plexus 0.0.2

3D mesh generation and manipulation.
Documentation 
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use num::{Integer, NumCast, Unsigned};
use std::hash::Hash;
use std::iter::FromIterator;

use generate::{HashIndexer, IndexVertices, IntoTriangles, IntoVertices, Topological, Triangulate};

pub struct ConjointBuffer<N, V>
where
    N: Integer + Unsigned,
{
    indeces: Vec<N>,
    vertices: Vec<V>,
}

impl<N, V> ConjointBuffer<N, V>
where
    N: Integer + Unsigned,
{
    pub fn new() -> Self {
        Self::default()
    }

    pub fn as_index_slice(&self) -> &[N] {
        self.indeces.as_slice()
    }

    pub fn as_vertex_slice(&self) -> &[V] {
        self.vertices.as_slice()
    }

    fn extend<I, J>(&mut self, indeces: I, vertices: J)
    where
        I: IntoIterator<Item = N>,
        J: IntoIterator<Item = V>,
    {
        self.indeces.extend(indeces);
        self.vertices.extend(vertices);
    }
}

impl<N, V> ConjointBuffer<N, V>
where
    N: Copy + Integer + NumCast + Unsigned,
{
    pub fn append<M, U>(&mut self, other: &mut ConjointBuffer<M, U>)
    where
        M: Copy + Integer + Into<N> + Unsigned,
        U: Into<V>,
    {
        let offset = N::from(self.vertices.len()).unwrap();
        self.vertices
            .extend(other.vertices.drain(..).map(|vertex| vertex.into()));
        self.indeces
            .extend(other.indeces.drain(..).map(|index| index.into() + offset))
    }
}

impl<N, V> Default for ConjointBuffer<N, V>
where
    N: Integer + Unsigned,
{
    fn default() -> Self {
        ConjointBuffer {
            indeces: vec![],
            vertices: vec![],
        }
    }
}

impl<T, N, V> FromIterator<T> for ConjointBuffer<N, V>
where
    T: IntoTriangles + IntoVertices + Topological,
    T::Vertex: Eq + Hash + Into<V>,
    N: Integer + NumCast + Unsigned,
{
    fn from_iter<I>(input: I) -> Self
    where
        I: IntoIterator<Item = T>,
    {
        let (indeces, vertices) = input
            .into_iter()
            .triangulate()
            .index_vertices(HashIndexer::default());
        let mut buffer = ConjointBuffer::new();
        buffer.extend(
            indeces.into_iter().map(|index| N::from(index).unwrap()),
            vertices.into_iter().map(|vertex| vertex.into()),
        );
        buffer
    }
}

#[cfg(test)]
mod tests {
    use r32;
    use buffer::conjoint::*;
    use generate::*;

    #[test]
    fn collect_topology_into_buffer() {
        let buffer = sphere::UVSphere::<f32>::with_unit_radius(3, 2)
            .polygons_with_position() // 6 triangles, 18 vertices.
            .map_vertices(|vertex| vertex.into_hash())
            .triangulate()
            .collect::<ConjointBuffer<u64, (r32, r32, r32)>>();

        assert_eq!(18, buffer.as_index_slice().len());
        assert_eq!(5, buffer.as_vertex_slice().len());
    }
}