directional vectors

2 files changed, 7 insertions, 6 deletions

diff --git a/_.c b/_.c
index 98c1912..cf596a2 100644
--- a/_.c
+++ b/_.c
@@ -97,10 +97,6 @@ vec2 v2r(f32 x) {
 	return v2(x, x);
 }
 
-vec2 v2_zero(void) {
-	return v2(0.0f, 0.0f);
-}
-
 bool v2_eq(vec2 a, vec2 b) {
 	return a.x == b.x && a.y == b.y;
 }
@@ -171,7 +167,7 @@ vec2 v2_lerp(vec2 a, vec2 b, f32 x) {
 }
 
 vec2 v2_transform(vec2 v, mat3 m) {
-	vec2 out = v2_zero();
+	vec2 out = v2_zero;
 	repeat (i, 2) {
 		out.a[i] = v.x * m.a[0][i] +
 		           v.y * m.a[1][i] +
diff --git a/_.h b/_.h
index 18b5f89..60518e0 100644
--- a/_.h
+++ b/_.h
@@ -106,9 +106,14 @@ union vec2 {
 	f32 a[2];
 };
 
+static const vec2 v2_zero  = {{  0,  0 }};
+static const vec2 v2_left  = {{ -1,  0 }};
+static const vec2 v2_right = {{  1,  0 }};
+static const vec2 v2_up    = {{  0, -1 }};
+static const vec2 v2_down  = {{  0,  1 }};
+
 vec2 v2(f32 x, f32 y);
 vec2 v2r(f32);
-vec2 v2_zero(void);
 bool v2_eq(vec2, vec2);
 vec2 v2_add(vec2, vec2);
 vec2 v2_sub(vec2, vec2);