Text3d: store number of characters and utf8 length separately

EditFont's use of Curve.len was very confusing, in editmode it
represented the number of characters, in object mode the number of
bytes. add Curve.len_wchar and keep track of both.

Also don't convert the editmode text into utf8 on every keystroke.
Now this is done on exiting editmode or save - to match most other
object types.

This also fixes curves 'body_format' being reported with an invalid size.

2 files changed, 12 insertions, 6 deletions

diff --git a/source/blender/blenloader/intern/versioning_260.c b/source/blender/blenloader/intern/versioning_260.c
index d63b72bc4c1..d8e3e02b196 100644
--- a/source/blender/blenloader/intern/versioning_260.c
+++ b/source/blender/blenloader/intern/versioning_260.c
@@ -2645,4 +2645,14 @@ void blo_do_versions_260(FileData *fd, Library *UNUSED(lib), Main *main)
 			}
 		}
 	}
+
+	if (!MAIN_VERSION_ATLEAST(main, 269, 8)) {
+		Curve *cu;
+
+		for (cu = main->curve.first; cu; cu = cu->id.next) {
+			if (cu->str) {
+				cu->len_wchar = BLI_strlen_utf8(cu->str);
+			}
+		}
+	}
 }
diff --git a/source/blender/blenloader/intern/writefile.c b/source/blender/blenloader/intern/writefile.c
index 9ffe4dae82a..beb8d584e41 100644
--- a/source/blender/blenloader/intern/writefile.c
+++ b/source/blender/blenloader/intern/writefile.c
@@ -1664,12 +1664,8 @@ static void write_curves(WriteData *wd, ListBase *idbase)
 			if (cu->adt) write_animdata(wd, cu->adt);
 			
 			if (cu->vfont) {
-				/* TODO, sort out 'cu->len', in editmode its character, object mode its bytes */
-				size_t len_bytes;
-				size_t len_chars = BLI_strlen_utf8_ex(cu->str, &len_bytes);
-
-				writedata(wd, DATA, len_bytes + 1, cu->str);
-				writestruct(wd, DATA, "CharInfo", len_chars + 1, cu->strinfo);
+				writedata(wd, DATA, cu->len + 1, cu->str);
+				writestruct(wd, DATA, "CharInfo", cu->len_wchar + 1, cu->strinfo);
 				writestruct(wd, DATA, "TextBox", cu->totbox, cu->tb);
 			}
 			else {