Use same population indexing in collide and stream

Increases consistency and should help to avoid confusion

1 files changed, 1 insertions, 1 deletions

diff --git a/src/shader/code/collide.glsl b/src/shader/code/collide.glsl
index 3510c4e..23e98f9 100644
--- a/src/shader/code/collide.glsl
+++ b/src/shader/code/collide.glsl
@@ -44,7 +44,7 @@ float norm(vec2 v) {
 /// Array indexing
 
 uint indexOfDirection(int i, int j) {
-	return 3*(j+1) + (i+1);
+	return 3*(i+1) + (j+1);
 }
 
 uint indexOfLatticeCell(uint x, uint y) {