feat: Refactor code structure and enhance functionality across multiple crates

3 files changed, 43 insertions, 24 deletions

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, //