Add logical device creation.

src/main.c

@@ -21,8 +21,19 @@ typedef struct ApplicationState {
     GLFWwindow* window;
     //information about the connection between application and vulkan itself
     VkInstance instance;
+    //the physical gpu
+    VkPhysicalDevice physical_device;
+    //the logical device including the features we wish to use
+    VkDevice device;
+    //the queue for draw commands
+    VkQueue graphics_queue;
 } ApplicationState;
 
+typedef struct QueueFamilyIndices {
+    bool graphics_present;
+    uint32_t graphics_queue;
+} QueueFamilyIndices;
+
 void create_window(ApplicationState* state) {
     glfwInit();
 
@@ -56,6 +67,8 @@ bool check_validation_layer_support() {
         }
     }
 
+    free (available_layers);
+
     return true;
 }
 
@@ -118,8 +131,106 @@ void create_instance(ApplicationState* state) {
     free(extensions);
 }
 
+QueueFamilyIndices find_queue_families(VkPhysicalDevice device) {
+    struct QueueFamilyIndices ret = {0};
+    uint32_t queue_family_count = 0;
+    vkGetPhysicalDeviceQueueFamilyProperties(device, &queue_family_count, NULL);
+    VkQueueFamilyProperties* queue_fam_props = malloc(sizeof(VkQueueFamilyProperties) * queue_family_count);
+    vkGetPhysicalDeviceQueueFamilyProperties(device, &queue_family_count, queue_fam_props);
+
+    for (int i = 0; i < queue_family_count; i++) {
+        if (queue_fam_props[i].queueFlags & VK_QUEUE_GRAPHICS_BIT) {
+            ret.graphics_present = true;
+            ret.graphics_queue = i;
+        }
+    }
+
+    free(queue_fam_props);
+
+    return ret;
+}
+
+void pick_physical_device(ApplicationState* state) {
+    uint32_t device_count = 0;
+    vkEnumeratePhysicalDevices(state->instance, &device_count, NULL);
+
+    if (device_count == 0) {
+        printf("vulkan is not supported\n");
+        exit(1);
+    }
+
+    VkPhysicalDevice* devices = malloc(sizeof(VkPhysicalDevice) * device_count);
+    vkEnumeratePhysicalDevices(state->instance, &device_count, devices);
+
+    //now let's check if any device is suitable for our usage
+    int i;
+    for (i = 0; i < device_count; i++) {
+        VkPhysicalDevice device = devices[i];
+
+        VkPhysicalDeviceProperties device_props;
+        vkGetPhysicalDeviceProperties(device, &device_props);
+
+        VkPhysicalDeviceFeatures device_features;
+        vkGetPhysicalDeviceFeatures(device, &device_features);
+
+        QueueFamilyIndices families = find_queue_families(device);
+
+        //for now we only require that a graphics queue is present
+        if (families.graphics_present) {
+            printf("graphics queue at %x\n", families.graphics_queue);
+            break;
+        }
+    }
+
+    state->physical_device = devices[i];
+    free(devices);
+}
+
+void create_logical_device(ApplicationState* state) {
+    //we already ensured that a graphics queue exists
+    QueueFamilyIndices indices = find_queue_families(state->physical_device);
+
+    //multiple of these will be needed once we require other kinds of queues
+    VkDeviceQueueCreateInfo queue_create_info = {0};
+    queue_create_info.sType = VK_STRUCTURE_TYPE_DEVICE_QUEUE_CREATE_INFO;
+    queue_create_info.queueFamilyIndex = indices.graphics_queue;
+    queue_create_info.queueCount = 1;
+    float prio = 1.0f;
+    queue_create_info.pQueuePriorities = &prio;
+
+    //for now we won't use any features
+    VkPhysicalDeviceFeatures device_features = {0};
+
+    //now create a logical device knowing which features and queues we need
+    VkDeviceCreateInfo create_info = {0};
+    create_info.sType = VK_STRUCTURE_TYPE_DEVICE_CREATE_INFO;
+    create_info.pQueueCreateInfos = &queue_create_info;
+    create_info.queueCreateInfoCount = 1;
+    create_info.pEnabledFeatures = &device_features;
+    create_info.enabledExtensionCount = 0;
+
+    if (VALIDATE) {
+        create_info.enabledLayerCount = ARRSIZE(validation_layers);
+        create_info.ppEnabledLayerNames = validation_layers;
+    } else {
+        create_info.enabledLayerCount = 0;;
+    }
+
+    if (vkCreateDevice(state->physical_device, &create_info, NULL, &state->device) != VK_SUCCESS) {
+        printf("Error creating logical device\n");
+        exit(1);
+    }
+
+    //get a handle to the queue
+    vkGetDeviceQueue(state->device, indices.graphics_queue, 0, &state->graphics_queue);
+
+    printf("Logical device created\n");
+}
+
 void init_vulkan(ApplicationState* state) {
     create_instance(state);
+    pick_physical_device(state);
+    create_logical_device(state);
 }
 
 void main_loop(ApplicationState* state) {
@@ -129,6 +240,7 @@ void main_loop(ApplicationState* state) {
 }
 
 void terminate(ApplicationState* state) {
+    vkDestroyDevice(state->device, NULL);
     vkDestroyInstance(state->instance, NULL);
     glfwDestroyWindow(state->window);
     glfwTerminate();