From e6f84148174fa79e3ecd437c87c84e13f11fd561 Mon Sep 17 00:00:00 2001
From: Serkyo <serkyo-dev@proton.me>
Date: Mon, 11 May 2026 00:04:42 +0200
Subject: [PATCH] feat(renderer): implement vertex buffer allocation and memory
 mapping

---
 crates/renderer/src/error.rs    |  6 +++++
 crates/renderer/src/lib.rs      | 47 +++++++++++++++++++++++++++++++++
 crates/renderer/src/renderer.rs | 11 +++++++-
 3 files changed, 63 insertions(+), 1 deletion(-)

diff --git a/crates/renderer/src/error.rs b/crates/renderer/src/error.rs
index e6132db..ac3c6e1 100644
--- a/crates/renderer/src/error.rs
+++ b/crates/renderer/src/error.rs
@@ -2,10 +2,16 @@ use thiserror::Error;
 
 #[derive(Debug, Error)]
 pub enum RendererError {
+    /// The Vulkan library could not be loaded from the system.
     #[error("Failed to load Vulkan library")]
     LoadFailed(#[from] ash::LoadingError),
+    /// A raw Vulkan result indicated a failure.
     #[error("Vulkan error")]
     VulkanError(#[from] ash::vk::Result),
+    /// No GPU was found that meets the engine's requirements.
     #[error("No suitable GPU found")]
     NoSuitableGpu,
+    /// An error occurred during GPU memory allocation.
+    #[error("GPU allocation error")]
+    AllocationError(#[from] gpu_allocator::AllocationError),
 }
\ No newline at end of file
diff --git a/crates/renderer/src/lib.rs b/crates/renderer/src/lib.rs
index 7929feb..9b706c6 100644
--- a/crates/renderer/src/lib.rs
+++ b/crates/renderer/src/lib.rs
@@ -89,6 +89,8 @@ impl Renderer {
         let sync =
             sync::create_sync_primitives(&device, MAX_FRAMES_IN_FLIGHT, swapchain_images.len())?;
 
+        // 11. GPU Memory Allocator
+        // The allocator handles the complexity of sub-allocating memory blocks from the GPU.
         let allocator_create_info = gpu_allocator::vulkan::AllocatorCreateDesc {
             instance: instance.clone(),
             device: device.clone(),
@@ -101,10 +103,53 @@ impl Renderer {
         let allocator = gpu_allocator::vulkan::Allocator::new(&allocator_create_info)
             .expect("Failed to create Vulkan allocator");
 
+        // 12. Graphics Pipeline Configuration
+        // The pipeline defines the fixed-function and programmable state for rendering voxel geometry.
         let pipeline_layout = pipeline::create_pipeline_layout(&device);
         let graphics_pipeline =
             pipeline::create_graphics_pipeline(&device, pipeline_layout, swapchain_format);
 
+        // 13. Vertex Buffer Initialization
+        // A simple triangle is defined in normalized device coordinates and moved to GPU memory.
+        let vertices = [
+            mesh::Vertex { position: [0.0, -0.5, 0.0], tex_coord: [0.5, 0.0] },
+            mesh::Vertex { position: [0.5, 0.5, 0.0], tex_coord: [1.0, 1.0] },
+            mesh::Vertex { position: [-0.5, 0.5, 0.0], tex_coord: [0.0, 1.0] },
+        ];
+
+        // Create the buffer handle and query its memory requirements.
+        let buffer_info = vk::BufferCreateInfo::default()
+            .size(std::mem::size_of_val(&vertices) as u64)
+            .usage(vk::BufferUsageFlags::VERTEX_BUFFER);
+
+        let vertex_buffer = unsafe { device.create_buffer(&buffer_info, None)? };
+        let requirements = unsafe { device.get_buffer_memory_requirements(vertex_buffer) };
+
+        let mut allocator = allocator;
+
+        // Allocate memory that is visible to the CPU for data transfer.
+        let vertex_allocation = allocator.allocate(&gpu_allocator::vulkan::AllocationCreateDesc {
+            name: "Vertex Buffer",
+            requirements,
+            location: gpu_allocator::MemoryLocation::CpuToGpu,
+            linear: true,
+            allocation_scheme: gpu_allocator::vulkan::AllocationScheme::GpuAllocatorManaged,
+        })?;
+
+        // Bind the allocated memory to the buffer handle and copy the vertex data.
+        unsafe { 
+            device.bind_buffer_memory(vertex_buffer, vertex_allocation.memory(), vertex_allocation.offset())?;
+
+            let ptr = vertex_allocation.mapped_ptr()
+                .expect("Failed to map vertex buffer memory")
+                .as_ptr();
+
+            std::ptr::copy_nonoverlapping(
+                vertices.as_ptr() as *const u8, 
+                ptr as *mut u8, 
+                std::mem::size_of_val(&vertices));
+        }
+
         Ok(Self {
             _entry: entry,
             instance,
@@ -127,6 +172,8 @@ impl Renderer {
             allocator,
             pipeline_layout,
             graphics_pipeline,
+            vertex_buffer,
+            vertex_allocation,
             sync,
             current_frame: 0,
         })
diff --git a/crates/renderer/src/renderer.rs b/crates/renderer/src/renderer.rs
index 3fc771e..66c4a3b 100644
--- a/crates/renderer/src/renderer.rs
+++ b/crates/renderer/src/renderer.rs
@@ -1,7 +1,7 @@
 use crate::error::RendererError;
 use crate::sync::SyncPrimitives;
 use ash::{Device, Instance, khr, vk};
-use gpu_allocator::vulkan::Allocator;
+use gpu_allocator::vulkan::{Allocation, Allocator};
 
 
 
@@ -49,6 +49,10 @@ pub struct Renderer {
     pub(crate) graphics_pipeline: vk::Pipeline,
     /// Memory manager for GPU allocations.
     pub(crate) allocator: Allocator,
+    /// Buffer containing the vertex data for the initial triangle.
+    pub(crate) vertex_buffer: vk::Buffer,
+    /// Memory allocation for the vertex buffer.
+    pub(crate) vertex_allocation: Allocation,
     /// Synchronization primitives for frame-by-frame execution.
     pub(crate) sync: SyncPrimitives,
     /// Index of the current frame being processed (0 to crate::MAX_FRAMES_IN_FLIGHT - 1).
@@ -202,6 +206,11 @@ impl Drop for Renderer {
             self.device
                 .destroy_pipeline_layout(self.pipeline_layout, None);
 
+            self.allocator.free(std::ptr::read(&self.vertex_allocation))
+                .expect(" Failed to free vertex buffer allocation");
+
+            self.device.destroy_buffer(self.vertex_buffer, None);
+
             self.device.destroy_command_pool(self.command_pool, None);
 
             // Use the safe cleanup function from sync module