076e6d600d
Write the right_edge to the binning output. More work on encoding the fill/stroke distinction and plumbing that through the pipeline. This is a bit unsatisfying because of the code duplication; having an extra fill/stroke bool might be better, but I want to avoid making the structs bigger (this could be solved by better packing in the struct encoding). Fills are plumbed through to the last stage. Backdrop is WIP. |
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|---|---|---|
| piet-gpu | ||
| piet-gpu-derive | ||
| piet-gpu-hal | ||
| piet-gpu-types | ||
| .gitignore | ||
| Cargo.lock | ||
| Cargo.toml | ||
| LICENSE-APACHE | ||
| LICENSE-MIT | ||
| README.md | ||
piet-gpu
This repo contains the new prototype for a new compute-centric 2D GPU renderer.
It succeeds the previous prototype, piet-metal.
Goals
The main goal is to answer research questions about the future of 2D rendering:
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Is a compute-centered approach better than rasterization (Direct2D)? How much so?
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To what extent do "advanced" GPU features (subgroups, descriptor arrays) help?
Another goal is to explore a standards-based, portable approach to GPU compute.
Non-goals
There are a great number of concerns that need to be addressed in production:
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Compatibility with older graphics hardware (including runtime detection)
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Asynchrony
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Swapchains and presentation
Notes
A more detailed explanation will come. But for now, a few notes.
Why not gfx-hal?
It makes a lot of sense to use gfx-hal, as it addresses the ability to write kernel and runtime code once and run it portably. But in exploring it I've found some points of friction, especially in using more "advanced" features. To serve the research goals, I'm enjoying using Vulkan directly, through ash, which I've found does a good job tracking Vulkan releases. One example is experimenting with VK_EXT_subgroup_size_control.
The hal layer in this repo is strongly inspired by gfx-hal, but with some differences. One is that we're shooting for a compile-time pipeline to generate GPU IR on DX12 and Metal, while gfx-hal ships SPIRV-Cross in the runtime. To access Shader Model 6, that would also require bundling DXC at runtime, which is not yet implemeted (though it's certainly possible).
Why not wgpu?
The case for wgpu is also strong, but it's even less mature. I'd love to see it become a solid foundation, at which point I'd use it as the main integration with druid.
In short, the goal is to facilitate the research now, collect the data, and then use that to choose a best path for shipping later.