SportsBallEngine/Sources/VulkanRenderer/VulkanRenderer.swift

/// VulkanRenderer - Vulkan rendering backend implementation
/// This is a PLATFORM-SPECIFIC module (Vulkan API)

import Foundation
import RendererAPI

// Note: In a real implementation, this would import Vulkan C bindings
// import CVulkan or similar Swift Vulkan wrapper

/// Vulkan-based renderer implementation
public final class VulkanRenderer: Renderer, @unchecked Sendable {
    
    private var config: RendererConfig?
    private var isInitialized: Bool = false
    
    // Vulkan handles (placeholders - would be actual Vulkan types)
    private var instance: UnsafeMutableRawPointer?
    private var device: UnsafeMutableRawPointer?
    private var physicalDevice: UnsafeMutableRawPointer?
    private var surface: UnsafeMutableRawPointer?
    private var swapchain: UnsafeMutableRawPointer?
    private var commandPool: UnsafeMutableRawPointer?
    private var graphicsQueue: UnsafeMutableRawPointer?
    private var presentQueue: UnsafeMutableRawPointer?
    
    // Resource storage
    private var meshes: [MeshHandle: VulkanMesh] = [:]
    private var textures: [TextureHandle: VulkanTexture] = [:]
    private var materials: [MaterialHandle: VulkanMaterial] = [:]
    
    private var currentFrameIndex: UInt32 = 0
    private let maxFramesInFlight: UInt32 = 2
    
    public init() {
        print("    🌋 VulkanRenderer created")
    }
    
    // MARK: - Renderer Protocol Implementation
    
    public func initialize(config: RendererConfig) async throws {
        print("    → Initializing Vulkan renderer...")
        self.config = config
        
        // 1. Create Vulkan Instance
        try createInstance()
        
        // 2. Create Surface (from window handle)
        try createSurface(windowHandle: config.windowHandle)
        
        // 3. Pick Physical Device (GPU)
        try pickPhysicalDevice()
        
        // 4. Create Logical Device
        try createLogicalDevice()
        
        // 5. Create Swapchain
        try createSwapchain(width: config.width, height: config.height, vsync: config.vsyncEnabled)
        
        // 6. Create Command Pools and Buffers
        try createCommandResources()
        
        // 7. Create Render Pass
        try createRenderPass()
        
        // 8. Create Framebuffers
        try createFramebuffers()
        
        // 9. Create Graphics Pipeline
        try createGraphicsPipeline()
        
        // 10. Create Descriptor Sets for materials
        try createDescriptorResources()
        
        isInitialized = true
        print("    ✓ Vulkan renderer initialized")
    }
    
    public func beginFrame() throws {
        guard isInitialized else { throw RendererError.notInitialized }
        
        // Wait for previous frame to finish
        // Acquire next swapchain image
        // Begin command buffer recording
    }
    
    public func draw(scene: Scene) throws {
        guard isInitialized else { throw RendererError.notInitialized }
        
        // Begin render pass
        // Set viewport and scissor
        // Bind pipeline
        
        // Draw each entity
        for entity in scene.entities {
            // Set up push constants / uniform buffers
            // Bind vertex and index buffers
            // Draw indexed
            drawEntity(entity, camera: scene.camera)
        }
        
        // End render pass
    }
    
    public func endFrame() throws {
        guard isInitialized else { throw RendererError.notInitialized }
        
        // End command buffer
        // Submit to graphics queue
        // Present to swapchain
        
        currentFrameIndex = (currentFrameIndex + 1) % maxFramesInFlight
    }
    
    public func shutdown() async {
        print("    → Shutting down Vulkan renderer...")
        
        // Wait for device idle
        // Destroy all resources in reverse order
        destroyDescriptorResources()
        destroyGraphicsPipeline()
        destroyFramebuffers()
        destroyRenderPass()
        destroyCommandResources()
        destroySwapchain()
        destroyLogicalDevice()
        destroySurface()
        destroyInstance()
        
        isInitialized = false
        print("    ✓ Vulkan renderer shutdown complete")
    }
    
    public func loadMesh(vertices: [Vertex], indices: [UInt32]) async throws -> MeshHandle {
        let handle = MeshHandle()
        
        // Create Vulkan vertex buffer
        // Create Vulkan index buffer
        // Upload data to GPU
        
        let vulkanMesh = VulkanMesh(
            vertexBuffer: nil,
            indexBuffer: nil,
            vertexCount: UInt32(vertices.count),
            indexCount: UInt32(indices.count)
        )
        
        meshes[handle] = vulkanMesh
        return handle
    }
    
    public func loadTexture(data: Data, width: Int, height: Int, format: TextureFormat) async throws -> TextureHandle {
        let handle = TextureHandle()
        
        // Create Vulkan image
        // Create Vulkan image view
        // Create Vulkan sampler
        // Upload texture data
        
        let vulkanTexture = VulkanTexture(
            image: nil,
            imageView: nil,
            sampler: nil,
            width: width,
            height: height
        )
        
        textures[handle] = vulkanTexture
        return handle
    }
    
    public func createMaterial(albedoTexture: TextureHandle?, normalTexture: TextureHandle?) async throws -> MaterialHandle {
        let handle = MaterialHandle()
        
        // Create descriptor set for this material
        // Bind textures to descriptor set
        
        let vulkanMaterial = VulkanMaterial(
            descriptorSet: nil,
            albedoTexture: albedoTexture,
            normalTexture: normalTexture
        )
        
        materials[handle] = vulkanMaterial
        return handle
    }
    
    public var info: RendererInfo {
        return RendererInfo(
            apiName: "Vulkan",
            apiVersion: "1.3",
            deviceName: "Vulkan Device (placeholder)",
            maxTextureSize: 16384
        )
    }
    
    // MARK: - Vulkan-Specific Implementation
    
    private func createInstance() throws {
        print("      • Creating Vulkan instance...")
        // vkCreateInstance(...) with validation layers in debug
    }
    
    private func createSurface(windowHandle: UnsafeMutableRawPointer?) throws {
        print("      • Creating Vulkan surface...")
        // Platform-specific surface creation:
        // - Linux: vkCreateXlibSurfaceKHR or vkCreateWaylandSurfaceKHR
        // - Windows: vkCreateWin32SurfaceKHR
    }
    
    private func pickPhysicalDevice() throws {
        print("      • Selecting physical device...")
        // vkEnumeratePhysicalDevices
        // Score devices and pick best one (dedicated GPU preferred)
    }
    
    private func createLogicalDevice() throws {
        print("      • Creating logical device...")
        // vkCreateDevice with required extensions and features
    }
    
    private func createSwapchain(width: Int, height: Int, vsync: Bool) throws {
        print("      • Creating swapchain (\(width)x\(height))...")
        // vkCreateSwapchainKHR with appropriate format and present mode
    }
    
    private func createCommandResources() throws {
        print("      • Creating command resources...")
        // vkCreateCommandPool
        // vkAllocateCommandBuffers
    }
    
    private func createRenderPass() throws {
        print("      • Creating render pass...")
        // vkCreateRenderPass with color and depth attachments
    }
    
    private func createFramebuffers() throws {
        print("      • Creating framebuffers...")
        // vkCreateFramebuffer for each swapchain image
    }
    
    private func createGraphicsPipeline() throws {
        print("      • Creating graphics pipeline...")
        // Load shaders (SPIR-V)
        // vkCreateGraphicsPipelines with all state
    }
    
    private func createDescriptorResources() throws {
        print("      • Creating descriptor resources...")
        // vkCreateDescriptorSetLayout
        // vkCreateDescriptorPool
    }
    
    private func drawEntity(_ entity: Entity, camera: Camera) {
        // Bind mesh
        // Bind material
        // Set push constants (MVP matrix)
        // vkCmdDrawIndexed
    }
    
    // MARK: - Cleanup
    
    private func destroyDescriptorResources() {
        // vkDestroyDescriptorPool
        // vkDestroyDescriptorSetLayout
    }
    
    private func destroyGraphicsPipeline() {
        // vkDestroyPipeline
        // vkDestroyPipelineLayout
    }
    
    private func destroyFramebuffers() {
        // vkDestroyFramebuffer for each
    }
    
    private func destroyRenderPass() {
        // vkDestroyRenderPass
    }
    
    private func destroyCommandResources() {
        // vkFreeCommandBuffers
        // vkDestroyCommandPool
    }
    
    private func destroySwapchain() {
        // vkDestroySwapchainKHR
    }
    
    private func destroyLogicalDevice() {
        // vkDestroyDevice
    }
    
    private func destroySurface() {
        // vkDestroySurfaceKHR
    }
    
    private func destroyInstance() {
        // vkDestroyInstance
    }
}

// MARK: - Vulkan Resource Types

private struct VulkanMesh {
    var vertexBuffer: UnsafeMutableRawPointer?
    var indexBuffer: UnsafeMutableRawPointer?
    var vertexCount: UInt32
    var indexCount: UInt32
}

private struct VulkanTexture {
    var image: UnsafeMutableRawPointer?
    var imageView: UnsafeMutableRawPointer?
    var sampler: UnsafeMutableRawPointer?
    var width: Int
    var height: Int
}

private struct VulkanMaterial {
    var descriptorSet: UnsafeMutableRawPointer?
    var albedoTexture: TextureHandle?
    var normalTexture: TextureHandle?
}

// MARK: - Errors

private enum RendererError: Error {
    case notInitialized
    case vulkanError(String)
}