The Ecere SDK - sdk/blob - ecere/src/gfx/3D/Plane.ec

   1 namespace gfx3D;
   2
   3 import "Display"
   4
   5 public struct Line
   6 {
   7    Vector3D p0;
   8    Vector3D delta;
   9
  10    bool IntersectSphere(double radius, double * t)
  11    {
  12       double a = delta.DotProduct(delta);
  13       double b = 2 * delta.DotProduct(p0);
  14       double c = p0.DotProduct(p0) - radius * radius;
  15       double disc = b * b - 4 * a * c;
  16       if(disc >= 0)
  17       {
  18          double distSqrt = sqrt(disc);
  19          double q = ((b < 0) ? (-b - distSqrt) : (-b + distSqrt)) /2;
  20          double t0 = q / a, t1 = c / q;
  21          if (t0 > t1)
  22          {
  23             double temp = t0;
  24             t0 = t1;
  25             t1 = temp;
  26          }
  27          if (t1 >= 0)
  28          {
  29             if(t)
  30               *t = (t0 >= 0) ? t0 : t1;
  31             return true;
  32          }
  33       }
  34       return false;
  35    }
  36 };
  37
  38 public struct Plane
  39 {
  40    union
  41    {
  42       struct { double a, b, c; };
  43       Vector3D normal;
  44    };
  45    double d;
  46
  47    void FromPoints(Vector3D v1, Vector3D v2, Vector3D v3)
  48    {
  49       Vector3D a, b;
  50
  51       a.Subtract(v3, v1);
  52       b.Subtract(v2, v1);
  53       normal.CrossProduct(a, b);
  54       normal.Normalize(normal);
  55
  56       d = -normal.DotProduct(v1);
  57    }
  58
  59    void FromPointsf(Vector3Df v1, Vector3Df v2, Vector3Df v3)
  60    {
  61       Vector3D v1d { (double)v1.x, (double)v1.y, (double)v1.z };
  62       Vector3D v2d { (double)v2.x, (double)v2.y, (double)v2.z };
  63       Vector3D v3d { (double)v3.x, (double)v3.y, (double)v3.z };
  64       Vector3D a, b;
  65
  66       a.Subtract(v3d, v1d);
  67       b.Subtract(v2d, v1d);
  68       normal.CrossProduct(a, b);
  69       normal.Normalize(normal);
  70
  71       d = -normal.DotProduct(v1d);
  72    }
  73
  74    void MultMatrix(Plane source, Matrix inverseTranspose)
  75    {
  76       a = source.a * inverseTranspose.m[0][0] +
  77           source.b * inverseTranspose.m[1][0] +
  78           source.c * inverseTranspose.m[2][0] +
  79           source.d * inverseTranspose.m[3][0];
  80       b = source.a * inverseTranspose.m[0][1] +
  81           source.b * inverseTranspose.m[1][1] +
  82           source.c * inverseTranspose.m[2][1] +
  83           source.d * inverseTranspose.m[3][1];
  84       c = source.a * inverseTranspose.m[0][2] +
  85           source.b * inverseTranspose.m[1][2] +
  86           source.c * inverseTranspose.m[2][2] +
  87           source.d * inverseTranspose.m[3][2];
  88       d = source.a * inverseTranspose.m[0][3] +
  89           source.b * inverseTranspose.m[1][3] +
  90           source.c * inverseTranspose.m[2][3] +
  91           source.d * inverseTranspose.m[3][3];
  92    }
  93
  94    void IntersectLine(Line line, Vector3D result)
  95    {
  96       double divisor = a * line.delta.x + b * line.delta.y + c * line.delta.z;
  97
  98       result.x = (b * line.delta.y * line.p0.x - b * line.delta.x * line.p0.y +
  99                   c * line.delta.z * line.p0.x - c * line.delta.x * line.p0.z -
 100                   d * line.delta.x ) / divisor;
 101
 102       result.y = (a * line.delta.x * line.p0.y - a * line.delta.y * line.p0.x +
 103                   c * line.delta.z * line.p0.y - c * line.delta.y * line.p0.z -
 104                   d * line.delta.y ) / divisor;
 105
 106       result.z = (a * line.delta.x * line.p0.z - a * line.delta.z * line.p0.x +
 107                   b * line.delta.y * line.p0.z - b * line.delta.z * line.p0.y -
 108                   d * line.delta.z ) / divisor;
 109    }
 110
 111    void IntersectLinef(Line line, Vector3Df result)
 112    {
 113       double divisor = a * line.delta.x + b * line.delta.y + c * line.delta.z;
 114
 115       result.x = (float)((b * line.delta.y * line.p0.x - b * line.delta.x * line.p0.y +
 116                   c * line.delta.z * line.p0.x - c * line.delta.x * line.p0.z -
 117                   d * line.delta.x ) / divisor);
 118
 119       result.y = (float)((a * line.delta.x * line.p0.y - a * line.delta.y * line.p0.x +
 120                   c * line.delta.z * line.p0.y - c * line.delta.y * line.p0.z -
 121                   d * line.delta.y ) / divisor);
 122
 123       result.z = (float)((a * line.delta.x * line.p0.z - a * line.delta.z * line.p0.x +
 124                   b * line.delta.y * line.p0.z - b * line.delta.z * line.p0.y -
 125                   d * line.delta.z ) / divisor);
 126    }
 127
 128    void FromPointNormal(Vector3D normal, Vector3D point)
 129    {
 130       this.normal = normal;
 131       d = -(normal.x * point.x + normal.y * point.y + normal.z * point.z);
 132    }
 133 };