default Crow.CairoBackend ok

1 files changed, 54 insertions, 0 deletions

diff --git a/Drawing2D/src/Encoding.cs b/Drawing2D/src/Encoding.cs
new file mode 100644
index 00000000..8999623d
--- /dev/null
+++ b/Drawing2D/src/Encoding.cs
@@ -0,0 +1,54 @@
+// Copyright (c) 2013-2021  Jean-Philippe Bruyère <jp_bruyere@hotmail.com>
+//
+// This code is licensed under the MIT license (MIT) (http://opensource.org/licenses/MIT)
+using System;
+
+namespace Drawing2D
+{
+	public static class Extensions
+    {
+        public static int ToUtf8 (this ReadOnlySpan<char> source, Span<byte> buff, int tabWidth = 4) {
+            int c = 0;
+            int encodedBytes = 0;
+            int encodedChar = 0;
+            while (c < source.Length) {
+                if (source[c] < 0xD800) {
+                    if (source[c] == '\t') {
+                        int encTabWidth = tabWidth - encodedChar % tabWidth;
+                        for (int i = 0; i < encTabWidth; i++) {
+                            buff[encodedBytes++] = 0x20;
+                            encodedChar++;
+                        }
+                        c++;
+                        continue;
+                    }
+
+                    if (source[c] < 0x80) { //1 byte
+                        buff[encodedBytes++] = (byte)source[c++];
+                    }else if (source[c] < 0x7FF) { //2 bytes
+                        buff[encodedBytes++] = (byte)((source[c] >> 6) + 0xC0);
+                        buff[encodedBytes++] = (byte)((source[c] & 0x3F) + 0x80);
+                        c++;
+                    } else { //3 bytes
+                        //ushort ch = (ushort)(source[c] - 0x10000u);
+                        buff[encodedBytes++] = (byte)((source[c] >> 12) + 0xE0);
+                        buff[encodedBytes++] = (byte)((source[c] >> 6) & 0x00BF);
+                        buff[encodedBytes++] = (byte)((source[c] & 0x3F) + 0x80);
+                        c++;
+                    }
+
+                    encodedChar++;
+                    continue;
+                }
+                throw new NotImplementedException();
+            }
+			buff[encodedBytes] = 0;
+            return encodedBytes;
+        }
+
+
+        /*unsafe static int Utf16toUtf8 (byte* cptr, byte* buff, int tabWidth) {
+
+        }*/
+    }
+}