/// <summary>Finds the lowest distance of point P to a line segment defined by points A and B</summary>
public static float distance_from_point_to_segment(crds2 a, crds2 b, crds2 p)
{
float l2 = a.dist_squared(b);
if (l2 < 0.000001f) return a.dist(p); // case : a == b
float t = crds2.dot(p-a, b-a) / l2;
if (t < 0f) return a.dist(p);
if (t > 1f) return b.dist(p);
crds2 proj = a.lerp(b, t);
return proj.dist(p);
}
/// <summary>same as segment-segment int. but points only define the line, don't limit it</summary>
public static bool line_line_intersection(crds2 A, crds2 B, crds2 C, crds2 D, out crds2 intersection_point)
{
intersection_point = crds2.zero;
var z = (D.y - C.y) * (B.x - A.x) - (D.x - C.x) * (B.y - A.y);
if (z.approximately(0f)) return false;
var U1 = ((D.x - C.x) * (A.y - C.y) - (D.y - C.y) * (A.x - C.x)) / z;
var U2 = ((B.x - A.x) * (A.y - C.y) - (B.y - A.y) * (A.x - C.x)) / z;
intersection_point = A.lerp(B, U1);
return true;
}
/// <summary> Returns the point of intersection of two segments, where first segment is defined by A and B, and 2nd segment by C and D. </summary>
/// <param name="A">Point A</param><param name="B">Point B</param><param name="C">Point C</param><param name="D">Point D</param><param name="intersection_point">Intersection point, if any</param>
/// <returns>True if there is an intersection, and if so, fills intersection_point with the exact location</returns>
public static bool segment_segment_intersection(crds2 A, crds2 B, crds2 C, crds2 D, out crds2 intersection_point)
{
intersection_point = crds2.zero;
var z = (D.y - C.y) * (B.x - A.x) - (D.x - C.x) * (B.y - A.y);
if (z.approximately(0f)) return false;
var U1 = ((D.x - C.x) * (A.y - C.y) - (D.y - C.y) * (A.x - C.x)) / z;
var U2 = ((B.x - A.x) * (A.y - C.y) - (B.y - A.y) * (A.x - C.x)) / z;
if ((U1 >= 0f && U1 <= 1f) && (U2 >= 0f && U2 <= 1f))
{
intersection_point = A.lerp(B, U1);
return true;
}
return false;
}
public static void set_extremes(crds2 upper_left, crds2 lower_right, float min_zoom, float max_zoom)
{
restrictions_low.x = upper_left.x;
restrictions_low.y = upper_left.y;
restrictions_high.x = lower_right.x;
restrictions_high.y = lower_right.y;
restrictions_low.w = min_zoom * ZOOM_FACTOR;
restrictions_high.w = max_zoom * ZOOM_FACTOR;
set_target(upper_left.lerp(lower_right, 0.5f));
}
