private LineSegment lineSegmentPerpendicularTo(LineSegment seg, float relativeLengthFraction)
{
float x0 = seg.P1.X,
y0 = seg.P1.Y,
x1 = seg.P2.X,
y1 = seg.P2.Y;
float dx = x1 - x0,
dy = y1 - y0;
float xa = x1 + relativeLengthFraction / 2 * dy,
ya = y1 - relativeLengthFraction / 2 * dx,
xb = x1 - relativeLengthFraction / 2 * dy,
yb = y1 + relativeLengthFraction / 2 * dx;
return new LineSegment()
{
P1 = new PointF(xa, ya),
P2 = new PointF(xb, yb)
};
}
private void panel1_MouseMove(object sender, MouseEventArgs e)
{
if (!_isMouseDown) return;
Graphics g = panel1.CreateGraphics();
g.SmoothingMode = SmoothingMode.HighQuality;
_counter += 1;
_points[_counter] = e.Location;
LineSegment[] ls = new LineSegment[4];
if (_counter == 4) {
GraphicsPath path = new GraphicsPath();
_points[3] = new Point((_points[2].X + _points[4].X) / 2,
(_points[2].Y + _points[4].Y) / 2);
if (_isFirstTouchPoint) {
ls[0] = new LineSegment(){
P1 = _points[0],
P2 = _points[0]
};
_isFirstTouchPoint = false;
}
else {
ls[0] = _lastSegmentOfPrev;
}
float frac1 = FF / clamp(len_sq(_points[0], _points[1]), LOWER, UPPER);
float frac2 = FF / clamp(len_sq(_points[1], _points[2]), LOWER, UPPER);
float frac3 = FF / clamp(len_sq(_points[2], _points[3]), LOWER, UPPER);
ls[1] = lineSegmentPerpendicularTo(new LineSegment()
{
P1 = _points[0],
P2 = _points[1]
}, frac1);
ls[2] = lineSegmentPerpendicularTo(new LineSegment()
{
P1 = _points[1],
P2 = _points[2]
}, frac2);
ls[3] = lineSegmentPerpendicularTo(new LineSegment()
{
P1 = _points[2],
P2 = _points[3]
}, frac3);
path.AddBezier(ls[0].P1, ls[1].P1, ls[2].P1, ls[3].P1);
path.AddLine(ls[3].P1, ls[3].P2);
path.AddBezier(ls[3].P2, ls[2].P2, ls[1].P2, ls[0].P2);
path.CloseFigure();
g.DrawPath(Pens.Black, path);
g.FillPath(Brushes.Black, path);
_lastSegmentOfPrev = ls[3];
_points[0] = _points[3];
_points[1] = _points[4];
_counter = 1;
}
}
private void panel1_MouseMove(object sender, MouseEventArgs e)
{
if (!_isMouseDown)
{
return;
}
Graphics g = panel1.CreateGraphics();
g.SmoothingMode = SmoothingMode.HighQuality;
_counter += 1;
_points[_counter] = e.Location;
LineSegment[] ls = new LineSegment[4];
if (_counter == 4)
{
GraphicsPath path = new GraphicsPath();
_points[3] = new Point((_points[2].X + _points[4].X) / 2,
(_points[2].Y + _points[4].Y) / 2);
if (_isFirstTouchPoint)
{
ls[0] = new LineSegment()
{
P1 = _points[0],
P2 = _points[0]
};
_isFirstTouchPoint = false;
}
else
{
ls[0] = _lastSegmentOfPrev;
}
float frac1 = FF / clamp(len_sq(_points[0], _points[1]), LOWER, UPPER);
float frac2 = FF / clamp(len_sq(_points[1], _points[2]), LOWER, UPPER);
float frac3 = FF / clamp(len_sq(_points[2], _points[3]), LOWER, UPPER);
ls[1] = lineSegmentPerpendicularTo(new LineSegment()
{
P1 = _points[0],
P2 = _points[1]
}, frac1);
ls[2] = lineSegmentPerpendicularTo(new LineSegment()
{
P1 = _points[1],
P2 = _points[2]
}, frac2);
ls[3] = lineSegmentPerpendicularTo(new LineSegment()
{
P1 = _points[2],
P2 = _points[3]
}, frac3);
path.AddBezier(ls[0].P1, ls[1].P1, ls[2].P1, ls[3].P1);
path.AddLine(ls[3].P1, ls[3].P2);
path.AddBezier(ls[3].P2, ls[2].P2, ls[1].P2, ls[0].P2);
path.CloseFigure();
g.DrawPath(Pens.Black, path);
g.FillPath(Brushes.Black, path);
_lastSegmentOfPrev = ls[3];
_points[0] = _points[3];
_points[1] = _points[4];
_counter = 1;
}
}