[move] pod to it's own module and update examples.

Author: vmarcella

crates/lambda-rs/examples/indexed_multi_vertex_buffers.rs

@@ -89,15 +89,15 @@ struct PositionVertex {
   position: [f32; 3],
 }
 
-unsafe impl lambda::render::buffer::PlainOldData for PositionVertex {}
+unsafe impl lambda::pod::PlainOldData for PositionVertex {}
 
 #[repr(C)]
 #[derive(Clone, Copy, Debug)]
 struct ColorVertex {
   color: [f32; 3],
 }
 
-unsafe impl lambda::render::buffer::PlainOldData for ColorVertex {}
+unsafe impl lambda::pod::PlainOldData for ColorVertex {}
 
 // --------------------------------- COMPONENT ---------------------------------
 

crates/lambda-rs/examples/instanced_quads.rs

@@ -92,7 +92,7 @@ struct QuadVertex {
   position: [f32; 3],
 }
 
-unsafe impl lambda::render::buffer::PlainOldData for QuadVertex {}
+unsafe impl lambda::pod::PlainOldData for QuadVertex {}
 
 #[repr(C)]
 #[derive(Clone, Copy, Debug)]
@@ -101,7 +101,7 @@ struct InstanceData {
   color: [f32; 3],
 }
 
-unsafe impl lambda::render::buffer::PlainOldData for InstanceData {}
+unsafe impl lambda::pod::PlainOldData for InstanceData {}
 
 // --------------------------------- COMPONENT ---------------------------------
 

crates/lambda-rs/examples/uniform_buffer_triangle.rs

@@ -101,7 +101,7 @@ pub struct GlobalsUniform {
   pub render_matrix: [[f32; 4]; 4],
 }
 
-unsafe impl lambda::render::buffer::PlainOldData for GlobalsUniform {}
+unsafe impl lambda::pod::PlainOldData for GlobalsUniform {}
 
 // --------------------------------- COMPONENT ---------------------------------
 

crates/lambda-rs/src/lib.rs

@@ -14,6 +14,7 @@
 pub mod component;
 pub mod events;
 pub mod math;
+pub mod pod;
 pub mod render;
 pub mod runtime;
 pub mod runtimes;

crates/lambda-rs/src/pod.rs

@@ -0,0 +1,42 @@
+//! Plain-old-data marker trait for safe byte uploads.
+//!
+//! The engine frequently uploads CPU data into GPU buffers by reinterpreting
+//! a value or slice as raw bytes. This is only sound for types that are safe
+//! to view as bytes.
+
+/// Marker trait for types that are safe to reinterpret as raw bytes.
+///
+/// This trait is required by typed buffer upload APIs (for example
+/// `render::buffer::Buffer::write_value` and `render::buffer::Buffer::write_slice`)
+/// and typed buffer creation APIs (for example
+/// `render::buffer::BufferBuilder::build`) because those operations upload the
+/// in-memory representation of a value to the GPU.
+///
+/// # Safety
+/// Types implementing `PlainOldData` MUST satisfy all of the following:
+/// - Every byte of the value is initialized (including any padding bytes).
+/// - The type has no pointers or references that would be invalidated by a
+///   raw byte copy.
+/// - The type's byte representation is stable for GPU consumption. Prefer
+///   `#[repr(C)]` or `#[repr(transparent)]`.
+///
+/// Implementing this trait incorrectly can cause undefined behavior.
+pub unsafe trait PlainOldData: Copy {}
+
+unsafe impl PlainOldData for u8 {}
+unsafe impl PlainOldData for i8 {}
+unsafe impl PlainOldData for u16 {}
+unsafe impl PlainOldData for i16 {}
+unsafe impl PlainOldData for u32 {}
+unsafe impl PlainOldData for i32 {}
+unsafe impl PlainOldData for u64 {}
+unsafe impl PlainOldData for i64 {}
+unsafe impl PlainOldData for u128 {}
+unsafe impl PlainOldData for i128 {}
+unsafe impl PlainOldData for usize {}
+unsafe impl PlainOldData for isize {}
+unsafe impl PlainOldData for f32 {}
+unsafe impl PlainOldData for f64 {}
+unsafe impl PlainOldData for bool {}
+unsafe impl PlainOldData for char {}
+unsafe impl<T: PlainOldData, const N: usize> PlainOldData for [T; N] {}

crates/lambda-rs/src/render/buffer.rs

@@ -27,43 +27,7 @@ use super::{
   mesh::Mesh,
   RenderContext,
 };
-
-/// Marker trait for types that are safe to reinterpret as raw bytes.
-///
-/// This trait is required by `Buffer::write_value`, `Buffer::write_slice`, and
-/// `BufferBuilder::build` because those APIs upload the in-memory representation
-/// of a value to the GPU.
-///
-/// # Safety
-/// Types implementing `PlainOldData` MUST satisfy all of the following:
-/// - Every byte of the value is initialized (including any padding bytes).
-/// - The type has no pointers or references that would be invalidated by a
-///   raw byte copy.
-/// - The type's byte representation is stable for GPU consumption. Prefer
-///   `#[repr(C)]` or `#[repr(transparent)]`.
-///
-/// Implementing this trait incorrectly can cause undefined behavior.
-pub unsafe trait PlainOldData: Copy {}
-
-unsafe impl PlainOldData for u8 {}
-unsafe impl PlainOldData for i8 {}
-unsafe impl PlainOldData for u16 {}
-unsafe impl PlainOldData for i16 {}
-unsafe impl PlainOldData for u32 {}
-unsafe impl PlainOldData for i32 {}
-unsafe impl PlainOldData for u64 {}
-unsafe impl PlainOldData for i64 {}
-unsafe impl PlainOldData for u128 {}
-unsafe impl PlainOldData for i128 {}
-unsafe impl PlainOldData for usize {}
-unsafe impl PlainOldData for isize {}
-unsafe impl PlainOldData for f32 {}
-unsafe impl PlainOldData for f64 {}
-unsafe impl PlainOldData for bool {}
-unsafe impl PlainOldData for char {}
-unsafe impl<T: PlainOldData, const N: usize> PlainOldData for [T; N] {}
-
-unsafe impl PlainOldData for super::vertex::Vertex {}
+pub use crate::pod::PlainOldData;
 
 /// High‑level classification for buffers created by the engine.
 #[derive(Clone, Copy, Debug, PartialEq, Eq)]

crates/lambda-rs/src/render/vertex.rs

@@ -78,6 +78,8 @@ pub struct Vertex {
   pub color: [f32; 3],
 }
 
+unsafe impl crate::pod::PlainOldData for Vertex {}
+
 /// Builder for constructing a `Vertex` instance incrementally.
 #[derive(Clone, Copy, Debug)]
 pub struct VertexBuilder {