/*************************************************************************
 * Copyright (C) 2008 Tavian Barnes <tavianator@gmail.com>               *
 *                                                                       *
 * This file is part of Dimension.                                       *
 *                                                                       *
 * Dimension is free software; you can redistribute it and/or modify it  *
 * under the terms of the GNU Lesser General Public License as published *
 * by the Free Software Foundation; either version 3 of the License, or  *
 * (at your option) any later version.                                   *
 *                                                                       *
 * Dimension is distributed in the hope that it will be useful, but      *
 * WITHOUT ANY WARRANTY; without even the implied warranty of            *
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU     *
 * Lesser General Public License for more details.                       *
 *                                                                       *
 * You should have received a copy of the GNU Lesser General Public      *
 * License along with this program.  If not, see                         *
 * <http://www.gnu.org/licenses/>.                                       *
 *************************************************************************/

/*
 * Core geometric types like scalars, vectors, and rays.
 */

#ifndef DIMENSION_GEOMETRY_H
#define DIMENSION_GEOMETRY_H

/* Scalar and vector types. */
typedef double                           dmnsn_scalar;
typedef struct { dmnsn_scalar x, y, z; } dmnsn_vector;

/* Vector arithmetic */

dmnsn_vector dmnsn_vector_construct(dmnsn_scalar x,
                                    dmnsn_scalar y,
                                    dmnsn_scalar z);

dmnsn_vector dmnsn_vector_add(dmnsn_vector lhs, dmnsn_vector rhs);
dmnsn_vector dmnsn_vector_sub(dmnsn_vector lhs, dmnsn_vector rhs);
dmnsn_vector dmnsn_vector_mul(dmnsn_scalar lhs, dmnsn_vector rhs);
dmnsn_vector dmnsn_vector_div(dmnsn_vector lhs, dmnsn_scalar rhs);

dmnsn_scalar dmnsn_vector_dot(dmnsn_vector lhs, dmnsn_vector rhs);
dmnsn_vector dmnsn_vector_cross(dmnsn_vector lhs, dmnsn_vector rhs);

/* A line, or ray. */
typedef struct {
  dmnsn_vector x0; /* A point on the line */
  dmnsn_vector n;  /* A normal vector; the direction of the line */
} dmnsn_line;

/* A point on a line, defined by x0 + t*n */
dmnsn_vector dmnsn_line_point(dmnsn_line l, dmnsn_scalar t);

#endif /* DIMENSION_GEOMETRY_H */