/// <summary>
/// Create and add new control point to the given curve at a given Vec2F gpt</summary>
/// <param name="curve">Curve to modify</param>
/// <param name="gpt">Location on the x-axis at which to add a control point. Whether
/// or not the y-coordinate is used depends on 'insert' parameter.</param>
/// <param name="insert">If true, the y-value is inserted on the existing curve, using
/// curve.Evaluate(gpt.X). If false, the y-value comes from gpt.Y.</param>
/// <param name="computeTangent">Whether ComputeTangent() should be called</param>
public static void AddControlPoint(ICurve curve, Vec2F gpt, bool insert, bool computeTangent)
{
if (curve == null)
{
throw new ArgumentNullException("curve");
}
// add/insert new control point to the given curve. Using the following rules.
// if adding then add the point at gpt and set is tangent type to spline.
// if inserting then add the point at (gpt.x,curve.eval(gpt.x)) and compute its tangent at the point.
// recompute tangents for the curve.
// find insersion index.
int index = GetValidInsertionIndex(curve, gpt.X);
if (index >= 0)
{
IControlPoint p = curve.CreateControlPoint();
p.EditorData.SelectedRegion = PointSelectionRegions.None;
if (insert)
{
p.X = gpt.X;
ICurveEvaluator cv = CurveUtils.CreateCurveEvaluator(curve);
float prevY = cv.Evaluate(gpt.X - s_epsilone);
float nextY = cv.Evaluate(gpt.X + s_epsilone);
p.Y = cv.Evaluate(gpt.X);
p.TangentInType = CurveTangentTypes.Fixed;
p.TangentOutType = CurveTangentTypes.Fixed;
Vec2F tanIn = new Vec2F(s_epsilone, p.Y - prevY);
tanIn.Normalize();
Vec2F tanOut = new Vec2F(s_epsilone, nextY - p.Y);
tanOut.Normalize();
p.TangentIn = tanIn;
p.TangentOut = tanOut;
}
else
{
p.X = gpt.X;
p.Y = gpt.Y;
p.TangentInType = CurveTangentTypes.Spline;
p.TangentOutType = CurveTangentTypes.Spline;
}
curve.InsertControlPoint(index, p);
if (computeTangent)
{
ComputeTangent(curve);
}
}
}
/// <summary>
/// Hit test curve</summary>
/// <param name="curve">Curve</param>
/// <param name="pickRect">Rectangle</param>
/// <returns>True iff hit</returns>
public bool HitTest(ICurve curve, RectangleF pickRect)
{
if (curve == null)
{
return(false);
}
ReadOnlyCollection <IControlPoint> points = curve.ControlPoints;
if (!curve.Visible || points.Count == 0)
{
return(false);
}
float step = m_tessellation / m_canvas.Zoom.X;
ICurveEvaluator cv = CurveUtils.CreateCurveEvaluator(curve);
float start = m_canvas.ClientToGraph(pickRect.X);
float end = m_canvas.ClientToGraph(pickRect.Right);
float rangeX = end - start;
PointF scrPt = new PointF();
float fpx = points[0].X;
float lpx = points[points.Count - 1].X;
if ((start < fpx && end < fpx) || (start > lpx && end > lpx))
{
return(false);
}
for (float x = 0; x < rangeX; x += step)
{
float xv = start + x;
float y = cv.Evaluate(xv);
scrPt = m_canvas.GraphToClient(xv, y);
if (pickRect.Contains(scrPt))
{
return(true);
}
}
return(false);
}
/// <summary>
/// Draws given curve</summary>
/// <param name="curve">Curve</param>
/// <param name="g">Graphics object</param>
public void DrawCurve(ICurve curve, Graphics g)
{
// draw pre-infinity
// draw actual
// draw post-inifiny.
ReadOnlyCollection <IControlPoint> points = curve.ControlPoints;
if (points.Count == 0)
{
return;
}
m_infinityPen.Color = curve.CurveColor;
m_curvePen.Color = curve.CurveColor;
if (points.Count == 1)
{
Vec2F p = m_canvas.GraphToClient(0, points[0].Y);
g.DrawLine(m_infinityPen, 0, p.Y, m_canvas.ClientSize.Width, p.Y);
return;
}
float w = m_canvas.ClientSize.Width;
float h = m_canvas.ClientSize.Height;
float x0 = m_canvas.ClientToGraph(0);
float x1 = m_canvas.ClientToGraph(w);
IControlPoint fpt = points[0];
IControlPoint lpt = points[points.Count - 1];
float step = m_tessellation / m_canvas.Zoom.X;
List <PointF> pointList = new List <PointF>(m_canvas.Width / m_tessellation);
ICurveEvaluator cv = CurveUtils.CreateCurveEvaluator(curve);
PointF scrPt = new PointF();
float bound = 500; // guard again gdi+ overflow.
float minY = -bound;
float maxY = h + bound;
// draw pre infinity
if (fpt.X > x0)
{
float start = x0;
float end = Math.Min(fpt.X, x1);
float rangeX = end - start;
for (float x = 0; x < rangeX; x += step)
{
float xv = start + x;
float y = cv.Evaluate(xv);
scrPt = m_canvas.GraphToClient(xv, y);
scrPt.Y = MathUtil.Clamp(scrPt.Y, minY, maxY);
pointList.Add(scrPt);
}
scrPt = m_canvas.GraphToClient(end, cv.Evaluate(end));
scrPt.Y = MathUtil.Clamp(scrPt.Y, minY, maxY);
pointList.Add(scrPt);
if (pointList.Count > 1)
{
g.DrawLines(m_infinityPen, pointList.ToArray());
}
}
// draw actual
if ((fpt.X > x0 || lpt.X > x0) && (fpt.X < x1 || lpt.X < x1))
{
int leftIndex;
int rightIndex;
ComputeIndices(curve, out leftIndex, out rightIndex);
if (curve.CurveInterpolation == InterpolationTypes.Linear)
{
for (int i = leftIndex; i < rightIndex; i++)
{
IControlPoint p1 = points[i];
IControlPoint p2 = points[i + 1];
PointF cp1 = m_canvas.GraphToClient(p1.X, p1.Y);
PointF cp2 = m_canvas.GraphToClient(p2.X, p2.Y);
g.DrawLine(m_curvePen, cp1.X, cp1.Y, cp2.X, cp2.Y);
}
}
else
{
for (int i = leftIndex; i < rightIndex; i++)
{
IControlPoint p1 = points[i];
IControlPoint p2 = points[i + 1];
if (p1.TangentOutType == CurveTangentTypes.Stepped)
{
PointF cp1 = m_canvas.GraphToClient(p1.X, p1.Y);
PointF cp2 = m_canvas.GraphToClient(p2.X, p2.Y);
g.DrawLine(m_curvePen, cp1.X, cp1.Y, cp2.X, cp1.Y);
g.DrawLine(m_curvePen, cp2.X, cp1.Y, cp2.X, cp2.Y);
}
else if (p1.TangentOutType != CurveTangentTypes.SteppedNext)
{
float start = Math.Max(p1.X, x0);
float end = Math.Min(p2.X, x1);
pointList.Clear();
float rangeX = end - start;
for (float x = 0; x < rangeX; x += step)
{
float xv = start + x;
float y = cv.Evaluate(xv);
scrPt = m_canvas.GraphToClient(xv, y);
scrPt.Y = MathUtil.Clamp(scrPt.Y, minY, maxY);
pointList.Add(scrPt);
}
scrPt = m_canvas.GraphToClient(end, cv.Evaluate(end));
scrPt.Y = MathUtil.Clamp(scrPt.Y, minY, maxY);
pointList.Add(scrPt);
if (pointList.Count > 1)
{
g.DrawLines(m_curvePen, pointList.ToArray());
}
}
}// for (int i = leftIndex; i < rightIndex; i++)
}
}
//draw post-infinity.
if (lpt.X < x1)
{
pointList.Clear();
float start = Math.Max(x0, lpt.X);
float end = x1;
float rangeX = end - start;
for (float x = 0; x < rangeX; x += step)
{
float xv = start + x;
float y = cv.Evaluate(xv);
scrPt = m_canvas.GraphToClient(xv, y);
scrPt.Y = MathUtil.Clamp(scrPt.Y, minY, maxY);
pointList.Add(scrPt);
}
scrPt = m_canvas.GraphToClient(end, cv.Evaluate(end));
scrPt.Y = MathUtil.Clamp(scrPt.Y, minY, maxY);
pointList.Add(scrPt);
if (pointList.Count > 1)
{
g.DrawLines(m_infinityPen, pointList.ToArray());
}
}
}