WM: Remove ASCII members from wmEvent & GHOST_TEventKeyData

The `ascii` member was only kept for historic reason as some platforms
didn't support utf8 when it was first introduced.

Remove the `ascii` struct members since many checks used this as a
fall-back for utf8_buf not being set which isn't needed.
There are a few cases where it's convenient to access the ASCII value
of an event (or nil) so a function has been added to do that.

*Details*

- WM_event_utf8_to_ascii() has been added for the few cases an events
  ASCII value needs to be accessed, this just avoids having to do
  multi-byte character checks in-line.

- RNA Event.ascii remains, using utf8_buf[0] for single byte characters.

- GHOST_TEventKeyData.ascii has been removed.

- To avoid regressions non-ASCII Latin1 characters from GHOST are
  converted into multi-byte UTF8, when building X11 without
  XInput & X_HAVE_UTF8_STRING it seems like could still occur.

1 files changed, 4 insertions, 2 deletions

diff --git a/intern/ghost/test/multitest/EventToBuf.c b/intern/ghost/test/multitest/EventToBuf.c
index baab32328c3..846a867a371 100644
--- a/intern/ghost/test/multitest/EventToBuf.c
+++ b/intern/ghost/test/multitest/EventToBuf.c
@@ -218,8 +218,10 @@ void event_to_buf(GHOST_EventHandle evt, char buf[128])
     case GHOST_kEventKeyUp: {
       GHOST_TEventKeyData *kd = data;
       pos += sprintf(pos, " - key: %s (%d)", keytype_to_string(kd->key), kd->key);
-      if (kd->ascii)
-        pos += sprintf(pos, " ascii: '%c' (%d)", kd->ascii, kd->ascii);
+      /* TODO: ideally this would print the unicode character. */
+      if (kd->utf8_buf[0]) {
+        pos += sprintf(pos, " ascii: '%c' (%d)", kd->utf8_buf[0], kd->utf8_buf[0]);
+      }
       break;
     }
   }