Stroke wrong display about thorvg

[mgrudzinska]

I think this is the expected behavior.

The fill itself draws correctly. After adding a stroke the 'problem' appears because we don't close it. If you add shape3->close(), the beginning and the end of the stroke will be joined together and you will get a smooth vertex.

Below I have drawn 4 separate cubics - as you can see the fill connects smoothly, while the strokes with the default cap do not connect.
If you change the stroke cap to Butt (shape->stroke(tvg::StrokeCap::Butt)) you will get a stroke that looks like one whole.

Default cap:

Butt cap:

The code:

shape3a->moveTo(cx, cy - radius);
shape3a->cubicTo(cx + halfRadius, cy - radius, cx + radius, cy - halfRadius, cx + radius, cy);

shape3b->moveTo(cx + radius, cy);
shape3b->cubicTo(cx + radius, cy + halfRadius, cx + halfRadius, cy + radius, cx, cy+ radius);

shape3c->moveTo(cx, cy + radius);
shape3c->cubicTo(cx - halfRadius, cy + radius, cx - radius, cy + halfRadius, cx - radius, cy);

shape3d->moveTo(cx - radius, cy);
shape3d->cubicTo(cx - radius, cy - halfRadius, cx - halfRadius, cy - radius, cx, cy - radius);

shape3a->fill(255, 0, 0, 255);
shape3b->fill(0, 255, 0, 255);
shape3c->fill(0, 0, 255, 255);
shape3d->fill(255, 0, 255, 255);

shape3a->stroke(255, 0, 0, 255);
shape3b->stroke(0, 255, 0, 255);
shape3c->stroke(0, 0, 255, 255);
shape3d->stroke(255, 0, 255, 255);

shape3a->stroke(100);
shape3b->stroke(100);
shape3c->stroke(100);
shape3d->stroke(100);

shape3a->stroke(tvg::StrokeCap::Butt);
shape3b->stroke(tvg::StrokeCap::Butt);
shape3c->stroke(tvg::StrokeCap::Butt);
shape3d->stroke(tvg::StrokeCap::Butt);

scene->push(move(shape3a));
scene->push(move(shape3b));
scene->push(move(shape3c));
scene->push(move(shape3d));

[JSUYA]

@mgrudzinska
Thank you for your kind explanation. I have checked there are no problems. I will close this issue. :)