为什么我的程序不能绘制任何东西？

Question

我制作了这个程序，希望能够根据滑块绘制一个很酷的形状。问题是，除滑块之外没有任何东西可以显示出来！为什么是这样？

var aslider, lslider, sslider, newx, newy; 
 
function setup() { 
 
    createCanvas(300,300); 
 
    aslider = createSlider(1,359,17); 
 
    lslider = createSlider(1,50,10); 
 
    sslider = createSlider(1,50,20); 
 
} 
 

 
function draw() { 
 
    var angle = aslider.value(); 
 
    var length = lslider.value(); 
 
    var size = sslider.value(); 
 
    var startx = width/2; 
 
    var starty = height/2; 
 
    var radians = angle * (Math.PI/180); 
 
    for (var i = 0; i++; i < size) { 
 
    newx = startx * Math.sin(radians) + starty * Math.cos(radians); 
 
    newy = startx * Math.sin(radians) + starty * -Math.cos(radians); 
 
    line(startx, starty, newx, newy); 
 
    startx = newx; 
 
    starty = newy; 
 
    } 
 
}

Answer 1

您的循环是错误的。它应该是

for (var i = 0; i < size; i++) 

我测试了它在这里：http://codepen.io/eerk/pen/wgOZVW?editors=1010