#ifndef VLR_TRANSFORM_H_
#define VLR_TRANSFORM_H_

 /** 3D transformation - can represent a combined translation and rotation */

typedef double dgc_transform_t[4][4];

  /** Print a 3D transform as a 4x4 matrix 
      @param t - transform to be printed 
      &param str - name of transform, which will be printed above matrix */

void dgc_transform_print(dgc_transform_t t, char *str);

  /** Initializes a transform as the identity transform */

void dgc_transform_identity(dgc_transform_t t);

  /** Left multiply transform t1 by transform t2 */

void dgc_transform_left_multiply(dgc_transform_t t1, dgc_transform_t t2);

  /** dest = left * src */

void dgc_transform_left_multiply_nc(dgc_transform_t dest, dgc_transform_t src, dgc_transform_t left);

  /** Rotate tranform around global x axis */

void dgc_transform_rotate_x(dgc_transform_t t, double theta);

  /** Rotate transform around global y axis */

void dgc_transform_rotate_y(dgc_transform_t t, double theta);

  /** Rotate transform around global z axis */

void dgc_transform_rotate_z(dgc_transform_t t, double theta);

  /** Add translation to transform */

void dgc_transform_translate(dgc_transform_t t, double x, double y, double z);

  /** Apply transform to 3D point */

inline void dgc_transform_point(double *x, double *y, double *z, dgc_transform_t t)
{
  double x2, y2, z2;

  x2 = t[0][0] * *x + t[0][1] * *y + t[0][2] * *z + t[0][3];
  y2 = t[1][0] * *x + t[1][1] * *y + t[1][2] * *z + t[1][3];
  z2 = t[2][0] * *x + t[2][1] * *y + t[2][2] * *z + t[2][3];
  *x = x2;
  *y = y2;
  *z = z2;
}

  /** Copy transform src to dest */

void dgc_transform_copy(dgc_transform_t dest, dgc_transform_t src);

  /** Read a transform from file */

int dgc_transform_read(dgc_transform_t t, char *filename);

  /** Read a transform from a string */

int dgc_transform_read_string(dgc_transform_t t, char *str);

  /** Get translation */

void dgc_transform_get_translation(dgc_transform_t t, double *x, double *y,
				   double *z);

  /** Get rotation */

void dgc_transform_get_rotation(dgc_transform_t t, double *x, double *y,
				double *z);

void dgc_transform_rpy(dgc_transform_t dest, dgc_transform_t src, double roll,
		       double pitch, double yaw);

void dgc_transform_inverse(dgc_transform_t in, dgc_transform_t out);

#endif