public static bool SweepIntersects(Vector2 a1, Vector2 a2, Vector2 b1, Vector2 b2, Vector2 l1, Vector2 l2, out Vector2 intersection, out float percent, float accuracy = 1)
{
intersection = Vector2.zero;
percent = 0;
Vector2 lineDelta = l2 - l1;
Vector2 point = l2;
b1 += -lineDelta;
b2 += -lineDelta;
Vector2[] poly = { a1, a2, b2, b1 };
FlatBounds bounds = new FlatBounds(poly);
if (!bounds.Contains(l1))
{
return(false);
}
// bounds.DrawDebug(Color.yellow);
Vector2 pointRight = point + new Vector2(Mathf.Max(bounds.width, bounds.height), 0);
// Vector2 pointRight = point - lineDelta * bounds.width * bounds.height;
// Debug.DrawLine(ToV3(point), ToV3(pointRight), Color.cyan);
int numberOfPolyPoints = poly.Length;
int numberOfCrossOvers = 0;
for (int i = 0; i < numberOfPolyPoints; i++)
{
Vector2 p0 = poly[i];
Vector2 p1 = poly[(i + 1) % numberOfPolyPoints];
// Debug.DrawLine(ToV3(p0), ToV3(p1), Color.blue);
if (FastLineIntersection(point, pointRight, p0, p1))
{
numberOfCrossOvers++;
}
}
if (numberOfCrossOvers % 2 == 0)
{
return(false);//point not within shape
}
bounds.DrawDebug(Color.green);
Vector2 delta1 = b1 - a1;
Vector2 delta2 = b2 - a2;
float maxDelta = Mathf.Max(delta1.magnitude, delta2.magnitude);
int iterations = Mathf.CeilToInt(Mathf.Sqrt(maxDelta / accuracy));
for (int i = 0; i < iterations; i++)
{
Vector2 c1 = Vector2.Lerp(a1, b1, 0.5f);
Vector2 c2 = Vector2.Lerp(a2, b2, 0.5f);
if (!Ccw(c1, c2, point))
{
a1 = c1;
a2 = c2;
percent = Mathf.Lerp(percent, 1, 0.5f);
}
else
{
b1 = c1;
b2 = c2;
percent = Mathf.Lerp(0, percent, 0.5f);
}
}
// Vector2 x1 = Vector2.Lerp(a1, b1, 0.5f);
// Vector2 x2 = Vector2.Lerp(a2, b2, 0.5f);
// float dist1 = Vector2.Distance(x1, point);
// float dist2 = Vector2.Distance(x2, point);
// float xpercent = dist1 / (dist1 + dist2);
// intersection = Vector2.Lerp(x1, x2, xpercent);
intersection = Vector2.Lerp(l1, l2, percent);//translate the point to the real movement point
Debug.DrawLine(ToV3(intersection), ToV3(intersection) + Vector3.up * 5, Color.red);
return(true);
}
public static bool SweepIntersects2(Vector2 a1, Vector2 a2, Vector2 b1, Vector2 b2, Vector2 l1, Vector2 l2, out Vector2 intersection, out float percent, float accuracy = 1, bool debug = false)
{
intersection = Vector2.zero;
percent = 0;
Vector2[] poly = { a1, a2, b2, b1 };
FlatBounds edgeBounds = new FlatBounds(poly);
FlatBounds lineBounds = new FlatBounds(new [] { l1, l2 });
if (!edgeBounds.Overlaps(lineBounds, true))
{
if (debug)
{
edgeBounds.DrawDebug(Color.cyan);
}
if (debug)
{
lineBounds.DrawDebug(Color.green);
}
if (debug)
{
Debug.DrawLine(ToV3(l1), ToV3(l2), Color.cyan);
}
return(false);
}
int numberOfPolyPoints = poly.Length;
bool lineIntersectsShape = false;
for (int i = 0; i < numberOfPolyPoints; i++)
{
Vector2 p0 = poly[i];
Vector2 p1 = poly[(i + 1) % numberOfPolyPoints];
if (debug)
{
Debug.DrawLine(ToV3(p0), ToV3(p1), Color.blue);
}
if (FastLineIntersection(p0, p1, l1, l2))
{
lineIntersectsShape = true;
break;
}
}
if (!lineIntersectsShape)//line never crosses shape
{
Vector2 right = new Vector2(Mathf.Max(edgeBounds.width, edgeBounds.height), 0);
int shapeIntersections = 0;
for (int i = 0; i < numberOfPolyPoints; i++)
{
Vector2 p0 = poly[i];
Vector2 p1 = poly[(i + 1) % numberOfPolyPoints];
if (debug)
{
Debug.DrawLine(ToV3(p0) + Vector3.up * 5, ToV3(p1) + Vector3.up * 5, Color.blue);
}
if (FastLineIntersection(l1, l1 + right, p0, p1))
{
if (debug)
{
Debug.DrawLine(ToV3(l1), ToV3(l1) + Vector3.up * 5, Color.magenta);
}
shapeIntersections++;
}
if (FastLineIntersection(l2, l2 + right, p0, p1))
{
if (debug)
{
Debug.DrawLine(ToV3(l1), ToV3(l1) + Vector3.up * 5, Color.magenta);
}
shapeIntersections++;
break;
}
}
if (shapeIntersections % 2 == 0)
{
return(false);//line not within shape
}
}
if (debug)
{
edgeBounds.DrawDebug(Color.green);
}
Vector2 delta1 = b1 - a1;
Vector2 delta2 = b2 - a2;
float maxDelta = Mathf.Max(delta1.magnitude, delta2.magnitude);
int iterations = Mathf.CeilToInt(maxDelta / accuracy);
bool initalState = Ccw(a1, a2, l1);
for (int i = 1; i < iterations; i++)
{
percent = i / (iterations - 1f);
Vector2 e1 = Vector2.Lerp(a1, b1, percent);
Vector2 e2 = Vector2.Lerp(a2, b2, percent);
if (debug)
{
Debug.DrawLine(ToV3(e1), ToV3(e2), new Color(1, 0, 1, 0.5f));
}
Vector2 p = Vector2.Lerp(l1, l2, percent);
bool currentState = Ccw(e1, e2, p);
if (currentState != initalState || i == iterations - 1)
{
float dist1 = Vector2.Distance(e1, p);
float dist2 = Vector2.Distance(e2, p);
float xpercent = dist1 / (dist1 + dist2);
intersection = Vector2.Lerp(e1, e2, xpercent);
if (debug)
{
Debug.DrawLine(ToV3(e1), ToV3(e2), Color.red);
}
if (debug)
{
Debug.DrawLine(ToV3(intersection), ToV3(intersection) + Vector3.up * 10, Color.red);
}
break;
}
}
return(true);
}
/// <summary>
/// Return a shape with a defined shape cut out of it.
/// Will test find the best closest non intersectional cut to make in the base shape
/// Assumes the cut doesn't intersect the shape lines and is inside the base shape
/// </summary>
/// <param name="baseShape"></param>
/// <param name="cut"></param>
/// <returns></returns>
public static Vector2[] Execute(Vector2[] baseShape, List <Vector2[]> cuts)
{
bool dbg = false;
Vector2[] cut = (Vector2[])cuts[0].Clone();//todo multiple cuts
int baseCount = baseShape.Length;
int cutCount = cut.Length;
int outputCount = baseCount + cutCount + 2;
Vector2[] output = new Vector2[outputCount];
FlatBounds bounds = new FlatBounds(cut);
if (dbg)
{
bounds.DrawDebug(Color.magenta);
}
Vector2 center = bounds.center;
float nrest = Mathf.Infinity;
int nearestIndex = 0;
Array.Reverse(cut);//reverse winding to create cut
for (int b = 0; b < baseCount; b++)
{
float sqrMag = (baseShape[b] - center).sqrMagnitude;
if (sqrMag < nrest)
{
Vector2 a1 = center;
Vector2 a2 = baseShape[b];
bool intersectsShape = false;
for (int x = 0; x < baseCount; x++)
{
if (b == x)
{
continue;
}
int x2 = (x + 1) % baseCount;
if (b == x2)
{
continue;
}
Vector2 b1 = baseShape[x];
Vector2 b2 = baseShape[x2];
if (dbg)
{
Debug.DrawLine(ToV3(b1), ToV3(b2), Color.yellow);
}
if (FastLineIntersection(a1, a2, b1, b2))
{
intersectsShape = true;
break;
}
}
if (!intersectsShape)
{
nearestIndex = b;
nrest = sqrMag;
}
//intersection check
}
}
//find nearest cut point to base point
int nearestCutIndex = 0;
float nearestCut = Mathf.Infinity;
Vector2 baseCut = baseShape[nearestIndex];
for (int i = 0; i < cutCount; i++)
{
float sqrMag = (cut[i] - baseCut).sqrMagnitude;
if (sqrMag < nearestCut)
{
nearestCutIndex = i;
nearestCut = sqrMag;
}
}
if (dbg)
{
Debug.Log(nearestIndex);
Debug.DrawLine(ToV3(baseShape[nearestIndex]), ToV3(center), Color.red);
}
for (int o = 0; o < outputCount; o++)
{
if (o <= nearestIndex)
{
output[o] = baseShape[o];
if (dbg && o > 0)
{
Debug.DrawLine(ToV3(output[o]), ToV3(output[o - 1]) + Vector3.up, Color.blue, 60);
}
if (dbg)
{
Debug.Log("0x " + baseCount + " " + cutCount + " " + output.Length + " " + o);
}
}
else if (o > nearestIndex && o <= nearestIndex + cutCount + 1)
{
int cutIndex = (nearestCutIndex + o - nearestIndex - 1) % cutCount;
output[o] = cut[cutIndex];
if (dbg && o > 0)
{
Debug.DrawLine(ToV3(output[o]), ToV3(output[o - 1]) + Vector3.up, Color.blue, 60);
}
if (dbg)
{
Debug.Log("1x " + cutIndex + " " + baseCount + " " + cutCount + " " + output.Length + " " + o);
}
}
else
{
int finalIndex = (o - cutCount - 2 + baseCount) % baseCount;
if (dbg)
{
Debug.Log("2x " + finalIndex + " " + baseCount + " " + cutCount + " " + output.Length + " " + o);
}
output[o] = baseShape[finalIndex];
if (dbg && o > 0)
{
Debug.DrawLine(ToV3(output[o]), ToV3(output[o - 1]) + Vector3.up, Color.blue, 60);
}
}
}
return(output);
}