'diamond':`M ${this.cx}${this.cy} m 0 ${-0.5*this.size} l ${0.5*this.size}${0.5*this.size} l ${-0.5*this.size}${0.5*this.size} l ${-0.5*this.size}${-0.5*this.size} Z`,
'rectangle':`M ${this.cx}${this.cy} m ${-0.5*this.size}${-0.5*this.size} h ${this.size} v ${this.size} h ${-this.size} Z`,
'triangle':`M ${this.cx}${this.cy} m 0 ${-0.5*this.size} l ${0.5*this.size}${this.size} h ${-this.size} Z`