feat(engine): add support for faces without texture/normal in obj

1 files changed, 27 insertions, 32 deletions

diff --git a/engine/src/file_format/wavefront/obj.rs b/engine/src/file_format/wavefront/obj.rs
index 7dab37c..4df5fe5 100644
--- a/engine/src/file_format/wavefront/obj.rs
+++ b/engine/src/file_format/wavefront/obj.rs
@@ -267,36 +267,37 @@ impl FaceVertex
     /// Tries to convert this face vertex into a [`Vertex`].
     pub fn to_vertex(&self, obj: &Obj) -> Result<Vertex, Error>
     {
+        let mut vertex_builder = VertexBuilder::new();
+
         let vertex_pos = *obj.vertex_positions.get(self.position as usize - 1).ok_or(
             Error::FaceVertexPositionNotFound { vertex_pos_index: self.position },
         )?;
 
-        let face_vertex_texture =
-            self.texture.ok_or(Error::NoFaceVertexTextureNotSupported)?;
-
-        let texture_pos = *obj
-            .texture_positions
-            .get(face_vertex_texture as usize - 1)
-            .ok_or(Error::FaceTexturePositionNotFound {
-                texture_pos_index: face_vertex_texture,
-            })?;
-
-        let face_vertex_normal =
-            self.normal.ok_or(Error::NoFaceVertexNormalNotSupported)?;
-
-        let vertex_normal = *obj
-            .vertex_normals
-            .get(face_vertex_normal as usize - 1)
-            .ok_or(Error::FaceVertexNormalNotFound {
-                vertex_normal_index: face_vertex_normal,
-            })?;
-
-        Ok(VertexBuilder::new()
-            .pos(vertex_pos)
-            .texture_coords(texture_pos)
-            .normal(vertex_normal)
-            .build()
-            .unwrap())
+        vertex_builder = vertex_builder.pos(vertex_pos);
+
+        if let Some(face_vertex_texture) = self.texture {
+            let texture_pos = obj
+                .texture_positions
+                .get(face_vertex_texture as usize - 1)
+                .ok_or(Error::FaceTexturePositionNotFound {
+                    texture_pos_index: face_vertex_texture,
+                })?;
+
+            vertex_builder = vertex_builder.texture_coords(texture_pos.clone());
+        }
+
+        if let Some(face_vertex_normal) = self.normal {
+            let vertex_normal = *obj
+                .vertex_normals
+                .get(face_vertex_normal as usize - 1)
+                .ok_or(Error::FaceVertexNormalNotFound {
+                    vertex_normal_index: face_vertex_normal,
+                })?;
+
+            vertex_builder = vertex_builder.normal(vertex_normal);
+        }
+
+        Ok(vertex_builder.build().unwrap())
     }
 }
 
@@ -345,12 +346,6 @@ pub enum Error
     #[error("Face index {0} is too big to fit into a 32-bit integer")]
     FaceIndexTooBig(usize),
 
-    #[error("Face vertices without textures are not yet supported")]
-    NoFaceVertexTextureNotSupported,
-
-    #[error("Face vertices without normals are not yet supported")]
-    NoFaceVertexNormalNotSupported,
-
     #[error(
         "Unsupported number of arguments ({arg_count}) to {keyword} at line {line_no}"
     )]