Crate alpha2_eval 

Pure, deterministic timeline evaluation.

Structs

ActiveAudioClip

One audio clip overlapping an evaluated timeline span.

ActiveCaption

The cue one caption track shows at a timestamp.

ActiveClip

A visible or audible clip mapped to its source timestamp.

ActiveComposition

A clip’s composition at one timeline timestamp.

ActiveEffect

One effect invocation at one timestamp (timeline time for transitions, composition time for composition steps).

ActiveIndex

A precomputed interval index for a validated project snapshot.

ActiveTransition

A transition evaluated at one timeline timestamp.

AudioSpan

The clips of one span, read from an AudioSpanScratch without copying.

AudioSpanDesc

Audio activity over one half-open timeline span.

AudioSpanScratch

Reusable working memory for evaluate_audio_in.

CompositionPlan

A composition’s output, drawn by steps in dependency order.

EffectParamValue

One effect parameter’s value at a timeline timestamp.

EvaluatedLayout

A layout tree with every value sampled.

EvaluatedNode

One box with its values sampled. Lengths are fractions of the picture’s shorter side.

EvaluatedText

A text node’s sampled text and the style it inherits.

EvaluatedVisual

Visual properties evaluated at one timeline timestamp.

FrameDesc

A timestamp-specific composition description with no GPU handles.

FrameNeed

A source-frame request emitted for host prefetch and decode scheduling.

LayoutPlan

A layout tree, evaluated once when it does not animate.

NodeLayout

A box’s sampled box-model, flex and grid values. Lengths are fractions or percents.

NodePaint

What a box draws under its content.

NodeVisual

How a box and its subtree are drawn after layout.

SampledAnimator

An animator’s selector and properties at one time.

ShapesPlan

A content tree with its static parts evaluated once.

Sides

A length on each side of a box, as a fraction of the picture’s shorter side.

SourceRead

One reader of a source over an export range (ActiveIndex::source_reads).

Step

One node of a composition, with its inputs resolved to earlier steps.

StepLayer

One layer of a StepOp::Merge.

Enums

EvalError

An evaluator failure.

GeneratorPlan

A shapes or layout generator’s tree, planned once. Other generators need none.

NodeContent

A box’s content.

PlanError

Why a composition’s output cannot be drawn.

SampledSelector

A selector at one time.

StepOp

The operation of a Step. Inputs are indices of earlier steps.

Constants

MAX_PLAN_BYTES

Most bytes all compiled composition plans of one project may hold together, estimated per Step (node path plus settings heap). Past this none draws (PlanError::TooLarge).

Functions

evaluate

Evaluates visual and audio clip descriptions at one timeline timestamp.

evaluate_audio

Evaluates every audible clip overlapping a half-open timeline span.

evaluate_audio_in

Evaluates the same clips as evaluate_audio into reusable memory.

evaluate_geometry

A geometry at time: a mask’s outline, or a content tree’s.

evaluate_item

One item at time. Opacities, trims and roundness clamp to 0..=1 and lengths to >= 0, since an overshooting curve can carry them past.

evaluate_items

A whole content tree at time, without a plan.

frame_needs

Describes all source frames needed at a timestamp.

hash_sampled_animators

Feeds every value of animators to hash.

picture_source_time

The source instant a clip’s picture shows at timeline time, mirroring by project frames at frame_rate exactly as evaluation draws it.

plan_composition

Compiles composition’s output into steps as a clip’s composition, where clip nodes draw the clip’s picture. compositions resolves group nodes and sources resolves media nodes.

plan_source_composition

Compiles composition as a composition source. Like plan_composition, but clip nodes and group inputs are errors because nothing feeds them.

sample_effect_param

Samples one effect parameter with the project’s keyframe semantics.

sample_hold

Samples a non-interpolating value: the last keyframe at or before time, else the first.

sample_insets

Samples per-side lengths like sample_size.

sample_length

Samples a layout length. Mismatched keyframe kinds keep the left kind.

sample_paint

Samples an animated paint. Colors interpolate premultiplied; gradient geometry and stop offsets interpolate numerically, then offsets are kept ordered in 0..=1 and radii positive. Mismatched keyframes hold the left paint.

sample_path

Samples an animated path, interpolating points and tangents linearly in f64. Mismatched keyframe structures hold the left path.

sample_point

Samples a position that may move along spatial curves.

sample_rgba

Samples an animated color, interpolated premultiplied.

sample_scalar

Samples one animated scalar with the project’s keyframe semantics.

sample_text_animators

animators sampled at time, in order.

sample_vec2

Samples an animated 2D value like sample_scalar. Use sample_point for positions that may follow spatial curves.

sample_visual

Evaluates visual properties at a timestamp. aspect is the canvas width over height, used to measure motion along spatial curves.