From f652b2a9c76194ee285e001e6b04a7dc585e8993 Mon Sep 17 00:00:00 2001
From: Bad Diode <bd@badd10de.dev>
Date: Fri, 23 Apr 2021 23:05:06 +0200
Subject: First steps to replace the input overlay

VRAM and rom consumption was too big with the previous input overlay.
Trying to separate button sprites into multiple states. Sprites can now
be composed of multiple objects.
---
 src/gba-buttons.c | 616 +++++++++---------------------------------------------
 src/main.c        | 415 ++++++++++++++++++++----------------
 2 files changed, 341 insertions(+), 690 deletions(-)

diff --git a/src/gba-buttons.c b/src/gba-buttons.c
index 7d40031..cbf6f8b 100644
--- a/src/gba-buttons.c
+++ b/src/gba-buttons.c
@@ -1,536 +1,66 @@
 // 1bpp packed
 u32 gba_btn_a_data[] = {
-    0x00000000, 0x00000000, 0x00000000, 0x000000c0,
-    0x00000000, 0x00000003, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x30080484, 0x4242c242,
-    0x0c102021, 0x42424342, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x42060c34, 0xc830c000,
-    0x4260302c, 0x130c0300, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0xc0300804, 0x844242c2,
-    0x030c1020, 0x21424243, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x4242040c, 0x38f0c000,
-    0x42422030, 0x1c0f0300, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000080,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00c43008, 0x04844242,
-    0x00230c10, 0x20214242, 0x00000000, 0x00000000,
-    0x80000000, 0x00000000, 0xc2424404, 0x0832c000,
-    0x43422220, 0x104c0300, 0x01000000, 0x00000000,
-    0x00000000, 0x00000000, 0x80000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00408000, 0x00000080, 0x80800001,
-    0x00000000, 0x00000080, 0x00000000, 0x00020100,
-    0x00000000, 0x00000000, 0x00c03008, 0x04844242,
-    0x00030c10, 0x20214242, 0x00000000, 0x00000000,
-    0x38000000, 0x00000080, 0xc2424404, 0x0830c000,
-    0x43422220, 0x100c0300, 0x1c000000, 0x00000001,
-    0x40200000, 0x00000000, 0x00008080, 0x80000000,
-    0x00000000, 0x00000000, 0x02040000, 0x00000000,
-    0x00000000, 0x20400000, 0x00008080, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x04020000,
-    0x00000000, 0x00000000, 0x00c03008, 0x04844242,
-    0x00030c10, 0x20214242, 0x00000000, 0x00000000,
-    0x0c000000, 0x00000000, 0xc2424404, 0x0830c000,
-    0x43422220, 0x100c0300, 0x30000000, 0x00000000,
-    0x00201000, 0x00000000, 0x00000080, 0x80000000,
-    0x00000000, 0x00000000, 0x00040800, 0x00000000,
-    0x00000000, 0x20000000, 0x00008000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x04000000,
-    0x00000000, 0x00000000, 0x00c03008, 0x04844242,
-    0x00030c10, 0x20214242, 0x00000000, 0x00000000,
-    0x04000000, 0x00000000, 0xc2424404, 0x0830c000,
-    0x43422220, 0x100c0300, 0x20000000, 0x00000000,
-    0x00001000, 0x00000000, 0x00000000, 0x80000000,
-    0x00000000, 0x00000000, 0x00000800, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00c03008, 0x04844242,
-    0x00030c10, 0x20214242, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0xc2424404, 0x0830c000,
-    0x43422220, 0x100c0300, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
+    0xc0300804, 0x844242c2, 0x030c1020, 0x21424243,
+    0x42440408, 0x30c00000, 0x42222010, 0x0c030000,
 };
 
 u32 gba_btn_b_data[] = {
-    0x00000000, 0x00000000, 0x00000000, 0x000000c0,
-    0x00000000, 0x00000003, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x300804c4, 0x42c24242,
-    0x0c102021, 0x42414242, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0xc2060c34, 0xc830c000,
-    0x4160302c, 0x130c0300, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0xc0300804, 0xc442c242,
-    0x030c1020, 0x21424142, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x42c2040c, 0x38f0c000,
-    0x42412030, 0x1c0f0300, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000080,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00c43008, 0x04c442c2,
-    0x00230c10, 0x20214241, 0x00000000, 0x00000000,
-    0x80000000, 0x00000000, 0x4242c404, 0x0832c000,
-    0x42422120, 0x104c0300, 0x01000000, 0x00000000,
-    0x00000000, 0x00000000, 0x80000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00408000, 0x00000080, 0x80800001,
-    0x00000000, 0x00000080, 0x00000000, 0x00020100,
-    0x00000000, 0x00000000, 0x00c03008, 0x04c442c2,
-    0x00030c10, 0x20214241, 0x00000000, 0x00000000,
-    0x38000000, 0x00000080, 0x4242c404, 0x0830c000,
-    0x42422120, 0x100c0300, 0x1c000000, 0x00000001,
-    0x40200000, 0x00000000, 0x00008080, 0x80000000,
-    0x00000000, 0x00000000, 0x02040000, 0x00000000,
-    0x00000000, 0x20400000, 0x00808000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x04020000,
-    0x00000000, 0x00000000, 0x00c03008, 0x04c442c2,
-    0x00030c10, 0x20214241, 0x00000000, 0x00000000,
-    0x0c000000, 0x00000000, 0x4242c404, 0x0830c000,
-    0x42422120, 0x100c0300, 0x30000000, 0x00000000,
-    0x00201000, 0x00000000, 0x00000000, 0x80800000,
-    0x00000000, 0x00000000, 0x00040800, 0x00000000,
-    0x00000000, 0x20000000, 0x00800000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x04000000,
-    0x00000000, 0x00000000, 0x00c03008, 0x04c442c2,
-    0x00030c10, 0x20214241, 0x00000000, 0x00000000,
-    0x04000000, 0x00000000, 0x4242c404, 0x0830c000,
-    0x42422120, 0x100c0300, 0x20000000, 0x00000000,
-    0x00001000, 0x00000000, 0x00000000, 0x00800000,
-    0x00000000, 0x00000000, 0x00000800, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00c03008, 0x04c442c2,
-    0x00030c10, 0x20214241, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x4242c404, 0x0830c000,
-    0x42422120, 0x100c0300, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
+    0xc0300804, 0xc442c242, 0x030c1020, 0x21424142,
+    0x42c40408, 0x30c00000, 0x42212010, 0x0c030000,
 };
 
-u32 gba_btn_up_data[] = {
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0xf80888c8, 0xe8888888,
-    0x0f080809, 0x0b080808, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x8818e810, 0xe0000000,
-    0x080c0b04, 0x03000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00f80888, 0xc8e88888,
-    0x000f0808, 0x090b0808, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x888818f0, 0xe0000000,
-    0x08080c07, 0x03000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000080,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x0002f808, 0x88c8e888,
-    0x00200f08, 0x08090b08, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x88888810, 0xe0000000,
-    0x08080804, 0x03000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000080, 0x00000000, 0x00808000,
-    0x00000000, 0x00000080, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x0100f808, 0x88c8e888,
-    0x40000f08, 0x08090b08, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x88888810, 0xe0000000,
-    0x08080804, 0x03000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00004080, 0x00000000, 0x80800000,
-    0x00000000, 0x00000080, 0x00000000, 0x00000100,
-    0x00000000, 0x00000000, 0x0000f808, 0x88c8e888,
-    0x00000f08, 0x08090b08, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x88888810, 0xe0000000,
-    0x08080804, 0x03000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00200000, 0x00000080, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00020000,
-    0x00000000, 0x00000000, 0x0000f808, 0x88c8e888,
-    0x00000f08, 0x08090b08, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x88888810, 0xe0000000,
-    0x08080804, 0x03000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x0000f808, 0x88c8e888,
-    0x00000f08, 0x08090b08, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x88888810, 0xe0000000,
-    0x08080804, 0x03000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
+u32 gba_btn_updown_data[] = {
+    0x00f01010, 0x90d01010, 0x001f1011, 0x13171111,
+    0x101020c0, 0x00000000, 0x11110807, 0x00000000,
 };
 
-u32 gba_btn_down_data[] = {
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00e01088, 0x888888e8,
-    0x00030408, 0x0808080b, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0xc88808f8, 0x08f80000,
-    0x0908080f, 0x080f0000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x0000e010, 0x88888888,
-    0x00000304, 0x08080808, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0xe8c88808, 0xf8f80000,
-    0x0b090808, 0x0f0f0000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x000000e0, 0x10888888,
-    0x00000003, 0x04080808, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x88e8c888, 0x08f80200,
-    0x080b0908, 0x080f2000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x80000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x000000e0, 0x10888888,
-    0x00000003, 0x04080808, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x88e8c888, 0x08f80001,
-    0x080b0908, 0x080f0040, 0x00000000, 0x00000000,
-    0x80000000, 0x00000000, 0x00808000, 0x00000000,
-    0x80000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x000000e0, 0x10888888,
-    0x00000003, 0x04080808, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x88e8c888, 0x08f80000,
-    0x080b0908, 0x080f0000, 0x00000000, 0x00000000,
-    0x80400000, 0x00000000, 0x00008080, 0x00000000,
-    0x80000000, 0x00000000, 0x00010000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x000000e0, 0x10888888,
-    0x00000003, 0x04080808, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x88e8c888, 0x08f80000,
-    0x080b0908, 0x080f0000, 0x00000000, 0x00000000,
-    0x00002000, 0x00000000, 0x00000000, 0x80000000,
-    0x00000000, 0x00000000, 0x00000200, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x000000e0, 0x10888888,
-    0x00000003, 0x04080808, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x88e8c888, 0x08f80000,
-    0x080b0908, 0x080f0000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
+u32 gba_btn_leftright_data[] = {
+    0x000000f8, 0x0888c8e8, 0x0000000f, 0x1020202f,
+    0xc88808f8, 0x00000000, 0x2020100f, 0x00000000,
 };
 
-u32 gba_btn_left_data[] = {
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x0000f808, 0x88c8e8c8,
-    0x00000f10, 0x20202f20, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x8808f808, 0xf8000000,
-    0x20302f10, 0x0f000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x000000f8, 0x0888c8e8,
-    0x0000000f, 0x1020202f, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0xc88808f8, 0xf8000000,
-    0x2020301f, 0x0f000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000400, 0xf80888c8,
-    0x00000000, 0x0f102020, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0xe9c88808, 0xf8000400,
-    0x2f202010, 0x0f000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x01020000, 0xf80888c8,
-    0x00000000, 0x0f102020, 0x00000000, 0x00000000,
-    0xc0000000, 0x00000000, 0xe8c88808, 0xf8000002,
-    0x2f202010, 0x0f000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x01000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000080, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x01000000, 0xf80888c8,
-    0x00000000, 0x0f102020, 0x00000000, 0x00000000,
-    0x60000000, 0x00000000, 0xe8c88808, 0xf8000000,
-    0x2f202010, 0x0f000000, 0x00000000, 0x00000000,
-    0x00800000, 0x00000000, 0x01000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00004000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0xf80888c8,
-    0x00000000, 0x0f102020, 0x00000000, 0x00000000,
-    0x10000000, 0x00000000, 0xe8c88808, 0xf8000000,
-    0x2f202010, 0x0f000000, 0x00000000, 0x00000000,
-    0x00004000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0xf80888c8,
-    0x00000000, 0x0f102020, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0xe8c88808, 0xf8000000,
-    0x2f202010, 0x0f000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
+u32 gba_btn_l_data[] = {
+    0xfc028181, 0x818101ff, 0xff808080, 0x808380ff,
 };
 
-u32 gba_btn_right_data[] = {
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x0000f008, 0x0404f404,
-    0x00001f10, 0x11131713, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x040cf408, 0xf0000000,
-    0x11101f10, 0x1f000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x000000f0, 0x080404f4,
-    0x0000001f, 0x10111317, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x04040cf8, 0xf0000000,
-    0x1311101f, 0x1f000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0xf0080404,
-    0x00002000, 0x1f101113, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0xf4040408, 0xf0000000,
-    0x97131110, 0x1f002000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0xf0080404,
-    0x80400000, 0x1f101113, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0xf4040408, 0xf0000000,
-    0x17131110, 0x1f000040, 0x03000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x80000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000001,
-    0x00000000, 0x00000000, 0x00000000, 0xf0080404,
-    0x80000000, 0x1f101113, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0xf4040408, 0xf0000000,
-    0x17131110, 0x1f000000, 0x06000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x80000000, 0x00000000, 0x00010000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000200,
-    0x00000000, 0x00000000, 0x00000000, 0xf0080404,
-    0x00000000, 0x1f101113, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0xf4040408, 0xf0000000,
-    0x17131110, 0x1f000000, 0x08000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000200, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0xf0080404,
-    0x00000000, 0x1f101113, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0xf4040408, 0xf0000000,
-    0x17131110, 0x1f000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
+u32 gba_btn_r_data[] = {
+    0xff018181, 0x818101ff, 0x3f408182, 0x818280ff,
 };
 
-u32 gba_btn_l_data[] = {
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x0000fc02, 0x01010101,
-    0x0000ff00, 0x01010107, 0x00000302, 0x02020202,
-    0x00000000, 0x00000000, 0x01ff01ff, 0x00000000,
-    0x00ff00ff, 0x00000000, 0x02030203, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x000000fc, 0x02010101,
-    0x000000ff, 0x00010101, 0x00000003, 0x02020202,
-    0x00000000, 0x00000000, 0x0101ffff, 0x00000000,
-    0x0700ffff, 0x00000000, 0x02020303, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000080, 0x00000040, 0x00001000, 0xfc020101,
-    0x00000000, 0xff000101, 0x00000000, 0x03020202,
-    0x00000000, 0x00000000, 0x010101ff, 0x00000000,
-    0x010700ff, 0x00000000, 0x02020203, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00204000, 0x00000030, 0x10100000, 0xfc020101,
-    0x00000000, 0xff000101, 0x00000000, 0x03020202,
-    0x00000000, 0x00000000, 0x010101ff, 0x00000000,
-    0x010700ff, 0x00000000, 0x02020203, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000010,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x10200000, 0x00000018, 0x10000000, 0xfc020101,
-    0x00000000, 0xff000101, 0x00000000, 0x03020202,
-    0x00000000, 0x00000000, 0x010101ff, 0x00000000,
-    0x010700ff, 0x00000000, 0x02020203, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000010,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x10000000, 0x00000004, 0x00000000, 0xfc020101,
-    0x00000000, 0xff000101, 0x00000000, 0x03020202,
-    0x00000000, 0x00000000, 0x010101ff, 0x00000000,
-    0x010700ff, 0x00000000, 0x02020203, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0xfc020101,
-    0x00000000, 0xff000101, 0x00000000, 0x03020202,
-    0x00000000, 0x00000000, 0x010101ff, 0x00000000,
-    0x010700ff, 0x00000000, 0x02020203, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
+u32 gba_btn_ab_shadow_data[] = {
+    0x00020204, 0x040830c0, 0x00404020, 0x20100c03,
 };
 
-u32 gba_btn_r_data[] = {
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x0000c040, 0x40404040, 0x0000ff00, 0x60a060a0,
-    0x00003f40, 0x80808080, 0x00000000, 0x00000000,
-    0x40c040c0, 0x00000000, 0x00ff00ff, 0x00000000,
-    0x80ff80ff, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x000000c0, 0x40404040, 0x000000ff, 0x0060a060,
-    0x0000003f, 0x40808080, 0x00000000, 0x00000000,
-    0x4040c0c0, 0x00000000, 0xa000ffff, 0x00000000,
-    0x8080ffff, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0xc0404040, 0x00000000, 0xff0060a0,
-    0x00000800, 0x3f408080, 0x00000001, 0x00000002,
-    0x404040c0, 0x00000000, 0x60a000ff, 0x00000000,
-    0x808080ff, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0xc0404040, 0x00000000, 0xff0060a0,
-    0x08080000, 0x3f408080, 0x00040200, 0x0000000c,
-    0x404040c0, 0x00000000, 0x60a000ff, 0x00000000,
-    0x808080ff, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000008, 0x00000000, 0x00000000,
-    0x00000000, 0xc0404040, 0x00000000, 0xff0060a0,
-    0x08000000, 0x3f408080, 0x08040000, 0x00000018,
-    0x404040c0, 0x00000000, 0x60a000ff, 0x00000000,
-    0x808080ff, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000008, 0x00000000, 0x00000000,
-    0x00000000, 0xc0404040, 0x00000000, 0xff0060a0,
-    0x00000000, 0x3f408080, 0x08000000, 0x00000020,
-    0x404040c0, 0x00000000, 0x60a000ff, 0x00000000,
-    0x808080ff, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0xc0404040, 0x00000000, 0xff0060a0,
-    0x00000000, 0x3f408080, 0x00000000, 0x00000000,
-    0x404040c0, 0x00000000, 0x60a000ff, 0x00000000,
-    0x808080ff, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
-    0x00000000, 0x00000000, 0x00000000, 0x00000000,
+u32 gba_btn_up_shadow_data[] = {
+    0x00000010, 0x1020c000, 0x00000010, 0x10080700,
 };
 
-u32 gba_btn_start_data[] = {
-    0x00000000, 0x00000000, 0x00000000, 0x0000f008,
-    0x00000000, 0x00001f20, 0x00000000, 0x00000000,
-    0x00000080, 0x80008000, 0xf8f000bb, 0x91929300,
-    0x3f1f009b, 0x2a1b2a00, 0x00000003, 0x01010100,
-    0x00000000, 0x00000000, 0x00000000, 0x000000f0,
-    0x00000000, 0x0000001f, 0x00000000, 0x00000000,
-    0x00000080, 0x80008000, 0x08f000bb, 0x91929300,
-    0x201f009b, 0x2a1b2a00, 0x00000003, 0x01010100,
-    0x00000000, 0x00000000, 0x00000000, 0x001000f0,
-    0x00000000, 0x0110001f, 0x00000000, 0x00000000,
-    0x00000080, 0x80008000, 0x0af000bb, 0x91929300,
-    0xa01f009b, 0x2a1b2a00, 0x00000003, 0x01010100,
-    0x00000000, 0x00000000, 0x00000004, 0x080000f0,
-    0x00000141, 0x2000001f, 0x00000000, 0x00000000,
-    0x80000080, 0x80008000, 0x09f000bb, 0x91929300,
-    0x201f009b, 0x2a1b2a00, 0x03000003, 0x01010100,
-    0x00000000, 0x00000000, 0x00000204, 0x000000f0,
-    0x00018140, 0x0000001f, 0x00000000, 0x00000000,
-    0xc0000080, 0x80008000, 0x08f000bb, 0x91929300,
-    0x201f009b, 0x2a1b2a00, 0x06000003, 0x01010100,
-    0x00000000, 0x00000000, 0x00000200, 0x000000f0,
-    0x00018000, 0x0000001f, 0x00000000, 0x00000000,
-    0x40000080, 0x80008000, 0x08f000bb, 0x91929300,
-    0x201f009b, 0x2a1b2a00, 0x04000003, 0x01010100,
-    0x00000000, 0x00000000, 0x00000000, 0x000000f0,
-    0x00000000, 0x0000001f, 0x00000000, 0x00000000,
-    0x00000080, 0x80008000, 0x08f000bb, 0x91929300,
-    0x201f009b, 0x2a1b2a00, 0x00000003, 0x01010100,
+u32 gba_btn_down_shadow_data[] = {
+    0x00000000, 0x10f00000, 0x00000000, 0x101f0000,
 };
 
-u32 gba_btn_select_data[] = {
-    0x00000000, 0x00000000, 0x00000000, 0x0000f008,
-    0x00000000, 0x00001f20, 0x00000000, 0x00000000,
-    0x000000e0, 0x6080e000, 0xf8f0002e, 0x2622ee00,
-    0x3f1f00ee, 0x2622ee00, 0x0000000e, 0x04040400,
-    0x00000000, 0x00000000, 0x00000000, 0x000000f0,
-    0x00000000, 0x0000001f, 0x00000000, 0x00000000,
-    0x000000e0, 0x6080e000, 0x08f0002e, 0x2622ee00,
-    0x201f00ee, 0x2622ee00, 0x0000000e, 0x04040400,
-    0x00000000, 0x00000000, 0x00000000, 0x001000f0,
-    0x00000000, 0x0110001f, 0x00000000, 0x00000000,
-    0x000000e0, 0x6080e000, 0x0af0002e, 0x2622ee00,
-    0xa01f00ee, 0x2622ee00, 0x0000000e, 0x04040400,
-    0x00000000, 0x00000000, 0x00000004, 0x080000f0,
-    0x00000141, 0x2000001f, 0x00000000, 0x00000000,
-    0x800000e0, 0x6080e000, 0x09f0002e, 0x2622ee00,
-    0x201f00ee, 0x2622ee00, 0x0300000e, 0x04040400,
-    0x00000000, 0x00000000, 0x00000204, 0x000000f0,
-    0x00018140, 0x0000001f, 0x00000000, 0x00000000,
-    0xc00000e0, 0x6080e000, 0x08f0002e, 0x2622ee00,
-    0x201f00ee, 0x2622ee00, 0x0600000e, 0x04040400,
-    0x00000000, 0x00000000, 0x00000200, 0x000000f0,
-    0x00018000, 0x0000001f, 0x00000000, 0x00000000,
-    0x400000e0, 0x6080e000, 0x08f0002e, 0x2622ee00,
-    0x201f00ee, 0x2622ee00, 0x0400000e, 0x04040400,
-    0x00000000, 0x00000000, 0x00000000, 0x000000f0,
-    0x00000000, 0x0000001f, 0x00000000, 0x00000000,
-    0x000000e0, 0x6080e000, 0x08f0002e, 0x2622ee00,
-    0x201f00ee, 0x2622ee00, 0x0000000e, 0x04040400,
+u32 gba_btn_leftright_shadow_data[] = {
+    0x00000000, 0x000008f8, 0x00000000, 0x2020100f,
+};
+
+u32 gba_btn_lr_shadow_data[] = {
+    0x00000000, 0x000001ff, 0x00000000, 0x000080ff,
+};
+
+u32 gba_btn_startselect_data[] = {
+    0x0000f804, 0xfcf80000, 0x00001f20, 0x3f1f0000,
+    0x000000f8, 0x04f80000, 0x0000001f, 0x201f0000,
+};
+
+u32 gba_btn_fx_downup[] = {
+    0x00000000, 0x00000000, 0x04000000, 0x00000000,
+    0x40000100, 0x00000000, 0x00000000, 0x00000000,
+    0x00000000, 0x00000000, 0x00000201, 0x00000000,
+    0x00008000, 0x01010000, 0x00000001, 0x00000000,
+    0x00000000, 0x80000000, 0x00000001, 0x00000000,
+    0x00000000, 0x00010100, 0x00000001, 0x02000000,
+    0x00000000, 0x00400000, 0x00000000, 0x00000000,
+    0x00000000, 0x00000001, 0x00000000, 0x00040000,
 };
 
 typedef struct SpriteAnimation {
@@ -538,10 +68,11 @@ typedef struct SpriteAnimation {
     size_t n_frames;
 } SpriteAnimation;
 
-typedef enum {BTN_STATE_IDLE, BTN_STATE_PRESSED} BtnState;
+typedef enum {BTN_STATE_IDLE, BTN_STATE_PRESSED, BTN_STATE_RELEASED, BTN_STATE_HOLD} BtnState;
 
 static size_t btn_state_idle[] = {0};
-static size_t btn_state_pressed[] = {16, 16, 32, 32, 48, 48, 64, 64, 80, 96};
+// static size_t btn_state_pressed[] = {16, 16, 32, 32, 48, 48, 64, 64, 80, 96};
+static size_t btn_state_pressed[] = {0};
 
 static SpriteAnimation *animation_states[] = {
     &(SpriteAnimation){
@@ -553,3 +84,60 @@ static SpriteAnimation *animation_states[] = {
         .n_frames = sizeof(btn_state_pressed) / sizeof(size_t),
     },
 };
+
+typedef struct AnimationEntry {
+    int x_offset;
+    int y_offset;
+    int tile_offset;
+    // NOTE: Maybe this should be a part of an animation?
+    // For example, hidden state, h/v flip.
+    u16 hidden;
+    // u16 obj_attr_1;
+    // u16 obj_attr_2;
+} AnimationEntry;
+
+typedef struct ObjState {
+    size_t id;
+    int x;
+    int y;
+    u32 *data;
+    size_t base_tile;
+    size_t n_tiles;
+    size_t frames;
+    u16 obj_attr_0;
+    u16 obj_attr_1;
+    u16 obj_attr_2;
+} ObjState;
+
+AnimationEntry *btn_down_animation[] = {
+    &(AnimationEntry[]){
+        {0, 0, 0, 0},
+        {0, 0, 0, 0},
+        {0, 1, 0, 0},
+        {0, 1, 0, 0},
+        {0, 2, 0, 0},
+        {0, 2, 0, 0},
+        {0, 2, 0, 0},
+        {0, 2, 0, 0},
+    },
+    &(AnimationEntry[]){
+        {0, 11, 0, 0},
+        {0, 11, 0, 0},
+        {0, 11, 0, 0},
+        {0, 11, 0, 0},
+        {0, 11, 0, 0},
+        {0, 11, 0, 0},
+        {0, 11, 0, 0},
+        {0, 11, 0, 0},
+    },
+    &(AnimationEntry[]){
+        {-8, 17, 0,  1},
+        {-8, 17, 0,  0},
+        {-8, 17, 4,  0},
+        {-8, 17, 4,  0},
+        {-8, 17, 8,  0},
+        {-8, 17, 8,  0},
+        {-8, 17, 12, 0},
+        {-8, 17, 12, 1},
+    },
+};
diff --git a/src/main.c b/src/main.c
index 4dd2554..e74df00 100644
--- a/src/main.c
+++ b/src/main.c
@@ -142,6 +142,33 @@ rgb15(u32 red, u32 green, u32 blue ) {
 #define OBJ_AFFINE_PC(N) *((vs16*)(MEM_OAM + 6 + 8 * 2 + 8 * 4 * (N)))
 #define OBJ_AFFINE_PD(N) *((vs16*)(MEM_OAM + 6 + 8 * 3 + 8 * 4 * (N)))
 
+// OBJ_ATTR_0 parameters
+#define OBJ_Y_COORD(N)   ((N) & 0xFF)
+#define OBJ_NORMAL       (0x00 << 0x8)
+#define OBJ_AFFINE       (0x01 << 0x8)
+#define OBJ_HIDDEN       (0x02 << 0x8)
+#define OBJ_AFFINE_2X    (0x03 << 0x8)
+#define OBJ_ALPHA_BLEND  (0x01 << 0xA)
+#define OBJ_WINDOW       (0x02 << 0xA)
+#define OBJ_SHAPE_SQUARE (0x00 << 0xE)
+#define OBJ_SHAPE_WIDE   (0x01 << 0xE)
+#define OBJ_SHAPE_TALL   (0x02 << 0xE)
+
+// OBJ_ATTR_1 parameters
+#define OBJ_X_COORD(N)    ((N) & 0x1FF)
+#define OBJ_AFFINE_IDX(N) ((N) << 0x9)
+#define OBJ_H_FLIP        (0x01 << 0xC)
+#define OBJ_V_FLIP        (0x01 << 0xD)
+#define OBJ_SIZE_SMALL    (0x00 << 0xE)
+#define OBJ_SIZE_MID      (0x01 << 0xE)
+#define OBJ_SIZE_BIG      (0x02 << 0xE)
+#define OBJ_SIZE_HUGE     (0x03 << 0xE)
+
+// OBJ_ATTR_2 parameters
+#define OBJ_TILE_INDEX(N) ((N) & 0x3FF)
+#define OBJ_PRIORITY(N)   ((N) << 0xA)
+#define OBJ_PAL_BANK(N)   ((N) << 0xC)
+
 // Using bd-font, an 8x8 bitmap font.
 static void
 put_char(int x, int y, Color clr, u8 chr) {
@@ -504,6 +531,15 @@ typedef struct ButtonSprite {
     BtnState state;
 } ButtonSprite;
 
+typedef struct MultiSprite {
+    ObjState *sprites;
+    AnimationEntry **animations;
+    int frame;
+    size_t n_obj;
+    size_t n_frames;
+    BtnState state;
+} MultiSprite;
+
 #define NUM_SPRITES 128
 
 Sprite sprites[NUM_SPRITES];
@@ -550,6 +586,73 @@ load_packed_sprite_data(u32 *sprite_data, size_t n_tiles, size_t n_frames) {
     return sprite_counter++;
 }
 
+void
+init_button_sprite(MultiSprite *btn) {
+    for (size_t i = 0; i < btn->n_obj; ++i) {
+        btn->sprites[i].id = load_packed_sprite_data(
+                btn->sprites[i].data,
+                btn->sprites[i].n_tiles,
+                btn->sprites[i].frames);
+        btn->sprites[i].base_tile = sprites[btn->sprites[i].id].tile_start;
+    }
+}
+
+void
+button_tick(MultiSprite *btn) {
+    // Nothing to do here.
+    if (btn->state == BTN_STATE_IDLE) {
+        return;
+    }
+
+    // Reset animation state.
+    if (btn->state == BTN_STATE_PRESSED && btn->frame != 0) {
+        btn->frame = 0;
+    }
+
+    // Continue the animation.
+    if (btn->state == BTN_STATE_HOLD || btn->state == BTN_STATE_PRESSED ) {
+        if(btn->frame < btn->n_frames - 1) {
+            btn->frame++;
+        }
+    }
+
+    // Finish the animation and return to idle.
+    if (btn->state == BTN_STATE_RELEASED) {
+        if (btn->frame > 0 && btn->frame < btn->n_frames - 1) {
+            btn->frame++;
+        } else {
+            btn->frame = 0;
+            btn->state = BTN_STATE_IDLE;
+        }
+    }
+    for (size_t i = 0; i < btn->n_obj; ++i) {
+        AnimationEntry anim_frame = btn->animations[i][btn->frame];
+        int x = btn->sprites[i].x + anim_frame.x_offset;
+        int y = btn->sprites[i].y + anim_frame.y_offset;
+        int base_tile = btn->sprites[i].base_tile + anim_frame.tile_offset;
+
+        // Clear the previous x/y coordinate and base tiles.
+        btn->sprites[i].obj_attr_0 &= ~0xFF;
+        btn->sprites[i].obj_attr_1 &= ~0x1FF;
+        btn->sprites[i].obj_attr_2 &= ~0x3FF;
+
+        // Update x/y/tile and hidden state from the animations.
+        btn->sprites[i].obj_attr_0 |= OBJ_Y_COORD(y);
+        btn->sprites[i].obj_attr_1 |= OBJ_X_COORD(x);
+        btn->sprites[i].obj_attr_2 |= base_tile;
+        if (anim_frame.hidden) {
+            btn->sprites[i].obj_attr_0 |= OBJ_HIDDEN;
+        } else {
+            btn->sprites[i].obj_attr_0 &= ~OBJ_HIDDEN;
+        }
+
+        // Update OBJ attributes.
+        OBJ_ATTR_0(btn->sprites[i].id) = btn->sprites[i].obj_attr_0;
+        OBJ_ATTR_1(btn->sprites[i].id) = btn->sprites[i].obj_attr_1;
+        OBJ_ATTR_2(btn->sprites[i].id) = btn->sprites[i].obj_attr_2;
+    }
+}
+
 int main(void) {
 
     // Add colors to the sprite color palette. Tiles with color number 0 are
@@ -586,93 +689,152 @@ int main(void) {
     int buttons_x = SCREEN_WIDTH / 2;
     int buttons_y = SCREEN_HEIGHT / 2;
     ButtonSprite btn_b = {
-        .id = load_packed_sprite_data(&gba_btn_b_data, 16, 7),
+        .id = load_packed_sprite_data(&gba_btn_b_data, 4, 1),
         .x = buttons_x + 32,
         .y = buttons_y + 32,
         .frame = 0,
         .state = BTN_STATE_IDLE,
     };
     OBJ_ATTR_0(btn_b.id) = btn_b.y;
-    OBJ_ATTR_1(btn_b.id) = btn_b.x | (1 << 0xF);
+    OBJ_ATTR_1(btn_b.id) = btn_b.x | (1 << 0xE);
     OBJ_ATTR_2(btn_b.id) = sprites[btn_b.id].tile_start;
 
     ButtonSprite btn_a = {
-        .id = load_packed_sprite_data(&gba_btn_a_data, 16, 7),
+        .id = load_packed_sprite_data(&gba_btn_a_data, 4, 1),
         .x = buttons_x + 32 + 20,
         .y = buttons_y + 32 - 16,
         .frame = 0,
         .state = BTN_STATE_IDLE,
     };
     OBJ_ATTR_0(btn_a.id) = btn_a.y;
-    OBJ_ATTR_1(btn_a.id) = btn_a.x | (1 << 0xF);
+    OBJ_ATTR_1(btn_a.id) = btn_a.x | (1 << 0xE);
     OBJ_ATTR_2(btn_a.id) = sprites[btn_a.id].tile_start;
 
-    ButtonSprite btn_down = {
-        .id = load_packed_sprite_data(&gba_btn_down_data, 16, 7),
-        .x = buttons_x - 64 - 16,
-        .y = buttons_y + 32,
-        .frame = 0,
-        .state = BTN_STATE_IDLE,
-    };
-    OBJ_ATTR_0(btn_down.id) = btn_down.y;
-    OBJ_ATTR_1(btn_down.id) = btn_down.x | (1 << 0xF);
-    OBJ_ATTR_2(btn_down.id) = sprites[btn_down.id].tile_start;
-
     ButtonSprite btn_up = {
-        .id = load_packed_sprite_data(&gba_btn_up_data, 16, 7),
+        .id = load_packed_sprite_data(&gba_btn_updown_data, 4, 1),
         .x = buttons_x - 64 - 16,
         .y = buttons_y + 32 - 18,
         .frame = 0,
         .state = BTN_STATE_IDLE,
     };
     OBJ_ATTR_0(btn_up.id) = btn_up.y;
-    OBJ_ATTR_1(btn_up.id) = btn_up.x | (1 << 0xF);
+    OBJ_ATTR_1(btn_up.id) = btn_up.x | (1 << 0xE);
     OBJ_ATTR_2(btn_up.id) = sprites[btn_up.id].tile_start;
 
     ButtonSprite btn_left = {
-        .id = load_packed_sprite_data(&gba_btn_left_data, 16, 7),
-        .x = buttons_x - 64 - 16 - 12,
+        .id = load_packed_sprite_data(&gba_btn_leftright_data, 4, 1),
+        .x = buttons_x - 64 - 16 - 10,
         .y = buttons_y + 32 - 10,
         .frame = 0,
         .state = BTN_STATE_IDLE,
     };
     OBJ_ATTR_0(btn_left.id) = btn_left.y;
-    OBJ_ATTR_1(btn_left.id) = btn_left.x | (1 << 0xF);
+    OBJ_ATTR_1(btn_left.id) = btn_left.x | (1 << 0xE);
     OBJ_ATTR_2(btn_left.id) = sprites[btn_left.id].tile_start;
 
     ButtonSprite btn_right = {
-        .id = load_packed_sprite_data(&gba_btn_right_data, 16, 7),
+        .id = load_packed_sprite_data(&gba_btn_leftright_data, 4, 1),
         .x = buttons_x - 64 - 16 + 11,
         .y = buttons_y + 32 - 10,
         .frame = 0,
         .state = BTN_STATE_IDLE,
     };
     OBJ_ATTR_0(btn_right.id) = btn_right.y;
-    OBJ_ATTR_1(btn_right.id) = btn_right.x | (1 << 0xF);
+    OBJ_ATTR_1(btn_right.id) = btn_right.x | (1 << 0xE) | (1 << 0xC);
     OBJ_ATTR_2(btn_right.id) = sprites[btn_right.id].tile_start;
 
     ButtonSprite btn_l = {
-        .id = load_packed_sprite_data(&gba_btn_l_data, 16, 7),
+        .id = load_packed_sprite_data(&gba_btn_l_data, 2, 1),
         .x = buttons_x - 64 - 28,
         .y = buttons_y - 32 - 20,
         .frame = 0,
         .state = BTN_STATE_IDLE,
     };
-    OBJ_ATTR_0(btn_l.id) = btn_l.y;
-    OBJ_ATTR_1(btn_l.id) = btn_l.x | (1 << 0xF);
+    OBJ_ATTR_0(btn_l.id) = btn_l.y | (1 << 0xE);
+    OBJ_ATTR_1(btn_l.id) = btn_l.x;
     OBJ_ATTR_2(btn_l.id) = sprites[btn_l.id].tile_start;
 
     ButtonSprite btn_r = {
-        .id = load_packed_sprite_data(&gba_btn_r_data, 16, 7),
+        .id = load_packed_sprite_data(&gba_btn_r_data, 2, 1),
         .x = buttons_x + 32 + 20,
         .y = buttons_y - 32 - 20,
         .frame = 0,
         .state = BTN_STATE_IDLE,
     };
-    OBJ_ATTR_0(btn_r.id) = btn_r.y;
-    OBJ_ATTR_1(btn_r.id) = btn_r.x | (1 << 0xF);
+    OBJ_ATTR_0(btn_r.id) = btn_r.y | (1 << 0xE);
+    OBJ_ATTR_1(btn_r.id) = btn_r.x;
     OBJ_ATTR_2(btn_r.id) = sprites[btn_r.id].tile_start;
 
+    ButtonSprite btn_start = {
+        .id = load_packed_sprite_data(&gba_btn_startselect_data, 2, 2),
+        .x = buttons_x - 10,
+        .y = buttons_y + 40,
+        .frame = 0,
+        .state = BTN_STATE_IDLE,
+    };
+    OBJ_ATTR_0(btn_start.id) = btn_start.y | (1 << 0xE);
+    OBJ_ATTR_1(btn_start.id) = btn_start.x;
+    OBJ_ATTR_2(btn_start.id) = sprites[btn_start.id].tile_start;
+
+    ButtonSprite btn_select = {
+        .id = load_packed_sprite_data(&gba_btn_startselect_data, 2, 2),
+        .x = buttons_x - 32,
+        .y = buttons_y + 40,
+        .frame = 0,
+        .state = BTN_STATE_IDLE,
+    };
+    OBJ_ATTR_0(btn_select.id) = btn_select.y | (1 << 0xE);
+    OBJ_ATTR_1(btn_select.id) = btn_select.x;
+    OBJ_ATTR_2(btn_select.id) = sprites[btn_select.id].tile_start;
+
+    MultiSprite buttons[] = {
+        {
+            .frame = 0,
+            .n_obj = 3,
+            .n_frames = 8,
+            .state = BTN_STATE_RELEASED,
+            .animations = &btn_down_animation,
+            .sprites = &(ObjState[]){
+                {
+                    .id = 0,
+                    .x = buttons_x - 64 - 16,
+                    .y = buttons_y + 29,
+                    .data = &gba_btn_updown_data,
+                    .n_tiles = 4,
+                    .frames = 1,
+                    .obj_attr_0 = 0,
+                    .obj_attr_1 = OBJ_V_FLIP | OBJ_SIZE_MID,
+                    .obj_attr_2 = 0
+                },
+                {
+                    .id = 0,
+                    .x = buttons_x - 64 - 16,
+                    .y = buttons_y + 29,
+                    .data = &gba_btn_down_shadow_data,
+                    .n_tiles = 2,
+                    .frames = 1,
+                    .obj_attr_0 = OBJ_SHAPE_WIDE,
+                    .obj_attr_1 = OBJ_SIZE_SMALL,
+                    .obj_attr_2 = 0
+                },
+                {
+                    .id = 0,
+                    .x = buttons_x - 64 - 16,
+                    .y = buttons_y + 29,
+                    .data = &gba_btn_fx_downup,
+                    .n_tiles = 4,
+                    .frames = 4,
+                    .obj_attr_0 = OBJ_SHAPE_WIDE,
+                    .obj_attr_1 = OBJ_SIZE_MID,
+                    .obj_attr_2 = 0
+                },
+            },
+        },
+    };
+    for (size_t i = 0; i < sizeof(buttons) / sizeof(MultiSprite); ++i) {
+        init_button_sprite(&buttons[i]);
+    }
+
     int frame_counter = 0;
     int x = 0;
     int y = 0;
@@ -680,149 +842,46 @@ int main(void) {
         wait_vsync();
         poll_keys();
 
-        if (key_pressed(KEY_B)) {
-            btn_b.frame = 0;
-            btn_b.state = BTN_STATE_PRESSED;
-        } else if (key_hold(KEY_B)) {
-            size_t n_frames = animation_states[btn_b.state]->n_frames;
-            if (btn_b.frame < n_frames - 1) {
-                btn_b.frame++;
-            }
-        } else {
-            // Finish the animation and reset idle state.
-            size_t n_frames = animation_states[btn_b.state]->n_frames;
-            if (btn_b.frame > 0 && btn_b.frame < n_frames - 1) {
-                btn_b.frame++;
-            } else {
-                btn_b.frame = 0;
-                btn_b.state = BTN_STATE_IDLE;
-            }
-        }
-        if (key_pressed(KEY_A)) {
-            btn_a.frame = 0;
-            btn_a.state = BTN_STATE_PRESSED;
-        } else if (key_hold(KEY_A)) {
-            size_t n_frames = animation_states[btn_a.state]->n_frames;
-            if (btn_a.frame < n_frames - 1) {
-                btn_a.frame++;
-            }
-        } else {
-            // Finish the animation and reset idle state.
-            size_t n_frames = animation_states[btn_a.state]->n_frames;
-            if (btn_a.frame > 0 && btn_a.frame < n_frames - 1) {
-                btn_a.frame++;
-            } else {
-                btn_a.frame = 0;
-                btn_a.state = BTN_STATE_IDLE;
-            }
-        }
+        // if (key_pressed(KEY_B)) {
+        //     btn_b.frame = 0;
+        //     btn_b.state = BTN_STATE_PRESSED;
+        // } else if (key_hold(KEY_B)) {
+        //     if (btn_b.frame < btn_b.n_frames - 1) {
+        //         btn_b.frame++;
+        //     }
+        // } else {
+        //     // Finish the animation and reset idle state.
+        //     if (btn_b.frame > 0 && btn_b.frame < btn_b.n_frames - 1) {
+        //         btn_b.frame++;
+        //     } else {
+        //         btn_b.frame = 0;
+        //         btn_b.state = BTN_STATE_IDLE;
+        //     }
+        // }
+        // if (key_pressed(KEY_A)) {
+        //     btn_a.frame = 0;
+        //     btn_a.state = BTN_STATE_PRESSED;
+        // } else if (key_hold(KEY_A)) {
+        //     size_t n_frames = animation_states[btn_a.state]->n_frames;
+        //     if (btn_a.frame < n_frames - 1) {
+        //         btn_a.frame++;
+        //     }
+        // } else {
+        //     // Finish the animation and reset idle state.
+        //     size_t n_frames = animation_states[btn_a.state]->n_frames;
+        //     if (btn_a.frame > 0 && btn_a.frame < n_frames - 1) {
+        //         btn_a.frame++;
+        //     } else {
+        //         btn_a.frame = 0;
+        //         btn_a.state = BTN_STATE_IDLE;
+        //     }
+        // }
         if (key_pressed(KEY_DOWN)) {
-            btn_down.frame = 0;
-            btn_down.state = BTN_STATE_PRESSED;
+            buttons[0].state = BTN_STATE_PRESSED;
         } else if (key_hold(KEY_DOWN)) {
-            size_t n_frames = animation_states[btn_down.state]->n_frames;
-            if (btn_down.frame < n_frames - 1) {
-                btn_down.frame++;
-            }
-        } else {
-            // Finish the animation and reset idle state.
-            size_t n_frames = animation_states[btn_down.state]->n_frames;
-            if (btn_down.frame > 0 && btn_down.frame < n_frames - 1) {
-                btn_down.frame++;
-            } else {
-                btn_down.frame = 0;
-                btn_down.state = BTN_STATE_IDLE;
-            }
-        }
-        if (key_pressed(KEY_UP)) {
-            btn_up.frame = 0;
-            btn_up.state = BTN_STATE_PRESSED;
-        } else if (key_hold(KEY_UP)) {
-            size_t n_frames = animation_states[btn_up.state]->n_frames;
-            if (btn_up.frame < n_frames - 1) {
-                btn_up.frame++;
-            }
-        } else {
-            // Finish the animation and reset idle state.
-            size_t n_frames = animation_states[btn_up.state]->n_frames;
-            if (btn_up.frame > 0 && btn_up.frame < n_frames - 1) {
-                btn_up.frame++;
-            } else {
-                btn_up.frame = 0;
-                btn_up.state = BTN_STATE_IDLE;
-            }
-        }
-        if (key_pressed(KEY_LEFT)) {
-            btn_left.frame = 0;
-            btn_left.state = BTN_STATE_PRESSED;
-        } else if (key_hold(KEY_LEFT)) {
-            size_t n_frames = animation_states[btn_left.state]->n_frames;
-            if (btn_left.frame < n_frames - 1) {
-                btn_left.frame++;
-            }
-        } else {
-            // Finish the animation and reset idle state.
-            size_t n_frames = animation_states[btn_left.state]->n_frames;
-            if (btn_left.frame > 0 && btn_left.frame < n_frames - 1) {
-                btn_left.frame++;
-            } else {
-                btn_left.frame = 0;
-                btn_left.state = BTN_STATE_IDLE;
-            }
-        }
-        if (key_pressed(KEY_RIGHT)) {
-            btn_right.frame = 0;
-            btn_right.state = BTN_STATE_PRESSED;
-        } else if (key_hold(KEY_RIGHT)) {
-            size_t n_frames = animation_states[btn_right.state]->n_frames;
-            if (btn_right.frame < n_frames - 1) {
-                btn_right.frame++;
-            }
-        } else {
-            // Finish the animation and reset idle state.
-            size_t n_frames = animation_states[btn_right.state]->n_frames;
-            if (btn_right.frame > 0 && btn_right.frame < n_frames - 1) {
-                btn_right.frame++;
-            } else {
-                btn_right.frame = 0;
-                btn_right.state = BTN_STATE_IDLE;
-            }
-        }
-        if (key_pressed(KEY_L)) {
-            btn_l.frame = 0;
-            btn_l.state = BTN_STATE_PRESSED;
-        } else if (key_hold(KEY_L)) {
-            size_t n_frames = animation_states[btn_l.state]->n_frames;
-            if (btn_l.frame < n_frames - 1) {
-                btn_l.frame++;
-            }
+            buttons[0].state = BTN_STATE_HOLD;
         } else {
-            // Finish the animation and reset idle state.
-            size_t n_frames = animation_states[btn_l.state]->n_frames;
-            if (btn_l.frame > 0 && btn_l.frame < n_frames - 1) {
-                btn_l.frame++;
-            } else {
-                btn_l.frame = 0;
-                btn_l.state = BTN_STATE_IDLE;
-            }
-        }
-        if (key_pressed(KEY_R)) {
-            btn_r.frame = 0;
-            btn_r.state = BTN_STATE_PRESSED;
-        } else if (key_hold(KEY_R)) {
-            size_t n_frames = animation_states[btn_r.state]->n_frames;
-            if (btn_r.frame < n_frames - 1) {
-                btn_r.frame++;
-            }
-        } else {
-            // Finish the animation and reset idle state.
-            size_t n_frames = animation_states[btn_r.state]->n_frames;
-            if (btn_r.frame > 0 && btn_r.frame < n_frames - 1) {
-                btn_r.frame++;
-            } else {
-                btn_r.frame = 0;
-                btn_r.state = BTN_STATE_IDLE;
-            }
+            buttons[0].state = BTN_STATE_RELEASED;
         }
 
         if (key_hold(KEY_DOWN)) {
@@ -838,17 +897,21 @@ int main(void) {
             x += 3;
         }
 
-        OBJ_ATTR_2(btn_b.id) = sprites[btn_b.id].tile_start + animation_states[btn_b.state]->tile_offsets[btn_b.frame];
-        OBJ_ATTR_2(btn_a.id) = sprites[btn_a.id].tile_start + animation_states[btn_a.state]->tile_offsets[btn_a.frame];
-        OBJ_ATTR_2(btn_up.id) = sprites[btn_up.id].tile_start + animation_states[btn_up.state]->tile_offsets[btn_up.frame];
-        OBJ_ATTR_2(btn_down.id) = sprites[btn_down.id].tile_start + animation_states[btn_down.state]->tile_offsets[btn_down.frame];
-        OBJ_ATTR_2(btn_left.id) = sprites[btn_left.id].tile_start + animation_states[btn_left.state]->tile_offsets[btn_left.frame];
-        OBJ_ATTR_2(btn_right.id) = sprites[btn_right.id].tile_start + animation_states[btn_right.state]->tile_offsets[btn_right.frame];
-        OBJ_ATTR_2(btn_l.id) = sprites[btn_l.id].tile_start + animation_states[btn_l.state]->tile_offsets[btn_l.frame];
-        OBJ_ATTR_2(btn_r.id) = sprites[btn_r.id].tile_start + animation_states[btn_r.state]->tile_offsets[btn_r.frame];
+        // OBJ_ATTR_2(btn_b.id) = sprites[btn_b.id].tile_start + animation_states[btn_b.state]->tile_offsets[btn_b.frame];
+        // OBJ_ATTR_2(btn_a.id) = sprites[btn_a.id].tile_start + animation_states[btn_a.state]->tile_offsets[btn_a.frame];
+        // OBJ_ATTR_2(btn_up.id) = sprites[btn_up.id].tile_start + animation_states[btn_up.state]->tile_offsets[btn_up.frame];
+        // // OBJ_ATTR_2(btn_down.id) = sprites[btn_down.id].tile_start + animation_states[btn_down.state]->tile_offsets[btn_down.frame];
+        // OBJ_ATTR_2(btn_left.id) = sprites[btn_left.id].tile_start + animation_states[btn_left.state]->tile_offsets[btn_left.frame];
+        // OBJ_ATTR_2(btn_right.id) = sprites[btn_right.id].tile_start + animation_states[btn_right.state]->tile_offsets[btn_right.frame];
+        // OBJ_ATTR_2(btn_l.id) = sprites[btn_l.id].tile_start + animation_states[btn_l.state]->tile_offsets[btn_l.frame];
+        // OBJ_ATTR_2(btn_r.id) = sprites[btn_r.id].tile_start + animation_states[btn_r.state]->tile_offsets[btn_r.frame];
         frame_counter++;
         BG_H_SCROLL_0 = x;
         BG_V_SCROLL_0 = y;
+
+        for (size_t i = 0; i < sizeof(buttons) / sizeof(MultiSprite); ++i) {
+            button_tick(&buttons[i]);
+        }
     };
 
     return 0;
-- 
cgit v1.2.1