From 3b226ba81a4fd5217dcc2004d30a82e97fddbf17 Mon Sep 17 00:00:00 2001
From: emersion <contact@emersion.fr>
Date: Wed, 4 Oct 2017 22:01:54 +0200
Subject: [PATCH] rootston: rotation by steps

---
 rootston/cursor.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/rootston/cursor.c b/rootston/cursor.c
index c26ca43a..aad6751e 100644
--- a/rootston/cursor.c
+++ b/rootston/cursor.c
@@ -1,3 +1,4 @@
+#define _XOPEN_SOURCE 500
 #include <stdbool.h>
 #include <stdint.h>
 #include <string.h>
@@ -114,6 +115,8 @@ void cursor_update_position(struct roots_input *input, uint32_t time) {
 			int vx = input->cursor->x - ox,
 				vy = input->cursor->y - oy;
 			float angle = atan2(vx*uy - vy*ux, vx*ux + vy*uy);
+			int steps = 12;
+			angle = round(angle/M_PI*steps) / (steps/M_PI);
 			view->rotation = input->view_rotation + angle;
 		}
 		break;