rationalize allocations in Color

diff --git a/Crow/src/Colors.cs b/Crow/src/Colors.cs
index d6435bd1bb93d76b5d74d043d5208577f397f6e3..ebdfd198427e8601601806d7c5b402f2163932ec 100644 (file)
--- a/Crow/src/Colors.cs
+++ b/Crow/src/Colors.cs
@@ -162,7 +162,7 @@ namespace Crow
        /// <summary>
        /// Universal Color structure
        /// </summary>
-       public struct Color : IEquatable<Color>//, IEquatable<Colors>
+       public struct Color : IEquatable<Color>
     {
                #region CTOR
                public Color (int r, int g, int b, int a) :
@@ -188,6 +188,13 @@ namespace Crow
                                (((uint)Math.Round (b * 255.0)) << 8) +
                                (((uint)Math.Round (a * 255.0)));
                }
+               public Color (ReadOnlySpan<double> rgba) {
+                       value =
+                               (((uint)Math.Round (rgba[0] * 255.0)) << 24) +
+                               (((uint)Math.Round (rgba[1] * 255.0)) << 16) +
+                               (((uint)Math.Round (rgba[2] * 255.0)) << 8) +
+                               (((uint)Math.Round (rgba[3] * 255.0)));
+               }
                public Color (UInt32 rgba)
                {
                        this.value = rgba;
@@ -238,18 +245,9 @@ namespace Crow
                public static bool operator ==(Color a, Color b) => a.Equals (b);
                public static bool operator != (Color a, Color b) => !a.Equals (b);
 
-               public static Color operator *(Color c, Double f)
-               {
-                       return new Color(c.R,c.G,c.B,c.A * f);
-               }
-               public static Color operator +(Color c1, Color c2)
-               {
-                       return new Color(c1.R + c2.R,c1.G + c2.G,c1.B + c2.B,c1.A + c2.A);
-               }
-               public static Color operator -(Color c1, Color c2)
-               {
-                       return new Color(c1.R - c2.R,c1.G - c2.G,c1.B - c2.B,c1.A - c2.A);
-               }
+               public static Color operator *(Color c, Double f) => new Color(c.R,c.G,c.B,c.A * f);
+               public static Color operator +(Color c1, Color c2) => new Color(c1.R + c2.R,c1.G + c2.G,c1.B + c2.B,c1.A + c2.A);
+               public static Color operator -(Color c1, Color c2) =>new Color(c1.R - c2.R,c1.G - c2.G,c1.B - c2.B,c1.A - c2.A);
                #endregion
 
                /// <summary>
@@ -328,9 +326,7 @@ namespace Crow
                        => value == (UInt32)other;*/
 
                public bool Equals (Color other)
-                       => value == other.value;
-               
-
+                       => value == other.value;                
                public override int GetHashCode ()
                        => value.GetHashCode ();
 
@@ -339,22 +335,28 @@ namespace Crow
                        
                public static Color FromIml (string iml)
                {
-                       string [] c = iml.Split (new char [] { ',' });
-                       return new Color (
-                               double.Parse (c [0]),
-                               double.Parse (c [1]),
-                               double.Parse (c [2]),
-                               double.Parse (c [3]));
+                       Span<double> components = stackalloc double[4];
+                       components[3] = 1;//init alpha to 1 so that it can be ommitted
+                       ReadOnlySpan<char> c = iml.AsSpan ();                   
+                       int i = 0;
+                       int ioc = c.IndexOf (',');
+
+                       while (ioc >= 0) {
+                               components[i++] = double.Parse (c.Slice (0, ioc));
+                               c = c.Slice (ioc + 1);
+                               ioc = c.IndexOf (',');
+                       }
+                       components[i++] = double.Parse (c);                     
+                       return new Color (components);
                }
 
                public static object Parse(string s)
                        => (string.IsNullOrEmpty (s)) ? new Color (Colors.White) :
-                               (s.StartsWith ("#", StringComparison.Ordinal)) ? new Color (UInt32.Parse (s.Substring (1), System.Globalization.NumberStyles.HexNumber)) :
-                               (char.IsDigit(s[0])) ? FromIml (s) :
-                               (FastEnum.TryParse<Colors> (s, out Colors cc)) ? new Color(cc) :
+                               s[0] == '#' ? new Color (UInt32.Parse (s.AsSpan().Slice (1), System.Globalization.NumberStyles.HexNumber)) :
+                               char.IsDigit(s[0]) ? FromIml (s) :
+                               FastEnum.TryParse<Colors> (s, out Colors cc) ? new Color(cc) :
                                throw new Exception ("Unknown color name: " + s);
 
-
                public static Color FromHSV (double _h, double _v = 0xff, double _s = 0xff, double _alpha = 0xff) {
                        _h /= 255.0;
                        _v /= 255.0;
@@ -363,26 +365,20 @@ namespace Crow
                        double H = _h * 360;
                        double C = _v * _s;
                        //X = C × (1 - | (H / 60°) mod 2 - 1 |)
-                       double X = C * (1 - Math.Abs((H/60.0)%2 - 1));
+                       double X = C * (1 - Math.Abs ((H / 60.0) % 2 - 1));
                        double m = _v - C;
 
-                       double [] rgb = null;
-
                        if (H >= 300)
-                               rgb = new double [] { C, 0, X };
+                               return new Color (C + m, m, X + m, _alpha / 255.0);
                        else if (H >= 240)
-                               rgb = new double [] { X, 0, C };
+                               return new Color (X + m, m, C + m, _alpha / 255.0);
                        else if (H >= 180)
-                               rgb = new double [] { 0, X, C };
+                               return new Color (m, X + m, C + m, _alpha / 255.0);
                        else if (H >= 120)
-                               rgb = new double [] { 0, C, X };
+                               return new Color ( m, C + m, X + m, _alpha / 255.0);
                        else if (H >= 60)
-                               rgb = new double [] { X, C, 0};
-                       else
-                               rgb = new double [] { C, X, 0 };
-
-
-                       return new Color (rgb [0] + m, rgb [1] + m, rgb [2] + m, _alpha / 255.0);
+                               return new Color (X + m, C + m,  m, _alpha / 255.0);
+                       return new Color (C + m, X + m,  m, _alpha / 255.0);
                }
        }
 }