如何使用JavaScript编写脚本以在SVG中线性移动形状。我想使用requestanimframe。
这里有一个使用canvas的示例。我只想做同样的事情,但是使用svg。
脚本获取画布的上下文,然后使用JavaScript绘制具有上下文属性的形状。然后,它以线性运动方式管理画布上形状的动画。我只想将SVG用于形状,而不是画布上下文属性。
<!DOCTYPE HTML>
<html>
<head>
<style>
body {
margin: 0px;
padding: 0px;
}
#myCanvas {
border: 1px solid #9C9898;
}
</style>
<script>
window.requestAnimFrame = (function(callback){
return window.requestAnimationFrame ||
window.webkitRequestAnimationFrame ||
window.mozRequestAnimationFrame ||
window.oRequestAnimationFrame ||
window.msRequestAnimationFrame ||
function(callback){
window.setTimeout(callback, 1000 / 60);
};
})();
function animate(lastTime, myRectangle){
var canvas = document.getElementById("myCanvas");
var context = canvas.getContext("2d");
// update
var date = new Date();
var time = date.getTime();
var timeDiff = time - lastTime;
var linearSpeed = 100; // pixels / second
var linearDistEachFrame = linearSpeed * timeDiff / 1000;
var currentX = myRectangle.x;
if (currentX < canvas.width - myRectangle.width - myRectangle.borderWidth / 2) {
var newX = currentX + linearDistEachFrame;
myRectangle.x = newX;
}
lastTime = time;
// clear
context.clearRect(0, 0, canvas.width, canvas.height);
// draw
context.beginPath();
context.rect(myRectangle.x, myRectangle.y, myRectangle.width, myRectangle.height);
context.fillStyle = "#8ED6FF";
context.fill();
context.lineWidth = myRectangle.borderWidth;
context.strokeStyle = "black";
context.stroke();
// request new frame
requestAnimFrame(function(){
animate(lastTime, myRectangle);
});
}
window.onload = function(){
var myRectangle = {
x: 0,
y: 50,
width: 100,
height: 50,
borderWidth: 5
};
var date = new Date();
var time = date.getTime();
animate(time, myRectangle);
};
</script>
</head>
<body onmousedown="return false;">
<canvas id="myCanvas" width="578" height="200">
</canvas>
</body>
requestAnimationFrame
? - robertc