From: Lukas Krickl <lukas@krickl.dev>
Date: Sat, 20 Sep 2025 16:01:20 +0000 (+0200)
Subject: video: made scroll smooth
X-Git-Url: https://git.krickl.dev/?a=commitdiff_plain;h=578bee2332741babf74c8b58154079275ed84789;p=gbrg%2F.git

video: made scroll smooth
---

diff --git a/src/video.s b/src/video.s
index 8b4dc62..657c927 100644
--- a/src/video.s
+++ b/src/video.s
@@ -22,33 +22,48 @@ vblank:
   ; get inputs 
   call poll_inputs
 
+	call video_map_adjust_scroll
+
   ld a, 1
   ld [frame_ready], a
   pop_all
   ret
 	
 	; scrolls if the flag is set
+	; loads a new map row and sets the scroll
+	; timer
 video_map_perform_scroll:
 	ld a, [game_flags]
 	and a, GPF_SCROLL
 	ret z
 
-	ld a, [scroll_y]
-	sub a, MAP_ROW_H
-	ld [scroll_y], a
-
-	ld a, [player_next_scroll_y]
-	; sub a, MAP_ROW_H/2
-	ld [player_next_scroll_y], a
-	
 	call map_advance_row
 
-	call scroll_up_adjust
-
 	; unset flag
 	ld a, [game_flags]
 	and a, ~GPF_SCROLL & 0xFF
 	ld [game_flags], a
+
+	ld a, MAP_ROW_H
+	ld [scroll_timer], a
+	ret
+	
+	; adjusts the scroll slowly 1 pixel each frame
+	; until the timer reaches 0
+video_map_adjust_scroll:
+	ld a, [scroll_timer]
+	cp a, 0
+	ret z
+
+	dec a
+	ld [scroll_timer], a
+
+
+	ld a, [scroll_y]
+	dec a
+	ld [scroll_y], a
+
+	call scroll_up_adjust
 	ret
 	
 	; adjusts all actors and rectangles positions
@@ -63,7 +78,7 @@ scroll_up_adjust:
 	ld de, act_pos_y
 	add hl, de
 	ld a, [hl]
-	add a, MAP_ROW_H
+	add a, 1
 	ld [hl+], a ; hl = page y pos hi
 
 	ld a, [hl]
@@ -77,6 +92,16 @@ scroll_up_adjust:
 	add hl, de
 	jr nz, @act_loop REL
 
+	; adjust player
+
+	ld a, [player+act_pos_y]
+	add a, 1
+	ld [player+act_pos_y], a
+
+	ld a, [player+act_pos_y_hi]
+	adc a, 0
+	ld [player+act_pos_y_hi], a
+
 	; TODO: adjust rectangles
 	ret
 
diff --git a/src/wram.s b/src/wram.s
index adb6125..9728ae8 100644
--- a/src/wram.s
+++ b/src/wram.s
@@ -43,6 +43,8 @@ demo_inputs: .adv 2
 	; gameplay control flags
 game_flags: .adv 1
 
+scroll_timer: .adv 1
+
 ; dummy oam 
 ; same memory as empty_unit
 empty_oam: .adv oamsize