hans/wolf_dart
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

feat: Improve Sixel rendering stability by adjusting output height and anchoring behavior

Browse Source 
Signed-off-by: Hans Kokx <hans.d.kokx@gmail.com>
This commit is contained in:
Hans Kokx
2026-03-20 18:03:19 +01:00
parent 1e5222368a
commit 2598218a4d
2 changed files with 25 additions and 12 deletions
Download Patch File Download Diff File Expand all files Collapse all files

15
apps/wolf_3d_cli/lib/cli_game_loop.dart
View File

@@ -68,7 +68,8 @@ class CliGameLoop {
}
}
stdout.write('\x1b[?25l\x1b[2J');
// Disable Sixel scrolling mode so frames overwrite in-place.
stdout.write('\x1b[?80l\x1b[?25l\x1b[2J');
_stdinSubscription = _stdinStream.listen(_handleInput);
_stopwatch.start();
@@ -101,7 +102,8 @@ class CliGameLoop {
}
if (stdout.hasTerminal) {
stdout.write('\x1b[0m\x1b[?25h');
// Restore scrolling Sixel mode and cursor visibility.
stdout.write('\x1b[0m\x1b[?80h\x1b[?25h');
}
_isRunning = false;
@@ -200,12 +202,15 @@ class CliGameLoop {
return;
}
final int safeCols = cols > 1 ? cols - 1 : cols;
final String hint = _buildShortcutHintText();
final String visible = hint.length > cols ? hint.substring(0, cols) : hint;
final String padded = visible.padRight(cols);
final String visible = hint.length > safeCols
? hint.substring(0, safeCols)
: hint;
final String padded = visible.padRight(safeCols);
// Draw an overlay line without disturbing the renderer's cursor position.
stdout.write('\x1b[s\x1b[1;1H\x1b[0m\x1b[2m$padded\x1b[0m\x1b[u');
stdout.write('\x1b[s\x1b[1;1H\x1b[0m\x1b[2m\x1b[2K$padded\x1b[0m\x1b[u');
}
String _buildShortcutHintText() {

22
packages/wolf_3d_dart/lib/src/rendering/sixel_renderer.dart
View File

@@ -200,14 +200,22 @@ class SixelRenderer extends CliRendererBackend<String> {
// Horizontal: cell-width estimates vary by terminal/font and can cause
// right-shift clipping, so keep the image anchored at column 0.
// Vertical: keep one spare row to avoid scroll, but anchor to the bottom
// of the viewport so we avoid obvious empty space under the image.
final int imageRows = math.max(
1,
(_outputHeight / _defaultLineHeightPx).ceil() + _terminalRowSafetyMargin,
);
// Vertical: force top anchoring to keep repaint location stable across
// terminals that still scroll when rendering near the bottom edge.
_offsetColumns = 0;
_offsetRows = math.max(0, terminalRows - imageRows);
_offsetRows = 0;
// Clamp output height to a conservative terminal-row budget so Sixel data
// cannot extend beyond the viewport and trigger implicit scroll.
final int maxImageRows = math.max(
1,
terminalRows - _terminalRowSafetyMargin,
);
final int maxOutputHeight = maxImageRows * _defaultLineHeightPx;
if (_outputHeight > maxOutputHeight) {
_outputHeight = maxOutputHeight;
_outputWidth = math.max(1, (_outputHeight * _targetAspectRatio).floor());
}
if (_offsetColumns != previousOffsetColumns ||
_offsetRows != previousOffsetRows ||