Redesign GPU resource management

[amethyst]

Redesign GPU resource management

[ebkalderon]

Update: The current progress can be followed on the gpures branch.

[ebkalderon]

Idea: GPU resources are a separate concept from state objects, even though both are managed similarly. However, there are some marked differences in their construction and usage, and most next-gen APIs make the same distinction. Below are working definitions of both concepts.

• Resource
  • Definition: A chunk of structured data that is either pushed to or created directly on the GPU.
  • Examples: Buffer, sampler, render target, unlinked shaders.
• State Object
  • Definition: A collection of "switches" or "toggles" dictating how a certain piece of the graphics pipeline should process the given resources.
  • Examples: Pipeline state, blend state, depth-stencil state, rasterizer state, etc.

Remaining questions:

1. Are descriptor sets (basically packets of resources) considered resources themselves?
2. Should the "factory" be split into two halves, one generating resources and the other generating state objects?

[ebkalderon]

After re-evaluating the goals of the project, I have decided that implementing the gameplay framework is more urgent than completing the renderer at this time. While the renderer is a critical component, this is a game engine, and as such people should be able to make games with it first.

As such, I am shelving this redesign and marking this as "stalled" until further notice. Priority will shift towards the thread-safe ECS implementation. If anyone else wants to work on this while I focus on issue #10, they are welcome to do so.

[kvark]

Did you consider using gfx-rs directly?
Edit: moved to #16

[ebkalderon]

I have indeed. However, I drafted the design of my renderer well before gfx-rs officially rolled out pipeline state object support. Incorporating gfx-rs into the renderer is back on the table, now that PSO support is fully baked. Hopefully, gfx-rs will develop a working Vulkan backend and then the renderer can be greatly simplified.

[ebkalderon]

If the renderer depends on GFX for rendering (issue #16) is implemented, this improvement will be invalidated.

[ebkalderon]

With the recent 0.2.0 release, the renderer now depends on gfx-rs, making this issue invalid. Closing.