OOVector.h

Go to the documentation of this file.

/*
 
OOVector.h
 
Mathematical framework for Oolite.
 
Oolite
Copyright (C) 2004-2013 Giles C Williams and contributors
 
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2
of the License, or (at your option) any later version.
 
This program 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 General Public License for more details.
 
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
MA 02110-1301, USA.
 
*/
 
 
#ifndef INCLUDED_OOMATHS_h
    #error Do not include OOVector.h directly; include OOMaths.h.
#else
 
 
#ifndef OOMATHS_EXTERNAL_VECTOR_TYPES
 
typedef struct Vector
{
    OOScalar x;
    OOScalar y;
    OOScalar z;
} Vector;
 
 
typedef struct Vector2D
{
    OOScalar x;
    OOScalar y;
} Vector2D;
 
#endif
 
 
extern const Vector     kZeroVector,        /* 0, 0, 0 */
                        kBasisXVector,      /* 1, 0, 0 */
                        kBasisYVector,      /* 0, 1, 0 */
                        kBasisZVector;      /* 0, 0, 1 */
 
 
extern const Vector2D   kZeroVector2D,      /* 0, 0 */
                        kBasisXVector2D,    /* 1, 0 */
                        kBasisYVector2D;    /* 0, 1 */
 
 
/* Construct vector */
OOINLINE Vector make_vector(OOScalar vx, OOScalar vy, OOScalar vz) INLINE_CONST_FUNC;
OOINLINE Vector2D MakeVector2D(OOScalar vx, OOScalar vy) INLINE_CONST_FUNC;
 
#if !OOMATHS_STANDALONE
/* Generate random vectors. */
Vector OORandomUnitVector(void);
Vector OOVectorRandomSpatial(OOScalar maxLength);   // Random vector uniformly distributed in radius-maxLength sphere. (Longer vectors are more common.)
Vector OOVectorRandomRadial(OOScalar maxLength);        // Random vector with uniform distribution of direction and radius in radius-maxLength sphere. (Causes clustering at centre.)
// only needed in high-precision forms so far
//Vector OORandomPositionInCylinder(Vector centre1, OOScalar exclusion1, Vector centre2, OOScalar exclusion2, OOScalar radius);
//Vector OORandomPositionInShell(Vector centre, OOScalar inner, OOScalar outer);
#endif
 
/* Multiply vector by scalar (in place) */
OOINLINE void scale_vector(Vector *outVector, OOScalar factor) ALWAYS_INLINE_FUNC NONNULL_FUNC;
 
/* Multiply vector by scalar */
OOINLINE Vector vector_multiply_scalar(Vector v, OOScalar s) INLINE_CONST_FUNC;
 
/* Addition and subtraction of vectors */
OOINLINE Vector vector_add(Vector a, Vector b) INLINE_CONST_FUNC;
OOINLINE Vector vector_subtract(Vector a, Vector b) INLINE_CONST_FUNC;
#define vector_between(a, b) vector_subtract(b, a)
OOINLINE Vector vector_flip(Vector v) INLINE_CONST_FUNC;
 
/* Vector linear interpolation */
OOINLINE Vector OOVectorInterpolate(Vector a, Vector b, OOScalar where) INLINE_CONST_FUNC;
OOINLINE Vector OOVectorTowards(Vector a, Vector b, OOScalar where) INLINE_CONST_FUNC;
 
/* Comparison of vectors */
OOINLINE bool vector_equal(Vector a, Vector b) INLINE_CONST_FUNC;
 
/* Square of magnitude of vector */
OOINLINE OOScalar magnitude2(Vector vec) INLINE_CONST_FUNC;
 
/* Magnitude of vector */
OOINLINE OOScalar magnitude(Vector vec) INLINE_CONST_FUNC;
 
/* Normalize vector */
OOINLINE Vector vector_normal(Vector vec) INLINE_CONST_FUNC;
 
/* Normalize vector, returning fallback if zero vector. */
OOINLINE Vector vector_normal_or_fallback(Vector vec, Vector fallback) INLINE_CONST_FUNC;
OOINLINE Vector vector_normal_or_xbasis(Vector vec) INLINE_CONST_FUNC;
OOINLINE Vector vector_normal_or_ybasis(Vector vec) INLINE_CONST_FUNC;
OOINLINE Vector vector_normal_or_zbasis(Vector vec) INLINE_CONST_FUNC;
 
/* Square of distance between vectors */
OOINLINE OOScalar distance2(Vector v1, Vector v2) INLINE_CONST_FUNC;
 
/* Distance between vectors */
OOINLINE OOScalar distance(Vector v1, Vector v2) INLINE_CONST_FUNC;
 
/* Dot product */
OOINLINE OOScalar dot_product (Vector first, Vector second) INLINE_CONST_FUNC;
 
/* NORMALIZED cross product */
OOINLINE Vector cross_product(Vector first, Vector second) INLINE_CONST_FUNC;
 
/* General cross product */
OOINLINE Vector true_cross_product(Vector first, Vector second) CONST_FUNC;
 
/* Triple product */
OOINLINE OOScalar triple_product(Vector first, Vector second, Vector third) INLINE_CONST_FUNC;
 
/* Given three points on a surface, returns the normal to the surface. */
OOINLINE Vector normal_to_surface(Vector v1, Vector v2, Vector v3) CONST_FUNC;
 
#if __OBJC__
NSString *VectorDescription(Vector vector); // @"(x, y, z)"
 
/* For storing vectors in NSArrays */
@interface OONativeVector: NSObject
{
@private
    Vector v;
}
- (id) initWithVector:(Vector)vect;
- (Vector) getVector;
 
@end
 
#endif
 
#if OOMATHS_OPENGL_INTEGRATION
/*  OpenGL conveniences. Need to be macros to work with OOMacroOpenGL. */
#define GLVertexOOVector(v) do { Vector v_ = v; glVertex3f(v_.x, v_.y, v_.z); } while (0)
#define GLTranslateOOVector(v) do { Vector v_ = v; OOGL(glTranslatef(v_.x, v_.y, v_.z)); } while (0)
#endif
 
 
/*** Only inline definitions beyond this point ***/
 
OOINLINE Vector make_vector (OOScalar vx, OOScalar vy, OOScalar vz)
{
    Vector result;
    result.x = vx;
    result.y = vy;
    result.z = vz;
    return result;
}
 
 
OOINLINE Vector2D MakeVector2D(OOScalar vx, OOScalar vy)
{
    Vector2D result;
    result.x = vx;
    result.y = vy;
    return result;
}
 
 
OOINLINE void scale_vector(Vector *vec, OOScalar factor)
{
    /*
        Clang static analyzer: reports an unintialized value here when called
        from -[HeadUpDisplay rescaleByFactor:]. This is blatantly wrong, as
        the array the vector comes from is fully initialized in the range being
        looped over.
        -- Ahruman 2012-09-14
    */
    vec->x *= factor;
    vec->y *= factor;
    vec->z *= factor;
}
 
 
OOINLINE Vector vector_multiply_scalar(Vector v, OOScalar s)
{
    /*
        Clang static analyzer: reports a garbage value here when called from
        -[OOMesh rescaleByFactor:], apparently on baseless assumption that
        OOMesh._vertices points to only one vertex.
        -- Ahruman 2012-09-14
    */
    Vector r;
    r.x = v.x * s;
    r.y = v.y * s;
    r.z = v.z * s;
    return r;
}
 
 
OOINLINE Vector vector_add(Vector a, Vector b)
{
    Vector r;
    r.x = a.x + b.x;
    r.y = a.y + b.y;
    r.z = a.z + b.z;
    return r;
}
 
 
OOINLINE Vector OOVectorInterpolate(Vector a, Vector b, OOScalar where)
{
    return make_vector(OOLerp(a.x, b.x, where),
                       OOLerp(a.y, b.y, where),
                       OOLerp(a.z, b.z, where));
}
 
 
OOINLINE Vector OOVectorTowards(Vector a, Vector b, OOScalar where)
{
    return make_vector(a.x + b.x * where,
                       a.y + b.y * where,
                       a.z + b.z * where);
}
 
 
OOINLINE Vector vector_subtract(Vector a, Vector b)
{
    Vector r;
    r.x = a.x - b.x;
    r.y = a.y - b.y;
    r.z = a.z - b.z;
    return r;
}
 
 
OOINLINE Vector vector_flip(Vector v)
{
    return vector_subtract(kZeroVector, v);
}
 
 
OOINLINE bool vector_equal(Vector a, Vector b)
{
    return a.x == b.x && a.y == b.y && a.z == b.z;
}
 
 
OOINLINE OOScalar magnitude2(Vector vec)
{
    return vec.x * vec.x + vec.y * vec.y + vec.z * vec.z;
}
 
 
OOINLINE OOScalar magnitude(Vector vec)
{
    return sqrt(magnitude2(vec));
}
 
 
OOINLINE Vector vector_normal_or_fallback(Vector vec, Vector fallback)
{
    OOScalar mag2 = magnitude2(vec);
    if (EXPECT_NOT(mag2 == 0.0f))  return fallback;
    return vector_multiply_scalar(vec, 1.0f / sqrt(mag2));
}
 
 
OOINLINE Vector vector_normal_or_xbasis(Vector vec)
{
    return vector_normal_or_fallback(vec, kBasisXVector);
}
 
 
OOINLINE Vector vector_normal_or_ybasis(Vector vec)
{
    return vector_normal_or_fallback(vec, kBasisYVector);
}
 
 
OOINLINE Vector vector_normal_or_zbasis(Vector vec)
{
    return vector_normal_or_fallback(vec, kBasisZVector);
}
 
 
OOINLINE Vector vector_normal(Vector vec)
{
    return vector_normal_or_fallback(vec, kZeroVector);
}
 
 
OOINLINE OOScalar distance2(Vector v1, Vector v2)
{
    return magnitude2(vector_subtract(v1, v2));
}
 
 
OOINLINE OOScalar distance(Vector v1, Vector v2)
{
    return magnitude(vector_subtract(v1, v2));
}
 
 
OOINLINE Vector true_cross_product(Vector first, Vector second)
{
    Vector result;
    result.x = (first.y * second.z) - (first.z * second.y);
    result.y = (first.z * second.x) - (first.x * second.z);
    result.z = (first.x * second.y) - (first.y * second.x);
    return result;
}
 
 
OOINLINE Vector cross_product(Vector first, Vector second)
{
    return vector_normal(true_cross_product(first, second));
}
 
 
OOINLINE OOScalar dot_product (Vector a, Vector b)
{
    return (a.x * b.x) + (a.y * b.y) + (a.z * b.z); 
}
 
 
OOINLINE OOScalar triple_product(Vector first, Vector second, Vector third)
{
    return dot_product(first, true_cross_product(second, third));
}
 
 
OOINLINE Vector normal_to_surface(Vector v1, Vector v2, Vector v3)
{
    Vector d0, d1;
    d0 = vector_subtract(v2, v1);
    d1 = vector_subtract(v3, v2);
    return cross_product(d0, d1);
}
 
 
#endif  /* INCLUDED_OOMATHS_h */