Merge pull request #4 from kd7tck/vulkan-foundations

feat: Implement core Vulkan initialization and rendering loop

src/platforms/rcore_desktop_glfw.c

@@ -1343,9 +1343,9 @@ static void DeallocateWrapper(void* block, void* user)
 
 // Initialize platform: graphics, inputs and more
 #if defined(GRAPHICS_API_VULKAN)
-// Initialize platform for Vulkan (GLFW STUB)
+// Initialize platform for Vulkan
 static int InitPlatformVulkan(void) {
-    TRACELOG(LOG_INFO, "PLATFORM: Initializing platform for Vulkan (GLFW STUB)");
+    TRACELOG(LOG_INFO, "PLATFORM: Initializing platform for Vulkan");
 
     glfwSetErrorCallback(ErrorCallback);
 
@@ -1361,18 +1361,93 @@ static int InitPlatformVulkan(void) {
     glfwInitHint(GLFW_COCOA_CHDIR_RESOURCES, GLFW_FALSE);
     #endif
 
-    if (o">!glfwInit()) {
+    if (n">glfwInit() == GLFW_FALSE) {
         TRACELOG(LOG_FATAL, "PLATFORM: Failed to initialize GLFW for Vulkan");
         return RL_FALSE;
     }
 
-    if (o">!glfwVulkanSupported()) {
+    if (n">glfwVulkanSupported() == GLFW_FALSE) {
         TRACELOG(LOG_FATAL, "PLATFORM: Vulkan not supported by GLFW or system drivers");
         glfwTerminate();
         return RL_FALSE;
     }
     TRACELOG(LOG_INFO, "PLATFORM: GLFW Vulkan support detected.");
 
+    // Get required instance extensions
+    uint32_t requiredExtensionsCount = 0;
+    const char **requiredExtensions = glfwGetRequiredInstanceExtensions(&requiredExtensionsCount);
+    if (requiredExtensions == NULL) {
+        TRACELOG(LOG_FATAL, "PLATFORM: Could not get required Vulkan instance extensions");
+        glfwTerminate();
+        return RL_FALSE;
+    }
+
+    TRACELOG(LOG_INFO, "PLATFORM: Required Vulkan instance extensions (%u):", requiredExtensionsCount);
+    for (uint32_t i = 0; i < requiredExtensionsCount; i++) TRACELOG(LOG_INFO, "    %s", requiredExtensions[i]);
+
+    // Define desired validation layers
+    const char *validationLayers[] = { "VK_LAYER_KHRONOS_validation" };
+    uint32_t enabledLayerCount = 0;
+    const char *enabledLayers[1]; // Max 1 layer for now
+
+#if defined(RLGL_ENABLE_VULKAN_DEBUG) // Or a custom define for enabling validation layers
+    uint32_t layerCount = 0;
+    vkEnumerateInstanceLayerProperties(&layerCount, NULL);
+    if (layerCount > 0) {
+        VkLayerProperties *availableLayers = (VkLayerProperties *)RL_MALLOC(layerCount * sizeof(VkLayerProperties));
+        if (availableLayers == NULL) {
+            TRACELOG(LOG_WARNING, "PLATFORM: Failed to allocate memory for Vulkan layer properties");
+        } else {
+            vkEnumerateInstanceLayerProperties(&layerCount, availableLayers);
+            bool layerFound = false;
+            for (uint32_t i = 0; i < layerCount; i++) {
+                if (strcmp(validationLayers[0], availableLayers[i].layerName) == 0) {
+                    layerFound = true;
+                    break;
+                }
+            }
+            RL_FREE(availableLayers);
+
+            if (layerFound) {
+                enabledLayers[0] = validationLayers[0];
+                enabledLayerCount = 1;
+                TRACELOG(LOG_INFO, "PLATFORM: Enabled validation layer: %s", enabledLayers[0]);
+            } else {
+                TRACELOG(LOG_WARNING, "PLATFORM: Validation layer VK_LAYER_KHRONOS_validation not available");
+            }
+        }
+    } else {
+        TRACELOG(LOG_INFO, "PLATFORM: No Vulkan instance layers found.");
+    }
+#endif
+
+    VkApplicationInfo appInfo = {0};
+    appInfo.sType = VK_STRUCTURE_TYPE_APPLICATION_INFO;
+    appInfo.pApplicationName = (CORE.Window.title != NULL) ? CORE.Window.title : "raylib Vulkan App";
+    appInfo.applicationVersion = VK_MAKE_VERSION(1, 0, 0);
+    appInfo.pEngineName = "raylib";
+    appInfo.engineVersion = VK_MAKE_VERSION(RAYLIB_VERSION_MAJOR, RAYLIB_VERSION_MINOR, RAYLIB_VERSION_PATCH);
+    appInfo.apiVersion = VK_API_VERSION_1_1;
+
+    VkInstanceCreateInfo createInfo = {0};
+    createInfo.sType = VK_STRUCTURE_TYPE_INSTANCE_CREATE_INFO;
+    createInfo.pApplicationInfo = &appInfo;
+    createInfo.enabledExtensionCount = requiredExtensionsCount;
+    createInfo.ppEnabledExtensionNames = requiredExtensions;
+    createInfo.enabledLayerCount = enabledLayerCount;
+    createInfo.ppEnabledLayerNames = (enabledLayerCount > 0) ? enabledLayers : NULL;
+
+    // Initialize global vkInstanceHandle
+    vkInstanceHandle = VK_NULL_HANDLE; // Ensure it's NULL before creation
+    VkResult result = vkCreateInstance(&createInfo, NULL, &vkInstanceHandle);
+    if (result != VK_SUCCESS) {
+        TRACELOG(LOG_FATAL, "PLATFORM: Failed to create Vulkan instance (Error: %i)", result);
+        glfwTerminate();
+        return RL_FALSE;
+    }
+    TRACELOG(LOG_INFO, "PLATFORM: Vulkan instance created successfully");
+
+    // Window hints should be set *before* window creation
     glfwDefaultWindowHints();
     glfwWindowHint(GLFW_CLIENT_API, GLFW_NO_API); // Critical for Vulkan
 
@@ -1384,8 +1459,8 @@ static int InitPlatformVulkan(void) {
     else glfwWindowHint(GLFW_DECORATED, GLFW_TRUE);
     if ((CORE.Window.flags & FLAG_WINDOW_RESIZABLE) > 0) glfwWindowHint(GLFW_RESIZABLE, GLFW_TRUE);
     else glfwWindowHint(GLFW_RESIZABLE, GLFW_FALSE);
-    if ((CORE.Window.flags & FLAG_WINDOW_MINIMIZED) > 0) CORE.Window.flags &= ~FLAG_WINDOW_MINIMIZED; // Cannot be set on creation
-    if ((CORE.Window.flags & FLAG_WINDOW_MAXIMIZED) > 0) CORE.Window.flags &= ~FLAG_WINDOW_MAXIMIZED; // Cannot be set on creation
+    if ((CORE.Window.flags & FLAG_WINDOW_MINIMIZED) > 0) CORE.Window.flags &= ~FLAG_WINDOW_MINIMIZED; // Cannot be set on creation, will be handled later if set
+    if ((CORE.Window.flags & FLAG_WINDOW_MAXIMIZED) > 0) CORE.Window.flags &= ~FLAG_WINDOW_MAXIMIZED; // Cannot be set on creation, will be handled later if set
     if ((CORE.Window.flags & FLAG_WINDOW_UNFOCUSED) > 0) glfwWindowHint(GLFW_FOCUSED, GLFW_FALSE);
     else glfwWindowHint(GLFW_FOCUSED, GLFW_TRUE);
     if ((CORE.Window.flags & FLAG_WINDOW_TOPMOST) > 0) glfwWindowHint(GLFW_FLOATING, GLFW_TRUE);
@@ -1396,7 +1471,7 @@ static int InitPlatformVulkan(void) {
      if ((CORE.Window.flags & FLAG_WINDOW_HIGHDPI) > 0) {
         glfwWindowHint(GLFW_SCALE_TO_MONITOR, GLFW_TRUE);
         #if defined(__APPLE__)
-        glfwWindowHint(GLFW_SCALE_FRAMEBUFFER, GLFW_TRUE);
+        o">// glfwWindowHint(GLFW_SCALE_FRAMEBUFFER, GLFW_TRUE); // This hint might be managed differently or implicitly with Vulkan/MoltenVK
         #endif
     } else glfwWindowHint(GLFW_SCALE_TO_MONITOR, GLFW_FALSE);
     if ((CORE.Window.flags & FLAG_WINDOW_MOUSE_PASSTHROUGH) > 0) glfwWindowHint(GLFW_MOUSE_PASSTHROUGH, GLFW_TRUE);
@@ -1427,17 +1502,30 @@ static int InitPlatformVulkan(void) {
     int creationHeight = (CORE.Window.screen.height > 0) ? CORE.Window.screen.height : 480;
 
     platform.handle = glfwCreateWindow(creationWidth, creationHeight, (CORE.Window.title != 0)? CORE.Window.title : " ", CORE.Window.fullscreen ? monitor : NULL, NULL);
-    CORE.Window.handle = platform.handle;
-    if (!CORE.Window.handle) {
+    if (!platform.handle) {
         TRACELOG(LOG_FATAL, "PLATFORM: Failed to create GLFW window for Vulkan");
+        vkDestroyInstance(vkInstanceHandle, NULL); // Clean up created instance
+        vkInstanceHandle = VK_NULL_HANDLE;
         glfwTerminate();
         return RL_FALSE;
     }
     TRACELOG(LOG_INFO, "PLATFORM: GLFW window created for Vulkan");
-
-    vkInstanceHandle = (VkInstance)0x1;
-    vkSurfaceHandle = (VkSurfaceKHR)0x1;
-    TRACELOG(LOG_INFO, "PLATFORM: VkInstance and VkSurfaceKHR STUBBED as non-null for rlvkInit testing.");
+    CORE.Window.handle = platform.handle; // Assign global window handle after successful creation
+
+    // Create Vulkan surface
+    vkSurfaceHandle = VK_NULL_HANDLE; // Ensure it's NULL before creation
+    VkResult surfaceResult = glfwCreateWindowSurface(vkInstanceHandle, platform.handle, NULL, &vkSurfaceHandle);
+    if (surfaceResult != VK_SUCCESS) {
+        TRACELOG(LOG_FATAL, "PLATFORM: Failed to create Vulkan window surface (Error: %i)", surfaceResult);
+        vkDestroyInstance(vkInstanceHandle, NULL);
+        vkInstanceHandle = VK_NULL_HANDLE;
+        glfwDestroyWindow(platform.handle);
+        platform.handle = NULL;
+        CORE.Window.handle = NULL;
+        glfwTerminate();
+        return RL_FALSE;
+    }
+    TRACELOG(LOG_INFO, "PLATFORM: Vulkan window surface created successfully");
 
     // Setup GLFW callbacks
     glfwSetWindowSizeCallback(platform.handle, WindowSizeCallback);
@@ -1491,7 +1579,7 @@ static int InitPlatformVulkan(void) {
     }
 
     CORE.Window.ready = RL_TRUE;
-    TRACELOG(LOG_INFO, "PLATFORM: Vulkan platform initialized successfully (GLFW STUBBED VkInstance/Surface)");
+    TRACELOG(LOG_INFO, "PLATFORM: Vulkan platform initialized successfully");
 
     InitTimer();
     CORE.Storage.basePath = GetWorkingDirectory();
@@ -1500,20 +1588,50 @@ static int InitPlatformVulkan(void) {
 }
 
 static void ClosePlatformVulkan(void) {
-    TRACELOG(LOG_INFO, "PLATFORM: Closing Vulkan platform (GLFW STUB)");
-    #if defined(GRAPHICS_API_VULKAN)
-        vkSurfaceHandle = VK_NULL_HANDLE;
-        vkInstanceHandle = VK_NULL_HANDLE;
-        TRACELOG(LOG_INFO, "PLATFORM: VkInstance and VkSurfaceKHR STUBBED as NULL.");
-    #endif
-
-    if (CORE.Window.handle != NULL) {
-         glfwDestroyWindow(CORE.Window.handle);
-         CORE.Window.handle = NULL;
-         platform.handle = NULL;
-    }
+    TRACELOG(LOG_INFO, "PLATFORM: Closing Vulkan platform");
+
+    // Destroy Vulkan surface
+    // Note: vkGetInstanceProcAddr is not strictly needed for vkDestroySurfaceKHR if Vulkan headers are recent enough
+    // and vkDestroySurfaceKHR was linked directly or via a loader. However, explicitly getting the function pointer
+    // is safer if there's any doubt about the linking process or for older setups.
+    // For simplicity and modern Vulkan loaders (like the one GLFW might use internally or if linked with Vulkan SDK),
+    // direct call is often fine. If issues arise, use vkGetInstanceProcAddr.
+    if (vkSurfaceHandle != VK_NULL_HANDLE && vkInstanceHandle != VK_NULL_HANDLE) {
+        // PFN_vkDestroySurfaceKHR pfnDestroySurfaceKHR = (PFN_vkDestroySurfaceKHR)vkGetInstanceProcAddr(vkInstanceHandle, "vkDestroySurfaceKHR");
+        // if (pfnDestroySurfaceKHR) pfnDestroySurfaceKHR(vkInstanceHandle, vkSurfaceHandle, NULL);
+        // else TRACELOG(LOG_WARNING, "PLATFORM: Failed to get vkDestroySurfaceKHR proc address");
+        // Assuming vkDestroySurfaceKHR is available directly through linking/loader:
+        vkDestroySurfaceKHR(vkInstanceHandle, vkSurfaceHandle, NULL);
+        vkSurfaceHandle = VK_NULL_HANDLE; // Set to NULL after destruction
+        TRACELOG(LOG_INFO, "PLATFORM: Vulkan surface destroyed");
+    } else if (vkInstanceHandle == VK_NULL_HANDLE && vkSurfaceHandle != VK_NULL_HANDLE) {
+        TRACELOG(LOG_WARNING, "PLATFORM: vkInstanceHandle is NULL, cannot destroy vkSurfaceHandle. Surface might be leaked if instance was lost prematurely.");
+        vkSurfaceHandle = VK_NULL_HANDLE; // Still nullify to prevent reuse attempts
+    }
+
+
+    // Destroy Vulkan instance
+    if (vkInstanceHandle != VK_NULL_HANDLE) {
+        vkDestroyInstance(vkInstanceHandle, NULL);
+        vkInstanceHandle = VK_NULL_HANDLE; // Set to NULL after destruction
+        TRACELOG(LOG_INFO, "PLATFORM: Vulkan instance destroyed");
+    }
+
+    // Destroy GLFW window
+    // Use platform.handle as it's the direct reference to the created window.
+    // CORE.Window.handle should mirror platform.handle but platform.handle is the source of truth here.
+    if (platform.handle != NULL) {
+         glfwDestroyWindow(platform.handle);
+         platform.handle = NULL; // Set to NULL after destruction
+         CORE.Window.handle = NULL; // Ensure CORE's copy is also NULL
+         TRACELOG(LOG_INFO, "PLATFORM: GLFW window destroyed");
+    }
+
+    // Terminate GLFW
     glfwTerminate();
-    TRACELOG(LOG_INFO, "PLATFORM: Vulkan platform resources closed (GLFW STUBBED VkInstance/Surface)");
+    TRACELOG(LOG_INFO, "PLATFORM: GLFW terminated");
+
+    TRACELOG(LOG_INFO, "PLATFORM: Vulkan platform resources closed successfully");
 }
 #endif // GRAPHICS_API_VULKAN
 

src/rlvk.c

@@ -1,27 +1,784 @@
 #include "rlvk.h"
-#include "utils.h"      // For TRACELOG if needed
-#include <stdio.h>      // For printf in stubs
-#include <stdlib.h>     // For RL_MALLOC, RL_FREE if used
+#include "utils.h"      // For TRACELOG
+#include <stdio.h>      // For TRACELOG / printf
+#include <stdlib.h>     // For RL_MALLOC, RL_FREE, NULL
+#include <string.h>     // For strcmp, memset
+#include <stdbool.h>    // For bool type
+
+// Core Vulkan Handles
+static VkInstance vkInstance = VK_NULL_HANDLE;
+static VkSurfaceKHR vkSurface = VK_NULL_HANDLE;
+static VkPhysicalDevice vkPhysicalDevice = VK_NULL_HANDLE;
+static VkDevice vkDevice = VK_NULL_HANDLE;
+static VkQueue vkGraphicsQueue = VK_NULL_HANDLE;
+static VkQueue vkPresentQueue = VK_NULL_HANDLE;
+
+// Queue Family Indices
+typedef struct {
+    uint32_t graphicsFamily;
+    uint32_t presentFamily;
+    bool graphicsFamilyHasValue;
+    bool presentFamilyHasValue;
+} QueueFamilyIndices;
+static QueueFamilyIndices queueFamilyIndices;
+
+// Swapchain related
+static VkSwapchainKHR vkSwapchain = VK_NULL_HANDLE;
+static VkFormat vkSwapchainImageFormat;
+static VkExtent2D vkSwapchainExtent;
+static VkImage* vkSwapchainImages = NULL;
+static uint32_t vkSwapchainImageCount = 0;
+static VkImageView* vkSwapchainImageViews = NULL;
+
+// Render Pass and Framebuffers
+static VkRenderPass vkRenderPass = VK_NULL_HANDLE;
+static VkFramebuffer* vkFramebuffers = NULL; // One per swapchain image view
+
+// Depth Buffer
+static VkImage vkDepthImage = VK_NULL_HANDLE;
+static VkDeviceMemory vkDepthImageMemory = VK_NULL_HANDLE;
+static VkImageView vkDepthImageView = VK_NULL_HANDLE;
+static VkFormat vkDepthFormat;
+
+// Command Pool and Command Buffers
+static VkCommandPool vkCommandPool = VK_NULL_HANDLE;
+static VkCommandBuffer* vkCommandBuffers = NULL; // One per framebuffer
+
+// Synchronization Primitives
+static VkSemaphore vkImageAvailableSemaphore = VK_NULL_HANDLE;
+static VkSemaphore vkRenderFinishedSemaphore = VK_NULL_HANDLE;
+static VkFence* vkInFlightFences = NULL; // One per frame in flight (usually same as swapchain image count)
+// static VkFence* imagesInFlight; // Maps swapchain images to fences
 
-// Global or static variables for Vulkan state (minimal for stubs)
 static bool rlvkReady = false;
+static int screenWidth = 0;
+static int screenHeight = 0;
+
+// Drawing/Frame state
+static uint32_t currentFrame = 0;
+#define MAX_FRAMES_IN_FLIGHT 2 // Default to 2, will be set to vkSwapchainImageCount if different
+                               // This define might become a static variable if vkSwapchainImageCount can change (e.g. recreation)
+static uint32_t acquiredImageIndex = 0; // To store the image index from vkAcquireNextImageKHR
+
+// Clear values for the render pass
+static VkClearColorValue currentClearColor = {{0.0f, 0.0f, 0.0f, 1.0f}}; // Default to black
+static VkClearDepthStencilValue defaultDepthStencilClear = {1.0f, 0};    // Default depth/stencil clear
+
+
+// Helper function to find suitable queue families
+static QueueFamilyIndices findQueueFamilies(VkPhysicalDevice device, VkSurfaceKHR surface) {
+    QueueFamilyIndices indices = {0, 0, false, false};
+    uint32_t queueFamilyCount = 0;
+    vkGetPhysicalDeviceQueueFamilyProperties(device, &queueFamilyCount, NULL);
+
+    VkQueueFamilyProperties* queueFamilies = (VkQueueFamilyProperties*)RL_MALLOC(queueFamilyCount * sizeof(VkQueueFamilyProperties));
+    if (!queueFamilies) {
+        TRACELOG(LOG_ERROR, "RLVK: Failed to allocate memory for queue families");
+        return indices;
+    }
+    vkGetPhysicalDeviceQueueFamilyProperties(device, &queueFamilyCount, queueFamilies);
+
+    for (uint32_t i = 0; i < queueFamilyCount; i++) {
+        if (queueFamilies[i].queueFlags & VK_QUEUE_GRAPHICS_BIT) {
+            indices.graphicsFamily = i;
+            indices.graphicsFamilyHasValue = true;
+        }
+
+        VkBool32 presentSupport = false;
+        vkGetPhysicalDeviceSurfaceSupportKHR(device, i, surface, &presentSupport);
+        if (presentSupport) {
+            indices.presentFamily = i;
+            indices.presentFamilyHasValue = true;
+        }
+
+        if (indices.graphicsFamilyHasValue && indices.presentFamilyHasValue) {
+            break;
+        }
+    }
+    RL_FREE(queueFamilies);
+    return indices;
+}
+
+// Helper function to check device suitability
+static bool isDeviceSuitable(VkPhysicalDevice device, VkSurfaceKHR surface) {
+    QueueFamilyIndices indices = findQueueFamilies(device, surface);
+    // TODO: Check for required device extensions (e.g. swapchain)
+    // TODO: Query and check surface formats and present modes
+    return indices.graphicsFamilyHasValue && indices.presentFamilyHasValue;
+}
+
 
 void rlvkInit(VkInstance instance, VkSurfaceKHR surface, int width, int height) {
-    printf("rlvkInit called (STUB)\n");
-    // Minimal check or setup
-    if (instance != VK_NULL_HANDLE && surface != VK_NULL_HANDLE) {
-        rlvkReady = true;
-        TRACELOG(LOG_INFO, "RLVK: Vulkan backend initialized (stubbed).");
+    TRACELOG(LOG_INFO, "RLVK: Initializing Vulkan backend.");
+    if (rlvkReady) {
+        TRACELOG(LOG_WARNING, "RLVK: Vulkan backend already initialized.");
+        return;
+    }
+
+    vkInstance = instance;
+    vkSurface = surface;
+    screenWidth = width;
+    screenHeight = height;
+
+    if (vkInstance == VK_NULL_HANDLE) {
+        TRACELOG(LOG_FATAL, "RLVK: Provided VkInstance is NULL.");
+        return;
+    }
+    if (vkSurface == VK_NULL_HANDLE) {
+        TRACELOG(LOG_FATAL, "RLVK: Provided VkSurfaceKHR is NULL.");
+        return;
+    }
+
+    // --- Physical Device Selection ---
+    uint32_t deviceCount = 0;
+    VkResult result = vkEnumeratePhysicalDevices(vkInstance, &deviceCount, NULL);
+    if (result != VK_SUCCESS || deviceCount == 0) {
+        TRACELOG(LOG_FATAL, "RLVK: Failed to find GPUs with Vulkan support!");
+        return;
+    }
+
+    VkPhysicalDevice* devices = (VkPhysicalDevice*)RL_MALLOC(deviceCount * sizeof(VkPhysicalDevice));
+    if (!devices) {
+        TRACELOG(LOG_FATAL, "RLVK: Failed to allocate memory for physical devices list.");
+        return;
+    }
+    result = vkEnumeratePhysicalDevices(vkInstance, &deviceCount, devices);
+    if (result != VK_SUCCESS) {
+        TRACELOG(LOG_FATAL, "RLVK: Failed to enumerate physical devices.");
+        RL_FREE(devices);
+        return;
+    }
+
+    TRACELOG(LOG_INFO, "RLVK: Found %d physical device(s).", deviceCount);
+    VkPhysicalDeviceProperties chosenDeviceProperties; // To store properties of the chosen device for logging or other uses
+
+    for (uint32_t i = 0; i < deviceCount; i++) {
+        VkPhysicalDeviceProperties deviceProperties;
+        vkGetPhysicalDeviceProperties(devices[i], &deviceProperties);
+        TRACELOG(LOG_DEBUG, "RLVK: Evaluating device: %s (ID: %u, Type: %u)", deviceProperties.deviceName, deviceProperties.deviceID, deviceProperties.deviceType);
+
+        if (isDeviceSuitable(devices[i], vkSurface)) {
+            // Prefer discrete GPU if available
+            if (vkPhysicalDevice == VK_NULL_HANDLE || deviceProperties.deviceType == VK_PHYSICAL_DEVICE_TYPE_DISCRETE_GPU) {
+                vkPhysicalDevice = devices[i];
+                chosenDeviceProperties = deviceProperties; // Store its properties
+                // If it's a discrete GPU, we might want to break early, or continue to see if there are others.
+                // For now, take the first suitable discrete GPU or the first suitable integrated/other if no discrete.
+                if (deviceProperties.deviceType == VK_PHYSICAL_DEVICE_TYPE_DISCRETE_GPU) {
+                    TRACELOG(LOG_INFO, "RLVK: Selected discrete GPU: %s", deviceProperties.deviceName);
+                    break;
+                }
+            }
+        }
+    }
+    RL_FREE(devices);
+
+    if (vkPhysicalDevice == VK_NULL_HANDLE) {
+        TRACELOG(LOG_FATAL, "RLVK: Failed to find a suitable GPU!");
+        return;
+    }
+    TRACELOG(LOG_INFO, "RLVK: Selected physical device: %s", chosenDeviceProperties.deviceName);
+
+
+    queueFamilyIndices = findQueueFamilies(vkPhysicalDevice, vkSurface);
+    if (!queueFamilyIndices.graphicsFamilyHasValue || !queueFamilyIndices.presentFamilyHasValue) {
+        TRACELOG(LOG_FATAL, "RLVK: Could not find required queue families on selected physical device.");
+        vkPhysicalDevice = VK_NULL_HANDLE; // Reset since it's not fully suitable
+        return;
+    }
+    TRACELOG(LOG_INFO, "RLVK: Graphics Queue Family Index: %u", queueFamilyIndices.graphicsFamily);
+    TRACELOG(LOG_INFO, "RLVK: Present Queue Family Index: %u", queueFamilyIndices.presentFamily);
+
+
+    // Placeholder for further initialization steps
+    // For now, if we reached here with a physical device, consider it partially ready for this phase.
+    // rlvkReady = true; // This will be set at the very end of the full Init function.
+    TRACELOG(LOG_INFO, "RLVK: Physical device selected successfully. Further initialization pending.");
+
+    // TODO: Implement steps 3-11 as per the plan.
+    // For now, stubbing the rest of the function.
+    // This is just Phase 1.
+    if (vkPhysicalDevice != VK_NULL_HANDLE) {
+         // rlvkReady = true; // This will be at the end of the full function
+         TRACELOG(LOG_INFO, "RLVK: Stub: Phase 1 (Device Selection) complete.");
+    } else {
+         TRACELOG(LOG_ERROR, "RLVK: Stub: Phase 1 (Device Selection) failed.");
+         rlvkReady = false;
+         return;
+    }
+    // --- Logical Device Creation ---
+    float queuePriority = 1.0f;
+    VkDeviceQueueCreateInfo queueCreateInfos[2]; // Max 2: one for graphics, one for present (if different)
+    uint32_t uniqueQueueFamilyCount = 0;
+
+    // Graphics Queue
+    queueCreateInfos[uniqueQueueFamilyCount].sType = VK_STRUCTURE_TYPE_DEVICE_QUEUE_CREATE_INFO;
+    queueCreateInfos[uniqueQueueFamilyCount].queueFamilyIndex = queueFamilyIndices.graphicsFamily;
+    queueCreateInfos[uniqueQueueFamilyCount].queueCount = 1;
+    queueCreateInfos[uniqueQueueFamilyCount].pQueuePriorities = &queuePriority;
+    queueCreateInfos[uniqueQueueFamilyCount].pNext = NULL;
+    queueCreateInfos[uniqueQueueFamilyCount].flags = 0;
+    uniqueQueueFamilyCount++;
+
+    // Present Queue (if different from graphics)
+    if (queueFamilyIndices.presentFamily != queueFamilyIndices.graphicsFamily) {
+        queueCreateInfos[uniqueQueueFamilyCount].sType = VK_STRUCTURE_TYPE_DEVICE_QUEUE_CREATE_INFO;
+        queueCreateInfos[uniqueQueueFamilyCount].queueFamilyIndex = queueFamilyIndices.presentFamily;
+        queueCreateInfos[uniqueQueueFamilyCount].queueCount = 1;
+        queueCreateInfos[uniqueQueueFamilyCount].pQueuePriorities = &queuePriority;
+        queueCreateInfos[uniqueQueueFamilyCount].pNext = NULL;
+        queueCreateInfos[uniqueQueueFamilyCount].flags = 0;
+        uniqueQueueFamilyCount++;
+    }
+
+    VkPhysicalDeviceFeatures deviceFeatures = {0}; // Initialize all features to VK_FALSE
+    // Enable specific features if needed, e.g. deviceFeatures.samplerAnisotropy = VK_TRUE;
+
+    const char* deviceExtensions[] = {
+        VK_KHR_SWAPCHAIN_EXTENSION_NAME
+    };
+
+    VkDeviceCreateInfo deviceCreateInfo = {0};
+    deviceCreateInfo.sType = VK_STRUCTURE_TYPE_DEVICE_CREATE_INFO;
+    deviceCreateInfo.queueCreateInfoCount = uniqueQueueFamilyCount;
+    deviceCreateInfo.pQueueCreateInfos = queueCreateInfos;
+    deviceCreateInfo.pEnabledFeatures = &deviceFeatures;
+    deviceCreateInfo.enabledExtensionCount = sizeof(deviceExtensions) / sizeof(deviceExtensions[0]);
+    deviceCreateInfo.ppEnabledExtensionNames = deviceExtensions;
+    // deviceCreateInfo.enabledLayerCount is deprecated and ignored for vkCreateDevice. Validation layers are instance-level.
+
+    result = vkCreateDevice(vkPhysicalDevice, &deviceCreateInfo, NULL, &vkDevice);
+    if (result != VK_SUCCESS) {
+        TRACELOG(LOG_FATAL, "RLVK: Failed to create logical device (Error: %i)", result);
+        // Potentially reset vkPhysicalDevice here if cleanup is needed
+        return;
+    }
+    TRACELOG(LOG_INFO, "RLVK: Logical device created successfully.");
+
+    vkGetDeviceQueue(vkDevice, queueFamilyIndices.graphicsFamily, 0, &vkGraphicsQueue);
+    vkGetDeviceQueue(vkDevice, queueFamilyIndices.presentFamily, 0, &vkPresentQueue);
+    TRACELOG(LOG_INFO, "RLVK: Graphics and Present queues obtained.");
+
+    // --- Swapchain Creation ---
+    VkSurfaceCapabilitiesKHR capabilities;
+    vkGetPhysicalDeviceSurfaceCapabilitiesKHR(vkPhysicalDevice, vkSurface, &capabilities);
+
+    uint32_t formatCount;
+    vkGetPhysicalDeviceSurfaceFormatsKHR(vkPhysicalDevice, vkSurface, &formatCount, NULL);
+    VkSurfaceFormatKHR* formats = NULL;
+    if (formatCount != 0) {
+        formats = (VkSurfaceFormatKHR*)RL_MALLOC(formatCount * sizeof(VkSurfaceFormatKHR));
+        vkGetPhysicalDeviceSurfaceFormatsKHR(vkPhysicalDevice, vkSurface, &formatCount, formats);
+    } else {
+        TRACELOG(LOG_FATAL, "RLVK: No surface formats found for swapchain creation.");
+        vkDestroyDevice(vkDevice, NULL); vkDevice = VK_NULL_HANDLE;
+        return;
+    }
+
+    uint32_t presentModeCount;
+    vkGetPhysicalDeviceSurfacePresentModesKHR(vkPhysicalDevice, vkSurface, &presentModeCount, NULL);
+    VkPresentModeKHR* presentModes = NULL;
+    if (presentModeCount != 0) {
+        presentModes = (VkPresentModeKHR*)RL_MALLOC(presentModeCount * sizeof(VkPresentModeKHR));
+        vkGetPhysicalDeviceSurfacePresentModesKHR(vkPhysicalDevice, vkSurface, &presentModeCount, presentModes);
+    } else {
+        TRACELOG(LOG_FATAL, "RLVK: No present modes found for swapchain creation.");
+        RL_FREE(formats);
+        vkDestroyDevice(vkDevice, NULL); vkDevice = VK_NULL_HANDLE;
+        return;
+    }
+
+    // Choose swap surface format
+    VkSurfaceFormatKHR surfaceFormat = formats[0]; // Default to first available
+    for (uint32_t i = 0; i < formatCount; i++) {
+        if (formats[i].format == VK_FORMAT_B8G8R8A8_SRGB && formats[i].colorSpace == VK_COLOR_SPACE_SRGB_NONLINEAR_KHR) {
+            surfaceFormat = formats[i];
+            break;
+        }
+    }
+    vkSwapchainImageFormat = surfaceFormat.format;
+    TRACELOG(LOG_INFO, "RLVK: Chosen swapchain format: %d, color space: %d", surfaceFormat.format, surfaceFormat.colorSpace);
+
+    // Choose swap present mode
+    VkPresentModeKHR presentMode = VK_PRESENT_MODE_FIFO_KHR; // Guaranteed to be available
+    for (uint32_t i = 0; i < presentModeCount; i++) {
+        if (presentModes[i] == VK_PRESENT_MODE_MAILBOX_KHR) {
+            presentMode = presentModes[i];
+            break;
+        }
+    }
+    TRACELOG(LOG_INFO, "RLVK: Chosen present mode: %d", presentMode);
+
+    RL_FREE(formats);
+    RL_FREE(presentModes);
+
+    // Choose swap extent
+    if (capabilities.currentExtent.width != UINT32_MAX) {
+        vkSwapchainExtent = capabilities.currentExtent;
+    } else {
+        vkSwapchainExtent.width = (uint32_t)screenWidth;
+        vkSwapchainExtent.height = (uint32_t)screenHeight;
+        vkSwapchainExtent.width = MAX(capabilities.minImageExtent.width, MIN(capabilities.maxImageExtent.width, vkSwapchainExtent.width));
+        vkSwapchainExtent.height = MAX(capabilities.minImageExtent.height, MIN(capabilities.maxImageExtent.height, vkSwapchainExtent.height));
+    }
+    TRACELOG(LOG_INFO, "RLVK: Swapchain extent: %u x %u", vkSwapchainExtent.width, vkSwapchainExtent.height);
+
+    vkSwapchainImageCount = capabilities.minImageCount + 1;
+    if (capabilities.maxImageCount > 0 && vkSwapchainImageCount > capabilities.maxImageCount) {
+        vkSwapchainImageCount = capabilities.maxImageCount;
+    }
+    TRACELOG(LOG_INFO, "RLVK: Swapchain image count: %u", vkSwapchainImageCount);
+
+    VkSwapchainCreateInfoKHR swapchainCreateInfo = {0};
+    swapchainCreateInfo.sType = VK_STRUCTURE_TYPE_SWAPCHAIN_CREATE_INFO_KHR;
+    swapchainCreateInfo.surface = vkSurface;
+    swapchainCreateInfo.minImageCount = vkSwapchainImageCount;
+    swapchainCreateInfo.imageFormat = surfaceFormat.format;
+    swapchainCreateInfo.imageColorSpace = surfaceFormat.colorSpace;
+    swapchainCreateInfo.imageExtent = vkSwapchainExtent;
+    swapchainCreateInfo.imageArrayLayers = 1;
+    swapchainCreateInfo.imageUsage = VK_IMAGE_USAGE_COLOR_ATTACHMENT_BIT; // For rendering directly to swapchain images
+
+    uint32_t qFamilyIndices[] = {queueFamilyIndices.graphicsFamily, queueFamilyIndices.presentFamily};
+    if (queueFamilyIndices.graphicsFamily != queueFamilyIndices.presentFamily) {
+        swapchainCreateInfo.imageSharingMode = VK_SHARING_MODE_CONCURRENT;
+        swapchainCreateInfo.queueFamilyIndexCount = 2;
+        swapchainCreateInfo.pQueueFamilyIndices = qFamilyIndices;
     } else {
-        TRACELOG(LOG_ERROR, "RLVK: Failed to initialize Vulkan backend due to null instance or surface (stubbed).");
-        rlvkReady = false;
+        swapchainCreateInfo.imageSharingMode = VK_SHARING_MODE_EXCLUSIVE;
+        swapchainCreateInfo.queueFamilyIndexCount = 0; // Optional
+        swapchainCreateInfo.pQueueFamilyIndices = NULL; // Optional
+    }
+
+    swapchainCreateInfo.preTransform = capabilities.currentTransform;
+    swapchainCreateInfo.compositeAlpha = VK_COMPOSITE_ALPHA_OPAQUE_BIT_KHR; // No alpha blending with window system
+    swapchainCreateInfo.presentMode = presentMode;
+    swapchainCreateInfo.clipped = VK_TRUE; // Allow clipping if other windows obscure parts of the surface
+    swapchainCreateInfo.oldSwapchain = VK_NULL_HANDLE; // For resizing, not used now
+
+    result = vkCreateSwapchainKHR(vkDevice, &swapchainCreateInfo, NULL, &vkSwapchain);
+    if (result != VK_SUCCESS) {
+        TRACELOG(LOG_FATAL, "RLVK: Failed to create swapchain (Error: %i)", result);
+        vkDestroyDevice(vkDevice, NULL); vkDevice = VK_NULL_HANDLE;
+        return;
+    }
+    TRACELOG(LOG_INFO, "RLVK: Swapchain created successfully.");
+
+    // Get swapchain images
+    // vkSwapchainImageCount was requested, now query actual count (can be higher)
+    vkGetSwapchainImagesKHR(vkDevice, vkSwapchain, &vkSwapchainImageCount, NULL);
+    vkSwapchainImages = (VkImage*)RL_MALLOC(vkSwapchainImageCount * sizeof(VkImage));
+    if (!vkSwapchainImages) {
+        TRACELOG(LOG_FATAL, "RLVK: Failed to allocate memory for swapchain images.");
+        vkDestroySwapchainKHR(vkDevice, vkSwapchain, NULL); vkSwapchain = VK_NULL_HANDLE;
+        vkDestroyDevice(vkDevice, NULL); vkDevice = VK_NULL_HANDLE;
+        return;
+    }
+    vkGetSwapchainImagesKHR(vkDevice, vkSwapchain, &vkSwapchainImageCount, vkSwapchainImages);
+    TRACELOG(LOG_INFO, "RLVK: Retrieved %u swapchain images.", vkSwapchainImageCount);
+
+    // --- Image View Creation (Step 5) ---
+    vkSwapchainImageViews = (VkImageView*)RL_MALLOC(vkSwapchainImageCount * sizeof(VkImageView));
+    if (!vkSwapchainImageViews) {
+        TRACELOG(LOG_FATAL, "RLVK: Failed to allocate memory for swapchain image views.");
+        // Perform necessary cleanup from previous steps
+        RL_FREE(vkSwapchainImages); vkSwapchainImages = NULL;
+        vkDestroySwapchainKHR(vkDevice, vkSwapchain, NULL); vkSwapchain = VK_NULL_HANDLE;
+        vkDestroyDevice(vkDevice, NULL); vkDevice = VK_NULL_HANDLE;
+        return;
+    }
+
+    for (uint32_t i = 0; i < vkSwapchainImageCount; i++) {
+        VkImageViewCreateInfo viewInfo = {0};
+        viewInfo.sType = VK_STRUCTURE_TYPE_IMAGE_VIEW_CREATE_INFO;
+        viewInfo.image = vkSwapchainImages[i];
+        viewInfo.viewType = VK_IMAGE_VIEW_TYPE_2D;
+        viewInfo.format = vkSwapchainImageFormat;
+        viewInfo.components.r = VK_COMPONENT_SWIZZLE_IDENTITY;
+        viewInfo.components.g = VK_COMPONENT_SWIZZLE_IDENTITY;
+        viewInfo.components.b = VK_COMPONENT_SWIZZLE_IDENTITY;
+        viewInfo.components.a = VK_COMPONENT_SWIZZLE_IDENTITY;
+        viewInfo.subresourceRange.aspectMask = VK_IMAGE_ASPECT_COLOR_BIT;
+        viewInfo.subresourceRange.baseMipLevel = 0;
+        viewInfo.subresourceRange.levelCount = 1;
+        viewInfo.subresourceRange.baseArrayLayer = 0;
+        viewInfo.subresourceRange.layerCount = 1;
+
+        result = vkCreateImageView(vkDevice, &viewInfo, NULL, &vkSwapchainImageViews[i]);
+        if (result != VK_SUCCESS) {
+            TRACELOG(LOG_FATAL, "RLVK: Failed to create image view %u (Error: %i)", i, result);
+            // Perform cleanup
+            for (uint32_t j = 0; j < i; j++) vkDestroyImageView(vkDevice, vkSwapchainImageViews[j], NULL);
+            RL_FREE(vkSwapchainImageViews); vkSwapchainImageViews = NULL;
+            RL_FREE(vkSwapchainImages); vkSwapchainImages = NULL;
+            vkDestroySwapchainKHR(vkDevice, vkSwapchain, NULL); vkSwapchain = VK_NULL_HANDLE;
+            vkDestroyDevice(vkDevice, NULL); vkDevice = VK_NULL_HANDLE;
+            return;
+        }
+    }
+    TRACELOG(LOG_INFO, "RLVK: Swapchain image views created successfully.");
+
+    // --- Render Pass Creation (Step 6) ---
+    // Find supported depth format (helper function recommended)
+    // VkFormat findSupportedFormat(const VkFormat* candidates, uint32_t candidateCount, VkImageTiling tiling, VkFormatFeatureFlags features);
+    // For now, assume VK_FORMAT_D32_SFLOAT is supported. A real implementation needs findSupportedFormat.
+    vkDepthFormat = VK_FORMAT_D32_SFLOAT; // Placeholder - must be queried
+
+    VkAttachmentDescription colorAttachment = {0};
+    colorAttachment.format = vkSwapchainImageFormat;
+    colorAttachment.samples = VK_SAMPLE_COUNT_1_BIT;
+    colorAttachment.loadOp = VK_ATTACHMENT_LOAD_OP_CLEAR;
+    colorAttachment.storeOp = VK_ATTACHMENT_STORE_OP_STORE;
+    colorAttachment.stencilLoadOp = VK_ATTACHMENT_LOAD_OP_DONT_CARE;
+    colorAttachment.stencilStoreOp = VK_ATTACHMENT_STORE_OP_DONT_CARE;
+    colorAttachment.initialLayout = VK_IMAGE_LAYOUT_UNDEFINED;
+    colorAttachment.finalLayout = VK_IMAGE_LAYOUT_PRESENT_SRC_KHR;
+
+    VkAttachmentDescription depthAttachment = {0};
+    depthAttachment.format = vkDepthFormat; // Must be a supported depth format
+    depthAttachment.samples = VK_SAMPLE_COUNT_1_BIT;
+    depthAttachment.loadOp = VK_ATTACHMENT_LOAD_OP_CLEAR;
+    depthAttachment.storeOp = VK_ATTACHMENT_STORE_OP_DONT_CARE;
+    depthAttachment.stencilLoadOp = VK_ATTACHMENT_LOAD_OP_DONT_CARE;
+    depthAttachment.stencilStoreOp = VK_ATTACHMENT_STORE_OP_DONT_CARE;
+    depthAttachment.initialLayout = VK_IMAGE_LAYOUT_UNDEFINED;
+    depthAttachment.finalLayout = VK_IMAGE_LAYOUT_DEPTH_STENCIL_ATTACHMENT_OPTIMAL;
+
+    VkAttachmentReference colorAttachmentRef = {0};
+    colorAttachmentRef.attachment = 0;
+    colorAttachmentRef.layout = VK_IMAGE_LAYOUT_COLOR_ATTACHMENT_OPTIMAL;
+
+    VkAttachmentReference depthAttachmentRef = {0};
+    depthAttachmentRef.attachment = 1;
+    depthAttachmentRef.layout = VK_IMAGE_LAYOUT_DEPTH_STENCIL_ATTACHMENT_OPTIMAL;
+
+    VkSubpassDescription subpass = {0};
+    subpass.pipelineBindPoint = VK_PIPELINE_BIND_POINT_GRAPHICS;
+    subpass.colorAttachmentCount = 1;
+    subpass.pColorAttachments = &colorAttachmentRef;
+    subpass.pDepthStencilAttachment = &depthAttachmentRef;
+
+    VkSubpassDependency dependency = {0};
+    dependency.srcSubpass = VK_SUBPASS_EXTERNAL;
+    dependency.dstSubpass = 0;
+    dependency.srcStageMask = VK_PIPELINE_STAGE_COLOR_ATTACHMENT_OUTPUT_BIT | VK_PIPELINE_STAGE_EARLY_FRAGMENT_TESTS_BIT;
+    dependency.srcAccessMask = 0;
+    dependency.dstStageMask = VK_PIPELINE_STAGE_COLOR_ATTACHMENT_OUTPUT_BIT | VK_PIPELINE_STAGE_EARLY_FRAGMENT_TESTS_BIT;
+    dependency.dstAccessMask = VK_ACCESS_COLOR_ATTACHMENT_WRITE_BIT | VK_ACCESS_DEPTH_STENCIL_ATTACHMENT_WRITE_BIT;
+
+    VkAttachmentDescription attachments[] = {colorAttachment, depthAttachment};
+    VkRenderPassCreateInfo renderPassInfo = {0};
+    renderPassInfo.sType = VK_STRUCTURE_TYPE_RENDER_PASS_CREATE_INFO;
+    renderPassInfo.attachmentCount = sizeof(attachments) / sizeof(VkAttachmentDescription);
+    renderPassInfo.pAttachments = attachments;
+    renderPassInfo.subpassCount = 1;
+    renderPassInfo.pSubpasses = &subpass;
+    renderPassInfo.dependencyCount = 1;
+    renderPassInfo.pDependencies = &dependency;
+
+    result = vkCreateRenderPass(vkDevice, &renderPassInfo, NULL, &vkRenderPass);
+    if (result != VK_SUCCESS) {
+        TRACELOG(LOG_FATAL, "RLVK: Failed to create render pass (Error: %i)", result);
+        // Perform cleanup... (image views, swapchain, device etc.)
+        return; // Simplified cleanup for now
+    }
+    TRACELOG(LOG_INFO, "RLVK: Render pass created successfully.");
+
+    // --- Depth Resources Creation (Step 7) ---
+    VkImageCreateInfo imageInfo = {0};
+    imageInfo.sType = VK_STRUCTURE_TYPE_IMAGE_CREATE_INFO;
+    imageInfo.imageType = VK_IMAGE_TYPE_2D;
+    imageInfo.extent.width = vkSwapchainExtent.width;
+    imageInfo.extent.height = vkSwapchainExtent.height;
+    imageInfo.extent.depth = 1;
+    imageInfo.mipLevels = 1;
+    imageInfo.arrayLayers = 1;
+    imageInfo.format = vkDepthFormat;
+    imageInfo.tiling = VK_IMAGE_TILING_OPTIMAL; // For best performance
+    imageInfo.initialLayout = VK_IMAGE_LAYOUT_UNDEFINED;
+    imageInfo.usage = VK_IMAGE_USAGE_DEPTH_STENCIL_ATTACHMENT_BIT;
+    imageInfo.samples = VK_SAMPLE_COUNT_1_BIT;
+    imageInfo.sharingMode = VK_SHARING_MODE_EXCLUSIVE;
+
+    result = vkCreateImage(vkDevice, &imageInfo, NULL, &vkDepthImage);
+    if (result != VK_SUCCESS) {
+        TRACELOG(LOG_FATAL, "RLVK: Failed to create depth image (Error: %i)", result);
+        // Cleanup...
+        return;
+    }
+
+    VkMemoryRequirements memRequirements;
+    vkGetImageMemoryRequirements(vkDevice, vkDepthImage, &memRequirements);
+
+    VkMemoryAllocateInfo allocInfo = {0};
+    allocInfo.sType = VK_STRUCTURE_TYPE_MEMORY_ALLOCATE_INFO;
+    allocInfo.allocationSize = memRequirements.size;
+    // allocInfo.memoryTypeIndex = findMemoryType(memRequirements.memoryTypeBits, VK_MEMORY_PROPERTY_DEVICE_LOCAL_BIT); // Helper needed
+    // For now, assume memoryTypeIndex 0 is valid (highly unlikely in real scenario without querying)
+    // This needs a proper findMemoryType implementation.
+    uint32_t memoryTypeIndex = 0; // Placeholder - THIS IS A BUG without proper findMemoryType
+    VkPhysicalDeviceMemoryProperties memProperties;
+    vkGetPhysicalDeviceMemoryProperties(vkPhysicalDevice, &memProperties);
+    bool memoryTypeFound = false;
+    for (uint32_t i = 0; i < memProperties.memoryTypeCount; i++) {
+        if ((memRequirements.memoryTypeBits & (1 << i)) && (memProperties.memoryTypes[i].propertyFlags & VK_MEMORY_PROPERTY_DEVICE_LOCAL_BIT)) {
+            memoryTypeIndex = i;
+            memoryTypeFound = true;
+            break;
+        }
+    }
+    if (!memoryTypeFound) {
+        TRACELOG(LOG_FATAL, "RLVK: Failed to find suitable memory type for depth image!");
+        // Cleanup...
+        return;
+    }
+    allocInfo.memoryTypeIndex = memoryTypeIndex;
+
+
+    result = vkAllocateMemory(vkDevice, &allocInfo, NULL, &vkDepthImageMemory);
+    if (result != VK_SUCCESS) {
+        TRACELOG(LOG_FATAL, "RLVK: Failed to allocate depth image memory (Error: %i)", result);
+        // Cleanup...
+        return;
+    }
+    vkBindImageMemory(vkDevice, vkDepthImage, vkDepthImageMemory, 0);
+
+    VkImageViewCreateInfo depthViewInfo = {0};
+    depthViewInfo.sType = VK_STRUCTURE_TYPE_IMAGE_VIEW_CREATE_INFO;
+    depthViewInfo.image = vkDepthImage;
+    depthViewInfo.viewType = VK_IMAGE_VIEW_TYPE_2D;
+    depthViewInfo.format = vkDepthFormat;
+    depthViewInfo.subresourceRange.aspectMask = VK_IMAGE_ASPECT_DEPTH_BIT;
+    depthViewInfo.subresourceRange.baseMipLevel = 0;
+    depthViewInfo.subresourceRange.levelCount = 1;
+    depthViewInfo.subresourceRange.baseArrayLayer = 0;
+    depthViewInfo.subresourceRange.layerCount = 1;
+
+    result = vkCreateImageView(vkDevice, &depthViewInfo, NULL, &vkDepthImageView);
+    if (result != VK_SUCCESS) {
+        TRACELOG(LOG_FATAL, "RLVK: Failed to create depth image view (Error: %i)", result);
+        // Cleanup...
+        return;
+    }
+    TRACELOG(LOG_INFO, "RLVK: Depth resources created successfully.");
+
+    // --- Framebuffer Creation (Step 8) ---
+    vkFramebuffers = (VkFramebuffer*)RL_MALLOC(vkSwapchainImageCount * sizeof(VkFramebuffer));
+    if (!vkFramebuffers) {
+        TRACELOG(LOG_FATAL, "RLVK: Failed to allocate memory for framebuffers.");
+        // Perform cleanup... (this is getting repetitive, a helper might be good)
+        return;
+    }
+    for (uint32_t i = 0; i < vkSwapchainImageCount; i++) {
+        VkImageView attachments[] = {
+            vkSwapchainImageViews[i],
+            vkDepthImageView
+        };
+
+        VkFramebufferCreateInfo framebufferInfo = {0};
+        framebufferInfo.sType = VK_STRUCTURE_TYPE_FRAMEBUFFER_CREATE_INFO;
+        framebufferInfo.renderPass = vkRenderPass;
+        framebufferInfo.attachmentCount = sizeof(attachments) / sizeof(VkImageView);
+        framebufferInfo.pAttachments = attachments;
+        framebufferInfo.width = vkSwapchainExtent.width;
+        framebufferInfo.height = vkSwapchainExtent.height;
+        framebufferInfo.layers = 1;
+
+        result = vkCreateFramebuffer(vkDevice, &framebufferInfo, NULL, &vkFramebuffers[i]);
+        if (result != VK_SUCCESS) {
+            TRACELOG(LOG_FATAL, "RLVK: Failed to create framebuffer %u (Error: %i)", i, result);
+            // Perform cleanup...
+            return;
+        }
+    }
+    TRACELOG(LOG_INFO, "RLVK: Framebuffers created successfully.");
+
+    // --- Command Pool and Command Buffers (Step 9) ---
+    VkCommandPoolCreateInfo poolInfo = {0};
+    poolInfo.sType = VK_STRUCTURE_TYPE_COMMAND_POOL_CREATE_INFO;
+    poolInfo.flags = VK_COMMAND_POOL_CREATE_RESET_COMMAND_BUFFER_BIT;
+    poolInfo.queueFamilyIndex = queueFamilyIndices.graphicsFamily;
+
+    result = vkCreateCommandPool(vkDevice, &poolInfo, NULL, &vkCommandPool);
+    if (result != VK_SUCCESS) {
+        TRACELOG(LOG_FATAL, "RLVK: Failed to create command pool (Error: %i)", result);
+        // Perform cleanup...
+        return;
+    }
+    TRACELOG(LOG_INFO, "RLVK: Command pool created successfully.");
+
+    vkCommandBuffers = (VkCommandBuffer*)RL_MALLOC(vkSwapchainImageCount * sizeof(VkCommandBuffer));
+    if(!vkCommandBuffers) {
+        TRACELOG(LOG_FATAL, "RLVK: Failed to allocate memory for command buffers.");
+        // Perform cleanup...
+        return;
+    }
+
+    VkCommandBufferAllocateInfo cmdAllocInfo = {0};
+    cmdAllocInfo.sType = VK_STRUCTURE_TYPE_COMMAND_BUFFER_ALLOCATE_INFO;
+    cmdAllocInfo.commandPool = vkCommandPool;
+    cmdAllocInfo.level = VK_COMMAND_BUFFER_LEVEL_PRIMARY;
+    cmdAllocInfo.commandBufferCount = vkSwapchainImageCount; // Allocate all at once
+
+    result = vkAllocateCommandBuffers(vkDevice, &cmdAllocInfo, vkCommandBuffers);
+    if (result != VK_SUCCESS) {
+        TRACELOG(LOG_FATAL, "RLVK: Failed to allocate command buffers (Error: %i)", result);
+        // Perform cleanup...
+        return;
+    }
+    TRACELOG(LOG_INFO, "RLVK: Command buffers allocated successfully.");
+
+    // --- Synchronization Primitives (Step 10) ---
+    VkSemaphoreCreateInfo semaphoreInfo = {0};
+    semaphoreInfo.sType = VK_STRUCTURE_TYPE_SEMAPHORE_CREATE_INFO;
+
+    VkFenceCreateInfo fenceInfo = {0};
+    fenceInfo.sType = VK_STRUCTURE_TYPE_FENCE_CREATE_INFO;
+    fenceInfo.flags = VK_FENCE_CREATE_SIGNALED_BIT; // Create fences in signaled state
+
+    vkInFlightFences = (VkFence*)RL_MALLOC(vkSwapchainImageCount * sizeof(VkFence));
+    if (!vkInFlightFences) {
+         TRACELOG(LOG_FATAL, "RLVK: Failed to allocate memory for in-flight fences.");
+        // Perform cleanup...
+        return;
+    }
+
+    if (vkCreateSemaphore(vkDevice, &semaphoreInfo, NULL, &vkImageAvailableSemaphore) != VK_SUCCESS ||
+        vkCreateSemaphore(vkDevice, &semaphoreInfo, NULL, &vkRenderFinishedSemaphore) != VK_SUCCESS) {
+        TRACELOG(LOG_FATAL, "RLVK: Failed to create semaphores.");
+        // Perform cleanup...
+        if (vkImageAvailableSemaphore != VK_NULL_HANDLE) vkDestroySemaphore(vkDevice, vkImageAvailableSemaphore, NULL);
+        if (vkRenderFinishedSemaphore != VK_NULL_HANDLE) vkDestroySemaphore(vkDevice, vkRenderFinishedSemaphore, NULL);
+        RL_FREE(vkInFlightFences); vkInFlightFences = NULL;
+        return;
+    }
+
+    for (uint32_t i = 0; i < vkSwapchainImageCount; i++) {
+        if (vkCreateFence(vkDevice, &fenceInfo, NULL, &vkInFlightFences[i]) != VK_SUCCESS) {
+            TRACELOG(LOG_FATAL, "RLVK: Failed to create fence %u.", i);
+            // Perform cleanup for already created fences and semaphores
+            for(uint32_t j=0; j < i; ++j) vkDestroyFence(vkDevice, vkInFlightFences[j], NULL);
+            RL_FREE(vkInFlightFences); vkInFlightFences = NULL;
+            vkDestroySemaphore(vkDevice, vkImageAvailableSemaphore, NULL);
+            vkDestroySemaphore(vkDevice, vkRenderFinishedSemaphore, NULL);
+            return;
+        }
     }
+    TRACELOG(LOG_INFO, "RLVK: Synchronization primitives created successfully.");
+
+    rlvkReady = true; // All initialization steps completed successfully
+    TRACELOG(LOG_INFO, "RLVK: Vulkan backend initialized successfully.");
 }
 
 void rlvkClose(void) {
-    printf("rlvkClose called (STUB)\n");
+    TRACELOG(LOG_INFO, "RLVK: Closing Vulkan backend.");
+
+    if (vkDevice != VK_NULL_HANDLE) {
+        vkDeviceWaitIdle(vkDevice); // Ensure device is idle before destroying resources
+    }
+
+    if (vkImageAvailableSemaphore != VK_NULL_HANDLE) {
+        vkDestroySemaphore(vkDevice, vkImageAvailableSemaphore, NULL);
+        vkImageAvailableSemaphore = VK_NULL_HANDLE;
+    }
+    if (vkRenderFinishedSemaphore != VK_NULL_HANDLE) {
+        vkDestroySemaphore(vkDevice, vkRenderFinishedSemaphore, NULL);
+        vkRenderFinishedSemaphore = VK_NULL_HANDLE;
+    }
+    if (vkInFlightFences != NULL) {
+        // Use MAX_FRAMES_IN_FLIGHT or actual count used for fences if different from vkSwapchainImageCount
+        uint32_t fenceCount = vkSwapchainImageCount; // Assuming fences per swapchain image for now
+        for (uint32_t i = 0; i < fenceCount; i++) {
+            if (vkInFlightFences[i] != VK_NULL_HANDLE) {
+                 vkDestroyFence(vkDevice, vkInFlightFences[i], NULL);
+            }
+        }
+        RL_FREE(vkInFlightFences);
+        vkInFlightFences = NULL;
+        TRACELOG(LOG_DEBUG, "RLVK: Fences destroyed.");
+    }
+
+    if (vkCommandPool != VK_NULL_HANDLE) {
+        vkDestroyCommandPool(vkDevice, vkCommandPool, NULL);
+        vkCommandPool = VK_NULL_HANDLE;
+        TRACELOG(LOG_DEBUG, "RLVK: Command pool destroyed.");
+    }
+     if (vkCommandBuffers != NULL) { // Command buffers are freed with the pool
+        RL_FREE(vkCommandBuffers);
+        vkCommandBuffers = NULL;
+    }
+
+    if (vkFramebuffers != NULL) {
+        for (uint32_t i = 0; i < vkSwapchainImageCount; i++) {
+            if (vkFramebuffers[i] != VK_NULL_HANDLE) {
+                vkDestroyFramebuffer(vkDevice, vkFramebuffers[i], NULL);
+            }
+        }
+        RL_FREE(vkFramebuffers);
+        vkFramebuffers = NULL;
+        TRACELOG(LOG_DEBUG, "RLVK: Framebuffers destroyed.");
+    }
+
+    if (vkDepthImageView != VK_NULL_HANDLE) {
+        vkDestroyImageView(vkDevice, vkDepthImageView, NULL);
+        vkDepthImageView = VK_NULL_HANDLE;
+    }
+    if (vkDepthImage != VK_NULL_HANDLE) {
+        vkDestroyImage(vkDevice, vkDepthImage, NULL);
+        vkDepthImage = VK_NULL_HANDLE;
+    }
+    if (vkDepthImageMemory != VK_NULL_HANDLE) {
+        vkFreeMemory(vkDevice, vkDepthImageMemory, NULL);
+        vkDepthImageMemory = VK_NULL_HANDLE;
+    }
+    TRACELOG(LOG_DEBUG, "RLVK: Depth resources destroyed.");
+
+    if (vkRenderPass != VK_NULL_HANDLE) {
+        vkDestroyRenderPass(vkDevice, vkRenderPass, NULL);
+        vkRenderPass = VK_NULL_HANDLE;
+        TRACELOG(LOG_DEBUG, "RLVK: Render pass destroyed.");
+    }
+
+    if (vkSwapchainImageViews != NULL) {
+        for (uint32_t i = 0; i < vkSwapchainImageCount; i++) {
+            if (vkSwapchainImageViews[i] != VK_NULL_HANDLE) {
+                vkDestroyImageView(vkDevice, vkSwapchainImageViews[i], NULL);
+            }
+        }
+        RL_FREE(vkSwapchainImageViews);
+        vkSwapchainImageViews = NULL;
+        TRACELOG(LOG_DEBUG, "RLVK: Swapchain image views destroyed.");
+    }
+
+    if (vkSwapchain != VK_NULL_HANDLE) {
+        vkDestroySwapchainKHR(vkDevice, vkSwapchain, NULL);
+        vkSwapchain = VK_NULL_HANDLE;
+        TRACELOG(LOG_DEBUG, "RLVK: Swapchain destroyed.");
+    }
+    if (vkSwapchainImages != NULL) {
+        RL_FREE(vkSwapchainImages);
+        vkSwapchainImages = NULL;
+    }
+
+    vkGraphicsQueue = VK_NULL_HANDLE;
+    vkPresentQueue = VK_NULL_HANDLE;
+    if (vkDevice != VK_NULL_HANDLE) {
+        vkDestroyDevice(vkDevice, NULL);
+        TRACELOG(LOG_DEBUG,"RLVK: Logical device destroyed.");
+    }
+    vkDevice = VK_NULL_HANDLE;
+    vkPhysicalDevice = VK_NULL_HANDLE;
+
+    vkSurface = VK_NULL_HANDLE;
+    vkInstance = VK_NULL_HANDLE;
+
+    memset(&queueFamilyIndices, 0, sizeof(QueueFamilyIndices));
+    screenWidth = 0;
+    screenHeight = 0;
+    currentFrame = 0; // Reset frame counter
+
     rlvkReady = false;
-    TRACELOG(LOG_INFO, "RLVK: Vulkan backend closed (stubbed).");
+    TRACELOG(LOG_INFO, "RLVK: Vulkan backend resources reset.");
 }
 
 bool rlvkIsReady(void) {
@@ -29,15 +786,144 @@ bool rlvkIsReady(void) {
 }
 
 void rlvkBeginDrawing(void) {
-    // printf("rlvkBeginDrawing called (STUB)\n");
+    if (!rlvkReady) return;
+
+    // Wait for the fence of the current frame to ensure the command buffer is free to be reused
+    // MAX_FRAMES_IN_FLIGHT should be used here instead of vkSwapchainImageCount if they can differ.
+    // For this implementation, we assume they are the same (fences per swapchain image).
+    VkResult fenceResult = vkWaitForFences(vkDevice, 1, &vkInFlightFences[currentFrame], VK_TRUE, UINT64_MAX);
+    if (fenceResult != VK_SUCCESS) {
+        TRACELOG(LOG_ERROR, "RLVK: Failed to wait for fence (Error: %i)", fenceResult);
+        // Handle error, possibly by trying to recreate resources or exiting
+        return;
+    }
+
+    // Acquire next image from swapchain
+    VkResult acquireResult = vkAcquireNextImageKHR(vkDevice, vkSwapchain, UINT64_MAX, vkImageAvailableSemaphore, VK_NULL_HANDLE, &acquiredImageIndex);
+
+    if (acquireResult == VK_ERROR_OUT_OF_DATE_KHR) {
+        TRACELOG(LOG_WARNING, "RLVK: Swapchain out of date during vkAcquireNextImageKHR. TODO: Recreate swapchain.");
+        // rlRecreateSwapchain(); // Placeholder for swapchain recreation logic
+        return; // Skip rendering this frame
+    } else if (acquireResult != VK_SUCCESS && acquireResult != VK_SUBOPTIMAL_KHR) {
+        TRACELOG(LOG_FATAL, "RLVK: Failed to acquire swapchain image (Error: %i)", acquireResult);
+        return; // Skip rendering this frame
+    }
+
+    // Only reset the fence if we are sure we will submit work with it.
+    // This happens after successfully acquiring an image.
+    vkResetFences(vkDevice, 1, &vkInFlightFences[currentFrame]);
+
+
+    // Begin Command Buffer
+    VkCommandBuffer currentCmdBuffer = vkCommandBuffers[acquiredImageIndex]; // Use command buffer corresponding to acquired image
+    // Or use vkCommandBuffers[currentFrame] if MAX_FRAMES_IN_FLIGHT is less than swapchain image count.
+    // For now, assume one command buffer per swapchain image.
+
+    // vkResetCommandBuffer(currentCmdBuffer, 0); // Not needed if VK_COMMAND_POOL_CREATE_RESET_COMMAND_BUFFER_BIT is set on pool
+
+    VkCommandBufferBeginInfo beginInfo = {0};
+    beginInfo.sType = VK_STRUCTURE_TYPE_COMMAND_BUFFER_BEGIN_INFO;
+    beginInfo.flags = VK_COMMAND_BUFFER_USAGE_ONE_TIME_SUBMIT_BIT;
+
+    if (vkBeginCommandBuffer(currentCmdBuffer, &beginInfo) != VK_SUCCESS) {
+        TRACELOG(LOG_FATAL, "RLVK: Failed to begin command buffer.");
+        return;
+    }
+
+    // Begin Render Pass
+    VkClearValue clearValues[2];
+    clearValues[0].color = currentClearColor; // Use the color set by rlvkClearBackground
+    clearValues[1].depthStencil = defaultDepthStencilClear;
+
+    VkRenderPassBeginInfo renderPassInfo = {0};
+    renderPassInfo.sType = VK_STRUCTURE_TYPE_RENDER_PASS_BEGIN_INFO;
+    renderPassInfo.renderPass = vkRenderPass;
+    renderPassInfo.framebuffer = vkFramebuffers[acquiredImageIndex];
+    renderPassInfo.renderArea.offset = (VkOffset2D){0, 0};
+    renderPassInfo.renderArea.extent = vkSwapchainExtent;
+    renderPassInfo.clearValueCount = sizeof(clearValues) / sizeof(VkClearValue);
+    renderPassInfo.pClearValues = clearValues;
+
+    vkCmdBeginRenderPass(currentCmdBuffer, &renderPassInfo, VK_SUBPASS_CONTENTS_INLINE);
+
+    // Set Dynamic Viewport and Scissor
+    VkViewport viewport = {0};
+    viewport.x = 0.0f;
+    viewport.y = 0.0f; // Or (float)vkSwapchainExtent.height and negative height if flipping
+    viewport.width = (float)vkSwapchainExtent.width;
+    viewport.height = (float)vkSwapchainExtent.height; // Or -(float)vkSwapchainExtent.height if flipping
+    viewport.minDepth = 0.0f;
+    viewport.maxDepth = 1.0f;
+    vkCmdSetViewport(currentCmdBuffer, 0, 1, &viewport);
+
+    VkRect2D scissor = {0};
+    scissor.offset = (VkOffset2D){0, 0};
+    scissor.extent = vkSwapchainExtent;
+    vkCmdSetScissor(currentCmdBuffer, 0, 1, &scissor);
 }
 
 void rlvkEndDrawing(void) {
-    // printf("rlvkEndDrawing called (STUB)\n");
+    if (!rlvkReady) return;
+
+    VkCommandBuffer currentCmdBuffer = vkCommandBuffers[acquiredImageIndex]; // Or vkCommandBuffers[currentFrame]
+
+    vkCmdEndRenderPass(currentCmdBuffer);
+    if (vkEndCommandBuffer(currentCmdBuffer) != VK_SUCCESS) {
+        TRACELOG(LOG_FATAL, "RLVK: Failed to end command buffer.");
+        return;
+    }
+
+    // Submit Command Buffer
+    VkSubmitInfo submitInfo = {0};
+    submitInfo.sType = VK_STRUCTURE_TYPE_SUBMIT_INFO;
+
+    VkSemaphore waitSemaphores[] = {vkImageAvailableSemaphore};
+    VkPipelineStageFlags waitStages[] = {VK_PIPELINE_STAGE_COLOR_ATTACHMENT_OUTPUT_BIT};
+    submitInfo.waitSemaphoreCount = 1;
+    submitInfo.pWaitSemaphores = waitSemaphores;
+    submitInfo.pWaitDstStageMask = waitStages;
+    submitInfo.commandBufferCount = 1;
+    submitInfo.pCommandBuffers = &currentCmdBuffer;
+    VkSemaphore signalSemaphores[] = {vkRenderFinishedSemaphore};
+    submitInfo.signalSemaphoreCount = 1;
+    submitInfo.pSignalSemaphores = signalSemaphores;
+
+    VkResult submitResult = vkQueueSubmit(vkGraphicsQueue, 1, &submitInfo, vkInFlightFences[currentFrame]);
+    if (submitResult != VK_SUCCESS) {
+        TRACELOG(LOG_FATAL, "RLVK: Failed to submit draw command buffer (Error: %i)", submitResult);
+        return;
+    }
+
+    // Present Image
+    VkPresentInfoKHR presentInfo = {0};
+    presentInfo.sType = VK_STRUCTURE_TYPE_PRESENT_INFO_KHR;
+    presentInfo.waitSemaphoreCount = 1;
+    presentInfo.pWaitSemaphores = signalSemaphores;
+    VkSwapchainKHR swapchains[] = {vkSwapchain};
+    presentInfo.swapchainCount = 1;
+    presentInfo.pSwapchains = swapchains;
+    presentInfo.pImageIndices = &acquiredImageIndex;
+
+    VkResult presentResult = vkQueuePresentKHR(vkPresentQueue, &presentInfo);
+
+    if (presentResult == VK_ERROR_OUT_OF_DATE_KHR || presentResult == VK_SUBOPTIMAL_KHR) {
+        TRACELOG(LOG_WARNING, "RLVK: Swapchain out of date or suboptimal during vkQueuePresentKHR. TODO: Recreate swapchain.");
+        // rlRecreateSwapchain();
+    } else if (presentResult != VK_SUCCESS) {
+        TRACELOG(LOG_FATAL, "RLVK: Failed to present swapchain image (Error: %i)", presentResult);
+    }
+
+    // MAX_FRAMES_IN_FLIGHT needs to be well defined. Assuming it's vkSwapchainImageCount for now for simplicity of fence management.
+    // If MAX_FRAMES_IN_FLIGHT is less than vkSwapchainImageCount, the logic for fences and command buffers needs adjustment.
+    currentFrame = (currentFrame + 1) % vkSwapchainImageCount;
 }
 
 void rlvkClearBackground(unsigned char r, unsigned char g, unsigned char b, unsigned char a) {
-    // printf("rlvkClearBackground called (STUB) with color: %u, %u, %u, %u\n", r, g, b, a);
+    currentClearColor.float32[0] = (float)r / 255.0f;
+    currentClearColor.float32[1] = (float)g / 255.0f;
+    currentClearColor.float32[2] = (float)b / 255.0f;
+    currentClearColor.float32[3] = (float)a / 255.0f;
 }
 
 unsigned int rlvkLoadTexture(const void *data, int width, int height, int format, int mipmaps) {