Added code for finding suitable graphics family queue

src/main.c

@@ -216,7 +216,38 @@ void DestroyDebugUtilsMessengerEXT(VkInstance instance,
   }
 }
 
-bool isDeviceSuitable(VkPhysicalDevice device) { return true; }
+struct QueueFamilyIndices_s {
+  bool graphicsFamilyExists;
+  uint32_t graphicsFamily;
+} QueueFamilyIndices_default = {.graphicsFamilyExists = false,
+                                .graphicsFamily = 0};
+typedef struct QueueFamilyIndices_s QueueFamilyIndices;
+
+QueueFamilyIndices findQueueFamilies(VkPhysicalDevice device) {
+  QueueFamilyIndices indices = QueueFamilyIndices_default;
+
+  uint32_t queueFamilyCount = 0;
+  vkGetPhysicalDeviceQueueFamilyProperties(device, &queueFamilyCount, NULL);
+  VkQueueFamilyProperties queueFamilies[queueFamilyCount];
+  vkGetPhysicalDeviceQueueFamilyProperties(device, &queueFamilyCount,
+                                           queueFamilies);
+
+  for (uint32_t i = 0; i < queueFamilyCount; i++) {
+    if (queueFamilies[i].queueFlags & VK_QUEUE_GRAPHICS_BIT) {
+      indices.graphicsFamily = i;
+      indices.graphicsFamilyExists = true;
+      break; // remove if we need additional checks in future
+    }
+  }
+
+  return indices;
+}
+
+bool isDeviceSuitable(VkPhysicalDevice device) {
+  QueueFamilyIndices indices = findQueueFamilies(device);
+
+  return indices.graphicsFamilyExists;
+}
 
 void pickPhysicalDevice(Application *app) {
   VkPhysicalDevice physicalDevice = VK_NULL_HANDLE;
@@ -231,13 +262,15 @@ void pickPhysicalDevice(Application *app) {
   vkEnumeratePhysicalDevices(app->instance, &physicalDeviceCount,
                              physicalDevices);
 
+  // TODO: pick device off of more than if it's just suitable
   for (int i = 0; i < physicalDeviceCount; i++) {
     if (isDeviceSuitable(physicalDevices[i])) {
       physicalDevice = physicalDevices[i];
+      break;
     }
   }
 
-  if (physicalDevice == VK_NULL_HANDLE){
+  if (physicalDevice == VK_NULL_HANDLE) {
     fprintf(stderr, "Failed to find suitable GPU\n");
     exit(EXIT_FAILURE);
   }