UI rewrite 3rd attempt

This commit is contained in:
Jorijn van der Graaf 2026-05-02 21:08:20 +02:00
commit 1f5697326c
48 changed files with 2155 additions and 6190 deletions

182
README.md
View file

@ -1,111 +1,105 @@
# Crafter.Graphics
Catcrafts' Vulkan-based graphics + UI library. C++20 modules, ray-traced 3D, compute-shader UI, fully bindless via `VK_EXT_descriptor_heap`.
Vulkan-based graphics library built around C++20 modules and the bindless
`VK_EXT_descriptor_heap` extension. Provides window management, ray
tracing, and a compute-shader-driven UI on a single, opinionated stack.
This is **V2** of the library — a from-scratch rewrite that replaces the
old `RenderingElement2D`-style UI (verbose, no batching, per-element
descriptor surgery) with a declarative widget tree rendered through a
single compute dispatch.
## What's in here
## Capabilities
- **Window** — Wayland and Win32 backends, swapchain ring, frame pacing,
input events. Pick a backend at build time via the target triple.
- **Device** — single-Vulkan-instance bring-up. The library targets
`VK_EXT_descriptor_heap` exclusively; pipelines are created with
`VK_PIPELINE_CREATE_2_DESCRIPTOR_HEAP_BIT_EXT` so there are no
descriptor-set layouts and push constants travel via
`vkCmdPushDataEXT`.
- **DescriptorHeapVulkan** — bindless slot allocator. `AllocateImageSlots`
/ `AllocateBufferSlots` / `AllocateSamplerSlots`, with byte-offset
helpers for direct descriptor writes.
- **VulkanBuffer\<T, Mapped\>** — typed buffer with optional host mapping
and a `FlushDevice` that issues the right host-write barrier.
- **ImageVulkan\<Pixel\>** — image + staging buffer, mip-chain support,
one-shot uploads via a command buffer.
- **PipelineRTVulkan / ShaderBindingTableVulkan / RTPass** — ray-tracing
pipeline, SBT, and a `RenderPass` that dispatches it.
- **ComputeShader** — the Tier 1 wrapper used by the UI system. Loads a
`.spv`, builds a heap-bound compute pipeline, dispatches with
`vkCmdPushDataEXT`. Use it directly for any custom compute.
- **UI** — three-tier UI system; see below.
- **FontAtlas** — single-channel SDF atlas (1024×1024, 32pt base,
shelf-packed, lazy `Ensure` per codepoint, dirty-flush via `Update`).
- **Mesh / RenderingElement3D / Animation** — BLAS/TLAS construction
and 3D scene plumbing for the ray-tracing path.
- **3D rendering** through `VK_KHR_ray_tracing_pipeline`. `RTPass` is the
reusable wrapper; `Mesh` builds BLAS, `RenderingElement3D` builds TLAS.
- **2D / UI rendering** through one compute shader per frame. Widgets
emit `UIItem`s into a per-frame mapped SSBO; the shader scans it and
composites onto the swapchain image. SDF glyph atlas means one
texture covers all sizes / DPI scales.
- **Bindless descriptor model** via `VK_EXT_descriptor_heap` — one
resource heap + one sampler heap, bound once per frame. RT and UI
passes share the same heap.
- **`Window::passes`** — render passes are pluggable (`RenderPass*`
vector). Add `RTPass`, `UIScene`, your own pass, in any order. Window
inserts storage→storage barriers between consecutive passes.
- **Cross-platform window backend** — Wayland (with fractional scale +
XKB keyboard) or Win32, picked at compile time from the target triple.
## UI system (three tiers)
## Quick start
The UI is *deliberately* layered to balance no-boilerplate against
no-lock-in:
- **Tier 1 — `ComputeShader`.** Load any `.spv`, dispatch with push
constants, library inserts inter-dispatch barriers. The escape hatch:
if the standard shaders don't fit, write your own compute and
dispatch it next to them.
- **Tier 2 — `UIRenderer` + standard shaders.** Four shipped compute
shaders (`drawQuads`, `drawCircles`, `drawImages`, `drawText`), POD
item structs (`QuadItem`, `CircleItem`, `ImageItem`, `GlyphItem`), a
shared GLSL contract in [shaders/ui-shared.glsl](shaders/ui-shared.glsl),
and helpers (`RegisterBuffer`, `RegisterImage`, `RegisterSampler`,
`FillHeader`, `Dispatch*`, `ShapeText`). You build your own per-shader
SSBOs (manual batching) and call one `Dispatch*` per shader type per
frame. Item array order = draw order.
- **Tier 3 — stateless presentation functions.** `DrawButton`,
`DrawCheckbox`, `DrawSlider`, `DrawProgressBar`. Each is a small
function that *appends* items to your buffers — they don't dispatch.
Colors come in as small inline `*Colors` aggregates, no library
`Theme` type. **The source is the customization API**: if a
component doesn't fit, copy its body and edit it. No virtual hooks,
no extension points.
What's *not* in the UI: widget tree, layout engine (just a `Rect::SubRect`
carving helper), theming, hit-testing, focus management. State for
interactive components (hover, drag, focus) lives in user-owned POD
structs, not the library.
### UI dispatch model
Standard shaders dispatch one workgroup per 8×8 *screen tile* — each
thread iterates every item in the SSBO in array order, accumulating
into a local `dst`, and stores once. Total cost is `O(W·H·N)`; works
well up to a few hundred items at 1080p. Splitting one buffer into
multiple dispatches doesn't help — the same total work plus barrier
overhead. If you need to render thousands of UI items, you want a
different shader (tile binning, per-item-list resolve), not more
dispatches.
## Build
The repository is built with `crafter-build` (a project-config based
build system; the project description lives in `project.cpp`):
```bash
# Build the library
cd Crafter.Graphics2
crafter-build
# Build + run an example
cd examples/VulkanUI
crafter-build -r
crafter-build # build the library
crafter-build -r # build and run (in an example directory)
```
Build dependencies (cloned automatically): `Vulkan-Headers`,
`Vulkan-Utility-Libraries`, `Crafter.Event`, `Crafter.Math`,
`Crafter.Asset`. System dependencies: `clang++` with C++20 modules and
`libstd` PCM, `libvulkan`, `libwayland-client` + `xkbcommon`
(or `kernel32/user32/gdi32` on Windows).
## Module layout
The library is one C++20 module, `Crafter.Graphics`, with partitions
grouped by concern:
| Partition family | Purpose |
|------------------------|------------------------------------------------------------|
| `:Window`, `:Device` | Window + Vulkan instance/device |
| `:RenderPass`, `:RTPass` | Pluggable pass interface + ray-tracing helper |
| `:DescriptorHeapVulkan`, `:VulkanBuffer`, `:ImageVulkan`, `:SamplerVulkan` | Bindless heap + GPU buffers / images / samplers |
| `:PipelineRTVulkan`, `:ShaderVulkan`, `:ShaderBindingTableVulkan` | RT pipeline plumbing |
| `:Mesh`, `:RenderingElement3D` | BLAS / TLAS for ray tracing |
| `:Font` | TTF loading + UTF-8 metrics |
| `:UI*` | Widget tree, layout, hit-testing, theme, draw list, atlas, renderer, scene |
The umbrella `import Crafter.Graphics;` re-exports everything.
## UI architecture (one paragraph)
Widgets are value types with a fluent builder API. Composite containers
(`VStack`, `HStack`, `Stack`, `Overlay`, `TabView`, `ScrollView`) take
children as `&&` parameter packs and own them inside a `UIScene` arena.
Layout is two-pass measure/arrange (WPF / Avalonia / Flutter style)
with `Length::Px` / `Pct` / `Auto` / `Frac` units and DPI scaling
threaded through. Each frame, `UIScene` walks the tree, emits a flat
`UIItem` array into a mapped SSBO, and the compute shader scans it
front-to-back compositing rectangles, rounded rectangles, SDF glyphs,
and bindless images. Mouse clicks bubble through `OnMouseClick`; focus
+ `OnTextInput` / `OnKeyDown` route to the focused widget. Themes are
flat structs (`ButtonStyle`, `InputFieldStyle`) applied per-instance via
`.style(theme.primary)`.
The build picks the window backend automatically: Wayland on Linux,
Win32 on Windows / mingw. Cross-compile via the standard `--target=...`
flag.
## Examples
- [`examples/VulkanTriangle`](examples/VulkanTriangle/) — minimal
ray-traced triangle. The reference for `RTPass` + descriptor heap
setup with no UI.
- [`examples/VulkanUI`](examples/VulkanUI/) — the full Phase 2/3
surface: stacks, themed buttons, progress bar, tab view, focusable
input fields with caret blink + key repeat.
- [`examples/VulkanAnimated`](examples/VulkanAnimated/) — `Observable<T>`
+ per-frame ticks driving live HUD bars and labels with no manual
invalidation.
See [examples/](examples/). Quick map:
## V1 known limitations
- Single-font, LTR-only text. No bold / italic / kerning beyond stb's
default. No multi-line wrap or BiDi.
- No tile-binning in the UI compute shader; the naive front-to-back
per-pixel scan handles a few hundred items effortlessly. Past
~5,000 items the data layout supports tile-binning without an API
change.
- No render-target-to-texture for world-space UI yet.
- No animation primitives in the UI module — drive `Observable<T>`s
yourself from `onUpdate`.
## Status
Phase 1, 2, and 3 V1 of the rewrite are complete:
ray-traced 3D path migrated to `RenderPass`, full UI widget set
rendering through compute, focus + keyboard input + Wayland key repeat
working end-to-end. Verified on NVIDIA GeForce RTX 4090 with
`VK_EXT_descriptor_heap` and `VK_LAYER_KHRONOS_validation` clean.
- [HelloWindow](examples/HelloWindow/) — minimal window, no rendering.
- [VulkanTriangle](examples/VulkanTriangle/) — ray-traced triangle, the
smallest test of the bindless + ray-tracing path.
- [HelloUI](examples/HelloUI/) — UI smoke test using all three tiers
(background quad, slider, progress bar, button with text label,
cursor-tracking circle).
- [CustomShader](examples/CustomShader/) — Tier 1 demo: a user-authored
compute shader inverting RGB under a list of item-circles, dispatched
alongside the standard `drawQuads`. The "could attempt #2 do this?" test.
## License
LGPL v3 — see [LICENSE](LICENSE).
LGPL 3.0. See per-file headers and `LICENSE`.