我试图将Paper.js中的一个库示例(http://paperjs.org/examples/smoothing/)从PaperScript转换为Javascript。在文档之后,我有
使范围全球化
安装了事件处理程序onFrame和onResize
创建了一个工具并安装了事件处理程序onMouseMove和onMouseDown
但画布没有显示。我只看到几条小蓝线:AFAIK问题出在view.onFrame()函数中,因为至少我可以看到它的形状,但不能与它交互。 JS控制台没有显示任何错误。缺少什么?
// Make the paper scope global, by injecting it into window
paper.install(window);
window.onload = function () {
// Setup directly from canvas id:
paper.setup('myCanvas');
// Create tool
tool = new Tool();
var width, height, center;
var points = 10;
var smooth = true;
var path = new Path();
var mousePos = view.center / 2;
var pathHeight = mousePos.y;
path.fillColor = 'black';
initializePath();
function initializePath() {
center = view.center;
width = view.size.width;
height = view.size.height / 2;
path.segments = [];
path.add(view.bounds.bottomLeft);
for (var i = 1; i < points; i++) {
var point = new Point(width / points * i, center.y);
path.add(point);
}
path.add(view.bounds.bottomRight);
path.fullySelected = true;
}
view.onFrame = function (event) {
pathHeight += (center.y - mousePos.y - pathHeight) / 10;
for (var i = 1; i < points; i++) {
var sinSeed = event.count + (i + i % 10) * 100;
var sinHeight = Math.sin(sinSeed / 200) * pathHeight;
var yPos = Math.sin(sinSeed / 100) * sinHeight + height;
path.segments[i].point.y = yPos;
}
if (smooth)
path.smooth({ type: 'continuous' });
}
tool.onMouseMove = function (event) {
mousePos = event.point;
}
tool.onMouseDown = function (event) {
smooth = !smooth;
if (!smooth) {
// If smooth has been turned off, we need to reset
// the handles of the path:
for (var i = 0, l = path.segments.length; i < l; i++) {
var segment = path.segments[i];
segment.handleIn = segment.handleOut = null;
}
}
}
// Reposition the path whenever the window is resized:
view.onResize = function (event) {
initializePath();
}
}
答案 0 :(得分:1)
找到解决方案(感谢Paper.js Google Group的StefanKrüger):
var mousePos = view.center / 2;
应该是:
var mousePos = view.center.divide(2);
事实是应该使用Math函数而不是Point和Size对象的运算符......我没有意识到view.center是一个Point对象:http://paperjs.org/reference/view/#center