use serde::{Deserialize, Serialize};

/// Primitive type the input mesh is composed of.
#[repr(C)]
#[derive(Copy, Clone, Debug, Hash, Eq, PartialEq, Serialize, Deserialize)]
pub enum PrimitiveTopology {
    /// Vertex data is a list of points. Each vertex is a new point.
    PointList = 0,

    /// Vertex data is a list of lines. Each pair of vertices composes a new line.
    ///
    /// Vertices `0 1 2 3` create two lines `0 1` and `2 3`
    LineList = 1,

    /// Vertex data is a strip of lines. Each set of two adjacent vertices form a line.
    ///
    /// Vertices `0 1 2 3` create three lines `0 1`, `1 2`, and `2 3`.
    LineStrip = 2,

    /// Vertex data is a list of triangles. Each set of 3 vertices composes a new triangle.
    ///
    /// Vertices `0 1 2 3 4 5` create two triangles `0 1 2` and `3 4 5`
    TriangleList = 3,

    /// Vertex data is a triangle strip. Each set of three adjacent vertices form a triangle.
    ///
    /// Vertices `0 1 2 3 4 5` creates four triangles `0 1 2`, `2 1 3`, `2 3 4`, and `4 3 5`
    TriangleStrip = 4,
}

impl Default for PrimitiveTopology {
    fn default() -> Self {
        PrimitiveTopology::TriangleList
    }
}