From ef4dbe789201bcb92596a67eb3fb3f3f03a09b49 Mon Sep 17 00:00:00 2001 From: Tavian Barnes Date: Sun, 1 Mar 2009 01:25:13 +0000 Subject: Initial commit. --- libdimension/dimension/geometry.h | 92 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 92 insertions(+) create mode 100644 libdimension/dimension/geometry.h (limited to 'libdimension/dimension/geometry.h') diff --git a/libdimension/dimension/geometry.h b/libdimension/dimension/geometry.h new file mode 100644 index 0000000..2c0c204 --- /dev/null +++ b/libdimension/dimension/geometry.h @@ -0,0 +1,92 @@ +/************************************************************************* + * Copyright (C) 2008 Tavian Barnes * + * * + * 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 * + * . * + *************************************************************************/ + +/* + * 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 */ + +inline dmnsn_vector +dmnsn_vector_construct(dmnsn_scalar x, dmnsn_scalar y, dmnsn_scalar z) +{ + dmnsn_vector v = { .x = x, .y = y, .z = z }; + return v; +} + +inline dmnsn_vector +dmnsn_vector_add(dmnsn_vector lhs, dmnsn_vector rhs) +{ + return dmnsn_vector_construct(lhs.x + rhs.x, lhs.y + rhs.y, lhs.z + rhs.z); +} + +inline dmnsn_vector +dmnsn_vector_sub(dmnsn_vector lhs, dmnsn_vector rhs) +{ + return dmnsn_vector_construct(lhs.x - rhs.x, lhs.y - rhs.y, lhs.z - rhs.z); +} + +inline dmnsn_vector +dmnsn_vector_mul(dmnsn_scalar lhs, dmnsn_vector rhs) +{ + return dmnsn_vector_construct(lhs*rhs.x, lhs*rhs.y, lhs*rhs.z); +} + +inline dmnsn_vector +dmnsn_vector_div(dmnsn_vector lhs, dmnsn_scalar rhs) +{ + return dmnsn_vector_construct(lhs.x/rhs, lhs.y/rhs, lhs.z/rhs); +} + +inline dmnsn_scalar +dmnsn_vector_dot(dmnsn_vector lhs, dmnsn_vector rhs) +{ + return lhs.x*rhs.x + lhs.y*rhs.y + lhs.z*rhs.z; +} + +inline dmnsn_vector +dmnsn_vector_cross(dmnsn_vector lhs, dmnsn_vector rhs) +{ + return dmnsn_vector_construct(lhs.y*rhs.z - lhs.z*rhs.y, + lhs.z*rhs.x - lhs.x*rhs.z, + lhs.x*rhs.y - lhs.y*rhs.x); +} + +/* 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 */ +inline dmnsn_vector +dmnsn_line_point(dmnsn_line l, dmnsn_scalar t) +{ + return dmnsn_vector_add(l.x0, dmnsn_vector_mul(t, l.n)); +} + +#endif /* DIMENSION_GEOMETRY_H */ -- cgit v1.2.3