From cb2d1c37df1b8c4f1b130a017c18c4de505a7784 Mon Sep 17 00:00:00 2001 From: Arti Zirk Date: Sun, 1 Nov 2026 11:22:05 +0200 Subject: [PATCH] docs(badapple): record the potrace y-up orientation fix --- bad-apple/REPORT.md | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/bad-apple/REPORT.md b/bad-apple/REPORT.md index 5801e14..7151873 100644 --- a/bad-apple/REPORT.md +++ b/bad-apple/REPORT.md @@ -47,6 +47,12 @@ rectangle 10..109 × 20..69 became exactly screen x 20..219. The first version was exactly twice as wide; the cause was the OS leaving PSIZE at 2 bpp. The primitive now re-asserts PSIZE=1 on every call. +Potrace emits **y-up** GeoJSON; the framebuffer is y-down. The first build was +vertically mirrored, and the VRAM checker still said EXACT because it consumed +the same flipped data. `trace()` now flips y before simplification, and +`test_trace_preserves_vertical_position` pins the orientation. The preview PNGs +were the visible symptom. + ## Pacing `wait_vsync()` programs `DPYINT=1`, clears `INTPEND`, and polls the DI bit at