class DrawList

Public so a harness outside LavaUI (LavaBench) can assert on the shape of a frame — command/glyph counts are exact where timings are noisy. See PerfCounters.

States where the enclosing node should end up. The renderer takes it there — at the display rate, without this process being scheduled again, and without stopping if this process gets busy.

A property left nil is not stated, and keeps whatever target it had. The first frame a node states one it snaps rather than eases: a node that has just appeared has nothing to have moved from. To animate an entrance, state the start on one frame and the end on the next. Pass duration instead of timeConstant when several nodes have to arrive together: a decay from a longer distance takes visibly longer to settle, so a group easing with one time constant lands raggedly, while a group sharing a duration lands on one frame.

Barrier: engine flushes UI drawn so far, blurs under this rect, composites. color is unused by the engine (tint the glass with a following fill).

cornerRadius is the radius of the surface that will be drawn over the frost. The composite is the one piece of a rounded glass panel the panel's own fill cannot hide — it is underneath it — so a square one shows as four bright tabs around the shape.

Barrier: engine draws everything until endContentBlur into an offscreen target, blurs it, and composites it back over this rect.

Opens a scene node — a subtree the renderer can move on its own.

id is yours to assign and must be stable across frames: it is what the renderer keys its retained state on, so an id that changes between frames scrolls back to the top on every one. Not routed through append, unlike every primitive: color here is a flags bitfield, and append exists to put a colour through the opacity multiplier. Fading a node would turn scrollY into clip. Opens a node for a view, taking its scene id from its NodeID.

The overload views should use: reconciliation already keeps NodeID stable across frames, and SceneNodeIdentity is what makes the number the renderer sees stable and safe to hand on when the node is gone.

Starts a frame: resets the counts and claims storage for it.

Claiming here rather than once at init is what a shared arena needs — it is triple buffered, so the slot a frame is written into is chosen per frame and the pointers move with it. The in-process sink hands back the same buffers every time, so nothing changes for a windowed app.

Emit chrome from a laid-out retained tree. originX/Y shift the tree (e.g. below ImGui menu). Viewport seeds the cull stack; ScrollView further intersects so long lists skip off-screen subtrees entirely (not only leaves).

Closes the innermost node. contentW/contentH are how big its children turned out to be, which is what bounds a scroll.

emittedTop/emittedBottom are the vertical span actually drawn, for a virtualized node that declares more content than it emits. Left at zero they mean "all of it", which is the truth for anything that draws its whole content. hoverTint/pressTint are drawn over the node while the pointer is inside it, and while it is additionally being pressed. The renderer applies them without asking, which is the point: hover is the most frequent state change in an interface and recomputing it here would cost a round trip per mouse move to reach an answer the renderer already had.

Textured quad. param = engine texture id; color = RGBA tint.

Textured quad from a UIImage, including compositor surface posters.

Stroke from (x1,y1) to (x2,y2). width is in pixels (capsule).

A rect filled with a two-stop linear ramp.

angle is in radians from +x towards +y, so 0 runs left to right and .pi / 2 runs top to bottom. The ramp spans the rect exactly whatever the angle and whatever the aspect ratio, and both stops carry their own alpha — a fade to transparent is to: with alpha 0, not a separate mechanism.

Falls back to a flat from fill if the frame has no room left for another gradient, which is the same shape as every other truncation here: draw less than was asked for rather than nothing.

Promises that x,y,w,h of this frame is fully opaque, so a compositor showing it can skip blending there — and skip drawing whatever is behind it entirely.

Only worth saying for a compositor surface; a windowed app is pasted onto a swapchain and nobody asks. Emit before the tree, at the top level: the renderer ignores a claim made inside a scene node or a faded subtree, because those are about pixels the frame may not own.

Claiming too little costs a blend. Claiming too much punches a hole through to the desktop, so anything uncertain — a translucent wash, a backdrop blur, a rounded corner the client drew itself — is a reason not to call this. The window's own rounding needs no allowance; the renderer insets for that, since it is the one that cuts the corners.

Filled pie or donut wedge. innerRadius <= 0 draws a solid slice (fanned from the centre); innerRadius > 0 draws a ring segment. segments defaults to a density that keeps the arc looking smooth without over-tessellating short spans.

Fills a custom region fanned from its first point. Correct for any convex polygon, or any shape star-shaped from points[0] (able to see its whole boundary from there) — a wedge fanned from its centre, for instance. Concave shapes that are not star-shaped from the first point will self-intersect; that triangulation isn't supported.

Draws connected points with one non-indexed LINE_STRIP GPU draw.

This is intentionally 1px: portable Vulkan does not guarantee wide native lines. A future thick-polyline API should expand joins/caps into triangles rather than depend on the optional wideLines device feature.

Hands the frame to its sink. Returns whether anything was published — false when no storage was claimed, which is a frame skipped rather than a failure.

Fills a ring segment (annulus sector) between two arcs of equal point count — the shape a donut-chart wedge needs, where a hole in the middle means no single point can fan to the whole boundary.

An outline of width pixels lying inside x,y,w,h, with the outer edge rounded by radius.

Inside, not centred on the edge, so a bordered view occupies exactly the rect it was laid out in — which is what .border() promises and what lets this take the same rect and radius as the fill underneath it.

The width crosses to the renderer as 24.8 fixed point because the command struct has no float field left. A hairline is 1.25 or 1.5 physical pixels on a fractional-scale output, so rounding it to whole pixels is the difference between a border and none at all.

Shapes string (cached on the font) and appends its glyphs at absolute positions. y is the line box top; the pen sits at the baseline, i.e. y + ascent.