前言

基于原生JavaScript, 在使用three.js的raycaster模拟瞄准及射击时用到.

一、代码

const obj = window;let eventList = [];
let isDouble = false;obj.addEventListener("mouseup", e => { mouseUp(e) });
obj.addEventListener("mousedown", e => { mouseDown(e) });
obj.addEventListener("mousemove", e => { mouseMove(e) });obj.addEventListener("contextmenu", e => { e.preventDefault() }); // 阻止浏览器默认右键菜单function mouseDown(e) {if (e.button === 1) return; // 中键eventList.push(e.button); // e.button 0左键 1中键 2右键judge();
}function mouseUp(e) {if (e.button === 1) return;if (eventList.length === 2) isDouble = false;remove(e.button);
}function mouseMove(e) {if(!isDouble) return;if(eventList[0] === 0) {console.log('left-right-moving');} else {console.log('right-left-moving');}
}function remove(val) {if (eventList[0] == val) {eventList.shift();return;}if (eventList[1] == val) {eventList.pop();return;}
}function judge() {if (eventList.length === 2) {if (eventList[0] === 0) { // 数组全等不区分元素顺序console.log('left-right');} else {console.log('right-left');}isDouble = true;}
}

总结