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Javascript HTML画布艺术，从草图生成坐标数据

javascript canvas html5-canvas

Javascript HTML画布艺术，从草图生成坐标数据,javascript,canvas,html5-canvas,Javascript,Canvas,Html5 Canvas,我使用HTML5画布绘制心形： <!DOCTYPE HTML> <html> <head> <style> body { margin: 0px; padding: 0px; } </style> </head> <body> <canvas id="myCanvas" width="1366" height="60

我使用HTML5画布绘制心形：

<!DOCTYPE HTML>
<html>
  <head>
    <style>
      body {
        margin: 0px;
        padding: 0px;
      }
    </style>
  </head>
  <body>
    <canvas id="myCanvas" width="1366" height="600"></canvas>
    <script>
     var heart = [
        [707,359],[707,359],[707,359],[707,359],[708,358],[711,354],[713,352],[714,348],[716,345],[720,335],
        [721,334],[722,333],[724,332],[725,330],[727,327],[731,322],[734,320],[737,318],[740,314],[743,312],
        [745,311],[749,309],[753,308],[757,306],[761,303],[764,302],[767,302],[771,301],[774,301],[778,301],
        [783,301],[786,301],[790,300],[796,300],[801,300],[805,300],[809,300],[811,300],[815,302],[817,303],
        [820,305],[822,306],[824,307],[827,309],[830,311],[834,313],[836,314],[838,316],[841,318],[844,321],
        [845,324],[847,326],[849,328],[852,332],[853,334],[855,336],[857,337],[858,339],[860,341],[862,345],
        [863,349],[863,352],[864,356],[864,359],[865,362],[866,364],[868,368],[869,372],[870,377],[871,381],
        [872,384],[872,388],[872,392],[872,395],[872,399],[872,401],[872,405],[872,409],[871,412],[870,417],
        [869,419],[869,422],[867,427],[866,429],[865,434],[863,438],[862,442],[861,443],[860,445],[857,448],
        [854,451],[852,454],[849,456],[846,459],[843,460],[836,466],[835,466],[833,467],[821,475],[820,477],
        [819,478],[817,481],[815,483],[811,486],[808,487],[803,491],[802,491],[800,492],[795,493],[791,497],
        [789,498],[786,498],[780,502],[772,507],[770,510],[767,511],[762,516],[758,520],[756,524],[753,527],
        [750,529],[746,532],[741,534],[736,537],[732,538],[731,539],[735,537],[735,537],[735,537],[730,543],
        [729,546],[727,551],[726,553],[723,555],[721,558],[715,568],[714,570],[714,572],[713,575],[708,585],
        [708,586],[707,586],[704,583],[704,359],[704,359],[700,356],[698,352],[697,350],[696,345],[694,343],
        [693,340],[690,335],[688,335],[687,334],[683,332],[681,329],[677,326],[675,323],[672,319],[669,314],
        [668,312],[663,310],[660,310],[656,310],[653,309],[647,309],[644,308],[642,308],[637,307],[632,303],
        [628,301],[624,297],[621,297],[619,297],[616,297],[616,298],[616,299],[614,300],[620,302],[620,302],
        [620,302],[618,302],[612,302],[605,302],[598,302],[596,303],[594,305],[592,307],[590,309],[586,310],
        [583,313],[582,315],[579,319],[576,320],[573,323],[571,325],[569,327],[563,329],[560,333],[558,336],
        [557,338],[556,341],[555,343],[551,346],[549,349],[549,354],[549,357],[547,361],[546,367],[543,372],
        [542,375],[541,380],[540,381],[540,382],[540,382],[540,382],[540,382],[540,384],[540,386],[540,389],
        [539,391],[539,394],[539,398],[539,404],[539,408],[539,412],[539,416],[540,423],[542,428],[544,433],
        [549,436],[552,439],[555,442],[557,445],[560,448],[562,452],[564,459],[565,461],[560,449],[560,449],
        [561,450],[571,458],[580,466],[584,469],[587,473],[589,476],[591,477],[575,466],[575,466],[575,466],
        [576,466],[582,471],[587,475],[590,477],[594,481],[598,484],[601,489],[604,491],[607,495],[611,496],
        [617,498],[622,500],[626,501],[629,504],[633,508],[636,510],[642,515],[650,522],[651,525],[655,528],
        [657,529],[660,530],[663,530],[667,533],[671,534],[676,536],[679,537],[681,539],[683,540],[676,536],
        [676,536],[676,536],[679,539],[684,546],[687,548],[689,551],[692,554],[696,558],[698,563],[701,567],
        [702,571],[704,574],[705,577],[706,579],[707,580],[708,582],[709,586]
    ];
    var canvas = document.getElementById('myCanvas');
    var context = canvas.getContext('2d');

    context.beginPath();
    context.moveTo(707, 359);
    for(var i = 1; i < (heart.length - 1) ; i++){
        context.lineTo(heart[i][0], heart[i][1])

    }
    // line 1


    context.lineWidth = 2;
    context.strokeStyle = 'blue';
    context.stroke();
    </script>
  </body>
</html>


身体{
边际：0px；
填充：0px；
}
心脏变异=[
[707,359],[707,359],[707,359],[707,359],[708,358],[711,354],[713,352],[714,348],[716,345],[720,335],
[721,334],[722,333],[724,332],[725,330],[727,327],[731,322],[734,320],[737,318],[740,314],[743,312],
[745,311],[749,309],[753,308],[757,306],[761,303],[764,302],[767,302],[771,301],[774,301],[778,301],
[783,301],[786,301],[790,300],[796,300],[801,300],[805,300],[809,300],[811,300],[815,302],[817,303],
[820,305],[822,306],[824,307],[827,309],[830,311],[834,313],[836,314],[838,316],[841,318],[844,321],
[845,324],[847,326],[849,328],[852,332],[853,334],[855,336],[857,337],[858,339],[860,341],[862,345],
[863,349],[863,352],[864,356],[864,359],[865,362],[866,364],[868,368],[869,372],[870,377],[871,381],
[872,384],[872,388],[872,392],[872,395],[872,399],[872,401],[872,405],[872,409],[871,412],[870,417],
[869,419],[869,422],[867,427],[866,429],[865,434],[863,438],[862,442],[861,443],[860,445],[857,448],
[854,451],[852,454],[849,456],[846,459],[843,460],[836,466],[835,466],[833,467],[821,475],[820,477],
[819,478],[817,481],[815,483],[811,486],[808,487],[803,491],[802,491],[800,492],[795,493],[791,497],
[789,498],[786,498],[780,502],[772,507],[770,510],[767,511],[762,516],[758,520],[756,524],[753,527],
[750,529],[746,532],[741,534],[736,537],[732,538],[731,539],[735,537],[735,537],[735,537],[730,543],
[729,546],[727,551],[726,553],[723,555],[721,558],[715,568],[714,570],[714,572],[713,575],[708,585],
[708,586],[707,586],[704,583],[704,359],[704,359],[700,356],[698,352],[697,350],[696,345],[694,343],
[693,340],[690,335],[688,335],[687,334],[683,332],[681,329],[677,326],[675,323],[672,319],[669,314],
[668,312],[663,310],[660,310],[656,310],[653,309],[647,309],[644,308],[642,308],[637,307],[632,303],
[628,301],[624,297],[621,297],[619,297],[616,297],[616,298],[616,299],[614,300],[620,302],[620,302],
[620,302],[618,302],[612,302],[605,302],[598,302],[596,303],[594,305],[592,307],[590,309],[586,310],
[583,313],[582,315],[579,319],[576,320],[573,323],[571,325],[569,327],[563,329],[560,333],[558,336],
[557,338],[556,341],[555,343],[551,346],[549,349],[549,354],[549,357],[547,361],[546,367],[543,372],
[542,375],[541,380],[540,381],[540,382],[540,382],[540,382],[540,382],[540,384],[540,386],[540,389],
[539,391],[539,394],[539,398],[539,404],[539,408],[539,412],[539,416],[540,423],[542,428],[544,433],
[549,436],[552,439],[555,442],[557,445],[560,448],[562,452],[564,459],[565,461],[560,449],[560,449],
[561,450],[571,458],[580,466],[584,469],[587,473],[589,476],[591,477],[575,466],[575,466],[575,466],
[576,466],[582,471],[587,475],[590,477],[594,481],[598,484],[601,489],[604,491],[607,495],[611,496],
[617,498],[622,500],[626,501],[629,504],[633,508],[636,510],[642,515],[650,522],[651,525],[655,528],
[657,529],[660,530],[663,530],[667,533],[671,534],[676,536],[679,537],[681,539],[683,540],[676,536],
[676,536],[676,536],[679,539],[684,546],[687,548],[689,551],[692,554],[696,558],[698,563],[701,567],
[702,571],[704,574],[705,577],[706,579],[707,580],[708,582],[709,586]
];
var canvas=document.getElementById（'myCanvas'）；
var context=canvas.getContext（'2d'）；
context.beginPath（）；
上下文。moveTo（707359）；
对于（变量i=1；i<（heart.length-1）；i++）{
context.lineTo（heart[i][0]，heart[i][1]）
}
//第1行
context.lineWidth=2；
context.strokeStyle='blue'；
stroke（）；
看起来是这样的：

是否有更简单的方法为其他形状生成坐标数据？我希望有一些工具可以让我画一个形状草图并生成坐标数据。

是的

如何

AdobeIllustrator和Inkscape等应用程序可以让你用线和曲线“手”（鼠标）绘制形状。它们有一个创建直线的直线工具和一个创建曲线的笔工具

Illustrator可能是设计行业的“黄金标准”，但不是免费的。Inkscape的功能较少（还有一些bug），但它是免费的

由于图形由直线和曲线而不是像素组成，因此您的图形称为“矢量”图形，而不是“像素/光栅”图形

为什么

由直线/曲线组成的图形的重要性在于，您可以将图形导出为名为SVG的文件格式。如果查看导出的SVG文件，您将看到可以相当轻松地转换为html5画布绘制命令的命令。甚至有翻译人员会自动将Illustrator/Inkscape绘图转换为html5画布

示例

这是你的心画了4条曲线

演示：

以下是4条曲线的心脏代码：

context.beginPath();
context.moveTo(150,150);
context.bezierCurveTo( 150,120, 100,120, 100, 150);
context.bezierCurveTo( 100,180, 150,185, 150, 210 );
context.bezierCurveTo( 150,185, 200,180, 200, 150 );  
context.bezierCurveTo( 200,120, 150,120, 150, 150 );
context.lineWidth=2; 
context.stroke();
从这里开始…

你可以这样创造你的心脏（或任何你想要的形状！）：

  • 使用钢笔（曲线）工具在Illustrator/Inkscape中绘制心形
  • 将您的心脏导出到SVG
  • 使用SVG文件中的曲线坐标创建html5画布曲线命令
记录器

你需要一种方法来记录你的点，这样你就可以把它们复制成字符串、数组等

这将记录您在画布上绘制的任何内容：

var points = [],    /// holds strokes and points
    isDown = false, /// for draw mode
    prevX, prevY;   /// for draw mode
第一次单击时，记录第一个点：

canvas.onmousedown = function(e) {

    /// adjust mouse position (see below)
    var pos = getXY(e);

    /// this is used to draw a line
    prevX = pos.x;
    prevY = pos.y;

    /// add new stroke
    points.push([]);

    /// record point in this stroke
    points[points.length - 1].push([pos.x, pos.y]);

    /// we are in draw mode   
    isDown = true;
}
然后，只需将绘制的所有点推到当前笔划：

canvas.onmousemove = function(e) {

    if (!isDown) return;

    var pos = getXY(e);

    /// draw a line from previous point to this        
    ctx.beginPath();
    ctx.moveTo(prevX, prevY);
    ctx.lineTo(pos.x, pos.y);
    ctx.stroke();

    /// set previous to this point
    prevX = pos.x;
    prevY = pos.y;

    /// record to current stroke
    points[points.length - 1].push([pos.x, pos.y]);
}
和上鼠标；在演示中，它以字符串形式生成点，可以直接复制到JS代码中：

canvas.onmouseup = function() {
    isDown = false;
    coords.innerHTML = JSON.stringify(points);
}
我们调整鼠标位置，使其相对于画布：

function getXY(e) {
    var r = canvas.getBoundingClientRect();
    return {x: e.clientX - r.left, y: e.clientY - r.top}
}
伦德尔

function renderPoints(points) { ctx.clearRect(0, 0, canvas.width, canvas.height); ctx.strokeStyle = '#f00'; /// get a stroke for(var i = 0, t, p, pts; pts = points[i]; i++) { /// render stroke ctx.beginPath(); ctx.moveTo(pts[0][0], pts[0][2]); for(t = 1; p =pts[t]; t++) { ctx.lineTo(p[0], p[1]); } ctx.stroke(); } ctx.strokeStyle = '#000'; } 

var code = '    var points = ' + JSON.stringify(points) + ';';