[2751] | 1 | #include "Plane3.h"
|
---|
| 2 | #include "Matrix4x4.h"
|
---|
| 3 |
|
---|
| 4 |
|
---|
| 5 | namespace CHCDemo
|
---|
| 6 | {
|
---|
| 7 |
|
---|
| 8 | Plane3::Plane3(const Vector3 &a, const Vector3 &b, const Vector3 &c)
|
---|
| 9 | {
|
---|
[2755] | 10 | Vector3 v1 = a - b, v2 = c - b;
|
---|
| 11 | mNormal = Normalize(CrossProd(v2, v1));
|
---|
[2751] | 12 | mD = -DotProd(b, mNormal);
|
---|
| 13 | }
|
---|
| 14 |
|
---|
| 15 |
|
---|
[2762] | 16 | /*Plane3::Plane3(const Vector3 &normal, float dist):
|
---|
[2755] | 17 | mNormal(normal), mD(dist)
|
---|
| 18 | {
|
---|
[2762] | 19 | }*/
|
---|
[2755] | 20 |
|
---|
| 21 |
|
---|
[2751] | 22 | Plane3::Plane3(const Vector3 &normal, const Vector3 &point):
|
---|
| 23 | mNormal(normal)
|
---|
| 24 | {
|
---|
| 25 | mD = -DotProd(normal, point);
|
---|
| 26 | }
|
---|
| 27 |
|
---|
| 28 |
|
---|
| 29 | bool PlaneIntersection(const Plane3 &a,
|
---|
| 30 | const Plane3 &b,
|
---|
| 31 | const Plane3 &c,
|
---|
| 32 | Vector3 &result)
|
---|
| 33 | {
|
---|
| 34 | Vector3 sx(a.mNormal.x, b.mNormal.x, c.mNormal.x),
|
---|
| 35 | sy(a.mNormal.y, b.mNormal.y, c.mNormal.y),
|
---|
[2755] | 36 | sz(a.mNormal.z, b.mNormal.z, c.mNormal.z),
|
---|
| 37 | sd(a.mD, b.mD, c.mD);
|
---|
[2751] | 38 |
|
---|
[2755] | 39 | Matrix4x4 md(a.mNormal, b.mNormal, c.mNormal), mx, my, mz;
|
---|
[2751] | 40 |
|
---|
[2755] | 41 | mx.SetColumns(sd, sy, sz);
|
---|
| 42 | my.SetColumns(sx, sd, sz);
|
---|
| 43 | mz.SetColumns(sx, sy, sd);
|
---|
[2751] | 44 |
|
---|
[2755] | 45 | const float det = md.Det3x3();
|
---|
[2751] | 46 |
|
---|
[2755] | 47 | if (fabs(det) < TRASH)
|
---|
| 48 | return false;
|
---|
| 49 |
|
---|
| 50 | result.SetValue(mx.Det3x3()/det,
|
---|
| 51 | my.Det3x3()/det,
|
---|
| 52 | mz.Det3x3()/det);
|
---|
| 53 |
|
---|
| 54 | return true;
|
---|
[2751] | 55 | }
|
---|
| 56 |
|
---|
| 57 |
|
---|
[2755] | 58 | bool PlaneIntersection(const Plane3 &p1, const Plane3 &p2)
|
---|
| 59 | {
|
---|
| 60 | return
|
---|
| 61 | p1.mNormal.x != p2.mNormal.x ||
|
---|
| 62 | p1.mNormal.y != p2.mNormal.y ||
|
---|
| 63 | p1.mNormal.z != p2.mNormal.z ||
|
---|
| 64 | p1.mD == p2.mD;
|
---|
| 65 | }
|
---|
[2751] | 66 |
|
---|
| 67 |
|
---|
| 68 | Vector3 Plane3::FindIntersection(const Vector3 &a,
|
---|
| 69 | const Vector3 &b,
|
---|
| 70 | float *t,
|
---|
| 71 | bool *coplanar) const
|
---|
| 72 | {
|
---|
| 73 | // line from A to B
|
---|
| 74 | const Vector3 v = b - a;
|
---|
| 75 | float dv = DotProd(v, mNormal);
|
---|
| 76 |
|
---|
| 77 | if (signum(dv) == 0)
|
---|
| 78 | {
|
---|
| 79 | if (coplanar) (*coplanar) = true;
|
---|
| 80 |
|
---|
| 81 | if (t) (*t) = 0;
|
---|
| 82 |
|
---|
| 83 | return a;
|
---|
| 84 | }
|
---|
| 85 |
|
---|
| 86 | if (coplanar) (*coplanar) = false;
|
---|
| 87 |
|
---|
| 88 | float u = - Distance(a) / dv;
|
---|
| 89 |
|
---|
| 90 | if (t) (*t) = u;
|
---|
| 91 |
|
---|
| 92 | return a + u * v;
|
---|
| 93 | }
|
---|
| 94 |
|
---|
| 95 |
|
---|
| 96 | int Plane3::Side(const Vector3 &v, const float threshold) const
|
---|
| 97 | {
|
---|
| 98 | return signum(Distance(v), threshold);
|
---|
| 99 | }
|
---|
| 100 |
|
---|
| 101 |
|
---|
| 102 | float Plane3::FindT(const Vector3 &a, const Vector3 &b) const
|
---|
| 103 | {
|
---|
| 104 | const Vector3 v = b - a; // line from A to B
|
---|
| 105 | const float dv = DotProd(v, mNormal);
|
---|
| 106 |
|
---|
| 107 | // does not intersect or coincident
|
---|
| 108 | if (signum(dv) == 0)
|
---|
| 109 | return 0;
|
---|
| 110 |
|
---|
| 111 | return - Distance(a) / dv;
|
---|
| 112 | }
|
---|
| 113 |
|
---|
| 114 |
|
---|
| 115 | }
|
---|