/** Degrees → radians in the canonical (0° = up, clockwise) frame. */
export declare function polarAngleToRadians(angleDeg: number): number;
/**
 * Convert a polar coordinate to cartesian, using the canonical convention
 * (0° = up, clockwise positive).
 */
export declare function polarToCartesian(cx: number, cy: number, radius: number, angleDeg: number): {
    x: number;
    y: number;
};
/**
 * Inverse of {@link polarToCartesian}: given a pixel relative to a center,
 * return its angle (canonical: 0° = up, clockwise, normalized to [0, 360)) and
 * radius. Used by radial/radar hit-testing.
 */
export declare function angleFromPoint(cx: number, cy: number, px: number, py: number): {
    angleDeg: number;
    radius: number;
};
/**
 * Whether a point falls inside an annular sector (arc slice): between
 * [innerRadius, outerRadius] and within the [startAngle, endAngle] sweep.
 * Angles use the canonical convention. `startAngle`/`endAngle` are normalized
 * so wrap-around sweeps (e.g. 350° → 10°) are handled.
 */
export declare function isPointInSlice(cx: number, cy: number, px: number, py: number, innerRadius: number, outerRadius: number, startAngle: number, endAngle: number): boolean;
/** True if `angleDeg` lies within the clockwise sweep from start→end. */
export declare function angleInSweep(angleDeg: number, startAngle: number, endAngle: number): boolean;