Prepare for rendering and presentation

src/global.h

@@ -2,6 +2,7 @@
 #include "debug/vulkandebuglibs.h"
 #include <iostream>
 #include <vector>
+#include <optional>
 #include <vulkan/vulkan_core.h>
 
 #define GLFW_INCLUDE_VULKAN
@@ -12,4 +13,19 @@ namespace Global {
   // so that's one obvious global, as well as the glfw includes!
   extern const std::vector<const char*> validationLayers;
   extern const bool enableValidationLayers;
+  extern VkDevice device;  
+  struct QueueFamilyIndices {
+    // We need to check that the Queue families support graphics operations and window presentation, sometimes they can support one or the other,
+    // therefore, we take into account both for completion.
+    std::optional<uint32_t> graphicsFamily;
+    std::optional<uint32_t> presentFamily;
+
+    bool isComplete() {
+      return graphicsFamily.has_value() && presentFamily.has_value();
+    }
+  };
+
+  extern VkSurfaceKHR surface;
+  extern VkPhysicalDevice physicalDevice;
+  Global::QueueFamilyIndices findQueueFamilies(VkPhysicalDevice device);
 }