1 files changed, 122 insertions, 0 deletions
diff --git a/src/sdf/ftsdfcommon.h b/src/sdf/ftsdfcommon.h
new file mode 100644
index 000000000..2e806c74f
--- /dev/null
+++ b/src/sdf/ftsdfcommon.h
@@ -0,0 +1,122 @@
+
+  /****************************************************
+   *
+   * This file contain common function and properties
+   * for both `sdf' and `bsdf' renderer.
+   *
+   */
+
+#ifndef FTSDFCOMMON_H_
+#define FTSDFCOMMON_H_
+
+#include <ft2build.h>
+#include FT_CONFIG_CONFIG_H
+#include <freetype/freetype.h>
+
+FT_BEGIN_HEADER
+
+  /**************************************************************************
+   *
+   * default values (cannot be set individually for each renderer)
+   *
+   */
+
+  /* default spread value */
+  #define DEFAULT_SPREAD  8
+
+  /* minimum spread supported by the renderer. */
+  #define MIN_SPREAD      2
+
+  /* maximum spread supported by the renderer. */
+  #define MAX_SPREAD      32
+
+  /**************************************************************************
+   *
+   * common definitions (cannot be set individually for each renderer)
+   *
+   */
+
+  /* If it is defined to 1 then the rasterizer will use squared distances */
+  /* for computation. It can greatly improve the performance but there is */
+  /* a chance of overflow and artifacts. You can safely use it upto a     */
+  /* pixel size of 128.                                                   */
+  #ifndef USE_SQUARED_DISTANCES
+  #  define USE_SQUARED_DISTANCES 0
+  #endif
+
+  /**************************************************************************
+   *
+   * common macros
+   *
+   */
+
+  /* convert int to 26.6 fixed point   */
+  #define FT_INT_26D6( x )   ( x * 64 )
+
+  /* convert int to 16.16 fixed point  */
+  #define FT_INT_16D16( x )  ( x * 65536 )
+
+  /* convert 26.6 to 16.16 fixed point */
+  #define FT_26D6_16D16( x ) ( x * 1024 )
+
+  /* Convenient macro which calls the function */
+  /* and returns if any error occurs.          */
+  #define FT_CALL( x ) do                          \
+                       {                           \
+                         error = ( x );            \
+                         if ( error != FT_Err_Ok ) \
+                           goto Exit;              \
+                       } while ( 0 )
+
+  /**************************************************************************
+   *
+   * common typedefs
+   *
+   */
+
+  typedef  FT_Vector FT_26D6_Vec;   /* with 26.6 fixed point components  */
+  typedef  FT_Vector FT_16D16_Vec;  /* with 16.16 fixed point components */
+
+  typedef  FT_Fixed  FT_16D16;      /* 16.16 fixed point representation  */
+  typedef  FT_Fixed  FT_26D6;       /* 26.6 fixed point representation   */
+  typedef  FT_Short  FT_6D10;       /* 6.10 fixed point representation   */
+
+  typedef  FT_BBox   FT_CBox;       /* control box of a curve            */
+
+  /**************************************************************************
+   *
+   * common functions
+   *
+   */
+
+  /* Original Algorithm: https://github.com/chmike/fpsqrt */
+  static FT_16D16
+  square_root( FT_16D16  val )
+  {
+    FT_ULong t, q, b, r;
+
+
+    r = val;
+    b = 0x40000000;
+    q = 0;
+    while( b > 0x40 )
+    {
+      t = q + b;
+      if( r >= t )
+      {
+        r -= t;
+        q = t + b;
+      }
+      r <<= 1;
+      b >>= 1;
+    }
+    q >>= 8;
+
+    return q;
+  }
+
+FT_END_HEADER
+
+#endif /* FTSDFCOMMON_H_ */
+
+/* END */