Improved IO predicates (#648)

* enter proj_angular_input and proj_angular_output, exit proj_angular_left and proj_angular_right

* remove unused variable 'unit'

* In gie: remove unused func 'torad_if_needed', and add static keyword where needed

* In gie: add some comments

1 files changed, 3 insertions, 2 deletions

diff --git a/src/proj.h b/src/proj.h
index 7607c3d8..bc0e1e06 100644
--- a/src/proj.h
+++ b/src/proj.h
@@ -371,8 +371,9 @@ typedef enum PJ_DIRECTION PJ_DIRECTION;
 
 
 
-int proj_angular_left (PJ *P);
-int proj_angular_right (PJ *P);
+int proj_angular_input (PJ *P, enum PJ_DIRECTION dir);
+int proj_angular_output (PJ *P, enum PJ_DIRECTION dir);
+
 
 PJ_COORD proj_trans (PJ *P, PJ_DIRECTION direction, PJ_COORD coord);