gateRect(wireIndex, operationIndex, width=1, height=1) {
        let op = this.opRect(operationIndex);
        let wire = this.wireRect(wireIndex);
        let r = new Rect(
            op.center().x - Config.GATE_RADIUS,
            wire.center().y - Config.GATE_RADIUS,
            2*Config.GATE_RADIUS + (width-1)*Config.WIRE_SPACING,
            2*Config.GATE_RADIUS + (height-1)*Config.WIRE_SPACING);

        return new Rect(Math.round(r.x - 0.5) + 0.5, Math.round(r.y - 0.5) + 0.5, Math.round(r.w), Math.round(r.h));
    }
@param {!int} wireIndex
@param {!int} operationIndex
@param {!int=} width
@param {!int=} height