From 5078ef1578f56cfca6e6d98169cd6b367f4f82e6 Mon Sep 17 00:00:00 2001
From: Lucas <lucas@domain.invalid>
Date: Fri, 13 Mar 2020 01:33:12 +0000
Subject: [PATCH] [julia] change how azimuth is chosen for lighting

Use a vector that has always a z-coordinate in (0,1) range.
---
 julia.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/julia.c b/julia.c
index 138c6b9..7b5871c 100644
--- a/julia.c
+++ b/julia.c
@@ -203,7 +203,10 @@ julia_main(int argc, char *argv[])
 	if (do_light) {
 		long double angle_xy, angle_z;
 		angle_xy = drand48() * 2.0L * RADIAN;
-		angle_z = (0.2L + 0.6L * drand48()) * RADIAN;
+		do
+			angle_z = drand48();
+		while (angle_z == 0.0L || angle_z == 1.0L);
+		angle_z = angle_z * 0.5L * RADIAN;
 		light_x = cosl(angle_xy) * sinl(angle_z);
 		light_y = sinl(angle_xy) * sinl(angle_z);
 		light_z = cosl(angle_z);