使用two.js生成的卫星环绕动画效果
jjfat 11年前
two.js是一个帮助你实现绘图和动画效果的类库，同时支持三种前端绘图实现：
- webgl
- svg
- 2d画布
使用这个类库，可以方便的支持这三种不同的实现，你只需要设置参数：Two.Types.canvas, Two.Types.svg, or Two.Types.webgl
相关JS代码如下：
var el = document.getElementById("main"), two = new Two({ width: '800', height: '600' }); two.appendTo(el); var earthAngle = 0, moonAngle = 0, distance = 30, radius = 50, padding = 100, orbit = 200, offset = orbit + padding, orbits = two.makeGroup(); var earthOrbit = two.makeCircle(offset, offset, orbit); earthOrbit.noFill(); earthOrbit.linewidth = 2; earthOrbit.stroke = "#EFEFEF"; orbits.add(earthOrbit); two.update(); var pos = getPositions(earthAngle++, orbit), earth = two.makeCircle(pos.x + offset, pos.y + offset, radius); earth.stroke = "#444"; earth.linewidth = 3; earth.fill = "#CCCCCC"; var moonOrbit = two.makeCircle(earth.translation.x, earth.translation.y, radius + distance); moonOrbit.noFill(); moonOrbit.linewidth = 2; moonOrbit.stroke = "#ccc"; orbits.add(moonOrbit); var pos = getPositions(moonAngle, radius + distance), moon = two.makeCircle(earth.translation.x + pos.x, earth.translation.y + pos.y, radius / 4); moonAngle += 5; moon.fill = "#474747"; two.bind("update", function (frameCount) { var pos = getPositions(earthAngle++, orbit); earth.translation.x = pos.x + offset; earth.translation.y = pos.y + offset; var moonPos = getPositions(moonAngle, radius + distance); moon.translation.x = earth.translation.x + moonPos.x; moon.translation.y = earth.translation.y + moonPos.y; moonAngle += 5; moonOrbit.translation.x = earth.translation.x; moonOrbit.translation.y = earth.translation.y; }); function getPositions(angle, orbit) { return { x: Math.cos(angle * Math.PI / 180) * orbit, y: Math.sin(angle * Math.PI / 180) * orbit }; } two.play();