DEVLOG 10 - Working On The Vulkan Wrapper

 
For now, I’m focused on creating a wrapper for Vulkan to make it simpler and less repetitive to use. I don’t want to create a wrapper that abstracts too much, thus losing control; instead, I’m creating a fairly thin wrapper.
 
I’m currently restructured the Application class a bit and divided some of its parts into three “modules.” I’m structuring this using the Factory Pattern. I’ve created three Builders: one for the window and SDL initialization, one for creating a Vulkan context—VulkanInstace, PhysicalDevice, LogicalDevice, and the graphics queue—and the last one for building the swapchain. I chose this approach because I consider it flexible and I don’t want everything to fit into one huge monolith; I prefer having multiple modular classes.
 
In addition to these more or less complete builders, I’m focusing on creating a system that can allow shaders to see and manipulate the data stored in VRAM. This is usually done with DescriptorSets, which have been the standard for years. They’re more or less like pointers to objects in VRAM so shaders can access them. In reality, they’re fat pointers because they contain other information besides the address. However, this approach is good but not optimal because it introduces CPU overhead. Since the draw calls may not share the same materials and therefore require different textures, a new DescriptorSet must be bound before each draw call, which, with many draw calls, incurs CPU overhead.
 
What I’m doing to solve this problem is looking towards a more modern and efficient approach called Bindless. Basically, instead of having multiple small DescriptorSets, you have one huge global DescriptorSet that contains all the resources used by the application. So we could have a sort of array containing all the samplers, then another containing all the textures, another containing all the buffers of a specific type, etc.
Then we just need to bind this DescriptorSet at the start of rendering, which will be used for the entire rendering process, and pass indices to the shader that will tell it which resources to use from the DescriptorSet.
 
I’m a little slow in developing all this because I’ve never used Vulkan; in fact, I’m still learning. The second reason is that Vulkan is very complex and there’s a lot of boilerplate code.
 
I still have to finish the ECS system since I don’t yet have a centralized approach for obtaining the IDs and GenerationIds of new entities, which are verified and therefore safely managed internally by the engine. But I think I’ll do it later since I’m a little tired of fiddling with entities and want to do something different for a while.