非常简单的帆布漆作品无法在Chrome

我被this script这是从http://www.robodesign.ro/coding/canvas-paint/20090423/非常简单的帆布漆作品无法在Chrome

修改它非常好外汇10，但不是在所有的Chrome。

我摆脱了镀铬通过交换OFFSETX和layerX警告有关弃用event.layerX/Y，但它仍然没有吸取。

必须是非常简单的东西。
UPDATE：它是 - 评了两次context.moveTo(ev._x, ev._y);的伎俩

<!DOCTYPE html> 
<html lang="en"> 
    <head> 
    <meta charset="utf-8"> 
    <title>Paint</title> 
    <style type="text/css"><!-- 
     #container { position: relative; } 
     #imageView { border: 1px solid #000; } 
    --></style> 
    </head> 
    <body BGCOLOR="#CCFFFF"> 

    <div id="container"> 
     <canvas id="imageView" width="700" height="643" margin: 0 auto> 
     <p>Unfortunately, your browser is currently unsupported by our web 
     application. We are sorry for the inconvenience. Please use one of the 
     supported browsers listed below, or draw the image you want using an 
     offline tool.</p> 
     <p>Supported browsers: <a href="http://www.opera.com">Opera</a>, <a 
      href="http://www.mozilla.com">Firefox</a>, <a 
      href="http://www.apple.com/safari">Safari</a>, and <a 
      href="http://www.konqueror.org">Konqueror</a>.</p> 
     </canvas> 
    </div> 

    <script type="text/javascript"> 
/* © 2009 ROBO Design 
* http://www.robodesign.ro 
*/ 

// Keep everything in anonymous function, called on window load. 
if(window.addEventListener) { 
window.addEventListener('load', function() { 
    var canvas, context, tool; 

    function init() { 
    // Find the canvas element. 
    canvas = document.getElementById('imageView'); 
    if (!canvas) { 
     alert('Error: I cannot find the canvas element!'); 
     return; 
    } 

    if (!canvas.getContext) { 
     alert('Error: no canvas.getContext!'); 
     return; 
    } 

    // Get the 2D canvas context. 
    context = canvas.getContext('2d'); 
    if (!context) { 
     alert('Error: failed to getContext!'); 
     return; 
    } 

    var img=new Image(); 
    img.onload = function(){ 
    context.drawImage(img,0,0); 
    }; 
    img.src=" PainDiagram.png"; 

    // Pencil tool instance. 
    tool = new tool_pencil(); 

    // Attach the mousedown, mousemove and mouseup event listeners. 
    canvas.addEventListener('mousedown', ev_canvas, false); 
    canvas.addEventListener('mousemove', ev_canvas, false); 
    canvas.addEventListener('mouseup', ev_canvas, false); 
    } 

    // This painting tool works like a drawing pencil which tracks the mouse 
    // movements. 
    function tool_pencil() { 
    var tool = this; 
    this.started = false; 

    // This is called when you start holding down the mouse button. 
    // This starts the pencil drawing. 
    this.mousedown = function (ev) { 
     context.beginPath(); 
     context.lineWidth = 5; 
     context.lineCap = "round"; 
     context.globalAlpha=0.01; 
     context.shadowColor="red"; 
     context.shadowBlur=10; 
     context.strokeStyle = "red"; // line color 
     context.moveTo(ev._x, ev._y); 
     tool.started = true; 
    }; 

    // This function is called every time you move the mouse. Obviously, it only 
    // draws if the tool.started state is set to true (when you are holding down 
    // the mouse button). 
    this.mousemove = function (ev) { 
     if (tool.started) { 
     //var p = context.getImageData(ev._x, ev._y, 1, 1).data; 
     //if(p[0]==255 && p[1]==204 && p[2]==153){ 
      context.moveTo(ev._x, ev._y); 
      context.lineTo(ev._x, ev._y); 
      context.stroke(); 
     //} 
     } 
    }; 

    // This is called when you release the mouse button. 
    this.mouseup = function (ev) { 
     if (tool.started) { 
     tool.mousemove(ev); 
     tool.started = false; 
     } 
    }; 
    } 

    // The general-purpose event handler. This function just determines the mouse 
    // position relative to the canvas element. 


    function ev_canvas (ev) { 
    if (ev.offsetX || ev.offsetX == 0) { // Opera and WebKit 
     ev._x = ev.offsetX; 
     ev._y = ev.offsetY; 
    } 
    else if (ev.layerX || ev.layerX == 0) { // Firefox 
     ev._x = ev.layerX; 
     ev._y = ev.layerY; 
    } 

    // Call the event handler of the tool. 
    var func = tool[ev.type]; 
    if (func) { 
     func(ev); 
    } 
    } 

    init(); 

}, false); } 

// vim:set spell spl=en fo=wan1croql tw=80 ts=2 sw=2 sts=2 sta et ai cin fenc=utf-8 ff=unix: 

    </script> 
    </body> 
</html>

来源

2012-03-14 mplungjan

从this.mousemove删除线context.moveTo(ev._x, ev._y);。

moveTo()方法创建一个新的子路径，因此您要告诉画布将描边应用于长度为零像素的路径。 Firefox显然支持这一点。请参阅canvas documentation了解更多信息。

来源

2012-03-15 22:25:32 Xenethyl

你刚刚错过了一个赏金。谢谢！ – mplungjan 2012-03-16 07:48:16

没问题。很高兴帮助！ :) – Xenethyl 2012-03-16 12:02:07

非常简单的帆布漆作品无法在Chrome

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