import type { FnN2 } from "@thi.ng/api";
import type { BlendFnF, BlendFnI, Color, ReadonlyColor } from "./api.js";
export declare const ZERO: FnN2;
export declare const ONE: FnN2;
export declare const A: FnN2;
export declare const B: FnN2;
export declare const ONE_MINUS_A: FnN2;
export declare const ONE_MINUS_B: FnN2;
/**
 * General Porter-Duff HOF operator for **pre-multiplied** RGBA. Use
 * {@link porterDuffP} for applying pre & post multiplication of input and
 * output colors. The returned function takes 3 arguments:
 *
 * - `out` color (if `null` or `undefined` writes to `dest`)
 * - `src` color (background)
 * - `dest` color (foreground)
 *
 * Unlike the packed int version, here only the alpha channel of the result
 * color will be clamped. RGB components can potentially go out of `[0,1]` range
 * (depending on coefficient functions used).
 *
 * Reference: https://keithp.com/~keithp/porterduff/p253-porter.pdf
 *
 * @param fa - fn for src coeff
 * @param fb - fn for dest coeff
 */
export declare const porterDuff: (fa: FnN2, fb: FnN2) => BlendFnF;
export declare const porterDuffInt: (fa: FnN2, fb: FnN2) => BlendFnI;
/**
 * Higher order function. Takes existing PD operator and returns
 * function which accepts same args as the operator, but pre-multiplies
 * alpha for both input colors and then returns post-multiplied alpha
 * output.
 *
 * @param mode -
 */
export declare const porterDuffP: (mode: BlendFnF) => BlendFnF;
/**
 * Like {@link porterDuffP}, but for packed integers.
 *
 * @param mode -
 */
export declare const porterDuffPInt: (mode: BlendFnI) => BlendFnI;
/**
 * Porter-Duff operator. None of the terms are used. Always results in
 * `[0,0,0,0]`.
 *
 * {@link porterDuff}
 *
 * @param out -
 * @param src -
 * @param dest -
 */
export declare const CLEAR_F: (out: Color, _: ReadonlyColor, dest: ReadonlyColor) => Color;
/**
 * Porter-Duff operator. Always results in `src` color, `dest` ignored.
 *
 * {@link porterDuff}
 */
export declare const SRC_F: BlendFnF;
/**
 * Porter-Duff operator. Always results in `dest` color, `src` ignored.
 *
 * {@link porterDuff}
 */
export declare const DEST_F: BlendFnF;
/**
 * Porter-Duff operator. The source color is placed over the destination
 * color.
 *
 * {@link porterDuff}
 */
export declare const SRC_OVER_F: BlendFnF;
/**
 * Porter-Duff operator. The destination color is placed over the source
 * color.
 *
 * {@link porterDuff}
 */
export declare const DEST_OVER_F: BlendFnF;
/**
 * Porter-Duff operator. The source that overlaps the destination,
 * replaces the destination.
 *
 * {@link porterDuff}
 */
export declare const SRC_IN_F: BlendFnF;
/**
 * Porter-Duff operator. The destination that overlaps the source,
 * replaces the source.
 *
 * {@link porterDuff}
 */
export declare const DEST_IN_F: BlendFnF;
/**
 * Porter-Duff operator. The source that does not overlap the
 * destination replaces the destination.
 *
 * {@link porterDuff}
 */
export declare const SRC_OUT_F: BlendFnF;
/**
 * Porter-Duff operator. The destination that does not overlap the
 * source replaces the source.
 *
 * {@link porterDuff}
 */
export declare const DEST_OUT_F: BlendFnF;
/**
 * Porter-Duff operator. The source that overlaps the destination is
 * composited with the destination.
 *
 * {@link porterDuff}
 */
export declare const SRC_ATOP_F: BlendFnF;
/**
 * Porter-Duff operator. The destination that overlaps the source is
 * composited with the source and replaces the destination.
 *
 * {@link porterDuff}
 */
export declare const DEST_ATOP_F: BlendFnF;
/**
 * Porter-Duff operator. The non-overlapping regions of source and
 * destination are combined.
 *
 * {@link porterDuff}
 */
export declare const XOR_F: BlendFnF;
/**
 * Porter-Duff operator. Source & destination regions are added.
 */
export declare const PLUS_F: BlendFnF;
export declare const CLEAR_I: FnN2;
/**
 * Porter-Duff operator for packed ints. Always results in `src` color, `dest` ignored.
 *
 * {@link porterDuff}
 */
export declare const SRC_I: FnN2;
/**
 * Porter-Duff operator for packed ints. Always results in `dest` color, `src` ignored.
 *
 * {@link porterDuff}
 */
export declare const DEST_I: FnN2;
/**
 * Porter-Duff operator for packed ints. The source color is placed over the destination
 * color.
 *
 * {@link porterDuff}
 */
export declare const SRC_OVER_I: FnN2;
/**
 * Porter-Duff operator for packed ints. The destination color is placed over the source
 * color.
 *
 * {@link porterDuff}
 */
export declare const DEST_OVER_I: FnN2;
/**
 * Porter-Duff operator for packed ints. The source that overlaps the destination,
 * replaces the destination.
 *
 * {@link porterDuff}
 */
export declare const SRC_IN_I: FnN2;
/**
 * Porter-Duff operator for packed ints. The destination that overlaps the source,
 * replaces the source.
 *
 * {@link porterDuff}
 */
export declare const DEST_IN_I: FnN2;
/**
 * Porter-Duff operator for packed ints. The source that does not overlap the
 * destination replaces the destination.
 *
 * {@link porterDuff}
 */
export declare const SRC_OUT_I: FnN2;
/**
 * Porter-Duff operator for packed ints. The destination that does not overlap the
 * source replaces the source.
 *
 * {@link porterDuff}
 */
export declare const DEST_OUT_I: FnN2;
/**
 * Porter-Duff operator for packed ints. The source that overlaps the destination is
 * composited with the destination.
 *
 * {@link porterDuff}
 */
export declare const SRC_ATOP_I: FnN2;
/**
 * Porter-Duff operator for packed ints. The destination that overlaps the source is
 * composited with the source and replaces the destination.
 *
 * {@link porterDuff}
 */
export declare const DEST_ATOP_I: FnN2;
/**
 * Porter-Duff operator for packed ints. The non-overlapping regions of source and
 * destination are combined.
 *
 * {@link porterDuff}
 */
export declare const XOR_I: FnN2;
/**
 * Porter-Duff operator for packed ints. Source & destination regions
 * are added.
 */
export declare const PLUS_I: FnN2;
/**
 * Porter-Duff darken modifier. Multiplies RGB components of `src` with
 * `t`. Alpha remains unchanged. Writes results to `out`, or if `null`
 * modifies `src` in-place.
 *
 * @param out -
 * @param src -
 * @param t -
 */
export declare const darken: (out: Color | null, src: ReadonlyColor, t: number) => Color;
/**
 * Porter-Duff dissolve modifier. Multiplies all components of `src` with `t`.
 * Clamps alpha to `[0,1]` range, RGB unclamped. Writes results to `out`, or if
 * `null` modifies `src` in-place.
 *
 * @param out -
 * @param src -
 * @param t -
 */
export declare const dissolve: (out: Color | null, src: ReadonlyColor, t: number) => Color;
/**
 * Porter-Duff opacity modifier. Multiplies alpha component of `src` with `t`,
 * clamped to `[0,1]` range. Writes results to `out`, or if `null` modifies
 * `src` in-place.
 *
 * @param out -
 * @param src -
 * @param t -
 */
export declare const opacity: (out: Color | null, src: ReadonlyColor, t: number) => Color;
/**
 * Porter-Duff darken modifier for packed ints. Multiplies RGB components of
 * `src` with `t` (`[0,1]` range).
 *
 * @param src -
 * @param t -
 */
export declare const darkenInt: FnN2;
/**
 * Porter-Duff dissolve modifier for packed ints. Multiplies all
 * components of `src` with `t` (`[0,1]` range).
 *
 * @param src -
 * @param t -
 */
export declare const dissolveInt: FnN2;
/**
 * Porter-Duff opacity modifier for packed ints. Multiplies alpha component of
 * `src` with `t` (`[0,1]` range).
 *
 * @param src -
 * @param t -
 */
export declare const opacityInt: FnN2;
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