Singularity/Library/PackageCache/com.unity.2d.animation@7.0.10/Editor/SkinningModule/MathUtility.cs
2024-05-06 11:45:45 -07:00

137 lines
4.4 KiB
C#

using System;
using UnityEngine;
namespace UnityEditor.U2D.Animation
{
internal static class MathUtility
{
public static float DistanceToSegmentClamp(Vector3 p, Vector3 p1, Vector3 p2)
{
float l2 = (p2 - p1).sqrMagnitude; // i.e. |b-a|^2 - avoid a sqrt
if (l2 == 0.0)
return float.MaxValue; // a == b case
float t = Vector3.Dot(p - p1, p2 - p1) / l2;
if (t < 0.0)
return float.MaxValue; // Beyond the 'a' end of the segment
if (t > 1.0)
return float.MaxValue; // Beyond the 'b' end of the segment
Vector3 projection = p1 + t * (p2 - p1); // Projection falls on the segment
return (p - projection).magnitude;
}
public static Vector2 ClampPositionToRect(Vector2 position, Rect rect)
{
return new Vector2(Mathf.Clamp(position.x, rect.xMin, rect.xMax), Mathf.Clamp(position.y, rect.yMin, rect.yMax));
}
public static Vector2 MoveRectInsideFrame(Rect rect, Rect frame, Vector2 delta)
{
if (frame.size.x <= rect.size.x)
delta.x = 0f;
if (frame.size.y <= rect.size.y)
delta.y = 0f;
Vector2 min = rect.min + delta;
Vector2 max = rect.max + delta;
Vector2 size = rect.size;
Vector2 position = rect.position;
max.x = Mathf.Clamp(max.x, frame.min.x, frame.max.x);
max.y = Mathf.Clamp(max.y, frame.min.y, frame.max.y);
min = max - size;
min.x = Mathf.Clamp(min.x, frame.min.x, frame.max.x);
min.y = Mathf.Clamp(min.y, frame.min.y, frame.max.y);
max = min + size;
rect.min = min;
rect.max = max;
delta = rect.position - position;
return delta;
}
public static bool SegmentIntersection(Vector2 p0, Vector2 p1, Vector2 p2, Vector2 p3, ref Vector2 point)
{
Vector2 s1 = p1 - p0;
Vector2 s2 = p3 - p2;
float s, t, determinant;
determinant = (s1.x * s2.y - s2.x * s1.y);
if (Mathf.Approximately(determinant, 0f))
return false;
s = (-s1.y * (p0.x - p2.x) + s1.x * (p0.y - p2.y)) / determinant;
t = (s2.x * (p0.y - p2.y) - s2.y * (p0.x - p2.x)) / determinant;
if (s >= 0f && s <= 1f && t >= 0f && t <= 1f)
{
point = p0 + (t * s1);
return true;
}
return false;
}
//https://gamedev.stackexchange.com/a/49370
public static void Barycentric(Vector2 p, Vector2 a, Vector2 b, Vector2 c, out Vector3 coords)
{
Vector2 v0 = b - a, v1 = c - a, v2 = p - a;
float d00 = Vector2.Dot(v0, v0);
float d01 = Vector2.Dot(v0, v1);
float d11 = Vector2.Dot(v1, v1);
float d20 = Vector2.Dot(v2, v0);
float d21 = Vector2.Dot(v2, v1);
float invDenom = 1f / (d00 * d11 - d01 * d01);
coords.y = (d11 * d20 - d01 * d21) * invDenom;
coords.z = (d00 * d21 - d01 * d20) * invDenom;
coords.x = 1f - coords.y - coords.z;
}
public static Quaternion NormalizeQuaternion(Quaternion q)
{
Vector4 v = new Vector4(q.x, q.y, q.z, q.w).normalized;
return new Quaternion(v.x, v.y, v.z, v.w);
}
//From: https://answers.unity.com/questions/861719/a-fast-triangle-triangle-intersection-algorithm-fo.html
public static bool Intersect(Vector3 p1, Vector3 p2, Vector3 p3, Ray ray)
{
Vector3 e1, e2;
Vector3 p, q, t;
float det, invDet, u, v;
e1 = p2 - p1;
e2 = p3 - p1;
p = Vector3.Cross(ray.direction, e2);
det = Vector3.Dot(e1, p);
if (Mathf.Approximately(det, 0f))
return false;
invDet = 1.0f / det;
t = ray.origin - p1;
u = Vector3.Dot(t, p) * invDet;
if (u < 0 || u > 1)
return false;
q = Vector3.Cross(t, e1);
v = Vector3.Dot(ray.direction, q) * invDet;
if (v < 0 || u + v > 1)
return false;
if ((Vector3.Dot(e2, q) * invDet) > 0f)
return true;
return false;
}
}
}