Vulkan: phase 02

[midwan]

Phase 2: Vulkan Initialization & Swapchain

Objective

Initialize the Vulkan API context, create a Device, and hook it up to the SDL Window via a Swapchain.

Target Files to Modify

• CMakeLists.txt
• Makefile
• src/osdep/vulkan_renderer.cpp (New)
• src/osdep/vulkan_renderer.h (New)

Context and Instructions

1. Build System Updates

Modify the build scripts to detect and link against Vulkan (vulkan-headers and vulkan-loader / libvulkan.so or MoltenVK on macOS). Add -DUSE_VULKAN flag to toggle the feature using #ifdef USE_VULKAN.

2. Vulkan Context Implementation

Implement the VulkanRenderer class that inherits from the IRenderer interface created in Phase 1.

The initialize() method should perform the following:

• Create a VkInstance. Ensure you request the appropriate extensions (e.g., VK_KHR_surface).
• Use SDL_Vulkan_GetInstanceExtensions(window, ...) to get required window extensions.
• Create an SDL_Vulkan_CreateSurface to bind the window.
• Pick a Physical Device (VkPhysicalDevice) prioritizing discrete GPUs but settling for integrated if needed. Check for VK_KHR_swapchain support.
• Create a Logical Device (VkDevice) and retrieve the Graphics and Present queues.

3. The Swapchain

Create the Swapchain based on the current window size:

• Query Surface Capabilities, Formats, and Presentation Modes.
• Choose VK_PRESENT_MODE_MAILBOX_KHR or VK_PRESENT_MODE_FIFO_KHR (for VSync).
• Create the VkSwapchainKHR.
• Retrieve the Swapchain Images (VkImage) and create VkImageView for each of them.

Acceptance Criteria

• Building with CMake successfully links Vulkan libraries.
• The emulator launches successfully when the Vulkan backend is selected.
• No rendering happens yet, but Vulkan validation layers (if enabled) report 0 errors after creating the Swapchain and shutting down cleanly.