descriptor set bindings do not guarantee their order

[codethinki]

In the descriptor header is a bug: an unordered map does not guarantee its order or that index_n + 1 = index_{n + 1} when iterating. For Vulkan the bindings must be in order so you should use something like ordered_map. Also in vulkan its perfectly valid to not specify a binding in a set layout which would not be possible here.

LveDescriptorSetLayout::LveDescriptorSetLayout(
    LveDevice &lveDevice, std::unordered_map<uint32_t, VkDescriptorSetLayoutBinding> bindings)
    : lveDevice{lveDevice}, bindings{bindings} {
  std::vector<VkDescriptorSetLayoutBinding> setLayoutBindings{};
  for (auto kv : bindings) {
    setLayoutBindings.push_back(kv.second);
  }

  VkDescriptorSetLayoutCreateInfo descriptorSetLayoutInfo{};
  descriptorSetLayoutInfo.sType = VK_STRUCTURE_TYPE_DESCRIPTOR_SET_LAYOUT_CREATE_INFO;
  descriptorSetLayoutInfo.bindingCount = static_cast<uint32_t>(setLayoutBindings.size());
  descriptorSetLayoutInfo.pBindings = setLayoutBindings.data();

  if (vkCreateDescriptorSetLayout(
          lveDevice.device(),
          &descriptorSetLayoutInfo,
          nullptr,
          &descriptorSetLayout) != VK_SUCCESS) {
    throw std::runtime_error("failed to create descriptor set layout!");
  }