From 2f43a8851a89661b304edd9396677080dcb3e003 Mon Sep 17 00:00:00 2001
From: user <user@clank>
Date: Thu, 16 Jul 2026 16:40:45 +0200
Subject: term/osk: view-offset scroll region (lossless backlog on OSK toggle)

Replace the shrink-and-scroll region with a view offset. The terminal is
always 18 logical rows; term_write_tilemap maps screen row -> logical row +
wViewTop (rows the OSK covers clamp to the cursor line). Showing the OSK
sets the offset to OSK_ROWS so the cursor line lands at row 14 (above the
keyboard) and hiding it sets the offset back to 0 - now purely a remap, so
nothing is scrolled off or destroyed. term_set_view replaces term_set_rows;
term_scroll/cursor_down are back to plain 18-row scrolling.

Result: full 18-row backlog when the OSK is hidden, a shifted 15-row window
when shown, and toggling is lossless (verified: OSK-shown view == baseline
rows 3..17, and toggle on+off == baseline exactly).
---
 src/osk.asm | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

(limited to 'src/osk.asm')

diff --git a/src/osk.asm b/src/osk.asm
index a34a863..5e316e3 100644
--- a/src/osk.asm
+++ b/src/osk.asm
@@ -236,9 +236,9 @@ osk_toggle::
     ld [wOskVisible], a
     or a
     jr z, .hide
-    ; show: shrink the terminal to the rows above the keyboard, then enable window
-    ld a, 18 - OSK_ROWS
-    call term_set_rows
+    ; show: shift the view up so the cursor line clears the keyboard
+    ld a, OSK_ROWS
+    call term_set_view
     ld a, [rLCDC]
     or %00100000
     ld [rLCDC], a
@@ -247,8 +247,8 @@ osk_toggle::
     ld a, [rLCDC]
     and %11011111
     ld [rLCDC], a
-    ld a, 18                    ; restore full-height terminal
-    call term_set_rows
+    xor a                       ; view unshifted -> full 18-row backlog
+    call term_set_view
     ret
 
 ; movement with wrap-around; each moves the highlight
-- 
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