diff options
Diffstat (limited to 'engine')
| -rw-r--r-- | engine/src/file_format/wavefront/obj.rs | 49 |
1 files changed, 28 insertions, 21 deletions
diff --git a/engine/src/file_format/wavefront/obj.rs b/engine/src/file_format/wavefront/obj.rs index 88e6580..6ca11c2 100644 --- a/engine/src/file_format/wavefront/obj.rs +++ b/engine/src/file_format/wavefront/obj.rs @@ -2,6 +2,7 @@ //! //! File format documentation: <https://paulbourke.net/dataformats/obj> +use std::collections::HashMap; use std::fs::read_to_string; use std::path::PathBuf; @@ -82,26 +83,32 @@ impl Obj /// - A face index does not fit in a [`u32`] pub fn to_mesh(&self) -> Result<Mesh, Error> { - let vertices = self - .faces - .iter() - .flat_map(|face| face.vertices.clone()) - .map(|face_vertex| face_vertex.to_vertex(self)) - .collect::<Result<Vec<_>, Error>>()?; - - Ok(Mesh::new( - vertices, - Some( - self.faces - .iter() - .flat_map(|face| face.vertices.clone()) - .enumerate() - .map(|(index, _)| { - u32::try_from(index).map_err(|_| Error::FaceIndexTooBig(index)) - }) - .collect::<Result<Vec<_>, _>>()?, - ), - )) + let mut vertices = Vec::<Vertex>::with_capacity(self.faces.len() * 3); + let mut indices = Vec::<u32>::with_capacity(self.faces.len() * 3); + + let mut added_face_vertices = + HashMap::<FaceVertex, u32>::with_capacity(self.faces.len() * 3); + + for face in &self.faces { + for face_vertex in &face.vertices { + if let Some(index) = added_face_vertices.get(&face_vertex) { + indices.push(*index); + + continue; + } + + vertices.push(face_vertex.to_vertex(self)?); + + let vertex_index = u32::try_from(vertices.len() - 1) + .map_err(|_| Error::FaceIndexTooBig(vertices.len() - 1))?; + + indices.push(vertex_index); + + added_face_vertices.insert(face_vertex.clone(), vertex_index); + } + } + + Ok(Mesh::new(vertices, Some(indices))) } /// Reads and parses the material libraries of this `Obj`. @@ -142,7 +149,7 @@ pub struct Face pub material_name: Option<String>, } -#[derive(Debug, Clone)] +#[derive(Debug, Clone, PartialEq, Eq, Hash)] pub struct FaceVertex { pub position: u32, |