From d0d93c2496175aa42b4c4bb3a45e4f0a6d264112 Mon Sep 17 00:00:00 2001
From: "Jan Alexander Steffens (heftig)" <jan.steffens@gmail.com>
Date: Wed, 15 Jun 2016 14:10:20 +0200
Subject: [PATCH 3/3] Make subpixel hinting mode configurable

---
 include/freetype/config/ftoption.h |  4 ++--
 src/truetype/ttobjs.c              | 37 +++++++++++++++++++++++++++++++++++++
 2 files changed, 39 insertions(+), 2 deletions(-)

diff --git a/include/freetype/config/ftoption.h b/include/freetype/config/ftoption.h
index 33d563c4e1e47228..a401fc8e9efbbd79 100644
--- a/include/freetype/config/ftoption.h
+++ b/include/freetype/config/ftoption.h
@@ -631,8 +631,8 @@ FT_BEGIN_HEADER
   /* [1] http://www.microsoft.com/typography/cleartype/truetypecleartype.aspx */
   /*                                                                       */
 /* #define TT_CONFIG_OPTION_SUBPIXEL_HINTING  1     */
-#define TT_CONFIG_OPTION_SUBPIXEL_HINTING     2
-/* #define TT_CONFIG_OPTION_SUBPIXEL_HINTING  ( 1 | 2 ) */
+/* #define TT_CONFIG_OPTION_SUBPIXEL_HINTING  2     */
+#define TT_CONFIG_OPTION_SUBPIXEL_HINTING     ( 1 | 2 )
 
 
   /*************************************************************************/
diff --git a/src/truetype/ttobjs.c b/src/truetype/ttobjs.c
index ed3be2dbee79427c..d89f92e94d0e816b 100644
--- a/src/truetype/ttobjs.c
+++ b/src/truetype/ttobjs.c
@@ -36,6 +36,9 @@
 #include "ttgxvar.h"
 #endif
 
+#include <stdlib.h>
+#include <errno.h>
+
   /*************************************************************************/
   /*                                                                       */
   /* The macro FT_COMPONENT is used in trace mode.  It is an implicit      */
@@ -1286,6 +1289,7 @@
 #ifdef TT_USE_BYTECODE_INTERPRETER
 
     TT_Driver  driver = (TT_Driver)ttdriver;
+    const char *envval;
 
     driver->interpreter_version = TT_INTERPRETER_VERSION_35;
 #ifdef TT_SUPPORT_SUBPIXEL_HINTING_INFINALITY
@@ -1295,6 +1299,39 @@
     driver->interpreter_version = TT_INTERPRETER_VERSION_40;
 #endif
 
+    errno = 0;
+    envval = getenv( "FT2_SUBPIXEL_HINTING" );
+    if ( envval )
+    {
+      char *endptr = NULL;
+      unsigned long value = strtoul( envval, &endptr, 10 );
+
+      if ( !errno && endptr && !*endptr )
+      {
+        switch( value )
+        {
+        case 0:
+          driver->interpreter_version = TT_INTERPRETER_VERSION_35;
+          break;
+
+#ifdef TT_SUPPORT_SUBPIXEL_HINTING_INFINALITY
+        case 1:
+          driver->interpreter_version = TT_INTERPRETER_VERSION_38;
+          break;
+#endif
+
+#ifdef TT_SUPPORT_SUBPIXEL_HINTING_MINIMAL
+        case 2:
+          driver->interpreter_version = TT_INTERPRETER_VERSION_40;
+          break;
+#endif
+
+        default:
+          break;
+        }
+      }
+    }
+
 #else /* !TT_USE_BYTECODE_INTERPRETER */
 
     FT_UNUSED( ttdriver );
-- 
2.8.3