From 92a5312036a99dc6aab3993d7c595cf6c937ac51 Mon Sep 17 00:00:00 2001
From: Anuj Verma <anujv@iitbhilai.ac.in>
Date: Tue, 30 Jun 2020 17:25:51 +0530
Subject: [PATCH] * src/sdf/ftsdf.c: Use FT_16D16 instead of FT_Fixed to avoid
 confusion.

---
 [GSoC]ChangeLog |  5 +++++
 src/sdf/ftsdf.c | 20 +++++++++++---------
 2 files changed, 16 insertions(+), 9 deletions(-)

diff --git a/[GSoC]ChangeLog b/[GSoC]ChangeLog
index 22c1fe1d8..47509fb65 100644
--- a/[GSoC]ChangeLog
+++ b/[GSoC]ChangeLog
@@ -1,3 +1,8 @@
+2020-06-30  Anuj Verma  <anujv@iitbhilai.ac.in>
+
+	* src/sdf/ftsdf.c (square_root, cube_root, arc_cos):
+	  Use FT_16D16 instead of FT_Fixed to avoid confusion.
+
 2020-06-30  Anuj Verma  <anujv@iitbhilai.ac.in>
 
 	* src/sdf/ftsdf.c (cube_root, arc_cos): Added a few
diff --git a/src/sdf/ftsdf.c b/src/sdf/ftsdf.c
index 6ee6bcc97..ed20df963 100644
--- a/src/sdf/ftsdf.c
+++ b/src/sdf/ftsdf.c
@@ -600,8 +600,8 @@
    */
 
   /* Original Algorithm: https://github.com/chmike/fpsqrt */
-  static FT_Fixed
-  square_root( FT_Fixed  val )
+  static FT_16D16
+  square_root( FT_16D16  val )
   {
     FT_ULong t, q, b, r;
 
@@ -627,8 +627,8 @@
 
   /* This function uses newton's iteration to find */
   /* cube root of a fixed point integer.           */
-  static FT_Fixed
-  cube_root( FT_Fixed  val )
+  static FT_16D16
+  cube_root( FT_16D16  val )
   {
     /* [IMPORTANT]: This function is not good as it may */
     /* not break, so use a lookup table instead.        */
@@ -659,12 +659,14 @@
     return val < 0 ? -g : g;
   }
 
-  /* returns cos inverse of a value */
-  static FT_Fixed
-  arc_cos( FT_Fixed  val )
+  /* The function calculate the perpendicular */
+  /* using 1 - ( base ^ 2 ) and then use arc  */
+  /* tan to compute the angle.                */
+  static FT_16D16
+  arc_cos( FT_16D16  val )
   {
-    FT_Fixed  p, b = val;
-    FT_Fixed  one  = FT_INT_16D16( 1 );
+    FT_16D16  p, b = val;
+    FT_16D16  one  = FT_INT_16D16( 1 );
 
 
     if ( b >  one ) b =  one;