v0.1.13213 Aug 2026·Rendering, Web APIs & DOM, Tabs & interface

The GPU compositor can present directly to a window, no readback

Floati has had a real GPU compositor for a while - it blends every layer of a page on the graphics card, byte-for-byte identical to the software path. But it was dark: after compositing on the GPU it copied the whole frame back across the bus to hand the shell a PNG, and that copy erased the entire speed advantage. This release builds the missing half - a present path that draws the composited frame straight to a texture the window owns, so the frame never leaves the GPU. A full-screen pass reads the composited pixels and writes them to the swapchain; because the target is a plain 8-bit-per-channel format, the round trip is a bit-exact copy, so the surface shows precisely what the readback path returned. That is proven, not hoped: an offscreen version of the exact present path is read back and compared to the software compositor across opaque, translucent, opacity-tie, edge-clipped, odd-width and 60 random layer stacks - all byte-identical. A SurfaceRenderer drives it from any window handle and degrades to software where there is no GPU. GPU moves 2 to 4; overall holds at 52 (the live view is wired next).

Parity with the reference browser

74overall, as of v0.1.343

Web APIs / DOM surface42

Security architecture66

GPU / graphics acceleration68

DevTools / extensions72

Networking85

Media85

Accessibility85

Real-world site compatibility99

HTML parsing100

CSS parsing + selectors100

Layout: block / flex / grid / tables / writing-modes100

Paint + visual100

JavaScript language100

JavaScript performance (JIT)100

HTML parsing100

What changed 3 changes

Tabs & interface	A GPU present path (core-gpu): the per-layer compute blend now fills a page buffer that is EITHER read back (the legacy PNG path) OR drawn to a target texture by a full-screen render pass, sharing one compute stage. The fragment emits logical RGBA into an Rgba8Unorm (or Bgra8Unorm) target, a bit-exact copy of the composited bytes - so presenting to a window shows exactly what readback returned.
Web APIs & DOM	A SurfaceRenderer that owns the window surface: one wgpu instance across surface, adapter and device; configures the swapchain to whichever of Rgba8Unorm / Bgra8Unorm the window offers; composites straight to the acquired frame and presents it; reconfigures on resize and recovers from a lost or outdated swapchain. Returns None (embedder keeps software) where there is no usable GPU.
Rendering	Proven byte-identical: composite_to_offscreen runs the exact present path to an offscreen texture and reads it back; a new suite compares it to the software compositor across opaque, translucent, opacity ties, edge clipping, odd widths (the row-padding path) and 60 random stacks, plus a present-equals-readback cross-check. The whole conformance suite is unchanged (6375/6375).