implement lod fixups

src/lib.rs

@@ -108,15 +108,14 @@ fn index_range(index: i32, count: i32, size: usize) -> impl Iterator<Item = usiz
         .map(move |i| index as usize + i)
 }
 
-fn read_relative<T: ReadRelative, I: Iterator<Item = usize>>(
-    data: &[u8],
+fn read_relative_iter<'a, T: ReadRelative, I: 'a + Iterator<Item = usize>>(
+    data: &'a [u8],
     indexes: I,
-) -> Result<Vec<T>, ModelError>
+) -> impl Iterator<Item = Result<T, ModelError>> + 'a
 where
     <<T as ReadRelative>::Header as BinRead>::Args: Default,
 {
-    indexes
-        .map(|index| {
+    indexes.map(|index| {
         let data = data.get(index..).ok_or_else(|| ModelError::OutOfBounds {
             data: type_name::<T>(),
             offset: index,
@@ -125,7 +124,16 @@ where
         let header = reader.read_le()?;
         T::read(data, header)
     })
-        .collect()
+}
+
+fn read_relative<T: ReadRelative, I: Iterator<Item = usize>>(
+    data: &[u8],
+    indexes: I,
+) -> Result<Vec<T>, ModelError>
+where
+    <<T as ReadRelative>::Header as BinRead>::Args: Default,
+{
+    read_relative_iter(data, indexes).collect()
 }
 
 trait ReadRelative: Sized {

src/vvd/mod.rs

@@ -1,7 +1,7 @@
 mod raw;
 
-use crate::vvd::raw::VvdHeader;
-use crate::ModelError;
+use crate::vvd::raw::{VertexFileFixup, VvdHeader};
+use crate::{read_relative, read_relative_iter, ModelError};
 use binrw::BinReaderExt;
 pub use raw::{BoneWeight, Tangent, Vertex};
 use std::io::Cursor;
@@ -18,20 +18,21 @@ impl Vvd {
     pub fn read(data: &[u8]) -> Result<Self> {
         let mut reader = Cursor::new(data);
         let header: VvdHeader = reader.read_le()?;
-        Ok(Vvd {
-            vertices: header
-                .vertex_indexes(0)
-                .unwrap()
-                .map(|index| {
-                    let data = data.get(index..).ok_or_else(|| ModelError::OutOfBounds {
-                        data: "Vertex",
-                        offset: index,
-                    })?;
-                    let mut reader = Cursor::new(data);
-                    Ok(reader.read_le()?)
-                })
-                .collect::<Result<_>>()?,
-            header,
-        })
+        let source_vertices = read_relative(data, header.vertex_indexes(0).unwrap())?;
+        let vertices = if !header.has_fixups() {
+            source_vertices
+        } else {
+            let mut vertices = Vec::new();
+            for fixup in read_relative_iter::<'_, VertexFileFixup, _>(data, header.fixup_indexes())
+            {
+                let fixup = fixup?;
+                vertices.extend_from_slice(
+                    &source_vertices[fixup.source_vertex_id as usize
+                        ..(fixup.source_vertex_id + fixup.vertex_count) as usize],
+                );
+            }
+            vertices
+        };
+        Ok(Vvd { vertices, header })
     }
 }

src/vvd/raw.rs

@@ -24,10 +24,11 @@ impl VvdHeader {
         )
     }
 
-    pub fn vertex_indexes(&self, lod: i32) -> Option<impl Iterator<Item = usize>> {
-        if lod > 0 && lod > self.fixup_count {
-            todo!("lod fixup not supported")
+    pub fn has_fixups(&self) -> bool {
+        self.fixup_count > 0
     }
+
+    pub fn vertex_indexes(&self, lod: i32) -> Option<impl Iterator<Item = usize>> {
         if lod < self.lod_count {
             Some(index_range(
                 self.vertex_index,