Fabric.js - 需要为多边形使用填充图案和填充颜色

Question

I have a shape set up through fabric.js and I'm trying to use fill to achieve 2 goals simultaneously:

1) An rgba fill color rgba(255,0,0,0.5)

AND

2) A fabric.Pattern with an SVG image which has transparency.

I'm able to do the fill color and the fill fabric.Pattern with an SVG image separately , but I can't figure out how do do them together

The code I'm using:

var canvas = this.__canvas = new fabric.Canvas('c');

//To set the pattern with an SVG image
function loadPattern(url) {
    fabric.util.loadImage(url, function(img) {
      shape.set('fill', new fabric.Pattern({
        source: img,
        repeat: 'repeat'
      }));
      canvas.renderAll();
   });
}

//To set just a color
function setColor(color) {
   shape.set('fill', color);
   canvas.renderAll();
}

//To set the backgroundColor
function setbackgroundColor(color) {
   shape.set('backgroundColor', color);
   canvas.renderAll();
}

var shape = new fabric.Polyline([
    {x: 78, y: 138},
    {x: 146, y: 96},
    {x: 170, y: 117},
    {x: 275, y: 127},
    {x: 275, y: 216},
    {x: 78, y: 138}
    ], {
    fill: 'rgba(255,0,0,0.5)',
    stroke: 'red',
    left: 100,
    top: 100
});

canvas.add(shape);

This is what it looks like when using fill with just the color:

This is what it looks like when using fill with just the pattern:

I have tried using fill with the pattern plus ```shape.backgroundColor = 'rgba(255,0,0,0.5)';

But this is what happened:

The goal would be to have both the color and the pattern contained within the shape like this:

 // initialize fabric canvas and assign to global windows object for debug var canvas = window._canvas = new fabric.Canvas('c'); //To set the pattern with an SVG image function loadPattern(url) { fabric.util.loadImage(url, function(img) { shape.set('fill', new fabric.Pattern({ source: img, repeat: 'repeat' })); canvas.renderAll(); }); } //To set just a color function setColor(color) { shape.set('fill', color); canvas.renderAll(); } // function setbackgroundColor(color) { shape.set('backgroundColor', color); canvas.renderAll(); } var shape = new fabric.Polyline([ {x: 78, y: 138}, {x: 146, y: 96}, {x: 170, y: 117}, {x: 275, y: 127}, {x: 275, y: 216}, {x: 78, y: 138} ], { fill: 'rgba(255,0,0,0.5)', stroke: 'red', left: 100, top: 100 }); canvas.add(shape);

 canvas { border: 1px solid #999; } button { margin-top: 20px; }

 <script src="https://cdnjs.cloudflare.com/ajax/libs/fabric.js/3.6.3/fabric.min.js"></script> <button onclick="loadPattern('https://www.heropatterns.com/svg/anchors-away.svg');">Set pattern</button> <button onclick="setColor('rgba(255,0,0,0.5)');">Set color</button> <button onclick="setbackgroundColor('rgba(255,0,0,0.5)');">Set backgroundColor</button> <button onclick="setbackgroundColor('transparent');">Set backgroundColor to transparent</button> <canvas id="c" width="400" height="400"></canvas>

Here is my jsFiddle: http://jsfiddle.net/shehan11/1vgps2dw/5/

Thanks for your help!

Answer 1

My solution for this ended up being to pass the color information to a PHP file which renders the SVG with the color info.

JS:

var rgb = {
 r: 255,
 b: 0,
 g: 0
};

var url = '/pattern.php?pattern=' + pattern + '&r=' + rgb.r + '&g=' + rgb.g + '&b=' + rgb.b;

    fabric.util.loadImage(url, function (img) {
      shape.set('fill', new fabric.Pattern({
        source: img,
        repeat: 'repeat'
      }));
      shape.pattern = pattern;
      canvas.renderAll();
    });

PHP FILE:

echo '<svg style="background-color:'."rgba($r,$g,$b,0.5)".';" xmlns="http://www.w3.org/2000/svg" width="70" height="46" viewBox="0 0 70 46"><g fill-rule="evenodd"><g fill="#000"><polygon points="68 44 62 44 62 46 56 46 56 44 5```

In this way, the JS uses PHP to create an SVG image on the fly with color information