from child rules) and transform it:
+                let subgeom: Vec<(OpenMesh, &Vec<usize>)> = rs.children.iter().map(
-                let subgeom: Vec<(OpenMesh, Mat4, u32, Vec<usize>)> = rs.children.iter().map(|(subrule, subxform, mapping)| {
+                    |(subrule, subxform, vmap)| {
-                    let (m,n) = subrule.to_mesh(iters_left - 1);
+                        // Get sub-geometry (still un-transformed):
-                    (m, *subxform, n, mapping.clone())
+                        let (submesh,n) = subrule.to_mesh(iters_left - 1);
-                }).collect();
+                        // Tally up node count:
+                        nodes += n;
                         
-                // Tally up node count:
+                        let m2 = submesh.transform(*subxform);
-                subgeom.iter().for_each(|(_,_,n,_)| nodes += n);
                         
-                let g: Vec<(OpenMesh, Vec<usize>)> = subgeom.iter().map(|(m,x,_,mv)| (m.transform(*x), mv.clone())).collect();
+                        (m2, vmap)
-                // TODO: Not clone twice
+                    }).collect();
                 
                 // Connect geometry from this rule (not child rules):
-                return (rs.geom.connect(&g), nodes);
+                return (rs.geom.connect(&subgeom), nodes);
             }
             Rule::EmptyRule => {
                 return (prim::empty_mesh(), nodes);