From c343d14479295d517ae64ccee5a7e83d3ce0fc42 Mon Sep 17 00:00:00 2001
From: Karryanna <karry@karryanna.cz>
Date: Wed, 1 Jul 2015 12:05:24 +0200
Subject: [PATCH] Labelling: Rotation computation improved and commented on

---
 lab-evolution.c | 13 ++++++++++---
 lab-lines.c     | 14 ++++++++++++--
 2 files changed, 22 insertions(+), 5 deletions(-)

diff --git a/lab-evolution.c b/lab-evolution.c
index ccf7515..1978624 100644
--- a/lab-evolution.c
+++ b/lab-evolution.c
@@ -692,10 +692,17 @@ static void move_symbol_point(struct placement *p)
 
 static void move_symbol_segment(struct placement *p)
 {
+  struct request_segment *rs = (struct request_segment *) p->request;
   double m = gen_movement_uniform();
-  // CHECK ME
-  p->x += m;
-  p->y += m * ((struct request_segment *) p->request)->slope;
+  if (fabs(rs->x2 - rs->x1) > 0.01)
+  {
+    p->x += m;
+    p->y += m * rs->slope;
+  }
+  else
+  {
+    p->x += m;
+  }
 }
 
 static void hide_segment_labels(struct individual *individual)
diff --git a/lab-lines.c b/lab-lines.c
index 35f9f45..a0fc3c7 100644
--- a/lab-lines.c
+++ b/lab-lines.c
@@ -505,8 +505,18 @@ static void make_segments(void)
       rs->x2 = e->n2->o->x;
       rs->y2 = e->n2->o->y;
 
-      rs->slope = (rs->y2 - rs->y1) / (rs->x2 - rs->x1);
-      ((struct sym_text *) rs->label)->rotate = convert_to_deg(atan(rs->slope));
+      if (fabs(rs->x2 - rs->x1) > 0.01)
+      {
+        rs->slope = (rs->y2 - rs->y1) / (rs->x2 - rs->x1);
+        // This works a little bit magically :)
+        // It's possible not to care about quadrants as it "just works" as expected
+        ((struct sym_text *) rs->label)->rotate = convert_to_deg(atan(rs->slope));
+      }
+      else
+      {
+        rs->slope = 142; // Magic!
+        ((struct sym_text *) rs->label)->rotate = 1;
+      }
       struct variant *v = GARY_PUSH(rs->request.variants);
       make_bitmap(v, rs->label);
 
-- 
2.39.2