Add measure string function to Typesetter.

Quik/Typography/Typesetter.cs

@@ -2,9 +2,7 @@
 using Quik.Media;
 using System;
 using System.Collections.Generic;
-using System.Linq;
 using System.Text;
-using System.Threading.Tasks;
 
 namespace Quik.Typography
 {
@@ -76,10 +74,38 @@ namespace Quik.Typography
             }
         }
 
-        public static void TypesetHorizontalDirect(this CommandList list, string str, QVec2 origin, float size, QFont font)
+        public static QVec2 MeasureHorizontal(ReadOnlySpan<char> str, float size, QFont font)
+        {
+            var enumerator = new LineEnumerator(str);
+
+            float width = 0.0f;
+            float height = 0.0f;
+            
+            while (enumerator.MoveNext())
+            {
+                ReadOnlySpan<char> line = enumerator.Current;
+
+                float lineHeight = 0.0f;
+
+                foreach (Rune r in line.EnumerateRunes())
+                {
+                    int codepoint = r.Value;
+                    font.Get(codepoint, size, out FontGlyph glyph);
+                    
+                    width += glyph.Metrics.Advance.X;
+                    lineHeight = Math.Max(lineHeight, glyph.Metrics.Size.Y);
+                }
+
+                height += lineHeight;
+            }
+
+            return new QVec2(width, height);
+        }
+
+        public static void TypesetHorizontalDirect(this CommandList list, ReadOnlySpan<char> str, QVec2 origin, float size, QFont font)
         {
             Dictionary<QImage, FontDrawInfo> drawInfo = new Dictionary<QImage, FontDrawInfo>();
-            var enumerator = new LineEnumerator(str.AsSpan());
+            var enumerator = new LineEnumerator(str);
            
             QVec2 pen = origin;
             while (enumerator.MoveNext())