From f19d490243bceb91aed3dac0c1fc400d11ca6865 Mon Sep 17 00:00:00 2001
From: JaceCear <11230293+JaceCear@users.noreply.github.com>
Date: Wed, 15 Jan 2025 17:01:19 +0100
Subject: [PATCH] Some Sp Stage documentation and a crash fix (#187)

---
 src/game/special_stage/main.c   | 10 +++++-----
 src/game/special_stage/player.c | 11 ++++++-----
 src/game/special_stage/utils.c  | 15 ++++++++++++---
 3 files changed, 23 insertions(+), 13 deletions(-)

diff --git a/src/game/special_stage/main.c b/src/game/special_stage/main.c
index 75b403a8a..9475b05dd 100644
--- a/src/game/special_stage/main.c
+++ b/src/game/special_stage/main.c
@@ -130,10 +130,10 @@ void CreateSpecialStage(s16 selectedCharacter, s16 level)
 
 static void SetupIntroScreenRegisters(void)
 {
-    gDispCnt = 0x1641;
-    gBgCntRegs[1] = 0x703;
-    gBgCntRegs[2] = 0xD086;
-    gBldRegs.bldCnt = 0xAF;
+    gDispCnt = (DISPCNT_OBJ_ON | DISPCNT_BG1_ON | DISPCNT_BG2_ON | DISPCNT_OBJ_1D_MAP | DISPCNT_MODE_1);
+    gBgCntRegs[1] = (BGCNT_TXT256x256 | BGCNT_16COLOR | BGCNT_PRIORITY(3) | BGCNT_CHARBASE(0) | BGCNT_SCREENBASE(7));
+    gBgCntRegs[2] = (BGCNT_TXT512x512 | BGCNT_256COLOR | BGCNT_PRIORITY(2) | BGCNT_CHARBASE(1) | BGCNT_SCREENBASE(16));
+    gBldRegs.bldCnt = BLDCNT_EFFECT_LIGHTEN | (BLDCNT_TGT1_ALL & ~BLDCNT_TGT1_OBJ);
     gBldRegs.bldY = 0x10;
 
     gBgScrollRegs[1][0] = 0;
@@ -716,7 +716,7 @@ static void Task_ShowIntroScreen(void)
 {
     struct SpecialStage *stage = TASK_DATA(gCurTask);
     SetupIntroScreenRegisters();
-    sub_806CA88(&stage->introText, RENDER_TARGET_SCREEN, 0x28, 0x37C, 0, 0x78, 0x50, 0, 0, 0);
+    sub_806CA88(&stage->introText, RENDER_TARGET_SCREEN, 0x28, 0x37C, 0, (DISPLAY_WIDTH / 2), (DISPLAY_HEIGHT / 2), 0, 0, 0);
 
     stage->state = 1;
     m4aSongNumStart(MUS_SPECIAL_STAGE_INTRO);
diff --git a/src/game/special_stage/player.c b/src/game/special_stage/player.c
index 4b359227a..ac25822a9 100644
--- a/src/game/special_stage/player.c
+++ b/src/game/special_stage/player.c
@@ -106,7 +106,8 @@ struct Task *CreateSpecialStagePlayer(struct SpecialStage *stage)
         s->graphics.dest = player->unkA0;
         s->graphics.size = 0;
         s->graphics.anim = SA2_ANIM_SP_STAGE_ARROW;
-        s->frameFlags = 0x107E;
+        s->frameFlags = SPRITE_FLAG(PRIORITY, 1) | SPRITE_FLAG(ROT_SCALE_DOUBLE_SIZE, 1) | SPRITE_FLAG(ROT_SCALE_ENABLE, 1)
+            | SPRITE_FLAG(ROT_SCALE, 30);
         s->x = (DISPLAY_WIDTH / 2);
         s->y = (DISPLAY_HEIGHT / 2);
         s->oamFlags = SPRITE_OAM_ORDER(0);
@@ -296,19 +297,19 @@ void sub_806D4E4(void)
 
 void sub_806D548(Sprite *s, void *vram, s16 a, u8 b, const struct UNK_80DF670 *c4)
 {
-    u32 unk10 = 0x1000;
+    u32 frameFlags = SPRITE_FLAG(PRIORITY, 1);
     if (c4->unk7 & 1) {
-        unk10 |= 0x400;
+        frameFlags |= SPRITE_FLAG(X_FLIP, 1);
     }
 
     if (c4->unk7 & 2) {
-        unk10 |= 0x800;
+        frameFlags |= SPRITE_FLAG(Y_FLIP, 1);
     }
 
     s->graphics.dest = vram;
     s->graphics.size = 0;
     s->graphics.anim = c4->anim;
-    s->frameFlags = unk10;
+    s->frameFlags = frameFlags;
     s->x = (DISPLAY_WIDTH / 2);
     s->y = a;
     s->oamFlags = SPRITE_OAM_ORDER(b);
diff --git a/src/game/special_stage/utils.c b/src/game/special_stage/utils.c
index c81e28950..5cf8995b9 100644
--- a/src/game/special_stage/utils.c
+++ b/src/game/special_stage/utils.c
@@ -60,11 +60,20 @@ void sub_806CA88(Sprite *obj, s8 target, u32 size, u16 anim, u32 unk10, s16 xPos
 // TODO: SpecialStageCollectables_UNK874 is probably it's own type
 bool16 sub_806CB84(struct UNK_806CB84 *a, struct SpecialStageCollectables_UNK874_2 *unk874, struct SpecialStage *stage)
 {
-    struct SpecialStageWorld *world = TASK_DATA(stage->worldTask);
+    struct SpecialStageWorld *world;
     s32 r9;
     s32 r4;
     s16 val2, val;
 
+#ifdef BUG_FIX
+    // worldTask can sometimes be NULL when directly calling Special Stage code
+    if (stage->worldTask == NULL) {
+        return FALSE;
+    }
+#endif
+
+    world = TASK_DATA(stage->worldTask);
+
     {
         u16 deg = -stage->cameraBearing & 0x3FF;
         s32 r2 = SIN(deg) * 4;
@@ -181,14 +190,14 @@ void InitSpecialStageScreenVram(void)
     gUnknown_03005B58 = NULL;
 }
 
-void sub_806CEC4(Background *background, u32 a, u32 b, u8 assetId, u16 d, u16 e, u16 palOffset, u8 bg_id, u16 scrollX, u16 scrollY)
+void sub_806CEC4(Background *background, u32 a, u32 b, u8 tilemapId, u16 d, u16 e, u16 palOffset, u8 bg_id, u16 scrollX, u16 scrollY)
 {
     background->graphics.dest = (void *)BG_CHAR_ADDR(a);
     background->graphics.anim = 0;
     background->layoutVram = (void *)BG_SCREEN_ADDR(b);
     background->unk18 = 0;
     background->unk1A = 0;
-    background->tilemapId = assetId;
+    background->tilemapId = tilemapId;
     background->unk1E = 0;
     background->unk20 = 0;
     background->unk22 = 0;