Extend work started in #2935 to create code that draws lines more carefully and has features like edge interpolation. It can later be used by SignalXY plots too.
Here is relevant code from ScottPlot4:
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PointF[] PointsToDraw = PointBefore.Concat(VisiblePoints).Concat(PointAfter).ToArray(); |
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// Interpolate before displayed point to make it x = -1 (close to visible area) |
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// this fix extreme zoom in bug |
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if (PointBefore.Length > 0 && PointsToDraw.Length >= 2 && !StepDisplay) |
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{ |
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// only extrapolate if points are different (otherwise extrapolated point may be infinity) |
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if (PointsToDraw[0].X != PointsToDraw[1].X) |
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{ |
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float x0 = -1 + dims.DataOffsetX; |
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float y0 = PointsToDraw[1].Y + (PointsToDraw[0].Y - PointsToDraw[1].Y) * (x0 - PointsToDraw[1].X) / (PointsToDraw[0].X - PointsToDraw[1].X); |
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PointsToDraw[0] = new PointF(x0, y0); |
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} |
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} |
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// Interpolate after displayed point to make it x = datasize.Width(close to visible area) |
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// this fix extreme zoom in bug |
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if (PointAfter.Length > 0 && PointsToDraw.Length >= 2 && !StepDisplay) |
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{ |
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PointF lastPoint = PointsToDraw[PointsToDraw.Length - 2]; |
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PointF afterPoint = PointsToDraw[PointsToDraw.Length - 1]; |
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// only extrapolate if points are different (otherwise extrapolated point may be infinity) |
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if (afterPoint.X != lastPoint.X) |
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{ |
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float x1 = dims.DataWidth + dims.DataOffsetX; |
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float y1 = lastPoint.Y + (afterPoint.Y - lastPoint.Y) * (x1 - lastPoint.X) / (afterPoint.X - lastPoint.X); |
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PointsToDraw[PointsToDraw.Length - 1] = new PointF(x1, y1); |
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} |
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} |
EDIT: see #2935 (comment) for more information
