public override void MouseDown(Canvas canvas, PointO location)
{
switch (Mode)
{
case ToolMode.Create:
Curve = new DrawableCurve(location, location);
canvas.Drawables.AddLast(Curve);
Mode = ToolMode.Resize;
break;
case ToolMode.AddCurve:
if (Curve.Intersect(location))
{
Curve.AddCurve(location);
CurvePoint = location;
Mode = ToolMode.MoveCurve;
}
else
{
Curve.State = LockState.Instance;
Mode = ToolMode.Create;
}
break;
}
}
public override void Move(PointO offset)
{
foreach (var point in points)
{
point.Offset(offset);
}
}
private double PythagorasDistance(PointO a, PointO b)
{
var dx = a.X - b.X;
var dy = a.Y - b.Y;
return(Math.Sqrt(dx * dx + dy * dy));
}
public override void Move(PointO offset)
{
foreach (var drawable in drawables)
{
drawable.Move(offset);
}
}
private bool InBetween(PointO start, PointO mid, PointO end)
{
var alpha = FindAngle(mid, start, end);
var beta = FindAngle(mid, end, start);
return(alpha <= 90 && beta <= 90);
}
public override void MouseDown(Canvas canvas, PointO location)
{
var drawable = GetDrawableAtLocation(canvas, location);
switch (Mode)
{
case ToolMode.Select:
if (drawable == null)
{
canvas.LockDrawables();
}
else if (drawable.State == EditState.Instance)
{
moveDrawables = GetDrawableWithState(canvas, EditState.Instance);
moveStartLocation = location;
Mode = ToolMode.Move;
}
else
{
canvas.LockDrawables();
drawable.State = EditState.Instance;
}
break;
case ToolMode.MultiSelect:
if (drawable == null)
{
break;
}
ToggleDrawableState(drawable);
break;
}
}
public override bool Intersect(PointO point)
{
var minDistance = double.MaxValue;
// distance from curve point
for (var i = 0; i < points.Count; i++)
{
var distance = PythagorasDistance(point, points[i]);
minDistance = Math.Min(minDistance, distance);
if (minDistance < IntersectDistanceLimit)
{
return(true);
}
}
// distance from curve line
for (var i = 1; i < points.Count; i++)
{
var a = points[i - 1];
var b = points[i];
if (InBetween(a, point, b))
{
var distance = PerpendicularDistance(point, a, b);
minDistance = Math.Min(minDistance, distance);
if (minDistance < IntersectDistanceLimit)
{
return(true);
}
}
}
return(false);
}
public override void DrawGuide(Graphics graphics)
{
graphics.DrawLines(LineGuidePen, PointO.ToPrimitiveArray(points.ToArray()));
foreach (var point in points)
{
graphics.DrawEllipse(CurvePointGuidePen, point.X - 2, point.Y - 2, 4, 4);
}
}
public override void MouseUp(Canvas canvas, PointO location)
{
switch (Mode)
{
case ToolMode.Move:
Mode = ToolMode.Select;
break;
}
}
private double PerpendicularDistance(PointO point, PointO lineA, PointO lineB)
{
// reference: https://math.stackexchange.com/questions/637922/how-can-i-find-coefficients-a-b-c-given-two-points
var a = lineA.Y - lineB.Y;
var b = -(lineA.X - lineB.X);
var c = lineA.X * lineB.Y - lineB.X * lineA.Y;
return(PerpendicularDistance(point, a, b, c));
}
public override bool Intersect(PointO point)
{
foreach (var drawable in drawables)
{
if (drawable.Intersect(point))
{
return(true);
}
}
return(false);
}
private static Drawable GetDrawableAtLocation(Canvas canvas, PointO location)
{
foreach (var drawable in canvas.Drawables)
{
if (drawable.Intersect(location))
{
return(drawable);
}
}
return(null);
}
public override void MouseUp(Canvas canvas, PointO location)
{
switch (Mode)
{
case ToolMode.Resize:
Mode = ToolMode.AddCurve;
break;
case ToolMode.MoveCurve:
Mode = ToolMode.AddCurve;
break;
}
}
private double FindAngle(PointO a, PointO b, PointO c)
{
// reference: https://stackoverflow.com/questions/19729831/angle-between-3-points-in-3d-space
var v1 = new double[] { a.X - b.X, a.Y - b.Y };
var v2 = new double[] { c.X - b.X, c.Y - b.Y };
var v1Mag = Math.Sqrt(v1[0] * v1[0] + v1[1] * v1[1]);
var v2Mag = Math.Sqrt(v2[0] * v2[0] + v2[1] * v2[1]);
var v1Norm = new[] { v1[0] / v1Mag, v1[1] / v1Mag };
var v2Norm = new[] { v2[0] / v2Mag, v2[1] / v2Mag };
var res = v1Norm[0] * v2Norm[0] + v1Norm[1] * v2Norm[1];
return(Math.Acos(res) * 180.0 / 3.141592653589793);
}
public override void MouseMove(Canvas canvas, PointO location)
{
switch (Mode)
{
case ToolMode.Move:
foreach (var drawable in moveDrawables)
{
var offset = PointO.FromOffset(moveStartLocation, location);
drawable.Move(offset);
}
moveStartLocation = location;
break;
}
}
public override void MouseMove(Canvas canvas, PointO location)
{
switch (Mode)
{
case ToolMode.Resize:
Curve.SetEndPoint(location);
break;
case ToolMode.MoveCurve:
var offset = PointO.FromOffset(CurvePoint, location);
CurvePoint.Offset(offset);
break;
}
}
private int FindBestPointPosition(PointO point)
{
var bestPointPosition = -1;
var minDistance = double.MaxValue;
for (var i = 0; i < points.Count; i++)
{
var distance = PythagorasDistance(point, points[i]);
if (distance < IntersectDistanceLimit && distance < minDistance)
{
bestPointPosition = i;
minDistance = distance;
}
}
return(bestPointPosition);
}
public void AddCurve(PointO point)
{
// try use old curve
var position = FindBestPointPosition(point);
if (position != -1)
{
points[position] = point;
}
else
{
// try add curve between 2 point
position = FindBestPosition(point);
if (position != -1)
{
points.Insert(position, point);
}
}
}
private int FindBestPosition(PointO point)
{
var bestPosition = -1;
var minDistance = double.MaxValue;
for (var i = 1; i < points.Count; i++)
{
var a = points[i - 1];
var b = points[i];
if (!InBetween(a, point, b))
{
continue;
}
var distance = PerpendicularDistance(point, a, b);
if (!(distance < minDistance))
{
continue;
}
bestPosition = i;
minDistance = distance;
}
return(bestPosition);
}
public virtual void MouseMove(Canvas canvas, PointO location)
{
}
public virtual void MouseDown(Canvas canvas, PointO location)
{
}
public DrawableCurve(PointO from, PointO to)
{
points.Add(from);
points.Add(to);
}
private double PerpendicularDistance(PointO p, float a, float b, float c)
{
// reference: https://www.geeksforgeeks.org/perpendicular-distance-between-a-point-and-a-line-in-2-d/
return(Math.Abs(a * p.X + b * p.Y + c) / Math.Sqrt(a * a + b * b));
}
public void SetStartPoint(PointO newStartPoint)
{
points[0] = newStartPoint;
}
public void SetEndPoint(PointO newEndPoint)
{
points[points.Count - 1] = newEndPoint;
}
public abstract void Move(PointO offset);
public abstract bool Intersect(PointO point);
public override void DrawItem(Graphics graphics)
{
graphics.DrawCurve(DrawPen, PointO.ToPrimitiveArray(points.ToArray()));
}
