Raises an error when having no/exceeding vulkan device's limit

src/Manager.cpp

@@ -287,6 +287,25 @@ Manager::createDevice(const std::vector<uint32_t>& familyQueueIndices,
  }
 
  this->mFreeDevice = true;
+
+ // Getting an integer that says how many vuklan devices we have
+ uint32_t deviceCount = 0;
+ vkEnumeratePhysicalDevices(*(this->mInstance), &deviceCount, nullptr);
+
+ // This means there are no devices at all
+ if (deviceCount == 0) {
+ throw std::runtime_error("Failed to find GPUs with Vulkan support! "
+ "Maybe you haven't installed vulkan drivers?");
+ }
+
+ // This means that we're exceeding our device limit, for
+ // example if we have 2 devices, just physicalDeviceIndex
+ // 0 and 1 are acceptable. Hence, physicalDeviceIndex should
+ // always be less than deviceCount, else we raise an error
+ if ( !(deviceCount > physicalDeviceIndex) ) {
+ throw std::runtime_error("There is no such physical index or device, "
+ "please use your existing device");
+ }
 
  std::vector<vk::PhysicalDevice> physicalDevices =
  this->mInstance->enumeratePhysicalDevices();