libftm matrix, dynamic vector instead of fixed size

1 files changed, 33 insertions, 0 deletions

diff --git a/vendor/libftm/src/vec/ftm_veccross.c b/vendor/libftm/src/vec/ftm_veccross.c
new file mode 100644
index 0000000..48dda5f
--- /dev/null
+++ b/vendor/libftm/src/vec/ftm_veccross.c
@@ -0,0 +1,33 @@
+/* ************************************************************************** */
+/*                                                                            */
+/*                                                        :::      ::::::::   */
+/*   ftm_veccross.c                                     :+:      :+:    :+:   */
+/*                                                    +:+ +:+         +:+     */
+/*   By: charles <charles.cabergs@gmail.com>        +#+  +:+       +#+        */
+/*                                                +#+#+#+#+#+   +#+           */
+/*   Created: 2020/05/09 21:20:41 by charles           #+#    #+#             */
+/*   Updated: 2020/05/11 12:43:33 by charles          ###   ########.fr       */
+/*                                                                            */
+/* ************************************************************************** */
+
+#include "libftm_vec.h"
+
+/*
+** s1 = a2 * b - a * b2
+** s2 = a * b1 - a1 * b
+** s = a1 * b2 - a2 * b1
+*/
+
+t_ftmvec	*ftm_veccross(t_ftmvec *a, t_ftmvec *b)
+{
+	t_ftmvec	*dst;
+
+	if (a->size != 3 || b->size != 3)
+		return (NULL);
+	if ((dst = ftm_vecnew(3)) == NULL)
+		return (NULL);
+	dst->v[0] = a->v[1] * b->v[2] - a->v[2] * b->v[1];
+	dst->v[1] = a->v[2] * b->v[0] - a->v[0] * b->v[2];
+	dst->v[2] = a->v[0] * b->v[1] - a->v[1] * b->v[0];
+	return (dst);
+}