vector-operations.c

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/*
 * GDSII-Converter
 * Copyright (C) 2018  Mario Hüttel <mario.huettel@gmx.net>
 *
 * This file is part of GDSII-Converter.
 *
 * GDSII-Converter is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * GDSII-Converter 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 GDSII-Converter.  If not, see <http://www.gnu.org/licenses/>.
 */
 
#include <math.h>
#include <stdlib.h>
 
#include <gds-render/geometric/vector-operations.h>
 
#define ABS_DBL(a) ((a) < 0.0 ? -(a) : (a))
 
double vector_2d_scalar_multipy(struct vector_2d *a, struct vector_2d *b)
{
        if (a && b)
                return (a->x * b->x) + (a->y * b->y);
        else
                return 0.0;
}
 
void vector_2d_normalize(struct vector_2d *vec)
{
        double len;
 
        if (!vec)
                return;
        len = sqrt(pow(vec->x, 2) + pow(vec->y, 2));
        vec->x = vec->x/len;
        vec->y = vec->y/len;
}
 
void vector_2d_rotate(struct vector_2d *vec, double angle)
{
        double sin_val, cos_val;
        struct vector_2d temp;
 
        if (!vec)
                return;
 
        sin_val = sin(angle);
        cos_val = cos(angle);
 
        (void)vector_2d_copy(&temp, vec);
 
        /* Apply rotation matrix */
        vec->x = (cos_val * temp.x) - (sin_val * temp.y);
        vec->y = (sin_val * temp.x) + (cos_val * temp.y);
}
 
struct vector_2d *vector_2d_copy(struct vector_2d *opt_res, struct vector_2d *vec)
{
        struct vector_2d *res;
 
        if (!vec)
                return NULL;
 
        if (opt_res)
                res = opt_res;
        else
                res = vector_2d_alloc();
 
        if (res) {
                res->x = vec->x;
                res->y = vec->y;
        }
                return res;
}
 
struct vector_2d *vector_2d_alloc(void)
{
        return (struct vector_2d *)malloc(sizeof(struct vector_2d));
}
 
void vector_2d_free(struct vector_2d *vec)
{
        if (vec)
                free(vec);
}
 
void vector_2d_scale(struct vector_2d *vec, double scale)
{
        if (!vec)
                return;
 
        vec->x *= scale;
        vec->y *= scale;
}
 
double vector_2d_abs(struct vector_2d *vec)
{
        double len = 0.0;
 
        if (vec)
                len = sqrt(pow(vec->x, 2) + pow(vec->y, 2));
        return len;
}
 
double vector_2d_calculate_angle_between(struct vector_2d *a, struct vector_2d *b)
{
        double cos_angle;
 
        if (!a || !b)
                return 0.0;
 
        cos_angle = ABS_DBL(vector_2d_scalar_multipy(a, b)) / (vector_2d_abs(a) * vector_2d_abs(b));
        return acos(cos_angle);
}
 
void vector_2d_subtract(struct vector_2d *res, struct vector_2d *a, struct vector_2d *b)
{
        if (res && a && b) {
                res->x = a->x - b->x;
                res->y = a->y - b->y;
        }
}
 
void vector_2d_add(struct vector_2d *res, struct vector_2d *a, struct vector_2d *b)
{
        if (res && a && b) {
                res->x = a->x + b->x;
                res->y = a->y + b->y;
        }
}