From 79bedf969521997735a667437fc2a1ba2af17132 Mon Sep 17 00:00:00 2001
From: Garnet <garnet@disroot.org>
Date: Mon, 24 Oct 2022 14:41:49 +0200
Subject: [PATCH] Add validation layer support

---
 src/main.c | 135 ++++++++++++++++++++++++++++++++++++++++++++++++++---
 1 file changed, 128 insertions(+), 7 deletions(-)

diff --git a/src/main.c b/src/main.c
index 4e73a07..4f3fb41 100644
--- a/src/main.c
+++ b/src/main.c
@@ -1,25 +1,146 @@
 #define GLFW_INCLUDE_VULKAN
 #include <GLFW/glfw3.h>
+#include <vulkan/vulkan.h>
 
 #include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <stdbool.h>
 
-int main() {
+#define WIDTH  2560
+#define HEIGHT 1440
+#define VALIDATE true
+
+#define ARRSIZE(x) ((sizeof(x)/sizeof(0[x])) / ((size_t)(!(sizeof(x) % sizeof(0[x])))))
+
+const char* validation_layers[] = {
+    "VK_LAYER_KHRONOS_validation",
+};
+
+typedef struct ApplicationState {
+    GLFWwindow* window;
+    //information about the connection between application and vulkan itself
+    VkInstance instance;
+} ApplicationState;
+
+void create_window(ApplicationState* state) {
     glfwInit();
 
     glfwWindowHint(GLFW_CLIENT_API, GLFW_NO_API);
-    GLFWwindow* window = glfwCreateWindow(2560, 1440, "vulkan learning example", NULL, NULL);
+    state->window = glfwCreateWindow(WIDTH, HEIGHT, "vulkan learning example", NULL, NULL);
+}
+
+//check if all of our validation layers are supported
+bool check_validation_layer_support() {
+    uint32_t layer_count;
+    vkEnumerateInstanceLayerProperties(&layer_count, NULL);
+
+    VkLayerProperties* available_layers = malloc(sizeof(VkLayerProperties) * layer_count);
+    vkEnumerateInstanceLayerProperties(&layer_count, available_layers);
+
+    printf("supported validation layers:\n");
+    for (int i = 0; i < layer_count; i++) {
+        printf("\t%s\n", available_layers[i].layerName);
+    }
+
+    for (int i = 0; i < ARRSIZE(validation_layers); i++) {
+        bool found = false;
+        for (int j = 0; j < layer_count; j++) {
+            if (!strcmp(available_layers[j].layerName, validation_layers[i]))  {
+                found = true;
+            }
+        }
+
+        if (!found) {
+            return false;
+        }
+    }
+
+    return true;
+}
+
+//we first create an instance, filling it in with our application information.
+void create_instance(ApplicationState* state) {
+    if (VALIDATE && !check_validation_layer_support()) {
+        printf("Requested validation layers but they're not supported");
+        exit(1);
+    }
+
+    VkApplicationInfo appinfo = {0};
+
+    appinfo.sType = VK_STRUCTURE_TYPE_APPLICATION_INFO;
+    appinfo.pApplicationName = "Vulkan learning triangle example";
+    appinfo.applicationVersion = VK_MAKE_VERSION(1, 0, 0);
+    appinfo.pEngineName = "No Engine";
+    appinfo.engineVersion = VK_MAKE_VERSION(1, 0, 0);
+    appinfo.apiVersion = VK_API_VERSION_1_0;
+
+    VkInstanceCreateInfo create_info = {0};
+    create_info.sType = VK_STRUCTURE_TYPE_INSTANCE_CREATE_INFO;
+    create_info.pApplicationInfo = &appinfo;
 
-    uint32_t num_extensions = 0;
-    vkEnumerateInstanceExtensionProperties(NULL, &num_extensions, NULL);
+    //now let's require the global extensions that are required for GLFW to work
+    uint32_t glfw_extension_num = 0;
+    const char** glfw_extensions;
 
-    printf("number of supported extensions %Xh\n", num_extensions);
+    glfw_extensions = glfwGetRequiredInstanceExtensions(&glfw_extension_num);
 
-    while(!glfwWindowShouldClose(window)) {
+    create_info.enabledExtensionCount = glfw_extension_num;
+    create_info.ppEnabledExtensionNames = glfw_extensions;
+
+    if (VALIDATE) {
+        create_info.enabledLayerCount = ARRSIZE(validation_layers);
+        create_info.ppEnabledLayerNames = validation_layers;
+    } else {
+        create_info.enabledLayerCount = 0;
+    }
+
+    //now we actually create the instance
+    if (vkCreateInstance(&create_info, NULL, &state->instance) != VK_SUCCESS) {
+        printf("error creating instance\n");
+        exit(1);
+    }
+
+    printf("Instance successfully created\n");
+
+    //let's just list all supported vulkan instance extensions
+    uint32_t extension_num = 0;
+    vkEnumerateInstanceExtensionProperties(NULL, &extension_num, NULL);
+    VkExtensionProperties* extensions = malloc(sizeof(VkExtensionProperties) * extension_num);
+    vkEnumerateInstanceExtensionProperties(NULL, &extension_num, extensions);
+
+    printf("instance extensions:\n");
+
+    for (int i = 0; i < extension_num; i++) {
+        printf("\t%s\n", extensions[i].extensionName);
+    }
+
+    free(extensions);
+}
+
+void init_vulkan(ApplicationState* state) {
+    create_instance(state);
+}
+
+void main_loop(ApplicationState* state) {
+    while(!glfwWindowShouldClose(state->window)) {
         glfwPollEvents();
     }
+}
 
-    glfwDestroyWindow(window);
+void terminate(ApplicationState* state) {
+    vkDestroyInstance(state->instance, NULL);
+    glfwDestroyWindow(state->window);
     glfwTerminate();
+}
+
+int main() {
+    ApplicationState state = {0};
+    create_window(&state);
+    init_vulkan(&state);
+
+    main_loop(&state);
+    terminate(&state);
 
     return 0;
 }