<html>
<body>
<style>
html {
height: 100%;
overflow: auto;
}
body {
height: 100%;
padding: 0;
margin: 0;
background-color: rgb(244, 245, 249);
display: flex;
flex-direction: column;
justify-content: center;
align-items: center;
overflow: auto;
min-height: 1000px;
}
canvas {
/*border: 3px solid rgba(37, 44, 65,0.25);*/
border-radius: 12px;
box-shadow: 0 0 20px rgba(37, 44, 65, 0.25);
}
#executeButton {
min-width: 100px;
font-size: 24px;
cursor: pointer;
background: linear-gradient(45deg, #fe6b8b 30%, #ff8e53 90%);
border: 0;
border-radius: 3px;
box-shadow: 0 3px 5px 2px rgba(255, 105, 135, 0.3);
color: white;
margin: 24px;
text-align: center;
padding: 4px 0;
user-select: none;
}
#executeButton:active {
border-color: #fff;
box-shadow: inset 0 3px 5px 2px rgba(255, 105, 135, 0.3);
}
</style>
<div id="executeButton">执行</div>
<canvas id="myCanvas" width="800" height="800"></canvas>
<script>
const canvas = document.querySelector("#myCanvas");
const ctx = canvas.getContext("2d");
// 设置线条样式
ctx.lineWidth = 2;
// 起点
const P0 = { x: 0, y: 300 };
// 控制点1
const P1 = { x: 300, y: 300 };
// 控制点2
const P2 = { x: 300, y: 0 };
// 终点
const P3 = { x: 600, y: 0 };
function drawThirdOrderBezier(ctx, P0, P1, P2, P3, duration, color, cb) {
ctx.lineCap = "butt";
ctx.lineJoin = "round";
!duration && (duration = 1000);
!color && (color = "rgba(0,0,255,1)");
let SC1 = { ...P0 };
let SC2 = { ...P0 };
let SC3 = { ...P0 };
let End = { ...P0 };
let startTime;
function calcSC1(t) {
SC1.x = P0.x + (P1.x - P0.x) * t;
SC1.y = P0.y + (P1.y - P0.y) * t;
}
function calcSC3(t) {
SC3.x = P1.x + (P2.x - P1.x) * t;
SC3.y = P1.y + (P2.y - P1.y) * t;
}
function calcSC2(t) {
SC2.x = SC1.x + (SC3.x - SC1.x) * t;
SC2.y = SC1.y + (SC3.y - SC1.y) * t;
}
function calcEnd(t) {
End.x =
Math.pow(1 - t, 3) * P0.x +
3 * t * Math.pow(1 - t, 2) * P1.x +
3 * P2.x * Math.pow(t, 2) * (1 - t) +
Math.pow(t, 3) * P3.x;
End.y =
Math.pow(1 - t, 3) * P0.y +
3 * t * Math.pow(1 - t, 2) * P1.y +
3 * P2.y * Math.pow(t, 2) * (1 - t) +
Math.pow(t, 3) * P3.y;
}
const step = (currentTime) => {
!startTime && (startTime = currentTime);
let elapsedTime = currentTime - startTime;
let progress = Math.min(elapsedTime / duration, 1);
ctx.beginPath();
ctx.moveTo(P0.x, P0.y);
calcEnd(progress);
calcSC1(progress);
calcSC3(progress);
calcSC2(progress);
ctx.bezierCurveTo(SC1.x, SC1.y, SC2.x, SC2.y, End.x, End.y);
ctx.strokeStyle = color;
ctx.stroke();
if (progress < 1) {
requestAnimationFrame(step);
} else {
console.log("Completed");
cb();
}
};
requestAnimationFrame(step);
}
document
.querySelector("#executeButton")
.addEventListener("click", function () {
drawThirdOrderBezier(ctx, P0, P1, P2, P3, 1200, null, function () {
console.log("呵呵");
});
});
</script>
</body>
</html>
三阶贝塞尔曲线路径动画
最后编辑于 ：
?著作权归作者所有,转载或内容合作请联系作者
- 文/潘晓璐 我一进店门，熙熙楼的掌柜王于贵愁眉苦脸地迎上来，“玉大人，你说我怎么就摊上这事?！?“怎么了？”我有些...
- 文/花漫 我一把揭开白布。 她就那样静静地躺着，像睡着了一般。 火红的嫁衣衬着肌肤如雪。 梳的纹丝不乱的头发上，一...
- 文/苍兰香墨 我猛地睁开眼，长吁一口气：“原来是场噩梦啊……” “哼！你这毒妇竟也来了？” 一声冷哼从身侧响起，我...
