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/*
* Copyright (C) 2018-2019 - Vito Caputo - <vcaputo@pengaru.com>
*
* This program is free software: you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 3 as published
* by the Free Software Foundation.
*
* 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, see <http://www.gnu.org/licenses/>.
*/
/*
* 3D vector operations header
*
* Variants prefixed with _ return a result vector struct by value.
*
* Variants missing the _ prefix for vector result operations return a pointer
* and must be either supplied the result memory as the first "res" argument
* which is then returned after being populated with the result's value, or
* NULL to allocate space for the result and that pointer is resturned after being
* populated with its value. When supplying NULL result pointers the functions
* must allocate memory and thus may return NULL on OOM, so callers should
* check for NULL returns when supplying NULL for res.
*
* Example:
* v3f_t foo, *foop;
*
* foo = _v3f_mult(&(v3f_t){1.f,1.f,1.f}, &(v3f_t){2.f,2.f,2.f});
*
* is equivalent to:
*
* v3f_mult(&foo, &(v3f_t){1.f,1.f,1.f}, &(v3f_t){2.f,2.f,2.f});
*
* or dynamically allocated:
*
* foop = v3f_mult(NULL, &(v3f_t){1.f,1.f,1.f}, &(v3f_t){2.f,2.f,2.f});
* free(foop);
*
* is equivalent to:
*
* foop = malloc(sizeof(v3f_t));
* v3f_mult(foop, &(v3f_t){1.f,1.f,1.f}, &(v3f_t){2.f,2.f,2.f});
* free(foop);
*/
#ifndef _V3F_H
#define _V3F_H
#include <math.h>
#include <stdlib.h>
typedef struct v3f_t {
float x, y, z;
} v3f_t;
static inline v3f_t * _v3f_allocated(v3f_t **ptr)
{
if (!*ptr)
*ptr = malloc(sizeof(v3f_t));
return *ptr;
}
static inline v3f_t _v3f_add(const v3f_t *a, const v3f_t *b)
{
return (v3f_t){a->x + b->x, a->y + b->y, a->z + b->z};
}
static inline v3f_t * v3f_add(v3f_t *res, const v3f_t *a, const v3f_t *b)
{
if (_v3f_allocated(&res))
*res = _v3f_add(a, b);
return res;
}
static inline v3f_t _v3f_sub(const v3f_t *a, const v3f_t *b)
{
return (v3f_t){a->x - b->x, a->y - b->y, a->z - b->z};
}
static inline v3f_t * v3f_sub(v3f_t *res, const v3f_t *a, const v3f_t *b)
{
if (_v3f_allocated(&res))
*res = _v3f_sub(a, b);
return res;
}
static inline v3f_t _v3f_mult(const v3f_t *a, const v3f_t *b)
{
return (v3f_t){a->x * b->x, a->y * b->y, a->z * b->z};
}
static inline v3f_t * v3f_mult(v3f_t *res, const v3f_t *a, const v3f_t *b)
{
if (_v3f_allocated(&res))
*res = _v3f_mult(a, b);
return res;
}
static inline v3f_t _v3f_mult_scalar(const v3f_t *v, float scalar)
{
return (v3f_t){v->x * scalar, v->y * scalar, v->z * scalar};
}
static inline v3f_t * v3f_mult_scalar(v3f_t *res, const v3f_t *v, float scalar)
{
if (_v3f_allocated(&res))
*res = _v3f_mult_scalar(v, scalar);
return res;
}
static inline v3f_t _v3f_div_scalar(const v3f_t *v, float scalar)
{
return _v3f_mult_scalar(v, 1.f / scalar);
}
static inline v3f_t * v3f_div_scalar(v3f_t *res, const v3f_t *v, float scalar)
{
if (_v3f_allocated(&res))
*res = _v3f_div_scalar(v, scalar);
return res;
}
static inline float v3f_dot(const v3f_t *a, const v3f_t *b)
{
return a->x * b->x + a->y * b->y + a->z * b->z;
}
static inline float v3f_length(const v3f_t *v)
{
return sqrtf(v3f_dot(v, v));
}
static inline v3f_t _v3f_normalize(const v3f_t *v)
{
return _v3f_mult_scalar(v, 1.0f / v3f_length(v));
}
static inline v3f_t * v3f_normalize(v3f_t *res, const v3f_t *v)
{
if (_v3f_allocated(&res))
*res = _v3f_normalize(v);
return res;
}
static inline v3f_t _v3f_lerp(const v3f_t *a, const v3f_t *b, float t)
{
v3f_t lerp_a, lerp_b;
lerp_a = _v3f_mult_scalar(a, 1.0f - t);
lerp_b = _v3f_mult_scalar(b, t);
return _v3f_add(&lerp_a, &lerp_b);
}
static inline v3f_t * v3f_lerp(v3f_t *res, const v3f_t *a, const v3f_t *b, float t)
{
if (_v3f_allocated(&res))
*res = _v3f_lerp(a, b, t);
return res;
}
static inline v3f_t _v3f_nlerp(const v3f_t *a, const v3f_t *b, float t)
{
v3f_t lerp = _v3f_lerp(a, b, t);
return _v3f_normalize(&lerp);
}
static inline v3f_t * v3f_nlerp(v3f_t *res, const v3f_t *a, const v3f_t *b, float t)
{
if (_v3f_allocated(&res))
*res = _v3f_nlerp(a, b, t);
return res;
}
/*
* 1 ab-------bb
* | | |
* | | |
* | | |
* 0 aa-------ba
* t_x: 0---------1
* ^
* t_y
*/
static inline v3f_t _v3f_bilerp(const v3f_t *aa, const v3f_t *ab, const v3f_t *ba, const v3f_t *bb, float t_x, float t_y)
{
v3f_t xa = _v3f_lerp(aa, ba, t_x);
v3f_t xb = _v3f_lerp(ab, bb, t_x);
return _v3f_lerp(&xa, &xb, t_y);
}
static inline v3f_t * v3f_bilerp(v3f_t *res, const v3f_t *aa, const v3f_t *ab, const v3f_t *ba, const v3f_t *bb, float t_x, float t_y)
{
if (_v3f_allocated(&res))
*res = _v3f_bilerp(aa, ab, ba, bb, t_x, t_y);
return res;
}
static inline v3f_t _v3f_cross(const v3f_t *a, const v3f_t *b)
{
return (v3f_t){
.x = a->y * b->z - a->z * b->y,
.y = a->z * b->x - a->x * b->z,
.z = a->x * b->y - a->y * b->x,
};
}
static inline v3f_t * v3f_cross(v3f_t *res, const v3f_t *a, const v3f_t *b)
{
if (_v3f_allocated(&res))
*res = _v3f_cross(a, b);
return res;
}
#endif
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