在Raphaël的路径上附上文字?

时间:2010-04-10 08:33:50

标签: javascript canvas svg raphael

有没有人知道如何将文字附加到Raphaël的路径中?像http://www.w3.org/TR/SVG11/images/text/toap02.svg之类的东西 我知道jQuery SVG可以做到这一点,但我找不到一个简单的方法来使用Raphaëljs。我想将此文本附加到贝塞尔曲线并移动它。

3 个答案:

答案 0 :(得分:12)

有两种方法可以做到这一点。

  1. 更简单的方法是使用Raphael .print() 方法。这可以将文本转换为路径。每个角色都有自己的路径。然后,您可以使用 .translate() .angle() 对每个角色进行迭代并移动并适当旋转。

  2. 更难的方法是为路径上的 SVG VML 实现Raphael {{ 3}}

  3. 以下是使用.print() .text() 进行轮换的方法1的快速而粗略的开始:

    window.onload = function() {
        var i, newP,
            R = Raphael("canvas",500,400),
    
              // Create our set of letter paths
            t = R.print(100, 0, "this is a test", R.getFont("whoa"), 30),
    
              // Create the path to follow
            p = R.path("M 50 100 C 100 50 150 0 200 50 C 250 100 300 150 350 100" +
                       " C 400 50 450 50 450 50").attr("stroke", "none"),
            pLen = p.getTotalLength(), // Length of path to follow
            tLen = t.length,           // Number of characters
            oneL = pLen/tLen;          // Average length of 1 character
              // You can also use .getBBox() for each character instead       
    
          // Position each character
        for (i = 0; i < tLen; i++) {
    
              // Get x,y of the path to follow
            newP = p.getPointAtLength(i * oneL);
    
              // Move the letter
            t[i].translate((i * oneL)-newP.x, newP.y); 
            t[i].attr("fill", Raphael.getColor());
        }
    };​
    

    this font

    注意:上面的代码非常粗糙并且有一些重要的定位问题,但我认为通常的方法是将文本放在Raphael的路径上。

答案 1 :(得分:6)

raphael 2.1 print()函数不再返回一组路径,而是包含所有字母的单个路径。所以这里的所有解决方案都不适用于raphael 2.1(当前版本)。我开发了以下小插件,将printLetters()方法添加到纸上,单独打印字母并返回一个集合,就像旧的print()方法一样。此外,该插件还支持将此文本与路径对齐。例如,要使用插件对齐路径上的文本,您只需执行以下操作:

var r = Raphael(0, 0, 500, 500);
var path1 = "M 50 100 C 100 50 150 0 200 50" +
    " C 250 100 300 150 350 100" +
    " C 400 50 450 50 450 50";
var text1 = r.printLetters(20, 150, "habia una vez una vaca",
        r.getFont("my underwood"), 30, null, null, path1).attr({
    fill : "red",
    stroke : "black"
});

插件代码是:

(function() {
    /**
     * do the job of putting all letters in a set returned bu printLetters in a path
     * @param p - can be a rpahael path obejct or string
     */
    var _printOnPath = function(text, paper, p) {
        if(typeof(p)=="string")
            p = paper.path(p).attr({stroke: "none"});
        for ( var i = 0; i < text.length; i++) {       
            var letter = text[i];
            var newP = p.getPointAtLength(letter.getBBox().x);
            var newTransformation = letter.transform()+
                 "T"+(newP.x-letter.getBBox().x)+","+
                (newP.y-letter.getBBox().y-letter.getBBox().height);       
            //also rotate the letter to correspond the path angle of derivative
            newTransformation+="R"+
                (newP.alpha<360 ? 180+newP.alpha : newP.alpha);
            letter.transform(newTransformation);
        }
    };

    /** print letter by letter, and return the set of letters (paths), just like the old raphael print() method did. */
    Raphael.fn.printLetters = function(x, y, str, font, size,
            letter_spacing, line_height, onpath) {
        letter_spacing=letter_spacing||size/1.5;
        line_height=line_height||size;
        this.setStart();
        var x_=x, y_=y;
        for ( var i = 0; i < str.length; i++) {
            if(str.charAt(i)!='\n') {
                var letter = this.print(x_,y_,str.charAt(i),font,size);
                x_+=letter_spacing;               
            }
            else {
                x_=x;
                y_+=line_height;
            }
        }
        var set = this.setFinish();
        if(onpath) {
            _printOnPath(set, this, onpath);
        }
        return set;
    };   
})();

答案 2 :(得分:0)

这是基于raphael4gwt(java)的代码,但我认为javascript程序员可以很容易地适应它。它基于raphael 2.0。它类似于上面的溶剂但更好。它使用转换字符串绝对定位和旋转每个字母以将其放在路径上:

/* make some text follow a path */
Font anchorFont = paper.getFont("Anchor Steam NF");
Set text1 = paper.print(120,330,"a text that follows a path", anchorFont, 40);

//the path where we want to place the text
Path p = paper.path(
    "M 50 100 C 100 50 150 0 200 50" +
" C 250 100 300 150 350 100" +
" C 400 50 450 50 450 50");
p.attr(Attrs.create().stroke("none"));//hide the path

/* for each letter, we add an absolute translation to its 
 * transformation string and also add an absolute rotation 
 * to correspond to path angle of derivative. */
for(int i = 0; i<text1.size(); i++) {
    Shape letter = text1.item(i);

    //get the point of a letter on the path
    Point newP = p.getPointAtLength(letter.getBBox().getX());

    String newTransformation = letter.getTransform()+                   
        "T"+(newP.getX()-letter.getBBox().getX())+","+
        (newP.getY()-letter.getBBox().getY()-letter.getBBox().getHeight());

    //also rotate the letter to correspond the path angle of derivative
    newTransformation+="R"+
        (newP.getAlpha()<360 ? 180+newP.getAlpha() : newP.getAlpha());

    letter.setTransform(newTransformation);         
}