Method AddInputCharacterUTF16

KBotExt/imgui/imgui.cpp:1315–1347

UTF16 strings use surrogate pairs to encode codepoints >= 0x10000, so we should save the high surrogate.

// UTF16 strings use surrogate pairs to encode codepoints >= 0x10000, so
// we should save the high surrogate.
void ImGuiIO::AddInputCharacterUTF16(ImWchar16 c)
{
	if ((c == 0 && InputQueueSurrogate == 0) || !AppAcceptingEvents)
		return;

	if ((c & 0xFC00) == 0xD800) // High surrogate, must save
	{
		if (InputQueueSurrogate != 0)
			AddInputCharacter(IM_UNICODE_CODEPOINT_INVALID);
		InputQueueSurrogate = c;
		return;
	}

	ImWchar cp = c;
	if (InputQueueSurrogate != 0)
	{
		if ((c & 0xFC00) != 0xDC00) // Invalid low surrogate
		{
			AddInputCharacter(IM_UNICODE_CODEPOINT_INVALID);
		}
		else
		{
#if IM_UNICODE_CODEPOINT_MAX == 0xFFFF
			cp = IM_UNICODE_CODEPOINT_INVALID; // Codepoint will not fit in ImWchar
#else
			cp = (ImWchar)(((InputQueueSurrogate - 0xD800) << 10) + (c - 0xDC00) + 0x10000);
#endif
		}

		InputQueueSurrogate = 0;
	}
	AddInputCharacter((unsigned)cp);
}

void ImGuiIO::AddInputCharactersUTF8(const char* utf8_chars)
{