Decompile no0 func_us_801CE2E0 (#1960)

Big thanks to bismurphy for helping me work out the array copy that appears at the beginning of the function (ended up being an inline array declaration) https://decomp.me/scratch/Fo9ZW This entity does not appear in the entity list and doesn't seem to be called from anywhere so I think it may be unused and deadstripped out of the PSP.
Xeeynamo · Dec 3, 2024 · 54fcdd5 · 54fcdd5
1 parent 09cb3a7
commit 54fcdd5
Show file tree

Hide file tree

Showing 4 changed files with 106 additions and 4 deletions.
diff --git a/config/splat.us.stno0.yaml b/config/splat.us.stno0.yaml
@@ -56,7 +56,8 @@ segments:
       - [0x1B3C, .data, e_misc]
       - [0x1C14, data]
       - [0x1C34, data, clock_room]
-      - [0x1CA0, data]
+      - [0x1CA0, .data, 4E2E0]
+      - [0x1CC4, data]
       - [0x1E94, .data, e_skelerang]
       - [0x1F80, .data, e_plate_lord]
       - [0x1F90, data]
@@ -112,7 +113,7 @@ segments:
       - [0x4A4CC, c, e_misc]
       - [0x4C750, c]
       - [0x4CAAC, c, clock_room]
-      - [0x4E2E0, c]
+      - [0x4E2E0, c, 4E2E0]
       - [0x4E654, c, e_stage_name]
       - [0x4F4A8, c, e_diplocephalus]
       - [0x50990, c, e_diplocephalus_2]

diff --git a/include/entity.h b/include/entity.h
@@ -2249,6 +2249,18 @@ typedef struct {
     struct Entity* parent;
 } ET_801737F0;
 
+typedef struct {
+    /* 0x7C */ u8 unk7C;
+    /* 0x7D */ u8 : 8;
+    /* 0x7E */ u16 : 16;
+    /* 0x80 */ s16 unk80;
+    /* 0x82 */ u16 : 16;
+    /* 0x84 */ u16 posX;
+    /* 0x86 */ u16 posY;
+    /* 0x88 */ u16 unk88;
+    /* 0x8A */ s16 unk8A;
+} ET_801CE2E0;
+
 typedef union { // offset=0x7C
     struct Primitive* prim;
     ET_Placeholder ILLEGAL;
@@ -2437,6 +2449,7 @@ typedef union { // offset=0x7C
     ET_DiplocephalusFireball diplocephalusFireball;
     ET_PlateLord plateLord;
     ET_PlatelordUnknown plateLordUnknown;
+    ET_801CE2E0 et_801CE2E0;
 } Ext;
 
 #define SYNC_FIELD(struct1, struct2, field)                                    \

diff --git a/src/st/no0/4E2E0.c b/src/st/no0/4E2E0.c
@@ -1,6 +1,92 @@
 // SPDX-License-Identifier: AGPL-3.0-or-later
 #include "no0.h"
 
-INCLUDE_ASM("st/no0/nonmatchings/4E2E0", func_us_801CE2E0);
+static u8 anim_unk[] = {
+    0x01, 0x01, 0x01, 0x02, 0x01, 0x03, 0x01, 0x04, 0x01, 0x05, 0x01, 0x06,
+    0x01, 0x07, 0x01, 0x08, 0x01, 0x09, 0x01, 0x0A, 0x01, 0x0B, 0x01, 0x0C,
+    0x01, 0x0D, 0x01, 0x0E, 0x01, 0x0F, 0x01, 0x10, 0x00, 0x00, 0x00, 0x00};
 
-INCLUDE_RODATA("st/no0/nonmatchings/4E2E0", D_us_801C14A8);
+// Does not appear in the entity list and appears to be unused
+void func_us_801CE2E0(Entity* self) {
+    s16 yOffsets[8] = {-2, -1, -1, 0, 0, 1, 1, 2};
+    Entity* player;
+    s32 collision;
+    s16 offset;
+    u16 flags;
+
+    if (self->step != 0) {
+        UnkAnimFunc(anim_unk, self, 5);
+        self->rotZ += 0x80;
+        player = &PLAYER;
+        if (self->ext.et_801CE2E0.unk88 & 0x40) {
+            self->velocityY = FIX(-0.5);
+        } else {
+            self->velocityY = FIX(0.5);
+        }
+
+        self->velocityX = 0;
+        self->ext.et_801CE2E0.unk88++;
+        MoveEntity();
+        if (self->ext.et_801CE2E0.unk7C & 0x4) {
+            offset = (self->posY.i.hi + g_Tilemap.scrollY.i.hi) -
+                     self->ext.et_801CE2E0.posY;
+            if (offset > 0 || (offset < 0 && (g_Player.pl_vram_flag ^ 2) & 2)) {
+                player->posY.i.hi += offset;
+            }
+        }
+        flags = 15;
+        if (self->ext.et_801CE2E0.unk8A != 0) {
+            self->ext.et_801CE2E0.unk8A--;
+            flags = 11;
+        }
+
+        if (self->ext.et_801CE2E0.unk80 & 0xF &&
+            (self->ext.et_801CE2E0.unk80 & 0xF0)) {
+            flags |= 0x10;
+        }
+
+        collision = GetPlayerCollisionWith(self, 24, 8, flags);
+        if (self->ext.et_801CE2E0.unk80 & 0xF) {
+            if (self->ext.et_801CE2E0.unk80 & 0xF0) {
+                offset = -yOffsets[(self->ext.et_801CE2E0.unk80 & 0xF) - 1];
+            } else {
+                offset = yOffsets[self->ext.et_801CE2E0.unk80 - 1];
+            }
+            self->posY.i.hi += offset;
+            if (collision & 4) {
+                player->posY.i.hi += offset;
+            }
+            self->ext.et_801CE2E0.unk80--;
+        }
+
+        if (collision & 4) {
+            if (self->ext.et_801CE2E0.unk7C != 4 &&
+                !(self->ext.et_801CE2E0.unk80 & 0xF) &&
+                F(player->velocityY).i.hi > 0) {
+                self->ext.et_801CE2E0.unk80 = 8;
+            }
+            offset = self->posX.i.hi + g_Tilemap.scrollX.i.hi -
+                     self->ext.et_801CE2E0.posX;
+            if ((offset > 0 && g_Player.pl_vram_flag != 4) ||
+                (offset < 0 && g_Player.pl_vram_flag != 8)) {
+                player->posX.i.hi += offset;
+            }
+        } else if (self->ext.et_801CE2E0.unk7C & 4) {
+            self->ext.et_801CE2E0.unk8A = 8;
+        }
+
+        if ((collision & 0x2) && !(self->ext.et_801CE2E0.unk80 & 0xF)) {
+            self->ext.et_801CE2E0.unk80 = 24;
+        }
+        self->ext.et_801CE2E0.unk7C = collision;
+    } else {
+        InitializeEntity(D_us_80180AAC);
+        self->animCurFrame = 1;
+        self->hitboxWidth = 24;
+        self->hitboxHeight = 8;
+        self->hitboxState = 2;
+        self->ext.et_801CE2E0.unk88 = 0;
+    }
+    self->ext.et_801CE2E0.posX = self->posX.i.hi + g_Tilemap.scrollX.i.hi;
+    self->ext.et_801CE2E0.posY = self->posY.i.hi + g_Tilemap.scrollY.i.hi;
+}
diff --git a/src/st/no0/no0.h b/src/st/no0/no0.h
@@ -69,6 +69,8 @@ extern u16 g_EInitCommon[];
 extern u16 g_EInitParticle[];
 extern u16 g_EInitInteractable[];
 
+extern EInit D_us_80180AAC;
+
 // Axe knight
 extern EInit g_EInitAxeKnightAxe;