feat: PC change for gltf load algorithm change

src/app.rs

@@ -572,8 +572,7 @@ impl App {
                 enabled_extensions: required_extensions,
                 ..Default::default()
             },
-        )
-        .map_err(|e| {
+        ).map_err(|e| {
             let err = e.unwrap();
             format!("Failed to create instance: {err}")
         })

src/common/camera.rs

@@ -30,7 +30,7 @@ impl Camera {
     /// (0, 0, 0), and a default FOV of 70 degrees.
     pub fn new(extents: impl Into<Vector2<u32>>) -> Self {
         let extents = extents.into();
-        let position = Vector3::new(-7.0, 7.0, -7.0);
+        let position = Vector3::new(10.0, 0.0, 0.0);
         let target = Vector3::zeros();
 
         // Traveling along this vector moves us toward the target.

src/loaders/gltf_loader.rs

@@ -1,9 +1,25 @@
 use crate::loaders::mesh_loader::{MeshFileLoader, MeshInfo};
 use anyhow::Result;
 use std::path::Path;
+use nalgebra::Matrix4;
 
 pub struct GltfLoader;
 
+impl GltfLoader {
+    /// Traverses and loads all information from a GLTF/GLB node.
+    pub fn traverse_node(
+        node: &gltf::Node,
+        parent_transform: &Matrix4<f32>,
+        buffers: &[Vec<u8>],
+        vertices: &mut Vec<[f32; 3]>,
+        normals: &mut Vec<[f32; 3]>,
+        uvs: &mut Vec<[f32; 3]>,
+        indices: &mut Vec<u32>
+    ) {
+
+    }
+}
+
 impl MeshFileLoader for GltfLoader {
     fn load_mesh(&self, path: &Path) -> Result<MeshInfo> {
         let (document, buffers, _) = gltf::import(path)?;
@@ -13,6 +29,18 @@ impl MeshFileLoader for GltfLoader {
         let mut uvs = Vec::new();
         let mut indices = Vec::<u32>::new();
 
+        let scenes = document.scenes();
+
+        // We need to iterate through scenes and apply the transforms from each scene to their
+        // corresponding vertices.
+        println!("Parsing {} scenes from {:?}", scenes.len(), path);
+        for scene in scenes {
+            for node in scene.nodes() {
+                let transform = node.transform().matrix();
+                println!("Scene has transform: {:?}", transform);
+            }
+        }
+
         for mesh in document.meshes() {
             for primitive in mesh.primitives() {
                 // Read the primitives as vertices and indices,
@@ -23,7 +51,7 @@ impl MeshFileLoader for GltfLoader {
 
                 if let Some(positions) = reader.read_positions() {
                     for position in positions {
-                        vertices.push(position);
+                        vertices.push([position[0], position[2], -position[1]]);
                     }
                 }
 
@@ -35,7 +63,7 @@ impl MeshFileLoader for GltfLoader {
 
                 if let Some(tex_coords) = reader.read_tex_coords(0) {
                     for uv in tex_coords.into_f32() {
-                        uvs.push([uv[0], uv[1], 0.0]);
+                        uvs.push([uv[0], 1.0 - uv[1], 0.0]);
                     }
                 }
 

src/loaders/mesh_loader.rs

@@ -64,3 +64,38 @@ impl MeshLoader {
             .load_mesh(path.as_ref())
     }
 }
+
+#[cfg(test)]
+pub mod test_load_meshes {
+    use super::*;
+
+    fn load_gltf(loader: &MeshLoader) -> Result<MeshInfo> {
+        loader.load_mesh(&Path::new("meshes/laat_gltf/scene.gltf"))
+    }
+
+    fn load_obj(loader: &MeshLoader) -> Result<MeshInfo> {
+        loader.load_mesh(&Path::new("meshes/laat_gunship/scene.obj"))
+    }
+
+    #[test]
+    fn compare_obj_gltf() -> Result<()> {
+        // Create the mesh loader
+        let loader = MeshLoader::new();
+
+        let obj = load_obj(&loader)?;
+        let gltf = load_gltf(&loader)?;
+
+        // Compare mesh information between the two MeshInfo structs.
+        obj.vertices.iter()
+            .zip(gltf.vertices.iter())
+            .for_each(|(&a, &b)| assert_eq!(a, b));
+        obj.indices.iter()
+            .zip(gltf.indices.iter())
+            .for_each(|(&a, &b)| assert_eq!(a, b));
+        obj.normals.iter()
+            .zip(gltf.normals.iter())
+            .for_each(|(&a, &b)| assert_eq!(a, b));
+
+        Ok(())
+    }
+}