import type { Page } from 'playwright';
import type { ScreenshotOptions, Viewport } from '@variance-authority/core/format';
/**
 * The longest side, in device pixels, of a subject this package photographs.
 *
 * Chromium's largest texture side, and past any image a person reviews: a
 * subject that long is a document, and its change is read as text. Not a
 * setting. A subject past it is refused with its size, never clipped,
 * because a clipped image claims a review of pixels nobody saw.
 */
export declare const MAX_CAPTURE_PIXELS = 16384;
/**
 * The subject's pixels and its box, by the cheapest route that produces the same
 * bytes the element path produces.
 *
 * `locator.screenshot()` does not just capture. It first runs Playwright's
 * actionability wait, which requires the subject's box to hold still across two
 * consecutive animation frames — about 30 ms at 60 Hz, charged once per subject
 * whether or not anything on the page is moving. Measured by this package's own
 * benchmark (`yarn workspace @variance-authority/playwright host`), that wait is
 * most of a light subject's cost. Median ms per paint on macOS, one page reused:
 *
 *   engine     element   clip
 *   chromium      59.2   26.2
 *   firefox       33.3    8.5
 *   webkit        33.3    3.7
 *
 * We have already settled the page ourselves — the recipe's waits have run, fonts
 * have loaded, and every network channel is blocked for the whole lease — so the
 * wait re-establishes something we have just established, at the price of the
 * paint. It is also why the engines looked closer together than they are: a
 * constant every engine pays compressed a 7x spread into a 1.8x one. The
 * benchmark's heavy-subject arm shows what that concealed — WebKit is first on
 * the subject above and last on one that rasterizes — so the saving here is not
 * uniform across engines and is largest exactly where the paint is cheapest.
 *
 * The two paths are byte-identical only if the clip is rounded the way the
 * element path rounds it: see {@link outward}. Verified across 240 randomly
 * generated subjects — fractional sizes, fractional offsets, borders, shadows,
 * axis-aligned transforms — in all three engines at both device scale factors.
 *
 * Three subjects keep the slow path, which is why this is a fallback and not a
 * replacement. Each was measured, not assumed:
 *
 * - **No reported box.** Detached, or `display: none`. There is no rectangle to
 *   clip to, and the element path is left to raise its own error for it.
 * - **Not wholly inside the viewport.** A clip rect is viewport-relative and
 *   Playwright refuses one that leaves it — a subject below the fold throws
 *   `Clipped area is either empty or outside the resulting image` in all three
 *   engines — while an oversized subject would come back silently truncated. The
 *   element path scrolls and captures beyond the viewport, so it takes these.
 * - **Rotated or skewed.** The reported box is then not the rectangle the element
 *   path captures, and the two disagree by a pixel or two on every edge.
 *
 * The transform test reads the composed matrix rather than the declared string,
 * so a rotation reached through any spelling — `rotate`, `skew`, `matrix`, a
 * shorthand — is caught by one check. It is deliberately conservative:
 * `rotate(90deg)` is axis-aligned in its result but still takes the slow path,
 * because being wrong here rewrites every baseline a user owns.
 *
 * Animation handling is unchanged and still the browser's: the recipe's
 * `animations: 'disabled'` is passed to whichever path runs. It fast-forwards a
 * finite animation to completion — the state a user comes to rest on — and
 * cancels an infinite one to its initial frame. Injected CSS can only pin frame
 * zero, which captures a fade-in at the moment it is invisible.
 *
 * The box is returned rather than left to the caller because the fast path needs
 * it first, and reading it twice would be two protocol round trips for one fact.
 *
 * A subject that occupies no pixels comes back with no bytes and no box, and
 * neither path is asked for a screenshot of it. Both refuse, in their own words
 * and about their own internals: the clip path with `Expected options.clip.height
 * to be greater than 0` and the element path with a visibility complaint. Those
 * sentences describe a rectangle argument, and the reader has a component that
 * rendered nothing — a wrapper whose only child went to a portal, a fixture
 * captured before its content mounted. Naming that is the caller's job, and the
 * caller is the one holding the subject id.
 */
export declare function captureSubject(page: Page, viewport: Viewport, options: ScreenshotOptions & {
    readonly type: 'png';
}): Promise<SubjectCapture>;
/**
 * A subject's pixels, or the fact that it has none.
 *
 * One nullable field would let a caller read the bytes of a subject that was
 * never photographed. Two, moving together, do not.
 */
export type SubjectCapture = {
    readonly bytes: Buffer;
    readonly box: Box;
} | {
    readonly bytes: null;
    readonly box: null;
};
/** A rectangle as Playwright reports it, in CSS pixels relative to the viewport. */
export interface Box {
    readonly x: number;
    readonly y: number;
    readonly width: number;
    readonly height: number;
}
/**
 * A fractional box snapped to the pixel grid the way the element path snaps it:
 * floor the near edge, ceil the far one, and take everything between.
 *
 * This is the union of the pixels the subject touches — what a compositor's
 * damage rect is — and it is the only rounding of the five tried that reproduces
 * the element path's bytes. Rounding the *extent* instead of the far *edge* is
 * the tempting mistake: the two differ whenever a box starts at a fraction, which
 * includes a box of integer size sitting at a fractional offset.
 */
export declare function outward(box: Box): Box;
//# sourceMappingURL=capture.d.ts.map