Add MeshVertexAttribute instead of directly storing positions

lyra-resource/src/loader/model.rs

@@ -3,7 +3,7 @@ use std::sync::Arc;
 use base64::Engine;
 use glam::Vec3;
 
-use crate::{ResourceLoader, LoaderError, Mesh, Vertex, Model};
+use crate::{ResourceLoader, LoaderError, Mesh, Vertex, Model, MeshVertexAttribute, VertexAttributeData};
 
 impl From<gltf::Error> for LoaderError {
     fn from(value: gltf::Error) -> Self {
@@ -35,25 +35,44 @@ impl ModelLoader {
         let mut meshes = vec![];
         if let Some(mesh) = node.mesh() {
             for prim in mesh.primitives() {
-                let pos_accessor = prim.get(&gltf::Semantic::Positions).unwrap();
-                //assert_eq!(pos_accessor.dimensions(), gltf::accessor::Dimensions::Vec3); // TODO: dont do this
-                
                 let reader = prim.reader(|buf| Some(buffers[buf.index()].as_slice()));
-                let pos: Vec<Vec3> = reader.read_positions()
-                    .unwrap()
-                    .map(|pos| Vec3::new(pos[0], pos[1], pos[2]))
-                    .collect();
 
-                let indices: Option<Vec<u32>> = reader.read_indices()
-                    .map(|i| match i {
+                let mut new_mesh = Mesh::default();
+                
+                // read the positions
+                if let Some(pos) = reader.read_positions() {
+                    let pos: Vec<glam::Vec3> = pos.map(|t| t.into()).collect();
+                    new_mesh.add_attribute(MeshVertexAttribute::Position, VertexAttributeData::Vec3(pos));
+                }
+
+                // read the normals
+                if let Some(norms) = reader.read_normals() {
+                    let norms: Vec<glam::Vec3> = norms.map(|t| t.into()).collect();
+                    new_mesh.add_attribute(MeshVertexAttribute::Normals, VertexAttributeData::Vec3(norms));
+                }
+
+                // read the tangents
+                if let Some(tangents) = reader.read_tangents() {
+                    let tangents: Vec<glam::Vec4> = tangents.map(|t| t.into()).collect();
+                    new_mesh.add_attribute(MeshVertexAttribute::Tangents, VertexAttributeData::Vec4(tangents));
+                }
+
+                // read tex coords
+                if let Some(tex_coords) = reader.read_tex_coords(0) {
+                    let tex_coords: Vec<glam::Vec2> = tex_coords.into_f32().map(|t| t.into()).collect(); // TODO: u16, u8
+                    new_mesh.add_attribute(MeshVertexAttribute::TexCoords, VertexAttributeData::Vec2(tex_coords));
+                }
+
+                // read the indices
+                if let Some(indices) = reader.read_indices() {
+                    let indices: Vec<u32> = match indices {
                         gltf::mesh::util::ReadIndices::U8(i) => i.map(|i| i as u32).collect(),
                         gltf::mesh::util::ReadIndices::U16(i) => i.map(|i| i as u32).collect(),
                         gltf::mesh::util::ReadIndices::U32(i) => i.collect(),
-                    });
+                    };
 
-                let mut new_mesh = Mesh::default();
-                new_mesh.vertices = pos.into_iter().map(|p| Vertex::new(p, glam::Vec2::new(0.0, 0.0))).collect();
-                new_mesh.indices = indices;
+                    new_mesh.indices = Some(indices);
+                }
 
                 meshes.push(new_mesh);
             }
@@ -83,8 +102,6 @@ impl ResourceLoader for ModelLoader {
 
         let gltf = gltf::Gltf::open(path)?;
 
-        //let buffers: Vec<gltf::Buffer<'_>> = gltf.buffers().collect();
-
         let buffers: Vec<Vec<u8>> = gltf.buffers().map(|b| match b.source() {
                 gltf::buffer::Source::Bin => gltf.blob.as_deref().map(|v| v.to_vec()),
                 gltf::buffer::Source::Uri(uri) => ModelLoader::parse_uri(uri),
@@ -93,6 +110,8 @@ impl ResourceLoader for ModelLoader {
         // TODO: Read in multiple scenes
         let scene = gltf.scenes().next().unwrap();
 
+        // TODO: materials
+
         let meshes: Vec<Mesh> = scene.nodes()
             .map(|node| self.process_node(&buffers, node))
             .flatten().collect();
@@ -119,8 +138,11 @@ mod tests {
         let loader = ModelLoader::default();
         let model = loader.load(&path).unwrap();
         let model = Arc::downcast::<Model>(model.as_arc_any()).unwrap();
+        assert_eq!(model.meshes.len(), 1); // There should only be 1 mesh
         let mesh = &model.meshes[0];
-        assert!(mesh.vertices.len() > 0);
+        assert!(mesh.position().unwrap().len() > 0);
+        assert!(mesh.normals().unwrap().len() > 0);
+        assert!(mesh.tex_coords().unwrap().len() > 0);
         assert!(mesh.indices.clone().unwrap().len() > 0);
     }
 }

lyra-resource/src/model.rs

@@ -1,3 +1,5 @@
+use std::collections::HashMap;
+
 
 #[repr(C)]
 #[derive(Copy, Clone, Debug)]
@@ -15,12 +17,79 @@ impl Vertex {
     }
 }
 
+#[repr(C)]
+#[derive(Clone, Debug, PartialEq)]
+pub enum VertexAttributeData {
+    Vec2(Vec<glam::Vec2>),
+    Vec3(Vec<glam::Vec3>),
+    Vec4(Vec<glam::Vec4>),
+}
+
+impl VertexAttributeData {
+    /// Take self as a list of Vec2's 
+    pub fn as_vec2(&self) -> &Vec<glam::Vec2> {
+        match self {
+            VertexAttributeData::Vec2(v) => v,
+            _ => panic!("Attempt to get {self:?} as `Vec2`"),
+        }
+    }
+
+    pub fn as_vec3(&self) -> &Vec<glam::Vec3> {
+        match self {
+            VertexAttributeData::Vec3(v) => v,
+            _ => panic!("Attempt to get {self:?} as `Vec3`"),
+        }
+    }
+}
+
+#[derive(Clone, Debug, PartialEq, Eq, Hash)]
+pub enum MeshVertexAttribute {
+    Position,
+    Normals,
+    Tangents,
+    // Colors, // TODO: Store data in VertexAttributeData
+    Joints, // TODO: Animation
+    TexCoords,
+    Weights, // TODO: Animation
+    MorphTargets, // TODO: Animation
+    Other(String),
+}
+
 #[derive(Clone, Default)]
 pub struct Mesh {
-    pub vertices: Vec<Vertex>,
+    pub attributes: HashMap<MeshVertexAttribute, VertexAttributeData>,
     pub indices: Option<Vec<u32>>,
 }
 
+impl Mesh {
+    pub fn add_attribute(&mut self, attribute: MeshVertexAttribute, data: VertexAttributeData) {
+        self.attributes.insert(attribute, data);
+    }
+
+    /// Try to get the position attribute of the Mesh
+    pub fn position(&self) -> Option<&Vec<glam::Vec3>> {
+        self.attributes.get(&MeshVertexAttribute::Position)
+            .map(|p| p.as_vec3())
+    }
+
+    pub fn add_position(&mut self, pos: Vec<glam::Vec3>) {
+        self.attributes.insert(MeshVertexAttribute::Position, VertexAttributeData::Vec3(pos));
+    }
+
+    /// Try to get the normals attribute of the Mesh
+    pub fn normals(&self) -> Option<&Vec<glam::Vec3>> {
+        self.attributes.get(&MeshVertexAttribute::Normals)
+            .map(|p| p.as_vec3())
+    }
+
+    /// Try to get the texture coordinates attribute of the Mesh
+    pub fn tex_coords(&self) -> Option<&Vec<glam::Vec2>> {
+        self.attributes.get(&MeshVertexAttribute::TexCoords)
+            .map(|p| p.as_vec2())
+    }
+}
+
+#[derive(Clone, Default)]
 pub struct Model {
     pub meshes: Vec<Mesh>,
     //pub material