Crafter.Graphics

Catcrafts' Vulkan-based graphics + UI library. C++20 modules, ray-traced 3D, compute-shader UI, fully bindless via VK_EXT_descriptor_heap.

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.

Capabilities

• 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 UIItems 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.

Quick start

# Build the library
cd Crafter.Graphics2
crafter-build

# Build + run an example
cd examples/VulkanUI
crafter-build -r

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).

Examples

• examples/VulkanTriangle — minimal ray-traced triangle. The reference for RTPass + descriptor heap setup with no UI.
• 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 — Observable<T>
  • per-frame ticks driving live HUD bars and labels with no manual invalidation.

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.

License

LGPL v3 — see LICENSE.