use bevy_math::{primitives::Cuboid, Vec3};
use wgpu::PrimitiveTopology;
use crate::{
mesh::{Indices, Mesh, MeshBuilder, Meshable},
render_asset::RenderAssetUsages,
};
pub struct CuboidMeshBuilder {
half_size: Vec3,
}
impl MeshBuilder for CuboidMeshBuilder {
fn build(&self) -> Mesh {
let min = -self.half_size;
let max = self.half_size;
let vertices = &[
([min.x, min.y, max.z], [0.0, 0.0, 1.0], [0.0, 0.0]),
([max.x, min.y, max.z], [0.0, 0.0, 1.0], [1.0, 0.0]),
([max.x, max.y, max.z], [0.0, 0.0, 1.0], [1.0, 1.0]),
([min.x, max.y, max.z], [0.0, 0.0, 1.0], [0.0, 1.0]),
([min.x, max.y, min.z], [0.0, 0.0, -1.0], [1.0, 0.0]),
([max.x, max.y, min.z], [0.0, 0.0, -1.0], [0.0, 0.0]),
([max.x, min.y, min.z], [0.0, 0.0, -1.0], [0.0, 1.0]),
([min.x, min.y, min.z], [0.0, 0.0, -1.0], [1.0, 1.0]),
([max.x, min.y, min.z], [1.0, 0.0, 0.0], [0.0, 0.0]),
([max.x, max.y, min.z], [1.0, 0.0, 0.0], [1.0, 0.0]),
([max.x, max.y, max.z], [1.0, 0.0, 0.0], [1.0, 1.0]),
([max.x, min.y, max.z], [1.0, 0.0, 0.0], [0.0, 1.0]),
([min.x, min.y, max.z], [-1.0, 0.0, 0.0], [1.0, 0.0]),
([min.x, max.y, max.z], [-1.0, 0.0, 0.0], [0.0, 0.0]),
([min.x, max.y, min.z], [-1.0, 0.0, 0.0], [0.0, 1.0]),
([min.x, min.y, min.z], [-1.0, 0.0, 0.0], [1.0, 1.0]),
([max.x, max.y, min.z], [0.0, 1.0, 0.0], [1.0, 0.0]),
([min.x, max.y, min.z], [0.0, 1.0, 0.0], [0.0, 0.0]),
([min.x, max.y, max.z], [0.0, 1.0, 0.0], [0.0, 1.0]),
([max.x, max.y, max.z], [0.0, 1.0, 0.0], [1.0, 1.0]),
([max.x, min.y, max.z], [0.0, -1.0, 0.0], [0.0, 0.0]),
([min.x, min.y, max.z], [0.0, -1.0, 0.0], [1.0, 0.0]),
([min.x, min.y, min.z], [0.0, -1.0, 0.0], [1.0, 1.0]),
([max.x, min.y, min.z], [0.0, -1.0, 0.0], [0.0, 1.0]),
];
let positions: Vec<_> = vertices.iter().map(|(p, _, _)| *p).collect();
let normals: Vec<_> = vertices.iter().map(|(_, n, _)| *n).collect();
let uvs: Vec<_> = vertices.iter().map(|(_, _, uv)| *uv).collect();
let indices = Indices::U32(vec![
0, 1, 2, 2, 3, 0, 4, 5, 6, 6, 7, 4, 8, 9, 10, 10, 11, 8, 12, 13, 14, 14, 15, 12, 16, 17, 18, 18, 19, 16, 20, 21, 22, 22, 23, 20, ]);
Mesh::new(
PrimitiveTopology::TriangleList,
RenderAssetUsages::default(),
)
.with_inserted_attribute(Mesh::ATTRIBUTE_POSITION, positions)
.with_inserted_attribute(Mesh::ATTRIBUTE_NORMAL, normals)
.with_inserted_attribute(Mesh::ATTRIBUTE_UV_0, uvs)
.with_inserted_indices(indices)
}
}
impl Meshable for Cuboid {
type Output = CuboidMeshBuilder;
fn mesh(&self) -> Self::Output {
CuboidMeshBuilder {
half_size: self.half_size,
}
}
}
impl From<Cuboid> for Mesh {
fn from(cuboid: Cuboid) -> Self {
cuboid.mesh().build()
}
}