From 419633c3745dcb093ee26afb593895608417d73e Mon Sep 17 00:00:00 2001
From: Anuj Verma <anujv@iitbhilai.ac.in>
Date: Mon, 27 Jul 2020 17:04:33 +0530
Subject: [PATCH] * src/sdf/ftbsdf.c (bsdf_is_edge): Use macros to make it look
 cleaner.

Use `CHECK_NEIGHBOR' macro to check neighbors while
finding edges. Make the code more readable and look
cleaner.
---
 [GSoC]ChangeLog  |   9 ++++
 src/sdf/ftbsdf.c | 109 +++++++++++++----------------------------------
 2 files changed, 38 insertions(+), 80 deletions(-)

diff --git a/[GSoC]ChangeLog b/[GSoC]ChangeLog
index 798b61495..85d7f794a 100644
--- a/[GSoC]ChangeLog
+++ b/[GSoC]ChangeLog
@@ -1,3 +1,12 @@
+2020-07-27  Anuj Verma  <anujv@iitbhilai.ac.in>
+
+	* src/sdf/ftbsdf.c (bsdf_is_edge): Use macros to
+	  make it look cleaner.
+
+	  Use `CHECK_NEIGHBOR' macro to check neighbors while
+	  finding edges. Make the code more readable and look
+	  cleaner.
+
 2020-07-27  Anuj Verma  <anujv@iitbhilai.ac.in>
 
 	[sdf -> bsdf] Fix edge detection bug.
diff --git a/src/sdf/ftbsdf.c b/src/sdf/ftbsdf.c
index a42c4d4a4..69504342a 100644
--- a/src/sdf/ftbsdf.c
+++ b/src/sdf/ftbsdf.c
@@ -82,6 +82,24 @@
    *
    */
 
+  #ifdef CHECK_NEIGHBOR
+  #undef CHECK_NEIGHBOR
+  #endif
+
+  /* Use the macro only in `bsdf_is_edge' function. */
+  #define CHECK_NEIGHBOR( x_offset, y_offset )     \
+    if ( x + x_offset >= 0 && x + x_offset < w &&  \
+         y + y_offset >= 0 && y + y_offset < r )   \
+    {                                              \
+      num_neighbour++;                             \
+      to_check = s + y_offset * w + x_offset;      \
+      if ( *to_check == 0 )                        \
+      {                                            \
+        is_edge = 1;                               \
+        goto Done;                                 \
+      }                                            \
+    }
+
   /**************************************************************************
    *
    * @Function:
@@ -115,108 +133,39 @@
       goto Done;
 
     /* up */
-    if ( y > 0 )
-    {
-      num_neighbour++;
-      to_check = s - w;
-      if ( *to_check == 0 )
-      {
-        is_edge = 1;
-        goto Done;
-      }
-    }
+    CHECK_NEIGHBOR(  0, -1 );
 
     /* down */
-    if ( y < r - 2 )
-    {
-      num_neighbour++;
-      to_check = s + w;
-      if ( *to_check == 0 )
-      {
-        is_edge = 1;
-        goto Done;
-      }
-    }
+    CHECK_NEIGHBOR(  0,  1 );
 
     /* left */
-    if ( x > 0 )
-    {
-      num_neighbour++;
-      to_check = s - 1;
-      if ( *to_check == 0 )
-      {
-        is_edge = 1;
-        goto Done;
-      }
-    }
+    CHECK_NEIGHBOR( -1,  0 );
 
     /* right */
-    if ( x < w - 2 )
-    {
-      num_neighbour++;
-      to_check = s + 1;
-      if ( *to_check == 0 )
-      {
-        is_edge = 1;
-        goto Done;
-      }
-    }
+    CHECK_NEIGHBOR(  1,  0 );
 
     /* up left */
-    if ( y > 0 && x > 0 )
-    {
-      num_neighbour++;
-      to_check = s - w - 1;
-      if ( *to_check == 0 )
-      {
-        is_edge = 1;
-        goto Done;
-      }
-    }
+    CHECK_NEIGHBOR( -1, -1 );
 
     /* up right */
-    if ( y > 0 && x < w - 2 )
-    {
-      num_neighbour++;
-      to_check = s - w + 1;
-      if ( *to_check == 0 )
-      {
-        is_edge = 1;
-        goto Done;
-      }
-    }
+    CHECK_NEIGHBOR(  1, -1 );
 
     /* down left */
-    if ( y < r - 2 && x > 0 )
-    {
-      num_neighbour++;
-      to_check = s + w - 1;
-      if ( *to_check == 0 )
-      {
-        is_edge = 1;
-        goto Done;
-      }
-    }
+    CHECK_NEIGHBOR( -1,  1 );
 
     /* down right */
-    if ( y < r - 2 && x < w - 2 )
-    {
-      num_neighbour++;
-      to_check = s + w + 1;
-      if ( *to_check == 0 )
-      {
-        is_edge = 1;
-        goto Done;
-      }
-    }
+    CHECK_NEIGHBOR(  1,  1 );
 
     if ( num_neighbour != 8 )
       is_edge = 1;
 
   Done:
     return is_edge;
+
   }
 
+  #undef CHECK_NEIGHBOR
+
   /**************************************************************************
    *
    * @Function: