From: Lukas Krickl <lukas@krickl.dev>
Date: Fri, 21 Mar 2025 17:34:55 +0000 (+0100)
Subject: video: Added bg tileset cycles
X-Git-Url: https://git.krickl.dev/?a=commitdiff_plain;h=d5acbcfc316ed0138e291abc4f8b959f5805c6ce;p=gbrg%2F.git

video: Added bg tileset cycles
---

diff --git a/src/hw.inc b/src/hw.inc
index c117709..c2f9aa0 100644
--- a/src/hw.inc
+++ b/src/hw.inc
@@ -13,6 +13,7 @@
 #define LCDCF_BGON 0b00000001
 #define LCDCF_ON 0b10000000
 #define LCDCF_OBJON 0b00000010
+#define LCDCF_TILE_BANK 0b00010000
 #define LCDF_WINDOWON 0b00100000
 #define LCDF_OBJ_SIZE 0b00000100
 #define LCDF_WINBANKSELECT 0b01000000
diff --git a/src/video.s b/src/video.s
index d9ad061..efac8ef 100644
--- a/src/video.s
+++ b/src/video.s
@@ -1,5 +1,7 @@
 #define BGP 0b11100100
 
+#define BG_CYCLE_FRAMES 7
+
   ; vblank handler
 vblank:
   ; dma previous frame's oam
@@ -11,6 +13,16 @@ vblank:
 
   call scroll_write
 
+  ; cycle bg tiles for animations
+  ld a, [frame_count]
+  and a, BG_CYCLE_FRAMES
+  jr z, @skip_cycle REL
+
+  ld a, [RLCD]
+  xor a, LCDCF_TILE_BANK 
+  ld [RLCD], a
+@skip_cycle:
+
   ld a, 1
   ld [frame_ready], a
   ret
diff --git a/tiles/tileset1.inc b/tiles/tileset1.inc
index 5c77aa9..c6cb263 100644
--- a/tiles/tileset1.inc
+++ b/tiles/tileset1.inc
@@ -1116,11 +1116,11 @@
 .chr 22222222
 ; tile 124
 .chr 00000000
+.chr 01010000
+.chr 00101000
 .chr 00000000
-.chr 00000000
-.chr 00000000
-.chr 00000000
-.chr 00000000
+.chr 01010100
+.chr 00101000
 .chr 00000000
 .chr 00000000
 ; tile 125