lineTo with a duplicate point renders a gap in a line drawing.

Hey!

I was working on some line drawing and came across this potential issue:

If you create a graphics object, and then start drawing a line… when you add a duplicate point into to lineTo method, the renderer somehow seems to add a gap in the line. I am unintentionally adding the duplicate point, so I’m not sure how much of a ‘bug’ this is… However, this is certainly “unexpected behaviour” in my eyes.

Here is a working example using the latest PIXI:

var app = new PIXI.Application(800, 600, { antialias: true });
document.body.appendChild(app.view);

var lines = [
  [
    [-8.154,558.886],
    [121.097,294.348],
    [133.744,282.209],
    [134.591,281.512],
    [166.995,250.542], // < --- Duplicate set of points
    [166.995,250.542], // NOTE: comment this out to close the line
    [167.029,250.518],
    [170.649,248.128],
    [172.666,246.822],
    [176.68,244.274],
    [178.455,243.17],
    [292.488,-14.857]
  ]
]

lines.forEach(function(line){
   var graphics = new PIXI.Graphics();
   graphics.lineStyle(4, 0xffd900, 1);
   line.forEach(function(point, i) {
      if (i === 0) graphics.moveTo(point[0], point[1]);
      else graphics.lineTo(point[0], point[1]);
   })
   graphics.endFill();
   app.stage.addChild(graphics);
})

[gooderist]

Ignoring the call on duplicates, as @G-Rath suggested, seems to work even without digging up the moveTo polygon.

Here is an updated fiddle testing the change on this issue

and another fiddle showing the change working on #3592 despite not checking against the initial moveTo.

The change itself would look something like this

    lineTo(x, y)
    {
        const points = this.currentPath.shape.points;
        const prevY = points[points.length - 1];
        const prevX = points[points.length - 2];

        // Skip if x,y matches last lineTo coordinates
        if (prevX !== x || prevY !== y)
        {
            this.currentPath.shape.points.push(x, y);
            this.dirty++;
        }

        return this;
    }

Have I overlooked anything?

[lock[bot]]

This thread has been automatically locked since there has not been any recent activity after it was closed. Please open a new issue for related bugs.