QuickFont.QFontKerningConfiguration.GetOverridingCharacterKerningRuleForPair C# (CSharp) Method

        public CharacterKerningRule GetOverridingCharacterKerningRuleForPair(String str)
        {

            if (str.Length < 2)
            {
                return CharacterKerningRule.Normal;
            }

            char c1 = str[0];
            char c2 = str[1];

            if (GetCharacterKerningRule(c1) == CharacterKerningRule.Zero || GetCharacterKerningRule(c2) == CharacterKerningRule.Zero)
            {
                return CharacterKerningRule.Zero;
            }
            else if (GetCharacterKerningRule(c1) == CharacterKerningRule.NotMoreThanHalf || GetCharacterKerningRule(c2) == CharacterKerningRule.NotMoreThanHalf)
            {
                return CharacterKerningRule.NotMoreThanHalf;
            }

            return CharacterKerningRule.Normal;
        }

        /// <summary>
        /// Calculate the kerning between two glyphs
        /// </summary>
        /// <param name="g1">The first glyph</param>
        /// <param name="g2">The second glyph</param>
        /// <param name="lim1">The first glyph limits</param>
        /// <param name="lim2">The second glyph limits</param>
        /// <param name="config">The kerning configuration to use</param>
        /// <param name="font">The glyph's <see cref="IFont"/></param>
        /// <returns>The x coordinate kerning offset</returns>
        private static int Kerning(QFontGlyph g1, QFontGlyph g2, XLimits[] lim1, XLimits[] lim2, QFontKerningConfiguration config, IFont font)
        {
            // Use kerning information from the font if it exists
            if (font != null && font.HasKerningInformation)
            {
                return(font.GetKerning(g1.Character, g2.Character));
            }

            // Otherwise, calculate our own kerning
            int yOffset1 = g1.YOffset;
            int yOffset2 = g2.YOffset;

            int startY = Math.Max(yOffset1, yOffset2);
            int endY   = Math.Min(g1.Rect.Height + yOffset1, g2.Rect.Height + yOffset2);

            int w1 = g1.Rect.Width;

            int worstCase = w1;

            //TODO - offset startY, endY by yOffset1 so that lim1[j-yOffset1] can be written as lim1[j], will need another var for yOffset2

            for (int j = startY; j < endY; j++)
            {
                worstCase = Math.Min(worstCase, w1 - lim1[j - yOffset1].Max + lim2[j - yOffset2].Min);
            }

            worstCase = Math.Min(worstCase, g1.Rect.Width);
            worstCase = Math.Min(worstCase, g2.Rect.Width);

            //modify by character kerning rules
            CharacterKerningRule kerningRule = config.GetOverridingCharacterKerningRuleForPair("" + g1.Character + g2.Character);

            switch (kerningRule)
            {
            case CharacterKerningRule.Zero:
                return(1);

            case CharacterKerningRule.NotMoreThanHalf:
                return(1 - (int)Math.Min(Math.Min(g1.Rect.Width, g2.Rect.Width) * 0.5f, worstCase));
            }

            return(1 - worstCase);
        }