AlphaTab.Rendering.Glyphs.TieGlyph.PaintTie C# (CSharp) Method

        public static void PaintTie(ICanvas canvas, float scale, float x1, float y1, float x2, float y2,
            bool down = false)
        {
            // ensure endX > startX
            if (x2 > x1)
            {
                var t = x1;
                x1 = x2;
                x2 = t;
                t = y1;
                y1 = y2;
                y2 = t;
            }
            //
            // calculate control points
            //
            var offset = 15 * scale;
            var size = 4 * scale;
            // normal vector
            var normalVectorX = (y2 - y1);
            var normalVectorY = (x2 - x1);
            var length = (float)Math.Sqrt((normalVectorX * normalVectorX) + (normalVectorY * normalVectorY));
            if (down)
                normalVectorX *= -1;
            else
                normalVectorY *= -1;

            // make to unit vector
            normalVectorX /= length;
            normalVectorY /= length;

            // center of connection
            var centerX = (x2 + x1) / 2;
            var centerY = (y2 + y1) / 2;

            // control points
            var cp1X = centerX + (offset * normalVectorX);
            var cp1Y = centerY + (offset * normalVectorY);
            var cp2X = centerX + ((offset - size) * normalVectorX);
            var cp2Y = centerY + ((offset - size) * normalVectorY);
            canvas.BeginPath();
            canvas.MoveTo(x1, y1);
            canvas.QuadraticCurveTo(cp1X, cp1Y, x2, y2);
            canvas.QuadraticCurveTo(cp2X, cp2Y, x1, y1);
            canvas.ClosePath();
        }

        public override void Paint(float cx, float cy, ICanvas canvas)
        {
            // only render slur once per staff
            var slurId         = "score.slur." + _startBeat.SlurOrigin.Id;
            var renderer       = Renderer;
            var isSlurRendered = renderer.Staff.GetSharedLayoutData(slurId, false);

            if (!isSlurRendered)
            {
                renderer.Staff.SetSharedLayoutData(slurId, true);

                var startNoteRenderer = Renderer.ScoreRenderer.Layout.GetRendererForBar <BarRendererBase>(Renderer.Staff.StaveId, _startBeat.Voice.Bar);
                var direction         = GetBeamDirection(_startBeat, startNoteRenderer);

                var startX = cx + startNoteRenderer.X;
                var startY = cy + startNoteRenderer.Y;
                if (_startBeat.SlurOrigin.Id == _startBeat.Id)
                {
                    startX += startNoteRenderer.GetBeatX(_startBeat, BeatXPosition.MiddleNotes);
                    var note = direction == BeamDirection.Down ? _startBeat.MinNote : _startBeat.MaxNote;
                    startY += startNoteRenderer.GetNoteY(note);
                }
                else
                {
                    startY += startNoteRenderer.Height;
                }
                var endBeat = _startBeat.SlurOrigin.SlurDestination;

                var   endNoteRenderer = Renderer.ScoreRenderer.Layout.GetRendererForBar <ScoreBarRenderer>(Renderer.Staff.StaveId, endBeat.Voice.Bar);
                float endX;
                float endY;
                if (endNoteRenderer == null || startNoteRenderer.Staff != endNoteRenderer.Staff)
                {
                    endNoteRenderer = (ScoreBarRenderer)startNoteRenderer.Staff.BarRenderers[startNoteRenderer.Staff.BarRenderers.Count - 1];
                    endX            = cx + endNoteRenderer.X + endNoteRenderer.Width;
                    endY            = cy + endNoteRenderer.Y + endNoteRenderer.Height;
                }
                else
                {
                    endX = cx + endNoteRenderer.X + endNoteRenderer.GetBeatX(endBeat, BeatXPosition.MiddleNotes);

                    // if the note stem is pointing towards the slur, we need to let it end on top of the stem.
                    var endBeatHelper = endNoteRenderer.Helpers.GetBeamingHelperForBeat(endBeat);
                    if (endBeatHelper.Direction == direction)
                    {
                        endY = cy + endNoteRenderer.Y + endNoteRenderer.CalculateBeamY(endBeatHelper, endX);
                    }
                    else
                    {
                        var note = direction == BeamDirection.Down ? endBeat.MinNote : endBeat.MaxNote;
                        endY = cy + endNoteRenderer.Y + endNoteRenderer.GetNoteY(note);
                    }
                }

                var height = (endX - startX) * Renderer.Settings.SlurHeightFactor;

                TieGlyph.PaintTie(canvas, Scale, startX, startY, endX, endY, direction == BeamDirection.Down, height);
                canvas.Fill();
            }
        }