Trashed my 'exit group' nonsense for parent vertices.

README.md

@@ -11,8 +11,7 @@
 - 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
-  triple nested spiral
+  triple nested spiral.  See `examples.py`.
-- Lots of Rust-kosher refactoring (once I understand Rust better)
 - Actual Rust-style docs!
 
 ## If I'm bored:

src/examples.rs

@@ -12,33 +12,21 @@ fn curve_horn_start() -> RuleStep {
         std::f32::consts::PI).to_homogeneous();
     RuleStep {
         geom: OpenMesh {
-            verts: vec![],
+            verts: vec![
-            faces: vec![
+                vertex(-0.5, -0.5, 0.0),
-                Tag::Exit(1, 0), Tag::Exit(1, 2), Tag::Exit(0, 1),
+                vertex(-0.5,  0.5, 0.0),
-                Tag::Exit(1, 2), Tag::Exit(0, 3), Tag::Exit(0, 1), 
+                vertex( 0.5,  0.5, 0.0),
-                Tag::Exit(0, 0), Tag::Exit(0, 2), Tag::Exit(1, 1), 
+                vertex( 0.5, -0.5, 0.0),
-                Tag::Exit(0, 2), Tag::Exit(1, 3), Tag::Exit(1, 1), 
-                Tag::Exit(0, 3), Tag::Exit(1, 2), Tag::Exit(0, 2), 
-                Tag::Exit(1, 2), Tag::Exit(1, 3), Tag::Exit(0, 2), 
-                Tag::Exit(1, 0), Tag::Exit(0, 1), Tag::Exit(0, 0),
-                Tag::Exit(1, 1), Tag::Exit(1, 0), Tag::Exit(0, 0), 
-                // The above is connecting group 0 to group 1,
-                // straight across + with diagonal - but with group 1
-                // being flipped 180, so we remap vertices (0,1,2,3)
-                // to (1,0,3,2) and then flip winding order.
             ],
-            exit_groups: vec![4, 4],
+            faces: vec![],
         },
         final_geom: prim::empty_mesh(),
         children: vec![
-            (Rule::Recurse(curve_horn_thing_rule), id), // exit group 0
+            (Rule::Recurse(curve_horn_thing_rule), id),
-            (Rule::Recurse(curve_horn_thing_rule), flip180), // exit group 1
+            (Rule::Recurse(curve_horn_thing_rule), flip180),
         ],
     }
-    // TODO: The starting vertices above are duplicated because I
+    // TODO: Fix the consequences of the 180 flip
-    // don't have any way for an exit vertex to stand in for multiple
-    // child vertices that happen to share the same location.  I don't
-    // yet know a good way around this, so I am duplicating vertices.
 }
 
 fn curve_horn_thing_rule() -> RuleStep {
@@ -51,49 +39,45 @@ fn curve_horn_thing_rule() -> RuleStep {
 
     let verts = vec![
         vertex(-0.5, -0.5, 0.0),
-        vertex(0.5, -0.5, 0.0),
         vertex(-0.5,  0.5, 0.0),
         vertex( 0.5,  0.5, 0.0),
+        vertex( 0.5, -0.5, 0.0),
     ];
-    let final_verts: Vec<Vertex> = verts.iter().map(|v| m * v).collect();
+    let next_verts: Vec<Vertex> = verts.iter().map(|v| m * v).collect();
     
     let geom = OpenMesh {
-        verts: verts,
+        verts: next_verts.clone(),
         faces: vec![
             // The below is just connecting two groups of 4 vertices
-            // each, straight across and then to the next.  Note that
+            // each, straight across and then to the next.
-            // since 'verts' doesn't go in a circle, it will look a
+            Tag::Body(1), Tag::Parent(0), Tag::Body(0),
-            // little strange.
+            Tag::Parent(1), Tag::Parent(0), Tag::Body(1),
-            Tag::Body(1), Tag::Exit(0, 3), Tag::Exit(0, 1),
+            Tag::Body(2), Tag::Parent(1), Tag::Body(1),
-            Tag::Body(1), Tag::Body(3), Tag::Exit(0, 3),
+            Tag::Parent(2), Tag::Parent(1), Tag::Body(2),
-            Tag::Exit(0, 0), Tag::Body(2), Tag::Body(0),
+            Tag::Body(3), Tag::Parent(2), Tag::Body(2),
-            Tag::Exit(0, 0), Tag::Exit(0, 2), Tag::Body(2),
+            Tag::Parent(3), Tag::Parent(2), Tag::Body(3),
-            Tag::Body(2), Tag::Exit(0, 3), Tag::Body(3),
+            Tag::Body(0), Tag::Parent(3), Tag::Body(3),
-            Tag::Body(2), Tag::Exit(0, 2), Tag::Exit(0, 3),
+            Tag::Parent(0), Tag::Parent(3), Tag::Body(0),
-            Tag::Body(0), Tag::Body(1), Tag::Exit(0, 1),
-            Tag::Body(0), Tag::Exit(0, 1), Tag::Exit(0, 0),
             // TODO: I should really generate these, not hard-code them.
         ],
-        exit_groups: vec![4],
     };
 
     // TODO: This could be made slightly nicer by taking it to a peak
     // instead of just flattening it in XY, but this is a pretty minor
     // change.
     let final_geom = OpenMesh {
-        verts: final_verts,
+        verts: next_verts,
         faces: vec![
             Tag::Body(0), Tag::Body(1), Tag::Body(3),
             Tag::Body(0), Tag::Body(3), Tag::Body(2),
         ],
-        exit_groups: vec![],
     };
     
     RuleStep{
         geom: geom,
         final_geom: final_geom,
         children: vec![
-            (Rule::Recurse(curve_horn_thing_rule), m), // exit group 0
+            (Rule::Recurse(curve_horn_thing_rule), m),
         ],
     }
 }
@@ -127,11 +111,69 @@ fn cube_thing_rule() -> RuleStep {
 
     RuleStep {
         geom: mesh,
-        final_geom: prim::empty_mesh(), // no exit groups
+        final_geom: prim::empty_mesh(),
         children: turns.iter().map(gen_rulestep).collect(),
     }
 }
 
+/*
+// Conversion from Python & automata_scratch
+fn ram_horn_start() -> RuleStep {
+    let id = nalgebra::geometry::Transform3::identity().to_homogeneous();
+    let flip180 = nalgebra::geometry::Rotation3::from_axis_angle(
+        &nalgebra::Vector3::y_axis(),
+        std::f32::consts::PI).to_homogeneous();
+    RuleStep {
+        geom: OpenMesh {
+            // 'Bottom' vertices:
+            verts: vec![
+                vertex(-0.5, -0.5, -0.5),
+                vertex(-0.5,  0.5, -0.5),
+                vertex( 0.5,  0.5, -0.5),
+                vertex( 0.5, -0.5, -0.5),
+            ],
+            faces: vec![
+                // bottom face:
+                Tag::Body(0), Tag::Body(1), Tag::Body(2),
+                Tag::Body(0), Tag::Body(2), Tag::Body(3),
+                // two faces straddling edge from vertex 0:
+                Tag::Body(0), Tag::Exit(0, 0), Tag::Exit(0, 1),
+                Tag::Body(0), Tag::Exit(0, 3), Tag::Exit(0, 0),
+                // two faces straddling edge from vertex 1:
+                Tag::Body(1), Tag::Exit(1, 0), Tag::Exit(1, 1),
+                Tag::Body(1), Tag::Exit(1, 3), Tag::Exit(1, 0),
+                // two faces straddling edge from vertex 2:
+                Tag::Body(2), Tag::Exit(2, 0), Tag::Exit(2, 1),
+                Tag::Body(2), Tag::Exit(2, 3), Tag::Exit(2, 0),
+                // two faces straddling edge from vertex 3:
+                Tag::Body(3), Tag::Exit(3, 0), Tag::Exit(3, 1),
+                Tag::Body(3), Tag::Exit(3, 3), Tag::Exit(3, 0),
+                // four faces from edge (0,1), (1,2), (2,3), (3,0):
+                Tag::Body(0), Tag::Exit(0, 1)/*=Tag::Exit(1, 3)*/, Tag::Body(1),
+                Tag::Body(1), Tag::Exit(1, 1)/*=Tag::Exit(2, 3)*/, Tag::Body(2),
+                Tag::Body(2), Tag::Exit(2, 1)/*=Tag::Exit(3, 3)*/, Tag::Body(3),
+                Tag::Body(3), Tag::Exit(3, 1)/*=Tag::Exit(0, 3)*/, Tag::Body(0),
+            ],
+            exit_groups: vec![4, 4, 4, 4],
+        },
+        final_geom: prim::empty_mesh(),
+        children: vec![
+            (Rule::Recurse(ram_horn), id), // exit group 0
+            (Rule::Recurse(ram_horn), id), // exit group 1
+            (Rule::Recurse(ram_horn), id), // exit group 2
+            (Rule::Recurse(ram_horn), id), // exit group 3
+        ],
+    }
+    // TODO: How do I handle *duplicated* exit vertices?  In this
+    // instance, multiple children connect to some of them - e.g. all
+    // Tag::Exit(n,2) are together, and Tag::Exit(n,1) is the same as
+    // Tag::Exit((n+1)%4, 3).
+}
+
+fn ram_horn() -> RuleStep {
+}
+*/
+
 pub fn main() {
 
     let run_test = |r: Rule, iters, name| {
@@ -144,6 +186,6 @@ pub fn main() {
     };
 
     run_test(Rule::Recurse(cube_thing_rule), 3, "cube_thing");
-    run_test(Rule::Recurse(curve_horn_thing_rule), 100, "curve_horn_thing");
+    //run_test(Rule::Recurse(curve_horn_thing_rule), 100, "curve_horn_thing");
     run_test(Rule::Recurse(curve_horn_start), 100, "curve_horn2");
 }

src/openmesh.rs

@@ -16,7 +16,7 @@ pub fn vertex(x: f32, y: f32, z: f32) -> Vertex {
 #[derive(Clone, Debug)]
 pub enum Tag {
     Body(usize),
-    Exit(usize, usize),  // (group, vertex)
+    Parent(usize),
 }
 
 #[derive(Clone, Debug)]
@@ -26,7 +26,6 @@ pub struct OpenMesh {
     // Triangles, taken as every 3 values, treated each as indices
     // into 'verts':
     pub faces: Vec<Tag>,
-    pub exit_groups: Vec<usize>,
 }
 
 impl OpenMesh {
@@ -37,7 +36,6 @@ impl OpenMesh {
             // TODO: Is the above faster if I pack vectors into a
             // bigger matrix, and transform that?
             faces: self.faces.clone(), // TODO: Use Rc?
-            exit_groups: self.exit_groups.clone(),
         }
     }
 
@@ -59,7 +57,7 @@ impl OpenMesh {
         let get_vert = |j| {
             match self.faces[j] {
                 Tag::Body(n) => self.verts[n].xyz(),
-                Tag::Exit(_, _) => panic!("Cannot write_stl() if mesh has exit groups!"),
+                Tag::Parent(_) => panic!("Cannot write_stl() if mesh has parent references!"),
             }
         };
         // TODO: Handle this behavior
@@ -92,49 +90,31 @@ impl OpenMesh {
         let mut verts: Vec<Vertex> = self.verts.clone();
         let mut faces = self.faces.clone();
 
-        let mut exit_groups: Vec<usize> = vec![];
+        for other in others {
 
-        let mut body_offset = self.verts.len();
+            // body_offset corresponds to the position in 'verts' at
-        let mut exit_offset = 0;
+            // which we're appending everything in 'other.verts' -
-        let mut offsets: Vec<usize> = vec![0; others.len()];
+            // thus, the offset we shift all indices in 'others' by.
-        for (i,other) in others.iter().enumerate() {
+            let body_offset = verts.len();
             
-            // Append body vertices & exit vertices directly:
+            // Copy all vertices from 'other':
             verts.append(&mut other.verts.clone());
 
-            // Append faces, shifting each kind by respective offset:
+            // Append its faces:
             faces.extend(other.faces.iter().map(|t| {
                 match t {
+                    // Apply aforementioned shift to its body vertices:
                     Tag::Body(n) => Tag::Body(n + body_offset),
-                    Tag::Exit(g, n) => Tag::Exit(g + exit_groups.len(), n + exit_offset),
+                    // Since 'self' vertices are in the same order,
+                    // parent vertex references retain same index:
+                    Tag::Parent(n) => Tag::Body(*n),
                 }
             }));
-            if i < self.exit_groups.len() {
-                exit_offset += self.exit_groups[i];
-            }
-            exit_groups.append(&mut other.exit_groups.clone());
-
-            offsets[i] = body_offset;
-            // Increase offsets by the number of elements we appended:
-            body_offset += other.verts.len();
-        }
-
-        // All of the Exit face indices from 'self' need to be
-        // modified to refer to Body vertices of something in
-        // 'others':
-        for i in 0..faces.len() {
-            match faces[i] {
-                Tag::Exit(g, n) => {
-                    faces[i] = Tag::Body(n + offsets[g]);
-                },
-                _ => { },
-            };
         }
 
         OpenMesh {
             verts: verts,
             faces: faces,
-            exit_groups: exit_groups,
         }
     }
 }

src/prim.rs

@@ -6,7 +6,6 @@ pub fn empty_mesh() -> OpenMesh {
     OpenMesh {
         verts: vec![],
         faces: vec![],
-        exit_groups: vec![],
     }
 }
 
@@ -36,6 +35,5 @@ pub fn cube() -> OpenMesh {
             Tag::Body(0), Tag::Body(1), Tag::Body(5),
             Tag::Body(0), Tag::Body(5), Tag::Body(4),
         ],
-        exit_groups: vec![],
     }.transform(geometry::Translation3::new(-0.5, -0.5, -0.5).to_homogeneous())
 }

src/rule.rs

@@ -40,8 +40,6 @@ impl Rule {
 
     pub fn to_mesh(&self, iters_left: u32) -> (OpenMesh, u32) {
 
-        
-        
         let mut nodes: u32 = 1;
 
         if iters_left <= 0 {