Implements hslcolor parser.

mntone · Mar 20, 2018 · debf84f · debf84f
1 parent c65e19c
commit debf84f
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Showing 2 changed files with 97 additions and 3 deletions.
diff --git a/Mntone.SvgForXaml/Mntone.SvgForXaml.Shared/Primitives/SvgAngle.cs b/Mntone.SvgForXaml/Mntone.SvgForXaml.Shared/Primitives/SvgAngle.cs
@@ -117,6 +117,35 @@ internal static SvgAngle Parse(string angleText)
 			return new SvgAngle(SvgAngleType.Degree, value);
 		}
 
+		internal static SvgAngle Parse(StringPtr ptr)
+		{
+			var begin = ptr.Index;
+			ptr.AdvanceNumber();
+			if (begin == ptr.Index) throw new ArgumentException(nameof(ptr));
+
+			var value = float.Parse(ptr.Target.Substring(begin, ptr.Index - begin), System.Globalization.CultureInfo.InvariantCulture);
+			if (ptr.Index != ptr.Target.Length)
+			{
+				var unit = ptr.String;
+				if (unit.StartsWith("deg"))
+				{
+					ptr += 3;
+					return new SvgAngle(SvgAngleType.Degree, value);
+				}
+				if (unit.StartsWith("rad"))
+				{
+					ptr += 3;
+					return new SvgAngle(SvgAngleType.Radian, value);
+				}
+				if (unit.StartsWith("grad"))
+				{
+					ptr += 4;
+					return new SvgAngle(SvgAngleType.Grade, value);
+				}
+			}
+			return new SvgAngle(SvgAngleType.Degree, value);
+		}
+
 		public bool Equals(SvgAngle other) => this.UnitType == other.UnitType && this.Value == other.Value;
 
 		public static implicit operator SvgAngle(float f) => new SvgAngle(SvgAngleType.Degree, f);

diff --git a/Mntone.SvgForXaml/Mntone.SvgForXaml.Shared/Primitives/SvgColor.cs b/Mntone.SvgForXaml/Mntone.SvgForXaml.Shared/Primitives/SvgColor.cs
@@ -179,6 +179,8 @@ protected static RgbColor Parse(string color)
 		{
 			if (color[0] == '#') return ParseColorCode(color.Substring(1));
 			if (color.StartsWith("rgb(")) return ParseColorFunc(color.Substring(4));
+			if (color.StartsWith("hsl(")) return ParseHslColorFunc(color.Substring(4));
+			if (color.StartsWith("hsla(")) return ParseHslColorFunc(color.Substring(5));
 			if (_colors.ContainsKey(color)) return _colors[color];
 			throw new ArgumentException(nameof(color));
 		}
@@ -263,14 +265,77 @@ private static RgbColor ParseColorFunc(string color)
 				: new RgbColor(r, g, b);
 		}
 
+		private static RgbColor ParseHslColorFunc(string color)
+		{
+			var ptr = new StringPtr(color);
+			ptr.AdvanceWhiteSpace();
+
+			var s1 = ptr.Index;
+			var h = SvgAngle.Parse(ptr);
+			if (ptr.Index == s1) throw new ArgumentException(nameof(color));
+
+			ptr.AdvanceWhiteSpace();
+			if (ptr.Char != ',') throw new ArgumentException(nameof(color));
+			++ptr;
+			ptr.AdvanceWhiteSpace();
+
+			var s2 = ptr.Index;
+			ptr.AdvanceInteger();
+			if (ptr.Index == s2) throw new ArgumentException(nameof(color));
+			var s = byte.Parse(color.Substring(s2, ptr.Index - s2));
+			if (ptr.Char != '%') throw new ArgumentException(nameof(color));
+			++ptr;
+
+			ptr.AdvanceWhiteSpace();
+			if (ptr.Char != ',') throw new ArgumentException(nameof(color));
+			++ptr;
+			ptr.AdvanceWhiteSpace();
+
+			var s3 = ptr.Index;
+			ptr.AdvanceInteger();
+			if (ptr.Index == s3) throw new ArgumentException(nameof(color));
+			var l = byte.Parse(color.Substring(s3, ptr.Index - s3));
+			if (ptr.Char != '%') throw new ArgumentException(nameof(color));
+			++ptr;
+
+			ptr.AdvanceWhiteSpace();
+
+			if (ptr.Char != ')') throw new ArgumentException(nameof(color));
+
+			return HlsToRgb(h.ValueAsDegree, s / 100.0, l / 100.0);
+		}
+
+		private static RgbColor HlsToRgb(double hue, double sat, double light)
+		{
+			var t2 = light <= .5
+				? light * (sat + 1.0)
+				: light + sat - (light * sat);
+			var t1 = 2.0 * light - t2;
+			var r = HueToValue(t1, t2, hue + 120.0);
+			var g = HueToValue(t1, t2, hue);
+			var b = HueToValue(t1, t2, hue - 120.0);
+			return new RgbColor(r, g, b);
+		}
+
+		private static byte HueToValue(double t1, double t2, double hue)
+		{
+			while (hue < 0) hue += 360;
+			hue %= 360;
+
+			if (hue < 60) return (byte)(255.0 * ((t2 - t1) * hue / 60.0 + t1));
+			if (hue < 180) return (byte)(255.0 * t2);
+			if (hue < 240) return (byte)(255.0 * ((t2 - t1) * (240 - hue) / 60.0 + t1));
+			return (byte)(255.0 * t1);
+		}
+
 		private static RgbColor ParseOther(string color)
 		{
 			throw new NotImplementedException();
 		}
 
-		internal Windows.UI.Color ToPlatformColor(byte alpha)
+		internal Windows.UI.Color ToPlatformColor(byte alpha)
-		{
+		{
-			return Windows.UI.Color.FromArgb(alpha, this.RgbColor.Red, this.RgbColor.Green, this.RgbColor.Blue);
+			return Windows.UI.Color.FromArgb(alpha, this.RgbColor.Red, this.RgbColor.Green, this.RgbColor.Blue);
 		}
 	}
 }