tinsel.js

let startX = 0;
		let startY = 0;
		const mainTree = document.querySelector(".main-tree");
		function startTinsel(e) {
			if (decSelector.value === "tinsel") {
				startX = e.clientX - 58;
				startY = e.clientY - 82;
			}
		}
		function endTinsel(e) {
			if (decSelector.value === "tinsel") {
				const tinsel = document.createElementNS("http://www.w3.org/2000/svg", 'path');
				let endX = e.clientX - 58;
				let endY = e.clientY - 82;
				tinsel.classList.add("tinsel");
				tinsel.setAttribute("d", `M ${startX},${startY} C ${startX},${startY+18} ${endX},${endY+18} ${endX},${endY} `);
				mainTree.appendChild(tinsel);
			}
		}
		triangles.forEach(triangle => triangle.addEventListener('mousedown', startTinsel));
		triangles.forEach(triangle => triangle.addEventListener('mouseup', endTinsel));