From 7459e218fa8b5b86c059762519447cb8863d3e75 Mon Sep 17 00:00:00 2001 From: Lukasz Kasprzak Date: Fri, 21 Aug 2026 09:49:33 +0200 Subject: debug: MUX_DUMP writes one frame from the pixmap, then exits Verifying what the program actually draws by screenshotting its window is unreliable: X does not retain a window's contents while it is obscured or on an unfocused tag, so import and xwd can both return solid black while the rendering is correct. Reading back the off-screen pixmap always works. Used to confirm the XRectangle clip-truncation fix: rows now run unbroken from 2027-01-01 to 2027-01-29 with every column populated, where before the twelfth row lost everything but its name. --- README.md | 11 +++++++++++ 1 file changed, 11 insertions(+) (limited to 'README.md') diff --git a/README.md b/README.md index 920c056..b0872cf 100644 --- a/README.md +++ b/README.md @@ -76,6 +76,17 @@ and everything after it silently disappears, which looks like a layout or buffer-overflow bug and is neither. `set_clip()` clamps to the buffer bounds before converting. +### Verifying a frame without a screenshot + + MUX_DUMP=/tmp/frame.ppm ./colitur-mu # writes one frame, then exits + convert /tmp/frame.ppm /tmp/frame.png + +This reads back the off-screen PIXMAP, not the window. A window's contents +are not retained while it is obscured or sitting on an unfocused tag, so +`import`/`xwd` against one can return solid black while the program is +drawing perfectly -- which cost real time to work out once. A pixmap is +always there. + ### Which to use `colitur-x` renders; `colitur-mu` renders and lets you change the invocation. -- cgit v1.3