feat(renderer): add mesh module with Vertex struct

crates/renderer/src/mesh.rs

@@ -0,0 +1,47 @@
+use bytemuck::{Pod, Zeroable};
+
+/// Represents a single vertex in 3D space with position and texture coordinates.
+/// 
+/// Uses `repr(C)` to ensure the memory layout matches what the GPU expects (no Rust-specific reordering).
+/// `Pod` and `Zeroable` allows safely casting this struct to a raw byte slice.
+#[repr(C)]
+#[derive(Copy, Clone, Debug, Pod, Zeroable)]
+pub struct Vertex {
+    /// 3D position of the vertex (X, Y, Z).
+    pub position: [f32; 3],
+    /// 2D texture coordinates (U, V).
+    pub tex_coord: [f32; 2],
+}
+
+impl Vertex {
+    /// Describes how Vulkan should read the vertex data from a buffer.
+    /// 
+    /// This defines the 'stride' (distance between vertices) and specifies that
+    /// data is read per-vertex rather than per-instance.
+    pub fn get_binding_description() -> ash::vk::VertexInputBindingDescription {
+        ash::vk::VertexInputBindingDescription::default()
+            .binding(0)
+            .stride(std::mem::size_of::<Self>() as u32)
+            .input_rate(ash::vk::VertexInputRate::VERTEX)
+    }
+
+    /// Describes the layout of individual fields (attributes) within a single vertex.
+    /// 
+    /// These 'locations' must match the `layout(location = X)` qualifiers in the vertex shader.
+    pub fn get_attribute_descriptions() -> [ash::vk::VertexInputAttributeDescription; 2] {
+        [
+            // Location 0: position (vec3 -> R32G32B32_SFLOAT)
+            ash::vk::VertexInputAttributeDescription::default()
+                .binding(0)
+                .location(0)
+                .format(ash::vk::Format::R32G32B32_SFLOAT)
+                .offset(0),
+            // Location 1: tex_coord (vec2 -> R32G32_SFLOAT)
+            ash::vk::VertexInputAttributeDescription::default()
+                .binding(0)
+                .location(1)
+                .format(ash::vk::Format::R32G32_SFLOAT)
+                .offset(std::mem::size_of::<[f32; 3]>() as u32),
+        ]
+    }
+}