feat: Refactor code structure and enhance functionality across multiple crates

15 files changed, 232 insertions, 120 deletions

diff --git a/crates/common/src/lib.rs b/crates/common/src/lib.rs
index 69796d3..c0d57f7 100644
--- a/crates/common/src/lib.rs
+++ b/crates/common/src/lib.rs
@@ -1,4 +1,6 @@
+use std::fs;
 use std::io;
+use std::path::{Path, PathBuf};
 
 /// Resource payload that can be either borrowed from mapped bytes or owned.
 #[derive(Clone, Debug)]
@@ -42,3 +44,18 @@ impl OutputBuffer for Vec<u8> {
         Ok(())
     }
 }
+
+/// Recursively collects all files under `root`.
+pub fn collect_files_recursive(root: &Path, out: &mut Vec<PathBuf>) {
+    let Ok(entries) = fs::read_dir(root) else {
+        return;
+    };
+    for entry in entries.flatten() {
+        let path = entry.path();
+        if path.is_dir() {
+            collect_files_recursive(&path, out);
+        } else if path.is_file() {
+            out.push(path);
+        }
+    }
+}
diff --git a/crates/msh-core/Cargo.toml b/crates/msh-core/Cargo.toml
index cdea317..86b0846 100644
--- a/crates/msh-core/Cargo.toml
+++ b/crates/msh-core/Cargo.toml
@@ -4,4 +4,9 @@ version = "0.1.0"
 edition = "2021"
 
 [dependencies]
+encoding_rs = "0.8"
 nres = { path = "../nres" }
+
+[dev-dependencies]
+common = { path = "../common" }
+proptest = "1"
diff --git a/crates/msh-core/src/lib.rs b/crates/msh-core/src/lib.rs
index 1a50fb7..bc51357 100644
--- a/crates/msh-core/src/lib.rs
+++ b/crates/msh-core/src/lib.rs
@@ -1,6 +1,7 @@
 pub mod error;
 
 use crate::error::Error;
+use encoding_rs::WINDOWS_1251;
 use std::sync::Arc;
 
 pub type Result<T> = core::result::Result<T, Error>;
@@ -347,13 +348,18 @@ fn parse_res10_names(data: &[u8], node_count: usize) -> Result<Vec<Option<String
         } else {
             slice
         };
-        let decoded = String::from_utf8_lossy(text).to_string();
+        let decoded = decode_cp1251(text);
         out.push(Some(decoded));
         off = end;
     }
     Ok(out)
 }
 
+fn decode_cp1251(bytes: &[u8]) -> String {
+    let (decoded, _, _) = WINDOWS_1251.decode(bytes);
+    decoded.into_owned()
+}
+
 struct RawResource {
     meta: nres::EntryMeta,
     bytes: Vec<u8>,
diff --git a/crates/msh-core/src/tests.rs b/crates/msh-core/src/tests.rs
index 07b05c7..90a7fdc 100644
--- a/crates/msh-core/src/tests.rs
+++ b/crates/msh-core/src/tests.rs
@@ -1,22 +1,10 @@
 use super::*;
+use common::collect_files_recursive;
 use nres::Archive;
+use proptest::prelude::*;
 use std::fs;
 use std::path::{Path, PathBuf};
 
-fn collect_files_recursive(root: &Path, out: &mut Vec<PathBuf>) {
-    let Ok(entries) = fs::read_dir(root) else {
-        return;
-    };
-    for entry in entries.flatten() {
-        let path = entry.path();
-        if path.is_dir() {
-            collect_files_recursive(&path, out);
-        } else if path.is_file() {
-            out.push(path);
-        }
-    }
-}
-
 fn nres_test_files() -> Vec<PathBuf> {
     let root = Path::new(env!("CARGO_MANIFEST_DIR"))
         .join("..")
@@ -169,18 +157,17 @@ fn res13_single_batch(index_start: u32, index_count: u16) -> Vec<u8> {
     batch
 }
 
-fn res10_names(names: &[Option<&str>]) -> Vec<u8> {
+fn res10_names_raw(names: &[Option<&[u8]>]) -> Vec<u8> {
     let mut out = Vec::new();
     for name in names {
         match name {
             Some(name) => {
-                let bytes = name.as_bytes();
                 out.extend_from_slice(
-                    &u32::try_from(bytes.len())
+                    &u32::try_from(name.len())
                         .expect("name size overflow in test")
                         .to_le_bytes(),
                 );
-                out.extend_from_slice(bytes);
+                out.extend_from_slice(name);
                 out.push(0);
             }
             None => out.extend_from_slice(&0u32.to_le_bytes()),
@@ -189,6 +176,11 @@ fn res10_names(names: &[Option<&str>]) -> Vec<u8> {
     out
 }
 
+fn res10_names(names: &[Option<&str>]) -> Vec<u8> {
+    let raw: Vec<Option<&[u8]>> = names.iter().map(|name| name.map(str::as_bytes)).collect();
+    res10_names_raw(&raw)
+}
+
 fn base_synthetic_entries() -> Vec<SyntheticEntry> {
     vec![
         synthetic_entry(RES1_NODE_TABLE, "Res1", 38, res1_stride38_nodes(1, Some(0))),
@@ -340,6 +332,22 @@ fn parse_synthetic_model_with_optional_res4_res5_res10() {
 }
 
 #[test]
+fn parse_res10_names_decodes_cp1251() {
+    let mut entries = base_synthetic_entries();
+    entries[0] = synthetic_entry(RES1_NODE_TABLE, "Res1", 38, res1_stride38_nodes(1, Some(0)));
+    entries.push(synthetic_entry(
+        RES10_NAMES,
+        "Res10",
+        1,
+        res10_names_raw(&[Some(&[0xC0])]),
+    ));
+    let payload = build_nested_nres(&entries);
+
+    let model = parse_model_payload(&payload).expect("failed to parse model with cp1251 name");
+    assert_eq!(model.node_names, Some(vec![Some("А".to_string())]));
+}
+
+#[test]
 fn parse_fails_when_required_resource_missing() {
     let mut entries = base_synthetic_entries();
     entries.retain(|entry| entry.kind != RES13_BATCHES);
@@ -419,3 +427,12 @@ fn parse_fails_for_batch_index_range_out_of_bounds() {
         })
     ));
 }
+
+proptest! {
+    #![proptest_config(ProptestConfig::with_cases(64))]
+
+    #[test]
+    fn parse_model_payload_never_panics_on_random_bytes(data in proptest::collection::vec(any::<u8>(), 0..8192)) {
+        let _ = parse_model_payload(&data);
+    }
+}
diff --git a/crates/nres/src/tests.rs b/crates/nres/src/tests.rs
index 6de02e5..bfa75a8 100644
--- a/crates/nres/src/tests.rs
+++ b/crates/nres/src/tests.rs
@@ -1,4 +1,5 @@
 use super::*;
+use common::collect_files_recursive;
 use std::any::Any;
 use std::fs;
 use std::panic::{catch_unwind, AssertUnwindSafe};
@@ -13,20 +14,6 @@ struct SyntheticEntry<'a> {
     data: &'a [u8],
 }
 
-fn collect_files_recursive(root: &Path, out: &mut Vec<PathBuf>) {
-    let Ok(entries) = fs::read_dir(root) else {
-        return;
-    };
-    for entry in entries.flatten() {
-        let path = entry.path();
-        if path.is_dir() {
-            collect_files_recursive(&path, out);
-        } else if path.is_file() {
-            out.push(path);
-        }
-    }
-}
-
 fn nres_test_files() -> Vec<PathBuf> {
     let root = Path::new(env!("CARGO_MANIFEST_DIR"))
         .join("..")
diff --git a/crates/render-core/Cargo.toml b/crates/render-core/Cargo.toml
index b856d12..c93d624 100644
--- a/crates/render-core/Cargo.toml
+++ b/crates/render-core/Cargo.toml
@@ -7,4 +7,5 @@ edition = "2021"
 msh-core = { path = "../msh-core" }
 
 [dev-dependencies]
+common = { path = "../common" }
 nres = { path = "../nres" }
diff --git a/crates/render-core/src/lib.rs b/crates/render-core/src/lib.rs
index d06761a..c7a69d6 100644
--- a/crates/render-core/src/lib.rs
+++ b/crates/render-core/src/lib.rs
@@ -1,4 +1,5 @@
 use msh_core::Model;
+use std::collections::HashMap;
 
 pub const DEFAULT_UV_SCALE: f32 = 1024.0;
 
@@ -11,21 +12,24 @@ pub struct RenderVertex {
 #[derive(Clone, Debug)]
 pub struct RenderMesh {
     pub vertices: Vec<RenderVertex>,
+    pub indices: Vec<u16>,
     pub batch_count: usize,
+    pub index_overflow: bool,
 }
 
 impl RenderMesh {
     pub fn triangle_count(&self) -> usize {
-        self.vertices.len() / 3
+        self.indices.len() / 3
     }
 }
 
-/// Builds an expanded triangle list for a specific LOD/group pair.
-///
-/// The output is suitable for simple `glDrawArrays(GL_TRIANGLES, ...)` paths.
+/// Builds an indexed triangle mesh for a specific LOD/group pair.
 pub fn build_render_mesh(model: &Model, lod: usize, group: usize) -> RenderMesh {
     let mut vertices = Vec::new();
+    let mut indices = Vec::new();
+    let mut index_remap: HashMap<usize, u16> = HashMap::new();
     let mut batch_count = 0usize;
+    let mut index_overflow = false;
     let uv0 = model.uv0.as_ref();
 
     for node_index in 0..model.node_count {
@@ -49,36 +53,62 @@ pub fn build_render_mesh(model: &Model, lod: usize, group: usize) -> RenderMesh
                 continue;
             }
 
+            let batch_out_start = indices.len();
+            let mut batch_valid = true;
             for &idx in &model.indices[index_start..index_end] {
                 let final_idx_u64 = u64::from(batch.base_vertex).saturating_add(u64::from(idx));
                 let Ok(final_idx) = usize::try_from(final_idx_u64) else {
-                    continue;
+                    batch_valid = false;
+                    break;
                 };
                 let Some(pos) = model.positions.get(final_idx) else {
-                    continue;
+                    batch_valid = false;
+                    break;
                 };
-                let uv = uv0
-                    .and_then(|uvs| uvs.get(final_idx))
-                    .copied()
-                    .map(|packed| {
-                        [
-                            packed[0] as f32 / DEFAULT_UV_SCALE,
-                            packed[1] as f32 / DEFAULT_UV_SCALE,
-                        ]
-                    })
-                    .unwrap_or([0.0, 0.0]);
-                vertices.push(RenderVertex {
-                    position: *pos,
-                    uv0: uv,
-                });
+
+                let local_index = if let Some(&mapped) = index_remap.get(&final_idx) {
+                    mapped
+                } else {
+                    let Ok(mapped) = u16::try_from(vertices.len()) else {
+                        index_overflow = true;
+                        batch_valid = false;
+                        break;
+                    };
+                    let uv = uv0
+                        .and_then(|uvs| uvs.get(final_idx))
+                        .copied()
+                        .map(|packed| {
+                            [
+                                packed[0] as f32 / DEFAULT_UV_SCALE,
+                                packed[1] as f32 / DEFAULT_UV_SCALE,
+                            ]
+                        })
+                        .unwrap_or([0.0, 0.0]);
+                    vertices.push(RenderVertex {
+                        position: *pos,
+                        uv0: uv,
+                    });
+                    index_remap.insert(final_idx, mapped);
+                    mapped
+                };
+
+                indices.push(local_index);
             }
+
+            if !batch_valid {
+                indices.truncate(batch_out_start);
+                continue;
+            }
+
             batch_count += 1;
         }
     }
 
     RenderMesh {
         vertices,
+        indices,
         batch_count,
+        index_overflow,
     }
 }
 
diff --git a/crates/render-core/src/tests.rs b/crates/render-core/src/tests.rs
index c9b55a0..1c5285e 100644
--- a/crates/render-core/src/tests.rs
+++ b/crates/render-core/src/tests.rs
@@ -1,23 +1,10 @@
 use super::*;
+use common::collect_files_recursive;
 use msh_core::parse_model_payload;
 use nres::Archive;
 use std::fs;
 use std::path::{Path, PathBuf};
 
-fn collect_files_recursive(root: &Path, out: &mut Vec<PathBuf>) {
-    let Ok(entries) = fs::read_dir(root) else {
-        return;
-    };
-    for entry in entries.flatten() {
-        let path = entry.path();
-        if path.is_dir() {
-            collect_files_recursive(&path, out);
-        } else if path.is_file() {
-            out.push(path);
-        }
-    }
-}
-
 fn nres_test_files() -> Vec<PathBuf> {
     let root = Path::new(env!("CARGO_MANIFEST_DIR"))
         .join("..")
@@ -71,12 +58,20 @@ fn build_render_mesh_for_real_models() {
                 )
             });
             let mesh = build_render_mesh(&model, 0, 0);
-            if !mesh.vertices.is_empty() {
+            if !mesh.indices.is_empty() {
                 meshes_non_empty += 1;
             }
             if compute_bounds_for_mesh(&mesh.vertices).is_some() {
                 bounds_non_empty += 1;
             }
+            for &index in &mesh.indices {
+                assert!(
+                    usize::from(index) < mesh.vertices.len(),
+                    "index out of bounds for '{}' in {}",
+                    entry.meta.name,
+                    archive_path.display()
+                );
+            }
             for vertex in &mesh.vertices {
                 assert!(
                     vertex.uv0[0].is_finite() && vertex.uv0[1].is_finite(),
@@ -189,6 +184,7 @@ fn build_render_mesh_handles_empty_slot_model() {
 
     let mesh = build_render_mesh(&model, 0, 0);
     assert!(mesh.vertices.is_empty());
+    assert!(mesh.indices.is_empty());
     assert_eq!(mesh.batch_count, 0);
     assert_eq!(mesh.triangle_count(), 0);
 }
@@ -225,9 +221,36 @@ fn build_render_mesh_supports_multi_node_and_uv_scaling() {
     let mesh = build_render_mesh(&model, 0, 0);
     assert_eq!(mesh.batch_count, 2);
     assert_eq!(mesh.vertices.len(), 6);
+    assert_eq!(mesh.indices, vec![0, 1, 2, 3, 4, 5]);
     assert_eq!(mesh.triangle_count(), 2);
     assert_eq!(mesh.vertices[0].uv0, [1.0, -1.0]);
     assert_eq!(mesh.vertices[1].uv0, [0.5, 0.25]);
     assert_eq!(mesh.vertices[2].uv0, [0.0, 0.0]);
     assert_eq!(mesh.vertices[3].uv0, [1.0, 1.0]);
 }
+
+#[test]
+fn build_render_mesh_deduplicates_shared_vertices() {
+    let model = msh_core::Model {
+        node_stride: 38,
+        node_count: 1,
+        nodes_raw: nodes_with_slot_refs(&[Some(0)]),
+        slots: vec![slot(0, 1)],
+        positions: vec![
+            [0.0, 0.0, 0.0],
+            [1.0, 0.0, 0.0],
+            [0.0, 1.0, 0.0],
+            [1.0, 1.0, 0.0],
+        ],
+        normals: None,
+        uv0: None,
+        indices: vec![0, 1, 2, 2, 1, 3],
+        batches: vec![batch(0, 6, 0)],
+        node_names: None,
+    };
+
+    let mesh = build_render_mesh(&model, 0, 0);
+    assert_eq!(mesh.vertices.len(), 4);
+    assert_eq!(mesh.indices, vec![0, 1, 2, 2, 1, 3]);
+    assert_eq!(mesh.triangle_count(), 2);
+}
diff --git a/crates/render-demo/Cargo.toml b/crates/render-demo/Cargo.toml
index 94c2e46..b7b62cd 100644
--- a/crates/render-demo/Cargo.toml
+++ b/crates/render-demo/Cargo.toml
@@ -17,6 +17,9 @@ sdl2 = { version = "0.37", optional = true, default-features = false, features =
 glow = { version = "0.16", optional = true }
 image = { version = "0.25", optional = true, default-features = false, features = ["png"] }
 
+[dev-dependencies]
+common = { path = "../common" }
+
 [[bin]]
 name = "parkan-render-demo"
 path = "src/main.rs"
diff --git a/crates/render-demo/src/lib.rs b/crates/render-demo/src/lib.rs
index c82e055..9555151 100644
--- a/crates/render-demo/src/lib.rs
+++ b/crates/render-demo/src/lib.rs
@@ -435,23 +435,10 @@ fn decode_texture_entry(archive: &Archive, entry: EntryRef<'_>) -> Result<Loaded
 #[cfg(test)]
 mod tests {
     use super::*;
+    use common::collect_files_recursive;
     use std::fs;
     use std::path::{Path, PathBuf};
 
-    fn collect_files_recursive(root: &Path, out: &mut Vec<PathBuf>) {
-        let Ok(entries) = fs::read_dir(root) else {
-            return;
-        };
-        for entry in entries.flatten() {
-            let path = entry.path();
-            if path.is_dir() {
-                collect_files_recursive(&path, out);
-            } else if path.is_file() {
-                out.push(path);
-            }
-        }
-    }
-
     fn archive_with_msh() -> Option<PathBuf> {
         let root = Path::new(env!("CARGO_MANIFEST_DIR"))
             .join("..")
diff --git a/crates/render-demo/src/main.rs b/crates/render-demo/src/main.rs
index 8d309d1..70f2209 100644
--- a/crates/render-demo/src/main.rs
+++ b/crates/render-demo/src/main.rs
@@ -221,12 +221,17 @@ fn run(args: Args) -> Result<(), String> {
             )
         })?;
     let mesh = build_render_mesh(&loaded_model.model, args.lod, args.group);
-    if mesh.vertices.is_empty() {
+    if mesh.indices.is_empty() {
         return Err(format!(
             "model has no renderable triangles for lod={} group={}",
             args.lod, args.group
         ));
     }
+    if mesh.index_overflow {
+        eprintln!(
+            "warning: mesh exceeds u16 index space and may be partially rendered on GLES2 targets"
+        );
+    }
     let Some((bounds_min, bounds_max)) = compute_bounds_for_mesh(&mesh.vertices) else {
         return Err(String::from("failed to compute mesh bounds"));
     };
@@ -304,6 +309,7 @@ fn run(args: Args) -> Result<(), String> {
         vertex_data.push(vertex.uv0[1]);
     }
     let vertex_bytes = f32_slice_to_ne_bytes(&vertex_data);
+    let index_bytes = u16_slice_to_ne_bytes(&mesh.indices);
 
     let gl = unsafe {
         glow::Context::from_loader_function(|name| video.gl_get_proc_address(name) as *const _)
@@ -319,9 +325,13 @@ fn run(args: Args) -> Result<(), String> {
         .ok_or_else(|| String::from("shader attribute a_uv is missing"))?;
 
     let vbo = unsafe { gl.create_buffer().map_err(|e| e.to_string())? };
+    let ebo = unsafe { gl.create_buffer().map_err(|e| e.to_string())? };
     unsafe {
         gl.bind_buffer(glow::ARRAY_BUFFER, Some(vbo));
         gl.buffer_data_u8_slice(glow::ARRAY_BUFFER, &vertex_bytes, glow::STATIC_DRAW);
+        gl.bind_buffer(glow::ELEMENT_ARRAY_BUFFER, Some(ebo));
+        gl.buffer_data_u8_slice(glow::ELEMENT_ARRAY_BUFFER, &index_bytes, glow::STATIC_DRAW);
+        gl.bind_buffer(glow::ELEMENT_ARRAY_BUFFER, None);
         gl.bind_buffer(glow::ARRAY_BUFFER, None);
     }
 
@@ -341,8 +351,9 @@ fn run(args: Args) -> Result<(), String> {
             a_pos,
             a_uv,
             vbo,
+            ebo,
             gpu_texture.as_ref(),
-            mesh.vertices.len(),
+            mesh.indices.len(),
             &args,
             center,
             camera_distance,
@@ -360,8 +371,9 @@ fn run(args: Args) -> Result<(), String> {
             a_pos,
             a_uv,
             vbo,
+            ebo,
             gpu_texture.as_ref(),
-            mesh.vertices.len(),
+            mesh.indices.len(),
             &args,
             center,
             camera_distance,
@@ -372,6 +384,7 @@ fn run(args: Args) -> Result<(), String> {
         if let Some(texture) = gpu_texture {
             gl.delete_texture(texture.handle);
         }
+        gl.delete_buffer(ebo);
         gl.delete_buffer(vbo);
         gl.delete_program(program);
     }
@@ -452,8 +465,9 @@ fn run_capture(
     a_pos: u32,
     a_uv: u32,
     vbo: glow::NativeBuffer,
+    ebo: glow::NativeBuffer,
     texture: Option<&GpuTexture>,
-    vertex_count: usize,
+    index_count: usize,
     args: &Args,
     center: [f32; 3],
     camera_distance: f32,
@@ -478,8 +492,9 @@ fn run_capture(
             a_pos,
             a_uv,
             vbo,
+            ebo,
             texture,
-            vertex_count,
+            index_count,
             args.width,
             args.height,
             &mvp,
@@ -504,8 +519,9 @@ fn run_interactive(
     a_pos: u32,
     a_uv: u32,
     vbo: glow::NativeBuffer,
+    ebo: glow::NativeBuffer,
     texture: Option<&GpuTexture>,
-    vertex_count: usize,
+    index_count: usize,
     args: &Args,
     center: [f32; 3],
     camera_distance: f32,
@@ -543,8 +559,9 @@ fn run_interactive(
                 a_pos,
                 a_uv,
                 vbo,
+                ebo,
                 texture,
-                vertex_count,
+                index_count,
                 w,
                 h,
                 &mvp,
@@ -584,8 +601,9 @@ unsafe fn draw_frame(
     a_pos: u32,
     a_uv: u32,
     vbo: glow::NativeBuffer,
+    ebo: glow::NativeBuffer,
     texture: Option<&GpuTexture>,
-    vertex_count: usize,
+    index_count: usize,
     width: u32,
     height: u32,
     mvp: &[f32; 16],
@@ -614,17 +632,20 @@ unsafe fn draw_frame(
     }
 
     gl.bind_buffer(glow::ARRAY_BUFFER, Some(vbo));
+    gl.bind_buffer(glow::ELEMENT_ARRAY_BUFFER, Some(ebo));
     gl.enable_vertex_attrib_array(a_pos);
     gl.vertex_attrib_pointer_f32(a_pos, 3, glow::FLOAT, false, 20, 0);
     gl.enable_vertex_attrib_array(a_uv);
     gl.vertex_attrib_pointer_f32(a_uv, 2, glow::FLOAT, false, 20, 12);
-    gl.draw_arrays(
+    gl.draw_elements(
         glow::TRIANGLES,
+        index_count.min(i32::MAX as usize) as i32,
+        glow::UNSIGNED_SHORT,
         0,
-        vertex_count.min(i32::MAX as usize) as i32,
     );
     gl.disable_vertex_attrib_array(a_uv);
     gl.disable_vertex_attrib_array(a_pos);
+    gl.bind_buffer(glow::ELEMENT_ARRAY_BUFFER, None);
     gl.bind_buffer(glow::ARRAY_BUFFER, None);
     gl.bind_texture(glow::TEXTURE_2D, None);
     gl.use_program(None);
@@ -758,6 +779,14 @@ fn f32_slice_to_ne_bytes(slice: &[f32]) -> Vec<u8> {
     out
 }
 
+fn u16_slice_to_ne_bytes(slice: &[u16]) -> Vec<u8> {
+    let mut out = Vec::with_capacity(slice.len().saturating_mul(std::mem::size_of::<u16>()));
+    for &value in slice {
+        out.extend_from_slice(&value.to_ne_bytes());
+    }
+    out
+}
+
 fn mat4_identity() -> [f32; 16] {
     [
         1.0, 0.0, 0.0, 0.0, //
diff --git a/crates/rsli/Cargo.toml b/crates/rsli/Cargo.toml
index faad224..0ab3036 100644
--- a/crates/rsli/Cargo.toml
+++ b/crates/rsli/Cargo.toml
@@ -6,3 +6,6 @@ edition = "2021"
 [dependencies]
 common = { path = "../common" }
 flate2 = { version = "1", default-features = false, features = ["rust_backend"] }
+
+[dev-dependencies]
+proptest = "1"
diff --git a/crates/rsli/src/tests.rs b/crates/rsli/src/tests.rs
index 07807d3..ffd611d 100644
--- a/crates/rsli/src/tests.rs
+++ b/crates/rsli/src/tests.rs
@@ -1,14 +1,17 @@
 use super::*;
 use crate::compress::lzh::{LZH_MAX_FREQ, LZH_N_CHAR, LZH_R, LZH_T};
 use crate::compress::xor::xor_stream;
+use common::collect_files_recursive;
 use flate2::write::DeflateEncoder;
 use flate2::write::ZlibEncoder;
 use flate2::Compression;
+use proptest::prelude::*;
 use std::any::Any;
 use std::fs;
 use std::io::Write as _;
 use std::panic::{catch_unwind, AssertUnwindSafe};
 use std::path::PathBuf;
+use std::sync::Arc;
 
 #[derive(Clone, Debug)]
 struct SyntheticRsliEntry {
@@ -37,20 +40,6 @@ impl Default for RsliBuildOptions {
     }
 }
 
-fn collect_files_recursive(root: &Path, out: &mut Vec<PathBuf>) {
-    let Ok(entries) = fs::read_dir(root) else {
-        return;
-    };
-    for entry in entries.flatten() {
-        let path = entry.path();
-        if path.is_dir() {
-            collect_files_recursive(&path, out);
-        } else if path.is_file() {
-            out.push(path);
-        }
-    }
-}
-
 fn rsli_test_files() -> Vec<PathBuf> {
     let root = Path::new(env!("CARGO_MANIFEST_DIR"))
         .join("..")
@@ -1335,3 +1324,15 @@ fn rsli_validation_error_cases() {
     }
     let _ = fs::remove_file(&path);
 }
+
+proptest! {
+    #![proptest_config(ProptestConfig::with_cases(64))]
+
+    #[test]
+    fn parse_library_is_panic_free_on_random_bytes(data in proptest::collection::vec(any::<u8>(), 0..4096)) {
+        let _ = crate::parse::parse_library(
+            Arc::from(data.into_boxed_slice()),
+            OpenOptions::default(),
+        );
+    }
+}
diff --git a/crates/texm/Cargo.toml b/crates/texm/Cargo.toml
index 216bb44..f9c49b6 100644
--- a/crates/texm/Cargo.toml
+++ b/crates/texm/Cargo.toml
@@ -4,4 +4,6 @@ version = "0.1.0"
 edition = "2021"
 
 [dev-dependencies]
+common = { path = "../common" }
 nres = { path = "../nres" }
+proptest = "1"
diff --git a/crates/texm/src/tests.rs b/crates/texm/src/tests.rs
index ba8aeeb..49a7100 100644
--- a/crates/texm/src/tests.rs
+++ b/crates/texm/src/tests.rs
@@ -1,22 +1,10 @@
 use super::*;
+use common::collect_files_recursive;
 use nres::Archive;
+use proptest::prelude::*;
 use std::fs;
 use std::path::{Path, PathBuf};
 
-fn collect_files_recursive(root: &Path, out: &mut Vec<PathBuf>) {
-    let Ok(entries) = fs::read_dir(root) else {
-        return;
-    };
-    for entry in entries.flatten() {
-        let path = entry.path();
-        if path.is_dir() {
-            collect_files_recursive(&path, out);
-        } else if path.is_file() {
-            out.push(path);
-        }
-    }
-}
-
 fn nres_test_files() -> Vec<PathBuf> {
     let root = Path::new(env!("CARGO_MANIFEST_DIR"))
         .join("..")
@@ -327,3 +315,16 @@ fn texm_errors_for_page_chunk_and_mip_bounds() {
         Err(Error::MipDataOutOfBounds { .. })
     ));
 }
+
+proptest! {
+    #![proptest_config(ProptestConfig::with_cases(64))]
+
+    #[test]
+    fn parse_texm_is_panic_free_on_random_bytes(payload in proptest::collection::vec(any::<u8>(), 0..4096)) {
+        if let Ok(texture) = parse_texm(&payload) {
+            for mip_index in 0..texture.mip_levels.len() {
+                let _ = decode_mip_rgba8(&texture, &payload, mip_index);
+            }
+        }
+    }
+}