[update] tutorials.

Author: vmarcella

docs/tutorials/indexed-draws-and-multiple-vertex-buffers.md

@@ -3,13 +3,13 @@ title: "Indexed Draws and Multiple Vertex Buffers"
 document_id: "indexed-draws-multiple-vertex-buffers-tutorial-2025-11-22"
 status: "draft"
 created: "2025-11-22T00:00:00Z"
-last_updated: "2026-01-16T00:00:00Z"
-version: "0.3.1"
+last_updated: "2026-01-24T00:00:00Z"
+version: "0.3.3"
 engine_workspace_version: "2023.1.30"
 wgpu_version: "26.0.1"
 shader_backend_default: "naga"
 winit_version: "0.29.10"
-repo_commit: "9435ad1491b5930054117406abe08dd1c37f2102"
+repo_commit: "df476b77e1f2a17818869c3218cf223ab935c456"
 owners: ["lambda-sh"]
 reviewers: ["engine", "rendering"]
 tags: ["tutorial", "graphics", "indexed-draws", "vertex-buffers", "rust", "wgpu"]
@@ -123,14 +123,18 @@ struct PositionVertex {
   position: [f32; 3],
 }
 
+unsafe impl lambda::pod::PlainOldData for PositionVertex {}
+
 #[repr(C)]
 #[derive(Clone, Copy, Debug)]
 struct ColorVertex {
   color: [f32; 3],
 }
+
+unsafe impl lambda::pod::PlainOldData for ColorVertex {}
 ```
 
-The shader `location` qualifiers match the vertex buffer layouts declared on the pipeline, and the `PositionVertex` and `ColorVertex` types mirror the `vec3` inputs as `[f32; 3]` arrays in Rust.
+The shader `location` qualifiers match the vertex buffer layouts declared on the pipeline, and the `PositionVertex` and `ColorVertex` types mirror the `vec3` inputs as `[f32; 3]` arrays in Rust. The `PlainOldData` implementations mark the types as safe for `BufferBuilder` uploads.
 
 ### Step 2 — Component State and Shader Construction <a name="step-2"></a>
 
@@ -498,6 +502,8 @@ This tutorial demonstrates how indexed draws and multiple vertex buffers combine
 
 ## Changelog <a name="changelog"></a>
 
+- 2026-01-24 (v0.3.3) — Move `PlainOldData` to `lambda::pod::PlainOldData`.
+- 2026-01-24 (v0.3.2) — Add `PlainOldData` requirements for typed buffer data.
 - 2026-01-16 (v0.3.1) — Update resize handling examples to use `event_mask()` and `on_window_event`.
 - 2025-12-15 (v0.3.0) — Update builder API calls to use `render_context.gpu()` and add `surface_format`/`depth_format` parameters to `RenderPassBuilder` and `RenderPipelineBuilder`.
 - 2025-11-23 (v0.2.0) — Filled in the implementation steps for the indexed draws and multiple vertex buffers tutorial and aligned the narrative with the `indexed_multi_vertex_buffers` example.

docs/tutorials/instanced-quads.md

@@ -3,13 +3,13 @@ title: "Instanced Rendering: Grid of Colored Quads"
 document_id: "instanced-quads-tutorial-2025-11-25"
 status: "draft"
 created: "2025-11-25T00:00:00Z"
-last_updated: "2026-01-16T00:00:00Z"
-version: "0.2.1"
+last_updated: "2026-01-24T00:00:00Z"
+version: "0.2.3"
 engine_workspace_version: "2023.1.30"
 wgpu_version: "26.0.1"
 shader_backend_default: "naga"
 winit_version: "0.29.10"
-repo_commit: "9435ad1491b5930054117406abe08dd1c37f2102"
+repo_commit: "df476b77e1f2a17818869c3218cf223ab935c456"
 owners: ["lambda-sh"]
 reviewers: ["engine", "rendering"]
 tags: ["tutorial", "graphics", "instancing", "vertex-buffers", "rust", "wgpu"]
@@ -156,13 +156,17 @@ struct QuadVertex {
   position: [f32; 3],
 }
 
+unsafe impl lambda::pod::PlainOldData for QuadVertex {}
+
 #[repr(C)]
 #[derive(Clone, Copy, Debug)]
 struct InstanceData {
   offset: [f32; 3],
   color: [f32; 3],
 }
 
+unsafe impl lambda::pod::PlainOldData for InstanceData {}
+
 pub struct InstancedQuadsExample {
   vertex_shader: Shader,
   fragment_shader: Shader,
@@ -210,7 +214,7 @@ impl Default for InstancedQuadsExample {
 }
 ```
 
-The `QuadVertex` and `InstanceData` structures mirror the GLSL inputs as arrays of `f32`, and the component tracks resource identifiers and counts that are populated during attachment. The `Default` implementation constructs shader objects from the GLSL source so that the component is ready to build a pipeline when it receives a `RenderContext`.
+The `QuadVertex` and `InstanceData` structures mirror the GLSL inputs as arrays of `f32`, and the component tracks resource identifiers and counts that are populated during attachment. The `PlainOldData` implementations mark the types as safe for `BufferBuilder` uploads, which reinterpret values as raw bytes when initializing GPU buffers. The `Default` implementation constructs shader objects from the GLSL source so that the component is ready to build a pipeline when it receives a `RenderContext`.
 
 ### Step 3 — Render Pass, Geometry, Instances, and Buffers <a name="step-3"></a>
 
@@ -510,6 +514,8 @@ This tutorial demonstrates how the `lambda-rs` crate uses per-vertex and per-ins
 
 ## Changelog <a name="changelog"></a>
 
+- 2026-01-24 (v0.2.3) — Move `PlainOldData` to `lambda::pod::PlainOldData`.
+- 2026-01-24 (v0.2.2) — Add `PlainOldData` requirements for typed buffer data.
 - 2026-01-16 (v0.2.1) — Update resize handling examples to use `event_mask()` and `on_window_event`.
 - 2025-12-15 (v0.2.0) — Update builder API calls to use `render_context.gpu()` and add `surface_format`/`depth_format` parameters to `RenderPassBuilder` and `RenderPipelineBuilder`.
 - 2025-11-25 (v0.1.1) — Align feature naming with `render-validation-instancing` and update metadata.

docs/tutorials/uniform-buffers.md

@@ -3,13 +3,13 @@ title: "Uniform Buffers: Build a Spinning Triangle"
 document_id: "uniform-buffers-tutorial-2025-10-17"
 status: "draft"
 created: "2025-10-17T00:00:00Z"
-last_updated: "2026-01-16T00:00:00Z"
-version: "0.5.1"
+last_updated: "2026-01-24T00:00:00Z"
+version: "0.5.3"
 engine_workspace_version: "2023.1.30"
 wgpu_version: "26.0.1"
 shader_backend_default: "naga"
 winit_version: "0.29.10"
-repo_commit: "9435ad1491b5930054117406abe08dd1c37f2102"
+repo_commit: "df476b77e1f2a17818869c3218cf223ab935c456"
 owners: ["lambda-sh"]
 reviewers: ["engine", "rendering"]
 tags: ["tutorial", "graphics", "uniform-buffers", "rust", "wgpu"]
@@ -222,14 +222,16 @@ let mesh: Mesh = mesh_builder
 
 ### Step 4 — Uniform Data Layout in Rust <a name="step-4"></a>
 
-Mirror the shader’s uniform block with a Rust structure. Use `#[repr(C)]` so the memory layout is predictable. A `mat4` in the shader corresponds to a 4×4 `f32` array here. Many GPU interfaces expect column‑major matrices; transpose before upload if the local math library is row‑major. This avoids implicit driver conversions and prevents incorrect transforms.
+Mirror the shader’s uniform block with a Rust structure. Use `#[repr(C)]` so the memory layout is predictable. A `mat4` in the shader corresponds to a 4×4 `f32` array here. `PlainOldData` MUST be implemented so the engine can upload the uniform by reinterpreting its bytes. Many GPU interfaces expect column‑major matrices; transpose before upload if the local math library is row‑major. This avoids implicit driver conversions and prevents incorrect transforms.
 
 ```rust
 #[repr(C)]
 #[derive(Debug, Clone, Copy)]
 pub struct GlobalsUniform {
   pub render_matrix: [[f32; 4]; 4],
 }
+
+unsafe impl lambda::pod::PlainOldData for GlobalsUniform {}
 ```
 
 ### Step 5 — Bind Group Layout at Set 0 <a name="step-5"></a>
@@ -443,6 +445,8 @@ multiple objects and passes.
 
 ## Changelog <a name="changelog"></a>
 
+- 0.5.3 (2026-01-24): Move `PlainOldData` to `lambda::pod::PlainOldData`.
+- 0.5.2 (2026-01-24): Add `PlainOldData` requirements for uniform buffer data.
 - 0.5.1 (2026-01-16): Replace `on_event` resize handling with `event_mask()` and `on_window_event`.
 - 0.5.0 (2025-12-15): Update builder API calls to use `render_context.gpu()` and add `surface_format`/`depth_format` parameters to `RenderPassBuilder` and `RenderPipelineBuilder`.
 - 0.4.1 (2025‑11‑10): Add Conclusion section summarizing accomplishments; update