fix glyph rendering, handle multiple cmap

NOpenType/CharacterMap.cs

@@ -1,4 +1,6 @@
-using System;
+//Apache2, 2017, WinterDev
+//Apache2, 2014-2016, Samuel Carlsson, WinterDev
+using System;
 
 namespace NRasterizer
 {
@@ -20,7 +22,8 @@ internal CharacterMap(int segCount, ushort[] startCode, ushort[] endCode, ushort
             _idRangeOffset = idRangeOffset;
             _glyphIdArray = glyphIdArray;
         }
-
+        public ushort PlatformId { get; set; }
+        public ushort EncodingId { get; set; }
         public int CharacterToGlyphIndex(UInt32 character)
         {
             return (int)RawCharacterToGlyphIndex(character);

NOpenType/IGlyphRasterizer.cs

@@ -1,21 +1,78 @@
-using System;
+//MIT, 2016-2017, WinterDev
+//MIT, 2015, Michael Popoloski 
+//FTL, 3-clauses BSD, FreeType project
+//-----------------------------------------------------
 
 namespace NRasterizer
 {
+    //https://en.wikipedia.org/wiki/B%C3%A9zier_curve
+    //--------------------
+    //Line, has 2 points..
+    //  (x0,y0) begin point
+    //  (x1,y1) end point
+    //--------------------
+    //Curve3 (Quadratic Bézier curves), has 3 points
+    //  (x0,y0)  begin point
+    //  (x1,y1)  1st control point 
+    //  (x2,y2)  end point
+    //--------------------
+    //Curve4 (Cubic  Bézier curves), has 4 points
+    //  (x0,y0)  begin point
+    //  (x1,y1)  1st control point 
+    //  (x2,y2)  2nd control point
+    //  (x3,y3)  end point    
+    //-------------------- 
+    //please note that TrueType font
+    //compose of Quadractic Bezier 
     public interface IGlyphRasterizer
     {
         int Resolution { get; }
-
+        /// <summary>
+        /// begin read a glyph
+        /// </summary>
+        /// <param name="contourCount"></param>
         void BeginRead(int countourCount);
+        /// <summary>
+        /// end read a glyph
+        /// </summary>
         void EndRead();
-
-        void LineTo(double x, double y);
-        void Curve3(double p2x, double p2y, double x, double y);
-        void Curve4(double p2x, double p2y, double p3x, double p3y, double x, double y);
-        void MoveTo(double x, double y);
-        void CloseFigure();
-
-        // Called after all letters have been written.
+        /// <summary>
+        /// set CURRENT pen position to (x0,y0) And set the position as latest MOVETO position
+        /// </summary>
+        /// <param name="x0"></param>
+        /// <param name="y0"></param>
+        void MoveTo(double x0, double y0);
+        /// <summary>
+        /// add line,begin from CURRENT pen position to (x1,y1) then set (x1,y1) as CURRENT pen position
+        /// </summary>
+        /// <param name="x1">end point x</param>
+        /// <param name="y1">end point y</param>
+        void LineTo(double x1, double y1);
+        /// <summary>
+        /// add Quadratic Bézier curve,begin from CURRENT pen pos, to (x2,y2), then set (x2,y2) as CURRENT pen pos
+        /// </summary>
+        /// <param name="x1">x of 1st control point</param>
+        /// <param name="y1">y of 1st control point</param>
+        /// <param name="x2">end point x</param>
+        /// <param name="y2">end point y</param>
+        void Curve3(double x1, double y1, double x2, double y2);
+        /// <summary>
+        /// add Cubic Bézier curve,begin from CURRENT pen pos, to (x3,y3), then set (x3,y3) as CURRENT pen pos
+        /// </summary>
+        /// <param name="x1">x of 1st control point</param>
+        /// <param name="y1">y of 1st control point</param>
+        /// <param name="x2">x of 2nd control point</param>
+        /// <param name="y2">y of 2dn control point</param>
+        /// <param name="x3">end point x</param>
+        /// <param name="y3">end point y</param>
+        void Curve4(double x1, double y1, double x2, double y2, double x3, double y3);
+        /// <summary>
+        /// close current contour, create line from CURRENT pen position to latest MOVETO position
+        /// </summary>
+        void CloseFigure(); 
+        /// <summary>
+        ///  Called after all letters have been written.
+        /// </summary>
         void Flush();
     }
 }