2 files changed, 26 insertions, 0 deletions

diff --git a/maths.c b/maths.c
index 70b354e..a0c9ed5 100644
--- a/maths.c
+++ b/maths.c
@@ -282,6 +282,29 @@ int* vec_nrm(int* d, const int* a, int c) {
 	return d;
 }
 
+int* vec_sub(int* d, const int* a, const int* b, int c) {
+	int i;
+	for (i = 0; i < c; i++) {
+		d[i] = a[i] - b[i];
+	}
+	return d;
+}
+
+int* vec_add(int* d, const int* a, const int* b, int c) {
+	int i;
+	for (i = 0; i < c; i++) {
+		d[i] = a[i] + b[i];
+	}
+	return d;
+}
+
+int vec_dist(int* w, const int* a, const int* b, int c) {
+	int dot;
+	vec_sub(w, a, b, c);
+	dot = vec_dot(w, w, c);
+	return fsqrt(dot);
+}
+
 int* persp(int* v, int asp) {
 	v[2] += !v[2];
 	v[0] = ((v[0] << fbits) / v[2]);
diff --git a/maths.h b/maths.h
index e72f8fd..725e401 100644
--- a/maths.h
+++ b/maths.h
@@ -44,6 +44,9 @@ int* vec_ref(int* d, const int* i, const int* n, int c);
 int vec_dot(const int* a, const int* b, int d);
 int* vec_nrm(int* d, const int* a, int c);
 int* vec_minise(int* d, const int* a, int c);
+int* vec_sub(int* d, const int* a, const int* b, int c);
+int* vec_add(int* d, const int* a, const int* b, int c);
+int vec_dist(int* w, const int* a, const int* b, int c);
 int* persp(int* v, int asp);
 int* ndc2clip(const int* c, int* p);