From dac885748a8b822e197a4798ba6ec0a6a47698f8 Mon Sep 17 00:00:00 2001
From: Verox001 <verox@cimeyclust.com>
Date: Sun, 4 May 2025 11:27:55 +0200
Subject: [PATCH] Added Shader Input and vertex buffering

---
 simulator/src/main.rs     | 58 +++++++++++++++++++++++++++++++++++----
 simulator/src/shader.wgsl | 17 ++++++++----
 2 files changed, 63 insertions(+), 12 deletions(-)

diff --git a/simulator/src/main.rs b/simulator/src/main.rs
index 541f248..e3e9301 100644
--- a/simulator/src/main.rs
+++ b/simulator/src/main.rs
@@ -2,6 +2,7 @@ use std::cmp::max;
 use std::sync::Arc;
 
 use pollster::FutureExt;
+use wgpu::util::DeviceExt;
 use wgpu::{Adapter, Device, Instance, PresentMode, Queue, Surface, SurfaceCapabilities};
 use winit::application::ApplicationHandler;
 use winit::dpi::PhysicalSize;
@@ -16,6 +17,32 @@ pub async fn run() {
     let _ = event_loop.run_app(&mut window_state);
 }
 
+#[repr(C)]
+#[derive(Copy, Clone, Debug, bytemuck::Pod, bytemuck::Zeroable)]
+struct Vertex {
+    position: [f32; 3],
+    color: [f32; 3],
+}
+
+impl Vertex {
+    const ATTRIBS: [wgpu::VertexAttribute; 2] =
+        wgpu::vertex_attr_array![0 => Float32x3, 1 => Float32x3];
+
+    fn desc() -> wgpu::VertexBufferLayout<'static> {
+        wgpu::VertexBufferLayout {
+            array_stride: size_of::<Self>() as wgpu::BufferAddress,
+            step_mode: wgpu::VertexStepMode::Vertex,
+            attributes: &Self::ATTRIBS,
+        }
+    }
+}
+
+const VERTICES: &[Vertex] = &[
+    Vertex { position: [0.0, 0.5, 0.0], color: [1.0, 0.0, 0.0] },
+    Vertex { position: [-0.5, -0.5, 0.0], color: [0.0, 1.0, 0.0] },
+    Vertex { position: [0.5, -0.5, 0.0], color: [0.0, 0.0, 1.0] },
+];
+
 struct StateApplication<'a> {
     state: Option<State<'a>>,
 }
@@ -77,6 +104,8 @@ struct State<'a> {
     window: Arc<Window>,
     
     render_pipeline: wgpu::RenderPipeline,
+    vertex_buffer: wgpu::Buffer,
+    num_vertices: u32,
 }
 
 impl<'a> State<'a> {
@@ -92,6 +121,9 @@ impl<'a> State<'a> {
         surface.configure(&device, &config);
 
         let render_pipeline = Self::create_render_pipeline(&device, &config);
+        let vertex_buffer = Self::create_vertex_buffer(&device);
+
+        let num_vertices = VERTICES.len() as u32;
 
         Self {
             surface,
@@ -102,6 +134,9 @@ impl<'a> State<'a> {
             window: window_arc,
             
             render_pipeline,
+            vertex_buffer,
+            
+            num_vertices,
         }
     }
 
@@ -113,6 +148,16 @@ impl<'a> State<'a> {
         // TODO: Update logic here
     }
     
+    fn create_vertex_buffer(device: &Device) -> wgpu::Buffer {
+        device.create_buffer_init(
+            &wgpu::util::BufferInitDescriptor {
+                label: Some("Vertex Buffer"),
+                contents: bytemuck::cast_slice(VERTICES),
+                usage: wgpu::BufferUsages::VERTEX,
+            }
+        )
+    }
+    
     fn create_render_pipeline(device: &Device, config: &wgpu::SurfaceConfiguration) -> wgpu::RenderPipeline {
         let shader = device.create_shader_module(wgpu::ShaderModuleDescriptor {
             label: Some("Shader"),
@@ -132,8 +177,8 @@ impl<'a> State<'a> {
             vertex: wgpu::VertexState {
                 module: &shader,
                 entry_point: Some("vs_main"),
-                buffers: &[],
-                compilation_options: wgpu::PipelineCompilationOptions::default(),
+                buffers: &[Vertex::desc()],
+                compilation_options: Default::default(),
             },
             fragment: Some(wgpu::FragmentState {
                 module: &shader,
@@ -226,7 +271,7 @@ impl<'a> State<'a> {
     }
 
     pub fn render(&mut self) -> Result<(), wgpu::SurfaceError> {
-        let output = self.surface.get_current_texture().unwrap();
+        let output = self.surface.get_current_texture()?;
         let view = output.texture.create_view(&wgpu::TextureViewDescriptor::default());
 
         let mut encoder = self.device.create_command_encoder(&wgpu::CommandEncoderDescriptor {
@@ -234,7 +279,7 @@ impl<'a> State<'a> {
         });
 
         {
-            let mut _render_pass = encoder.begin_render_pass(&wgpu::RenderPassDescriptor {
+            let mut render_pass = encoder.begin_render_pass(&wgpu::RenderPassDescriptor {
                 label: Some("Render Pass"),
                 color_attachments: &[Some(wgpu::RenderPassColorAttachment {
                     view: &view,
@@ -254,8 +299,9 @@ impl<'a> State<'a> {
                 timestamp_writes: None,
             });
             
-            _render_pass.set_pipeline(&self.render_pipeline);
-            _render_pass.draw(0..3, 0..1);
+            render_pass.set_pipeline(&self.render_pipeline);
+            render_pass.set_vertex_buffer(0, self.vertex_buffer.slice(..));
+            render_pass.draw(0..self.num_vertices, 0..1);
         }
 
         self.queue.submit(std::iter::once(encoder.finish()));
diff --git a/simulator/src/shader.wgsl b/simulator/src/shader.wgsl
index f5a0eae..68f015a 100644
--- a/simulator/src/shader.wgsl
+++ b/simulator/src/shader.wgsl
@@ -1,19 +1,24 @@
+struct VertexInput {
+    @location(0) position: vec3<f32>,
+    @location(1) color: vec3<f32>,
+};
+
 struct VertexOutput {
     @builtin(position) clip_position: vec4<f32>,
+    @location(0) color: vec3<f32>,
 };
 
 @vertex
 fn vs_main(
-    @builtin(vertex_index) in_vertex_index: u32,
+    model: VertexInput,
 ) -> VertexOutput {
     var out: VertexOutput;
-    let x = f32(1 - i32(in_vertex_index)) * 0.5;
-    let y = f32(i32(in_vertex_index & 1u) * 2 - 1) * 0.5;
-    out.clip_position = vec4<f32>(x, y, 0.0, 1.0);
+    out.color = model.color;
+    out.clip_position = vec4<f32>(model.position, 1.0);
     return out;
 }
 
 @fragment
 fn fs_main(in: VertexOutput) -> @location(0) vec4<f32> {
-    return vec4<f32>(0.3, 0.2, 0.1, 1.0);
-}
\ No newline at end of file
+    return vec4<f32>(in.color, 1.0);
+}