issues/completed/phase-9/9-001b-implement-vulkan-compute-wrapper.md

Issue 9-001b: Implement Core Vulkan Compute Wrapper

Parent Issue

9-001: Implement Vulkan Compute Infrastructure

Current Behavior

No Vulkan wrapper exists.

Intended Behavior

Clean C library that handles Vulkan boilerplate and exposes simple compute dispatch API.

Implementation Steps

Step 1: Core Initialization

  • [x] Create VkInstance with validation layers (debug) or without (release)
  • [x] Select physical device (GTX 1080 Ti)
  • [x] Find compute queue family
  • [x] Create logical device and compute queue

Step 2: Memory Management

  • [x] Implement buffer creation (device-local and host-visible)
  • [x] Implement staging buffer pattern for uploads/downloads
  • [x] Create memory allocation helper

Step 3: Shader Pipeline

  • [x] Load SPIR-V from file
  • [x] Create compute pipeline
  • [x] Create descriptor set layout and pool
  • [x] Bind buffers to descriptors

Step 4: Command Execution

  • [x] Create command pool and command buffer
  • [x] Record dispatch commands
  • [x] Submit and wait for completion
  • [x] Implement fence-based synchronization

Step 5: API Design

// Proposed API
typedef struct VkComputeContext VkComputeContext;

VkComputeContext* vkc_init(void);
void vkc_destroy(VkComputeContext* ctx);

// Buffer operations
VkBuffer vkc_create_buffer(VkComputeContext* ctx, size_t size, bool device_local);
void vkc_upload_buffer(VkComputeContext* ctx, VkBuffer buf, void* data, size_t size);
void vkc_download_buffer(VkComputeContext* ctx, VkBuffer buf, void* data, size_t size);

// Shader operations
VkPipeline vkc_load_shader(VkComputeContext* ctx, const char* spv_path);
void vkc_dispatch(VkComputeContext* ctx, VkPipeline pipeline,
                  uint32_t x, uint32_t y, uint32_t z);

Quality Assurance Criteria

  • [x] Initialization succeeds with validation layers
  • [x] Buffer upload/download round-trips correctly
  • [x] Simple compute shader executes without errors
  • [x] Resource cleanup is complete (no leaks)
  • [x] Validation layers report no errors

Dependencies

  • 9-001a (Vulkan environment setup)

Implementation Summary

Complete Vulkan compute wrapper implemented in libs/vulkan-compute/src/vk_compute.c (934 lines):

Core Features:

  • VkInstance with debug messenger and validation layers
  • Physical device selection targeting GTX 1080 Ti
  • Compute queue family detection and logical device creation
  • Buffer management with staging buffer pattern
  • SPIR-V shader loading and pipeline creation
  • Command buffer recording and fence-based synchronization

API Exported:

  • vkc_init() / vkc_destroy() - Context management
  • vkc_create_buffer() - Buffer allocation
  • vkc_upload_buffer() / vkc_download_buffer() - Data transfer
  • vkc_load_shader() - Pipeline creation
  • vkc_dispatch() - Shader execution

Testing:

  • test_init.c - Initialization validation
  • test_buffers.c - Buffer operations
  • test_pipeline.c - Shader dispatch
  • All tests pass with validation layers enabled

ISSUE STATUS: COMPLETED

Created: 2025-12-14

Completed: 2026-01-09

Phase: 9 (GPU Acceleration)

Priority: High (blocking 9-001c)