public static lineIntersection getLineIntersection(lineSegment L1, lineSegment L2)
{
lineIntersection LI;
LI.isIntersection = 0;
LI.x = 0;
LI.y = 0;
double p0_x = L1.x0;
double p0_y = L1.y0;
double p1_x = L1.x1;
double p1_y = L1.y1;
double p2_x = L2.x0;
double p2_y = L2.y0;
double p3_x = L2.x1;
double p3_y = L2.y1;
double s02_x, s02_y, s10_x, s10_y, s32_x, s32_y, s_numer, t_numer, denom, t;
s10_x = p1_x - p0_x;
s10_y = p1_y - p0_y;
s32_x = p3_x - p2_x;
s32_y = p3_y - p2_y;
denom = s10_x * s32_y - s32_x * s10_y;
if (denom == 0)
return LI; // Collinear
bool denomPositive = denom > 0;
s02_x = p0_x - p2_x;
s02_y = p0_y - p2_y;
s_numer = s10_x * s02_y - s10_y * s02_x;
if ((s_numer < 0) == denomPositive)
return LI; // No collision
t_numer = s32_x * s02_y - s32_y * s02_x;
if ((t_numer < 0) == denomPositive)
return LI; // No collision
if (((s_numer > denom) == denomPositive) || ((t_numer > denom) == denomPositive))
return LI; // No collision
// Collision detected
t = t_numer / denom;
LI.x = p0_x + (t * s10_x);
LI.y = p0_y + (t * s10_y);
LI.isIntersection = 1; // there is intersection
return LI;
}
private bool doSegmentsIntersect(lineSegment a, lineSegment b)
{
if (a.StartPoint == b.StartPoint ||
a.StartPoint == b.EndPoint ||
a.EndPoint == b.StartPoint ||
a.EndPoint == b.EndPoint)
{
return(false);
}
return((Mathf.Max(a.StartPoint.x, a.EndPoint.x) >= Mathf.Min(b.StartPoint.x, b.EndPoint.x)) &&
(Mathf.Max(b.StartPoint.x, b.EndPoint.x) >= Mathf.Min(a.StartPoint.x, a.EndPoint.x)) &&
(Mathf.Max(a.StartPoint.y, a.EndPoint.y) >= Mathf.Min(b.StartPoint.y, b.EndPoint.y)) &&
(Mathf.Max(b.StartPoint.y, b.EndPoint.y) >= Mathf.Min(a.StartPoint.y, a.EndPoint.y)));
}
private bool trailCollided()
{
if (renderer.positionCount < 3)
{
if (renderer.positionCount > 0)
{
lastDeltaDistance = renderer.GetPosition(renderer.positionCount - 1);
}
return(false);
}
if (Vector2.Distance(lastDeltaDistance, renderer.GetPosition(renderer.positionCount - 1)) < deltaDistance)
{
return(false);
}
lastDeltaDistance = renderer.GetPosition(renderer.positionCount - 1);
lineSegment[] segs = new lineSegment[renderer.positionCount - 1];
if (renderer.positionCount > 1)
{
for (int i = 0; i < segs.Length; i++)
{
segs[i].StartPoint = renderer.GetPosition(i);
segs[i].EndPoint = renderer.GetPosition(i + 1);
}
}
for (int i = 0; i < segs.Length; i++)
{
lineSegment currentSegment = new lineSegment();
currentSegment.StartPoint = renderer.GetPosition(renderer.positionCount - 2);
currentSegment.StartPoint = renderer.GetPosition(renderer.positionCount - 1);
if (doSegmentsIntersect(segs[i], currentSegment))
{
return(true);
}
}
return(false);
}
