some more optimizations for unstable width lines

2 files changed, 34 insertions, 21 deletions

diff --git a/WinPort/src/Backend/TTY/TTYBackend.cpp b/WinPort/src/Backend/TTY/TTYBackend.cpp
index fc4af976..3919e175 100644
--- a/WinPort/src/Backend/TTY/TTYBackend.cpp
+++ b/WinPort/src/Backend/TTY/TTYBackend.cpp
@@ -420,12 +420,6 @@ void TTYBackend::DispatchOutput(TTYOutput &tty_out)
 		const CHAR_INFO *cur_line = &_cur_output[y * _cur_width];
 		const CHAR_INFO *prev_line = &_prev_output[y * _prev_width];
 
-		const auto UnstableWidth = [&](unsigned int x_)
-		{
-			return IsUnstableWidthCharCached(cur_line[x_].Char.UnicodeChar)
-				|| IsUnstableWidthCharCached(prev_line[x_].Char.UnicodeChar);
-		};
-
 		const auto ApproxWeight = [&](unsigned int x_)
 		{
 			return ((cur_line[x_].Char.UnicodeChar > 0x7f) ? 2 : 1);
@@ -437,22 +431,45 @@ void TTYBackend::DispatchOutput(TTYOutput &tty_out)
 				|| cur_line[x_].Attributes != prev_line[x_].Attributes);
 		};
 
+		const auto WriteLineDebugColored = [&](const CHAR_INFO *line, unsigned int cnt, WORD attrs)
+		{
+#if 0 // change to 1 to see affected lines as yellow/green on black
+			std::vector<CHAR_INFO> tmp_line(cnt);
+			for (unsigned int i = 0; i < cnt; ++i) {
+				tmp_line[i].Char.UnicodeChar = line[i].Char.UnicodeChar;
+				tmp_line[i].Attributes = attrs;
+			}
+			tty_out.WriteLine(tmp_line.data(), cnt);
+#else
+			tty_out.WriteLine(line, cnt);
+#endif
+		};
+
+
 
 		if (!_far2l_tty) {
 			// If some characters at line 'special' - like fullwidth or diacric then need
 			// to write whole line til the end to avoid artifacts on non-far2l terminals.
 			// Also need to do same if previous line had such special characters as they
 			// could wrap around to next (i.e. current) line.
-			bool unstable = false, modified = false;
+			bool unstable_cur = false, unstable_prev = false, modified = false;
 			for (unsigned int x = 0; x < _cur_width; ++x) {
-				if (x + 1 < _cur_width && UnstableWidth(x)) {
-					unstable = true;
+				if (x + 1 < _cur_width) {
+					if (IsUnstableWidthCharCached(cur_line[x].Char.UnicodeChar)) {
+						unstable_cur = true;
+					}
+					if (IsUnstableWidthCharCached(prev_line[x].Char.UnicodeChar)) {
+						unstable_prev = true;
+					}
 				}
 				if (Modified(x)) {
 					modified = true;
 				}
 			}
-			if (unstable && modified) {
+			if (!modified) {
+				continue;
+			}
+			if (unstable_cur) {
 				bool prev_simple = false;
 				for (unsigned int chunk_x = 0, x = 0; x <= _cur_width; ++x) {
 					const bool cur_simple = (x < _cur_width)
@@ -460,24 +477,19 @@ void TTYBackend::DispatchOutput(TTYOutput &tty_out)
 						&& (WCHAR_IS_PSEUDOGRAPHIC(prev_line[x].Char.UnicodeChar) || prev_line[x].Char.UnicodeChar < 0x7f);
 					if (cur_simple != prev_simple || x == _cur_width) {
 						tty_out.MoveCursorStrict(y + 1, chunk_x + 1);
-#if 0 // change to 1 to see affected lines as green on black
-						std::vector<CHAR_INFO> tmp_line(x - chunk_x);
-						memcpy(tmp_line.data(), &cur_line[chunk_x], (x - chunk_x) * sizeof(CHAR_INFO));
-						for (auto &ci : tmp_line) {
-							ci.Attributes = FOREGROUND_GREEN | FOREGROUND_INTENSITY;
-						}
-						tty_out.WriteLine(tmp_line.data(), x - chunk_x);
-#else
-						tty_out.WriteLine(&cur_line[chunk_x], x - chunk_x);
-#endif
+						WriteLineDebugColored(&cur_line[chunk_x], (x - chunk_x),
+							FOREGROUND_GREEN | FOREGROUND_RED | FOREGROUND_INTENSITY);
 						prev_simple = cur_simple;
 						chunk_x = x;
 					}
 				}
 				continue;
 			}
-			if (!modified)
+			if (unstable_prev) {
+				tty_out.MoveCursorStrict(y + 1, 1);
+				WriteLineDebugColored(cur_line, _cur_width, FOREGROUND_GREEN | FOREGROUND_INTENSITY);
 				continue;
+			}
 		}
 
 		for (unsigned int x = 0, skipped_start = 0, skipped_weight = 0; x < _cur_width; ++x) {
diff --git a/WinPort/src/Backend/TTY/TTYBackend.h b/WinPort/src/Backend/TTY/TTYBackend.h
index cf0f70c6..e8918e6b 100644
--- a/WinPort/src/Backend/TTY/TTYBackend.h
+++ b/WinPort/src/Backend/TTY/TTYBackend.h
@@ -88,6 +88,7 @@ class TTYBackend : IConsoleOutputBackend, ITTYInputSpecialSequenceHandler, IFar2
 	ClipboardBackendSetter _clipboard_backend_setter;
 
 	bool IsUnstableWidthCharCached(wchar_t c);
+	void WriteLineDebugColored(TTYOutput &tty_out, const CHAR_INFO *line, unsigned int cnt, WORD attrs);
 
 	void DispatchTermResized(TTYOutput &tty_out);
 	void DispatchOutput(TTYOutput &tty_out);