1
我想動畫出現在使用弧方法在我的畫布中的曲線出現的許多圓圈,出現一個奇怪的切線,並不應該是這樣,因爲我沒有包含任何代碼該行只出現在圓圈中。有人可以向我解釋爲什麼這行出現?這裏是所有的代碼奇怪的線出現在畫布上
window.requestAnimFrame = (function() {
/* window.requestAnimationFrame ||
window.webkitRequestAnimationFrame ||
window.mozRequestAnimationFrame ||
window.oRequestAnimationFrame ||
window.msRequestAnimationFrame || */
return function(callback) {
window.setTimeout(callback, 1000);
};
})();
var graph = {
x: 0,
y: 0,
incur: 0.6,
canvas: document.getElementsByTagName('canvas')[0],
ctx: null,
ratio: 640/1136,
init: function() {
graph.ctx = graph.canvas.getContext('2d');
graph.resize();
},
resize: function() {
graph.canvas.height = window.innerHeight;
graph.canvas.width = graph.ratio * window.innerHeight;
console.log("asd")
},
loop: function() {
graph.incur += 0.6
window.requestAnimFrame(graph.loop);
console.log(graph.incur)
graph.x += graph.incur
graph.y += graph.incur * graph.incur
//graph.draw.clear();
graph.draw.circle(graph.x, graph.y, 10, "#FF0000")
}
}
graph.draw = {
clear: function() {
graph.ctx.clearRect(0, 0, graph.canvas.width, graph.canvas.height)
},
circle: function(x, y, r, col) {
graph.ctx.fillStyle = col;
graph.ctx.arc(x, y, r, 0, Math.PI * 2, true)
graph.ctx.fill();
}
}
graph.init();
window.addEventListener("resize", graph.resize);
graph.loop();
canvas {
display: block;
margin: 0 auto;
background-color: #808080;
}
<canvas>
</canvas>
這裏是一個怪異線的截屏的鏈接:
你可能想'的moveTo(X + arc.radius,Y)'來避免繪製圓弧的中心和第一點之間畫一條線在圓弧(3點鐘),這將是可見的'stroke()'你的:https://jsfiddle.net/ovqyqcsh/修正:https://jsfiddle.net/ovqyqcsh/1/ – Kaiido
@Kaiido好點!編輯。 – Gerrit0