From 01367af99c7ab95507974ce2a035b2d500642dac Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Mario=20H=C3=BCttel?= <mario.huettel@gmx.net>
Date: Sat, 28 Jul 2018 10:37:00 +0200
Subject: [PATCH] vector operations added

---
 trigonometric/vector-operations.c | 85 +++++++++++++++++++++++++++++++
 trigonometric/vector-operations.h | 10 ++++
 2 files changed, 95 insertions(+)

diff --git a/trigonometric/vector-operations.c b/trigonometric/vector-operations.c
index b164471..f9e110d 100644
--- a/trigonometric/vector-operations.c
+++ b/trigonometric/vector-operations.c
@@ -24,3 +24,88 @@
  */
 
 #include "vector-operations.h"
+#include <math.h>
+#include <stdlib.h>
+
+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_normaize(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;
+
+	sin_val = sin(angle);
+	cos_val = cos(angle);
+
+	vecor_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 *vecor_2d_copy(struct vector_2d *opt_res, struct vector_2d *vec)
+{
+	struct vector_2d *res;
+
+	if (!vec)
+		return NULL;
+	if (opt_res) {
+		opt_res->x = vec->x;
+		opt_res->y = vec->y;
+		return 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;
+}
diff --git a/trigonometric/vector-operations.h b/trigonometric/vector-operations.h
index a89bc4f..59bfae5 100644
--- a/trigonometric/vector-operations.h
+++ b/trigonometric/vector-operations.h
@@ -31,4 +31,14 @@ struct vector_2d {
     double y;
 };
 
+
+double vector_2d_scalar_multipy(struct vector_2d *a, struct vector_2d *b);
+void vector_2d_normalize(struct vector_2d *vec);
+void vecor_2d_rotate(struct vector_2d *vec, double angle);
+struct vector_2d *vecor_2d_copy(struct vector_2d *opt_res, struct vector_2d *vec);
+struct vector_2d *vector_2d_alloc(void);
+void vector_2d_free(struct vector_2d *vec);
+void vector_2d_scale(struct vector_2d *vec, double scale);
+double vector_2d_abs(struct vector_2d *vec);
+
 #endif /* _VECTOR_OPERATIONS_H_ */