SWDiamond Class Reference

/*
File: swDiamond.js
Date: 2026-04-23
Author: klp + GitHub Copilot
Workspace: SketchWaveTNT2026-04-21-Stg8
Purpose: SWDiamond class for SketchWaveJS
Comment(s):

SWDiamond: A rhombus (diamond) shape extending SWKite.
A rhombus is a special case of a kite where diagTop === diagBottom === diagY,
making all four sides equal. Passes diagY as both diagTop and diagBottom to SWKite.

All four sides are equal; the shape is a square rotated 45° when diagX === diagY.
Breathing and rotation are inherited from SWKite.

Defaults: white fill, dark gray stroke, aspect ratio 1.5 (diagX=9, diagY=6).

TEACHABLE MOMENT (2026-04-24): Refactored from standalone to extend SWKite because
geometrically a rhombus is a special case of a kite, not the reverse.

Dependencies: p5.js, SWColor, SWPoint, SWGrid, SWSinusoid, SWKite
*/

console.log("[swDiamond.js] SWDiamond class loaded.");

class SWDiamond extends SWKite {
    /**
     * @param {SWPoint} center     - Center point (SWPoint instance)
     * @param {number}  diagX      - Half-length of horizontal diagonal (user units)
     * @param {number}  diagY      - Half-length of vertical diagonal (user units)
     *                               Sets both diagTop and diagBottom for rhombus constraint.
     * @param {SWColor} fillColor  - Fill color (SWColor instance)
     * @param {Object}  [options]
     *   strokeColor  : SWColor  — border color (optional)
     *   strokeWeight : number   — border thickness (default 3)
     *   showCenter   : boolean  — show center SWPoint (default false)
     *   rotation     : number   — initial rotation in degrees CCW (default 0)
     */
    constructor(center, diagX, diagY, fillColor, options = {}) {
        // A rhombus is a kite where diagTop === diagBottom === diagY
        super(center, diagX, diagY, diagY, fillColor, options);
    }//end constructor

    // ── diagY compatibility getter / setter ───────────────────────────────

    get diagY() { return this.diagTop; }
    set diagY(v) { this.diagTop = v; this.diagBottom = v; }
    get originalDiagY() { return this.originalDiagTop; }
    set originalDiagY(v) { this.originalDiagTop = v; this.originalDiagBottom = v; }

    // ── Rhombus-specific computed properties ──────────────────────────────

    /** Side length — all four sides equal; alias for topSideLength */
    get sideLength() { return this.topSideLength; }//end sideLength

    /** Aspect ratio: diagX / diagY */
    get aspectRatio() {
        return this.diagY !== 0 ? this.diagX / this.diagY : 0;
    }//end aspectRatio

    /** Diagonal ratio: diagX / diagY (alias for aspectRatio) */
    get diagonalRatio() { return this.aspectRatio; }//end diagonalRatio

    /** isSquare — true when diagX ≈ diagY (within 1% tolerance) */
    get isSquare() {
        if (this.diagY === 0) return false;
        return Math.abs(this.diagX - this.diagY) / Math.max(this.diagX, this.diagY) < 0.01;
    }//end isSquare

    // ── Inherited from SWKite ─────────────────────────────────────────────
    // draw(), drawOnGrid(), drawVerticesOnGrid()
    // breathe(), reset(), getVerticesUserCoords()
    // setShowCenter(), centerContainsPoint()
    // area, perimeter, isRhombus, topSideLength, bottomSideLength

    toString() {
        return `SWDiamond(center: (${this.center.x.toFixed(2)}, ${this.center.y.toFixed(2)}), ` +
               `diagX: ${this.diagX.toFixed(2)}, diagY: ${this.diagY.toFixed(2)}, ` +
               `area: ${this.area.toFixed(2)}, rotation: ${this.rotation.toFixed(1)}°)`;
    }//end toString
}//end class SWDiamond

// export default SWDiamond;