[hackers] [blind] blind-spiral-gradient: fix -a || Mattias Andrée

[git]

commit e2f2b65b49d1a47b1a749c5de4b0efcfc7ebb5bc
Author:     Mattias Andrée <maand...@kth.se>
AuthorDate: Tue Jul 11 19:21:08 2017 +0200
Commit:     Mattias Andrée <maand...@kth.se>
CommitDate: Tue Jul 11 19:21:08 2017 +0200

    blind-spiral-gradient: fix -a
    
    Signed-off-by: Mattias Andrée <maand...@kth.se>

diff --git a/src/blind-spiral-gradient.c b/src/blind-spiral-gradient.c
index 8bdda44..4cf5937 100644
--- a/src/blind-spiral-gradient.c
+++ b/src/blind-spiral-gradient.c
@@ -71,7 +71,7 @@ static int with_vector;
                                        } else {\
                                                v = atan2(y, x);\
                                                if (anticlockwise)\
-                                                       v = 1 - v;\
+                                                       v = -v;\
                                                v -= u;\
                                                v += 4 * (TYPE)M_PI;\
                                                v = mod(v, 2 * (TYPE)M_PI);\