Commit 712e0d1f06bf413213bc4a9d3be2ac8d9a34a9f9
2021-08-07T16:23:15
Fixing WM_CHAR event handling for Unicode characters outside the Basic Multilingual Plane.
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diff --git a/src/video/windows/SDL_windowsevents.c b/src/video/windows/SDL_windowsevents.c
index 1481b03..960443d 100644
--- a/src/video/windows/SDL_windowsevents.c
+++ b/src/video/windows/SDL_windowsevents.c
@@ -862,15 +862,41 @@ WIN_WindowProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)
case WM_UNICHAR:
if (wParam == UNICODE_NOCHAR) {
returnCode = 1;
- break;
- }
- /* otherwise fall through to below */
- case WM_CHAR:
- {
+ } else {
char text[5];
if (WIN_ConvertUTF32toUTF8((UINT32)wParam, text)) {
SDL_SendKeyboardText(text);
}
+ returnCode = 0;
+ }
+ break;
+
+ case WM_CHAR:
+ /* When a user enters a Unicode code point defined in the Basic Multilingual Plane, Windows sends a WM_CHAR
+ message with the code point encoded as UTF-16. When a user enters a Unicode code point from a Supplementary
+ Plane, Windows sends the code point in two separate WM_CHAR messages: The first message includes the UTF-16
+ High Surrogate and the second the UTF-16 Low Surrogate. The High and Low Surrogates cannot be individually
+ converted to valid UTF-8, therefore, we must save the High Surrogate from the first WM_CHAR message and
+ concatenate it with the Low Surrogate from the second WM_CHAR message. At that point, we have a valid
+ UTF-16 surrogate pair ready to re-encode as UTF-8. */
+ if (IS_HIGH_SURROGATE(wParam)) {
+ data->high_surrogate = (WCHAR)wParam;
+ } else if (IS_SURROGATE_PAIR(data->high_surrogate, wParam)) {
+ /* The code point is in a Supplementary Plane.
+ Here wParam is the Low Surrogate. */
+ const WCHAR surrogate_pair[] = {data->high_surrogate, (WCHAR)wParam, 0};
+ char *s;
+ s = SDL_iconv_string("UTF-8", "UTF-16LE", (const char *)surrogate_pair, sizeof(surrogate_pair));
+ SDL_SendKeyboardText(s);
+ SDL_free(s);
+ data->high_surrogate = 0;
+ } else {
+ /* The code point is in the Basic Multilingual Plane */
+ const WCHAR wchar[] = {(WCHAR)wParam, 0};
+ char *s;
+ s = SDL_iconv_string("UTF-8", "UTF-16LE", (const char *)wchar, sizeof(wchar));
+ SDL_SendKeyboardText(s);
+ SDL_free(s);
}
returnCode = 0;
break;
diff --git a/src/video/windows/SDL_windowswindow.c b/src/video/windows/SDL_windowswindow.c
index 93d1903..75fe64c 100644
--- a/src/video/windows/SDL_windowswindow.c
+++ b/src/video/windows/SDL_windowswindow.c
@@ -186,6 +186,7 @@ SetupWindowData(_THIS, SDL_Window * window, HWND hwnd, HWND parent, SDL_bool cre
data->hdc = GetDC(hwnd);
data->hinstance = (HINSTANCE) GetWindowLongPtr(hwnd, GWLP_HINSTANCE);
data->created = created;
+ data->high_surrogate = 0;
data->mouse_button_flags = 0;
data->last_pointer_update = (LPARAM)-1;
data->videodata = videodata;
diff --git a/src/video/windows/SDL_windowswindow.h b/src/video/windows/SDL_windowswindow.h
index 700566e..e64096c 100644
--- a/src/video/windows/SDL_windowswindow.h
+++ b/src/video/windows/SDL_windowswindow.h
@@ -41,6 +41,7 @@ typedef struct
SDL_bool created;
WPARAM mouse_button_flags;
LPARAM last_pointer_update;
+ WCHAR high_surrogate;
SDL_bool initializing;
SDL_bool expected_resize;
SDL_bool in_border_change;