From b69854826898be24a48e77733f629240756073a3 Mon Sep 17 00:00:00 2001
From: "Steinar H. Gunderson" <sgunderson@bigfoot.com>
Date: Fri, 6 Jul 2018 00:22:24 +0200
Subject: [PATCH] Visualize the flow consistently with .flo files (which have y
 = down).

---
 flow.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/flow.cpp b/flow.cpp
index e59a481..205b24f 100644
--- a/flow.cpp
+++ b/flow.cpp
@@ -523,7 +523,7 @@ int main(void)
 			float w = dense_flow[(yy * level_width + x) * 3 + 2];
 
 			du = (du / w) * level_width;
-			dv = (dv / w) * level_height;
+			dv = (-dv / w) * level_height;
 
 			uint8_t r, g, b;
 			flow2rgb(du, dv, &r, &g, &b);
-- 
2.39.2