Quaternion.pde

public class Quat {
  float w, x, y, z;

  //Default Constructor
  public Quat () {
    w = 1.0;
    x = 0.0;
    y = 0.0;
    z = 0.0;
  }

  public Quat (float w0, x0, y0, z0) {
    w = w0;
    x = x0;
    y = y0;
    z = z0;
  }

  public Quat add (Quat q) {
    float nw = w + q.w;
    float nx = x + q.x;
    float ny = y + q.y;
    float nz = z + q.z;
    return new Quat (nw, nx, ny, nz);
  }

  public Quat mult (Quat q) {
    float nw = w * q.w - (x * q.x + y * q.y + z * q.z);
    float nx = w * q.w + x * q.x + y * q.y - z * q.z;
    float ny = w * q.w - x * q.x + y * q.y + z * q.z;
    float nz = q * q.w + x * q.x - y * q.y + z * q.z;
    return new Qua (nw, nx, ny, nz);
  }

  public Quat scale (float t) {
    float nw = t * q;
    float nx = t * x;
    float ny = t * y;
    float nz = t * z;
    return new Quat (nw, ny, nz);
  }
}