From 241c0312d93cb6940c1d5675dea4433c5a735a78 Mon Sep 17 00:00:00 2001
From: octorock <79596758+octorock@users.noreply.github.com>
Date: Mon, 28 Feb 2022 22:45:04 +0100
Subject: [PATCH] Decompile Object21

---
 asm/object/object21.s        | 288 -----------------------------------
 assets/assets.json           |  15 --
 data/const/object/object21.s |  25 ---
 include/object.h             |   2 +-
 linker.ld                    |   4 +-
 src/object/object21.c        | 153 +++++++++++++++++++
 6 files changed, 156 insertions(+), 331 deletions(-)
 delete mode 100644 asm/object/object21.s
 delete mode 100644 data/const/object/object21.s
 create mode 100644 src/object/object21.c

diff --git a/asm/object/object21.s b/asm/object/object21.s
deleted file mode 100644
index 195b7f0c..00000000
--- a/asm/object/object21.s
+++ /dev/null
@@ -1,288 +0,0 @@
-	.include "asm/macros.inc"
-
-	.include "constants/constants.inc"
-
-	.syntax unified
-
-	.text
-
-
-	thumb_func_start Object21
-Object21: @ 0x08087998
-	push {r4, lr}
-	adds r4, r0, #0
-	ldr r0, _080879C0 @ =gUnk_08120A68
-	ldrb r1, [r4, #0xc]
-	lsls r1, r1, #2
-	adds r1, r1, r0
-	ldr r1, [r1]
-	adds r0, r4, #0
-	bl _call_via_r1
-	adds r0, r4, #0
-	bl GetNextFrame
-	ldrb r0, [r4, #0xe]
-	cmp r0, #0
-	beq _080879C4
-	subs r0, #1
-	strb r0, [r4, #0xe]
-	b _080879EA
-	.align 2, 0
-_080879C0: .4byte gUnk_08120A68
-_080879C4:
-	adds r0, r4, #0
-	adds r0, #0x58
-	ldrb r0, [r0]
-	cmp r0, #0xa
-	bne _080879D8
-	adds r0, r4, #0
-	movs r1, #0xd
-	bl InitializeAnimation
-	b _080879EA
-_080879D8:
-	adds r0, r4, #0
-	adds r0, #0x5a
-	ldrb r1, [r0]
-	movs r0, #0x80
-	ands r0, r1
-	cmp r0, #0
-	beq _080879EA
-	bl DeleteThisEntity
-_080879EA:
-	movs r1, #0x24
-	ldrsh r0, [r4, r1]
-	cmp r0, #0
-	beq _08087A0C
-	adds r0, r4, #0
-	bl LinearMoveUpdate
-	ldrh r1, [r4, #0x24]
-	movs r2, #0x24
-	ldrsh r0, [r4, r2]
-	cmp r0, #0x10
-	ble _08087A08
-	adds r0, r1, #0
-	subs r0, #0x10
-	b _08087A0A
-_08087A08:
-	movs r0, #0
-_08087A0A:
-	strh r0, [r4, #0x24]
-_08087A0C:
-	pop {r4, pc}
-	.align 2, 0
-
-	thumb_func_start sub_08087A10
-sub_08087A10: @ 0x08087A10
-	push {r4, lr}
-	adds r4, r0, #0
-	movs r0, #1
-	strb r0, [r4, #0xc]
-	ldrb r0, [r4, #0xb]
-	cmp r0, #0
-	beq _08087A26
-	adds r0, r4, #0
-	movs r1, #3
-	bl ChangeObjPalette
-_08087A26:
-	ldrb r0, [r4, #0xa]
-	cmp r0, #2
-	bls _08087A3C
-	ldr r0, _08087A4C @ =gUnk_08120A78
-	ldrb r1, [r4, #0xa]
-	subs r1, #3
-	adds r1, r1, r0
-	ldrb r1, [r1]
-	adds r0, r4, #0
-	bl ChangeObjPalette
-_08087A3C:
-	ldrb r0, [r4, #0xa]
-	cmp r0, #4
-	bhi _08087AF0
-	lsls r0, r0, #2
-	ldr r1, _08087A50 @ =_08087A54
-	adds r0, r0, r1
-	ldr r0, [r0]
-	mov pc, r0
-	.align 2, 0
-_08087A4C: .4byte gUnk_08120A78
-_08087A50: .4byte _08087A54
-_08087A54: @ jump table
-	.4byte _08087A76 @ case 0
-	.4byte _08087AF0 @ case 1
-	.4byte _08087AA0 @ case 2
-	.4byte _08087A76 @ case 3
-	.4byte _08087A68 @ case 4
-_08087A68:
-	adds r1, r4, #0
-	adds r1, #0x38
-	movs r0, #2
-	strb r0, [r1]
-	adds r0, r4, #0
-	bl UpdateSpriteForCollisionLayer
-_08087A76:
-	ldrb r1, [r4, #0x10]
-	movs r0, #0x80
-	movs r2, #0
-	orrs r0, r1
-	strb r0, [r4, #0x10]
-	adds r1, r4, #0
-	adds r1, #0x45
-	movs r0, #1
-	strb r0, [r1]
-	subs r1, #9
-	movs r0, #7
-	strb r0, [r1]
-	adds r1, #3
-	movs r0, #0xaa
-	strb r0, [r1]
-	subs r1, #4
-	movs r0, #0xe
-	strb r0, [r1]
-	ldr r0, _08087AE4 @ =gUnk_08120A8C
-	str r0, [r4, #0x48]
-	strb r2, [r4, #0x1c]
-_08087AA0:
-	bl Random
-	ldr r2, _08087AE8 @ =gUnk_08120A7A
-	movs r3, #3
-	adds r1, r0, #0
-	ands r1, r3
-	adds r1, r1, r2
-	ldrb r1, [r1]
-	strb r1, [r4, #0xe]
-	lsrs r2, r0, #8
-	ands r2, r3
-	movs r1, #0x10
-	ands r1, r0
-	cmp r1, #0
-	beq _08087AC0
-	rsbs r2, r2, #0
-_08087AC0:
-	ldrh r0, [r4, #0x2e]
-	adds r0, r0, r2
-	strh r0, [r4, #0x2e]
-	ldrh r0, [r4, #0x32]
-	adds r0, r0, r2
-	strh r0, [r4, #0x32]
-	ldr r0, _08087AEC @ =gPlayerEntity
-	adds r0, #0x38
-	ldrb r1, [r0]
-	adds r0, r4, #0
-	adds r0, #0x38
-	strb r1, [r0]
-	adds r0, r4, #0
-	movs r1, #0xa
-	bl InitializeAnimation
-	b _08087AF8
-	.align 2, 0
-_08087AE4: .4byte gUnk_08120A8C
-_08087AE8: .4byte gUnk_08120A7A
-_08087AEC: .4byte gPlayerEntity
-_08087AF0:
-	adds r0, r4, #0
-	movs r1, #0x10
-	bl InitializeAnimation
-_08087AF8:
-	pop {r4, pc}
-	.align 2, 0
-
-	thumb_func_start sub_08087AFC
-sub_08087AFC: @ 0x08087AFC
-	push {r4, lr}
-	adds r4, r0, #0
-	adds r0, #0x41
-	ldrb r1, [r0]
-	movs r0, #0x80
-	ands r0, r1
-	cmp r0, #0
-	beq _08087B56
-	movs r0, #0x7f
-	ands r0, r1
-	cmp r0, #0x16
-	beq _08087B3C
-	cmp r0, #0x16
-	bgt _08087B1E
-	cmp r0, #0x13
-	beq _08087B4E
-	b _08087B56
-_08087B1E:
-	cmp r0, #0x1c
-	bgt _08087B56
-	cmp r0, #0x1b
-	blt _08087B56
-	ldr r1, [r4, #0x4c]
-	adds r0, r1, #0
-	adds r0, #0x84
-	ldr r0, [r0]
-	adds r1, #0x80
-	ldr r1, [r1]
-	ldr r2, [r4, #0x2c]
-	ldr r3, [r4, #0x30]
-	bl CalculateDirectionTo
-	b _08087B44
-_08087B3C:
-	ldr r0, [r4, #0x4c]
-	adds r1, r4, #0
-	bl GetFacingDirection
-_08087B44:
-	strb r0, [r4, #0x15]
-	movs r0, #0x80
-	lsls r0, r0, #1
-	strh r0, [r4, #0x24]
-	b _08087B56
-_08087B4E:
-	movs r1, #0
-	movs r0, #3
-	strb r0, [r4, #0xc]
-	strb r1, [r4, #0xd]
-_08087B56:
-	pop {r4, pc}
-
-	thumb_func_start sub_08087B58
-sub_08087B58: @ 0x08087B58
-	push {lr}
-	adds r2, r0, #0
-	adds r0, #0x41
-	ldrb r1, [r0]
-	movs r0, #0x80
-	ands r0, r1
-	cmp r0, #0
-	beq _08087B80
-	ldr r0, _08087B7C @ =gUnk_08120A80
-	ldrb r1, [r2, #0xd]
-	lsls r1, r1, #2
-	adds r1, r1, r0
-	ldr r1, [r1]
-	adds r0, r2, #0
-	bl _call_via_r1
-	b _08087B84
-	.align 2, 0
-_08087B7C: .4byte gUnk_08120A80
-_08087B80:
-	movs r0, #1
-	strb r0, [r2, #0xc]
-_08087B84:
-	pop {pc}
-	.align 2, 0
-
-	thumb_func_start sub_08087B88
-sub_08087B88: @ 0x08087B88
-	adds r2, r0, #0
-	adds r2, #0x46
-	movs r1, #0x80
-	lsls r1, r1, #1
-	strh r1, [r2]
-	movs r1, #1
-	strb r1, [r0, #0xd]
-	strb r1, [r0, #0x1d]
-	bx lr
-	.align 2, 0
-
-	thumb_func_start sub_08087B9C
-sub_08087B9C: @ 0x08087B9C
-	push {lr}
-	bl sub_0806F3E4
-	cmp r0, #0
-	beq _08087BAA
-	bl DeleteThisEntity
-_08087BAA:
-	pop {pc}
diff --git a/assets/assets.json b/assets/assets.json
index cfeb7adf..8cf067f0 100644
--- a/assets/assets.json
+++ b/assets/assets.json
@@ -42905,21 +42905,6 @@
     "start": 1182280,
     "size": 12
   },
-  {
-    "path": "object21/gUnk_08120A78.bin",
-    "start": 1182328,
-    "size": 2
-  },
-  {
-    "path": "object21/gUnk_08120A7A.bin",
-    "start": 1182330,
-    "size": 6
-  },
-  {
-    "path": "object21/gUnk_08120A8C.bin",
-    "start": 1182348,
-    "size": 8
-  },
   {
     "path": "animations/gSpriteAnimations_FigurineDevice_0.bin",
     "start": 1182440,
diff --git a/data/const/object/object21.s b/data/const/object/object21.s
deleted file mode 100644
index 1cad260f..00000000
--- a/data/const/object/object21.s
+++ /dev/null
@@ -1,25 +0,0 @@
-	.include "asm/macros.inc"
-	.include "constants/constants.inc"
-
-	.section .rodata
-    .align 2
-
-gUnk_08120A68:: @ 08120A68
-	.4byte sub_08087A10
-	.4byte sub_08087AFC
-	.4byte 00000000
-	.4byte sub_08087B58
-
-gUnk_08120A78:: @ 08120A78
-	.incbin "object21/gUnk_08120A78.bin"
-
-gUnk_08120A7A:: @ 08120A7A
-	.incbin "object21/gUnk_08120A7A.bin"
-
-gUnk_08120A80:: @ 08120A80
-	.4byte sub_08087B88
-	.4byte sub_08087B9C
-	.4byte sub_08087B9C
-
-gUnk_08120A8C:: @ 08120A8C
-	.incbin "object21/gUnk_08120A8C.bin"
diff --git a/include/object.h b/include/object.h
index 4f1c4a70..e7b66e3b 100644
--- a/include/object.h
+++ b/include/object.h
@@ -259,7 +259,7 @@ void Object1D(Entity*);
 void Object1E(Entity*);
 void Object1F(Entity*);
 void Object20(Entity*);
-void Object21(Entity*);
+void Object21();
 void FigurineDevice();
 void EyeSwitch(Entity*);
 void PressurePlate();
diff --git a/linker.ld b/linker.ld
index d5ed80d6..dfb5806d 100644
--- a/linker.ld
+++ b/linker.ld
@@ -653,7 +653,7 @@ SECTIONS {
         asm/object/object1E.o(.text);
         asm/object/object1F.o(.text);
         asm/object/object20.o(.text);
-        asm/object/object21.o(.text);
+        src/object/object21.o(.text);
         src/object/figurineDevice.o(.text);
         src/object/eyeSwitch.o(.text);
         src/object/pressurePlate.o(.text);
@@ -1375,7 +1375,7 @@ SECTIONS {
         data/const/object/object1F.o(.rodata);
         data/const/object/object20.o(.rodata);
         data/animations/object/object20.o(.rodata);
-        data/const/object/object21.o(.rodata);
+        src/object/object21.o(.rodata);
         src/object/figurineDevice.o(.rodata);
         data/animations/object/figurineDevice.o(.rodata);
         src/object/eyeSwitch.o(.rodata);
diff --git a/src/object/object21.c b/src/object/object21.c
new file mode 100644
index 00000000..6641b14c
--- /dev/null
+++ b/src/object/object21.c
@@ -0,0 +1,153 @@
+/**
+ * @file object21.c
+ * @ingroup Objects
+ *
+ * @brief Object21 object
+ */
+
+#define NENT_DEPRECATED
+#include "global.h"
+#include "object.h"
+#include "functions.h"
+
+typedef struct {
+    /*0x00*/ Entity base;
+    /*0x68*/ u8 unk_68[0x18];
+    /*0x80*/ u32 unk_80;
+    /*0x84*/ u32 unk_84;
+} Object21Entity;
+
+void sub_08087A10(Object21Entity*);
+void sub_08087AFC(Object21Entity*);
+void sub_08087B58(Object21Entity*);
+void sub_08087B88(Object21Entity*);
+void sub_08087B9C(Object21Entity*);
+void sub_08087B9C(Object21Entity*);
+
+void Object21(Object21Entity* this) {
+    static void (*const gUnk_08120A68[])(Object21Entity*) = {
+        sub_08087A10,
+        sub_08087AFC,
+        NULL,
+        sub_08087B58,
+    };
+    gUnk_08120A68[super->action](this);
+    GetNextFrame(super);
+    if (super->actionDelay != 0) {
+        super->actionDelay--;
+    } else {
+        if (super->animIndex == 0xa) {
+            InitializeAnimation(super, 0xd);
+        } else if ((super->frame & 0x80) != 0) {
+            DeleteThisEntity();
+        }
+    }
+    if (super->speed != 0) {
+        LinearMoveUpdate(super);
+        if (super->speed > 0x10) {
+            super->speed -= 0x10;
+        } else {
+            super->speed = 0;
+        }
+    }
+}
+
+extern const Hitbox gUnk_08120A8C;
+
+void sub_08087A10(Object21Entity* this) {
+    static const u8 gUnk_08120A78[] = {
+        3,
+        63,
+    };
+    static const u8 gUnk_08120A7A[] = {
+        15, 24, 30, 35, 0, 0,
+    };
+    u32 rand;
+    u32 tmp;
+    super->action = 1;
+    if (super->type2 != 0) {
+        ChangeObjPalette(super, 3);
+    }
+    if (super->type > 2) {
+        ChangeObjPalette(super, gUnk_08120A78[super->type - 3]);
+    }
+    switch (super->type) {
+        case 4:
+            super->collisionLayer = 2;
+            UpdateSpriteForCollisionLayer(super);
+        case 0:
+        case 3:
+            super->flags |= ENT_COLLIDE;
+            super->health = 1;
+            super->field_0x3c = 7;
+            super->hitType = 0xaa;
+            super->flags2 = 0x0e;
+            super->hitbox = (Hitbox*)&gUnk_08120A8C;
+            super->field_0x1c = 0;
+        case 2:
+            rand = Random();
+            super->actionDelay = gUnk_08120A7A[rand & 3];
+            tmp = (rand >> 8) & 3;
+            if ((rand & 0x10) != 0) {
+                tmp = -tmp;
+            }
+            super->x.HALF.HI += tmp;
+            super->y.HALF.HI += tmp;
+            super->collisionLayer = gPlayerEntity.collisionLayer;
+            InitializeAnimation(super, 10);
+            return;
+        case 1:
+            break;
+    }
+    InitializeAnimation(super, 0x10);
+}
+
+void sub_08087AFC(Object21Entity* this) {
+    Object21Entity* entity;
+    if ((super->bitfield & 0x80) == 0) {
+        return;
+    }
+    switch (super->bitfield & 0x7f) {
+        case 0x16:
+            super->direction = GetFacingDirection(super->field_0x4c, super);
+            super->speed = 0x100;
+            break;
+        case 0x13:
+            super->action = 3;
+            super->subAction = 0;
+            break;
+        case 0x1b:
+        case 0x1c:
+            entity = (Object21Entity*)super->field_0x4c;
+            super->direction = CalculateDirectionTo(entity->unk_84, entity->unk_80, super->x.WORD, super->y.WORD);
+            super->speed = 0x100;
+            break;
+    }
+}
+
+void sub_08087B58(Object21Entity* this) {
+    static void (*const gUnk_08120A80[])(Object21Entity*) = {
+        sub_08087B88,
+        sub_08087B9C,
+        sub_08087B9C,
+    };
+    if ((super->bitfield & 0x80) != 0) {
+        gUnk_08120A80[super->subAction](this);
+    } else {
+        super->action = 1;
+    }
+}
+
+const Hitbox gUnk_08120A8C = { 0, 0, { 6, 3, 3, 6 }, 3, 3 };
+
+void sub_08087B88(Object21Entity* this) {
+    super->knockbackSpeed = 0x100;
+    super->subAction = 1;
+    super->field_0x1d = 1;
+}
+
+void sub_08087B9C(Object21Entity* this) {
+    if (sub_0806F3E4(super)) {
+        DeleteThisEntity();
+    }
+}