Document pass on WaterBox code (#2695)

* Document pass on WaterBox code

* implement suggestions, missing comment

---------

Co-authored-by: Dragorn421 <Dragorn421@users.noreply.github.com>

15 files changed, 117 insertions, 89 deletions

diff --git a/src/code/z_actor.c b/src/code/z_actor.c
index 13cd13160..4fb43be5b 100644
--- a/src/code/z_actor.c
+++ b/src/code/z_actor.c
@@ -1489,8 +1489,8 @@ void Actor_UpdateBgCheckInfo(PlayState* play, Actor* actor, f32 wallCheckHeight,
         sp64.y = actor->prevPos.y;
         func_8002E2AC(play, actor, &sp64, flags);
         waterBoxYSurface = actor->world.pos.y;
-        if (WaterBox_GetSurface1(play, &play->colCtx, actor->world.pos.x, actor->world.pos.z, &waterBoxYSurface,
-                                 &waterBox)) {
+        if (BgCheck_GetWaterSurfaceAllHack(play, &play->colCtx, actor->world.pos.x, actor->world.pos.z,
+                                           &waterBoxYSurface, &waterBox)) {
             actor->depthInWater = waterBoxYSurface - actor->world.pos.y;
             if (actor->depthInWater < 0.0f) {
                 actor->bgCheckFlags &= ~(BGCHECKFLAG_WATER | BGCHECKFLAG_WATER_TOUCH);
diff --git a/src/code/z_bgcheck.c b/src/code/z_bgcheck.c
index 656bb04b5..0cd8ab9e2 100644
--- a/src/code/z_bgcheck.c
+++ b/src/code/z_bgcheck.c
@@ -4247,7 +4247,14 @@ u32 func_80042108(CollisionContext* colCtx, CollisionPoly* poly, s32 bgId) {
 /**
  * Zora's Domain WaterBox in King Zora's Room
  */
-WaterBox sZorasDomainWaterBox = { -348, 877, -1746, 553, 780, 0x2104 };
+WaterBox sZorasDomainWaterBox = {
+    -348,  // xMin
+    877,   // ySurface
+    -1746, // zMin
+    553,   // xLength
+    780,   // zLength
+    WATERBOX_PROPERTIES(/* bgCamIndex */ 4, /* lightIndex */ 1, /* roomIndex */ 1, /* isDisabled */ false),
+};
 
 /**
  * WaterBox's effective bounding box
@@ -4260,31 +4267,38 @@ f32 sZorasDomainWaterBoxMaxY = 977.0f;
 f32 sZorasDomainWaterBoxMaxZ = -967.0f;
 
 /**
- * Public. Get the water surface at point (`x`, `ySurface`, `z`). `ySurface` doubles as position y input
- * returns true if point is within the xz boundaries of an active water box, else false
- * `ySurface` returns the water box's surface, while `outWaterBox` returns a pointer to the WaterBox
+ * Get the water surface at point (`x`, `y`, `z`). `y` doubles as `outWaterSurface` result
+ * returns true if point is within the xz boundaries of an active WaterBox, else false
+ * `y` returns the WaterBox's surface
+ * `outWaterBox` returns a pointer to the WaterBox
+ *
+ * This performs a special case check on a custom waterbox in Zora's Domain that has a finite depth
+ * Otherwise, the search performed assumes waterboxes do not overlap, and have infinite depth.
  */
-s32 WaterBox_GetSurface1(PlayState* play, CollisionContext* colCtx, f32 x, f32 z, f32* ySurface,
-                         WaterBox** outWaterBox) {
+s32 BgCheck_GetWaterSurfaceAllHack(PlayState* play, CollisionContext* colCtx, f32 x, f32 z, f32* y,
+                                   WaterBox** outWaterBox) {
     if (play->sceneId == SCENE_ZORAS_DOMAIN) {
         s32 pad;
 
-        if (sZorasDomainWaterBoxMinX < x && x < sZorasDomainWaterBoxMaxX && sZorasDomainWaterBoxMinY < *ySurface &&
-            *ySurface < sZorasDomainWaterBoxMaxY && sZorasDomainWaterBoxMinZ < z && z < sZorasDomainWaterBoxMaxZ) {
+        if (sZorasDomainWaterBoxMinX < x && x < sZorasDomainWaterBoxMaxX && sZorasDomainWaterBoxMinY < *y &&
+            *y < sZorasDomainWaterBoxMaxY && sZorasDomainWaterBoxMinZ < z && z < sZorasDomainWaterBoxMaxZ) {
             *outWaterBox = &sZorasDomainWaterBox;
-            *ySurface = sZorasDomainWaterBox.ySurface;
+            *y = sZorasDomainWaterBox.ySurface;
             return true;
         }
     }
-    return WaterBox_GetSurfaceImpl(play, colCtx, x, z, ySurface, outWaterBox);
+    return BgCheck_GetWaterSurface(play, colCtx, x, z, y, outWaterBox);
 }
 
 /**
- * Internal. Get the water surface at point (`x`, `ySurface`, `z`). `ySurface` doubles as position y input
- * returns true if point is within the xz boundaries of an active water box, else false
- * `ySurface` returns the water box's surface, while `outWaterBox` returns a pointer to the WaterBox
+ * Get the water surface at point (`x`, `z`).
+ * returns true if point is within the xz boundaries of an active WaterBox, else false
+ * `outWaterSurface` returns the WaterBox's surface
+ * `outWaterBox` returns a pointer to the WaterBox
+ *
+ * The search performed assumes waterboxes do not overlap, and have infinite depth.
  */
-s32 WaterBox_GetSurfaceImpl(PlayState* play, CollisionContext* colCtx, f32 x, f32 z, f32* ySurface,
+s32 BgCheck_GetWaterSurface(PlayState* play, CollisionContext* colCtx, f32 x, f32 z, f32* outWaterSurface,
                             WaterBox** outWaterBox) {
     CollisionHeader* colHeader = colCtx->colHeader;
     s32 room;
@@ -4296,15 +4310,20 @@ s32 WaterBox_GetSurfaceImpl(PlayState* play, CollisionContext* colCtx, f32 x, f3
 
     for (waterBox = colHeader->waterBoxes; waterBox < colHeader->waterBoxes + colHeader->numWaterBoxes; waterBox++) {
         room = WATERBOX_ROOM(waterBox->properties);
-        if (room == play->roomCtx.curRoom.num || room == WATERBOX_ROOM_ALL) {
-            if (!(waterBox->properties & WATERBOX_FLAG_19)) {
-                if (waterBox->xMin < x && x < waterBox->xMin + waterBox->xLength) {
-                    if (waterBox->zMin < z && z < waterBox->zMin + waterBox->zLength) {
-                        *outWaterBox = waterBox;
-                        *ySurface = waterBox->ySurface;
-                        return true;
-                    }
-                }
+        if (room != play->roomCtx.curRoom.num && room != WATERBOX_ROOM_ALL) {
+            continue;
+        }
+        if (waterBox->properties & WATERBOX_IS_DISABLED) {
+            continue;
+        }
+        //! @bug: WaterBox bounds check issue. This range check excludes all points falling exactly on the border of the
+        //! WaterBox. Thus, when two waterboxes are flush against each other, a seam will exist between them where no
+        //! water is detected.
+        if (waterBox->xMin < x && x < waterBox->xMin + waterBox->xLength) {
+            if (waterBox->zMin < z && z < waterBox->zMin + waterBox->zLength) {
+                *outWaterBox = waterBox;
+                *outWaterSurface = waterBox->ySurface;
+                return true;
             }
         }
     }
@@ -4312,12 +4331,12 @@ s32 WaterBox_GetSurfaceImpl(PlayState* play, CollisionContext* colCtx, f32 x, f3
 }
 
 /**
- * Gets the first active WaterBox at `pos` with WATERBOX_FLAG_19 not set
+ * Gets the first active WaterBox at `pos`, within +- `surfaceChkDist`
  * `surfaceChkDist` is the absolute y distance from the water surface to check
  * returns the index of the waterbox found, or -1 if no waterbox is found
  * `outWaterBox` returns the pointer to the waterbox found, or NULL if none is found
  */
-s32 WaterBox_GetSurface2(PlayState* play, CollisionContext* colCtx, Vec3f* pos, f32 surfaceChkDist,
+s32 BgCheck_FindWaterBox(PlayState* play, CollisionContext* colCtx, Vec3f* pos, f32 surfaceChkDist,
                          WaterBox** outWaterBox) {
     CollisionHeader* colHeader = colCtx->colHeader;
     s32 room;
@@ -4334,16 +4353,18 @@ s32 WaterBox_GetSurface2(PlayState* play, CollisionContext* colCtx, Vec3f* pos,
         waterBox = &colHeader->waterBoxes[i];
 
         room = WATERBOX_ROOM(waterBox->properties);
-        if (room == play->roomCtx.curRoom.num || room == WATERBOX_ROOM_ALL) {
-            if (!(waterBox->properties & WATERBOX_FLAG_19)) {
-                if (waterBox->xMin < pos->x && pos->x < waterBox->xMin + waterBox->xLength) {
-                    if (waterBox->zMin < pos->z && pos->z < waterBox->zMin + waterBox->zLength) {
-                        if (pos->y - surfaceChkDist < waterBox->ySurface &&
-                            waterBox->ySurface < pos->y + surfaceChkDist) {
-                            *outWaterBox = waterBox;
-                            return i;
-                        }
-                    }
+        if (room != play->roomCtx.curRoom.num && room != WATERBOX_ROOM_ALL) {
+            continue;
+        }
+        if (waterBox->properties & WATERBOX_IS_DISABLED) {
+            continue;
+        }
+        //! @bug: WaterBox bounds check issue. See BgCheck_GetWaterSurface for more details.
+        if ((waterBox->xMin < pos->x) && (pos->x < waterBox->xMin + waterBox->xLength)) {
+            if ((waterBox->zMin < pos->z) && (pos->z < waterBox->zMin + waterBox->zLength)) {
+                if (pos->y - surfaceChkDist < waterBox->ySurface && waterBox->ySurface < pos->y + surfaceChkDist) {
+                    *outWaterBox = waterBox;
+                    return i;
                 }
             }
         }
@@ -4386,12 +4407,15 @@ u32 WaterBox_GetLightIndex(CollisionContext* colCtx, WaterBox* waterBox) {
 }
 
 /**
- * Get the water surface at point (`x`, `ySurface`, `z`). `ySurface` doubles as position y input
- * same as WaterBox_GetSurfaceImpl, but tests if WATERBOX_FLAG_19 is set
- * returns true if point is within the xz boundaries of an active water box, else false
- * `ySurface` returns the water box's surface, while `outWaterBox` returns a pointer to the WaterBox
+ * Unused. Gets the water surface? at point (`x`, `z`) for disabled? waterboxes only.
+ * returns true if point is within the xz boundaries of a disabled? WaterBox, else false
+ * `outWaterSurface` returns the WaterBox's surface
+ * `outWaterBox` returns a pointer to the WaterBox
+ *
+ * The search performed assumes waterboxes do not overlap.
  */
-s32 func_800425B0(PlayState* play, CollisionContext* colCtx, f32 x, f32 z, f32* ySurface, WaterBox** outWaterBox) {
+s32 func_800425B0(PlayState* play, CollisionContext* colCtx, f32 x, f32 z, f32* outWaterSurface,
+                  WaterBox** outWaterBox) {
     CollisionHeader* colHeader = colCtx->colHeader;
     s32 room;
     WaterBox* waterBox;
@@ -4402,15 +4426,18 @@ s32 func_800425B0(PlayState* play, CollisionContext* colCtx, f32 x, f32 z, f32*
 
     for (waterBox = colHeader->waterBoxes; waterBox < colHeader->waterBoxes + colHeader->numWaterBoxes; waterBox++) {
         room = WATERBOX_ROOM(waterBox->properties);
-        if ((room == play->roomCtx.curRoom.num) || (room == WATERBOX_ROOM_ALL)) {
-            if (waterBox->properties & WATERBOX_FLAG_19) {
-                if (waterBox->xMin < x && x < (waterBox->xMin + waterBox->xLength)) {
-                    if (waterBox->zMin < z && z < (waterBox->zMin + waterBox->zLength)) {
-                        *outWaterBox = waterBox;
-                        *ySurface = waterBox->ySurface;
-                        return true;
-                    }
-                }
+        if ((room != play->roomCtx.curRoom.num) && (room != WATERBOX_ROOM_ALL)) {
+            continue;
+        }
+        if (!(waterBox->properties & WATERBOX_IS_DISABLED)) {
+            continue;
+        }
+        //! @bug: WaterBox bounds check issue. See BgCheck_GetWaterSurface for more details.
+        if (waterBox->xMin < x && x < (waterBox->xMin + waterBox->xLength)) {
+            if (waterBox->zMin < z && z < (waterBox->zMin + waterBox->zLength)) {
+                *outWaterBox = waterBox;
+                *outWaterSurface = waterBox->ySurface;
+                return true;
             }
         }
     }
diff --git a/src/code/z_camera.c b/src/code/z_camera.c
index b94c5beda..fb8b1ccf1 100644
--- a/src/code/z_camera.c
+++ b/src/code/z_camera.c
@@ -685,8 +685,8 @@ s32 Camera_GetWaterBoxBgCamIndex(Camera* camera, f32* waterY) {
     playerPosRot = Actor_GetWorldPosShapeRot(&camera->player->actor);
     *waterY = playerPosRot.pos.y;
 
-    if (!WaterBox_GetSurface1(camera->play, &camera->play->colCtx, playerPosRot.pos.x, playerPosRot.pos.z, waterY,
-                              &waterBox)) {
+    if (!BgCheck_GetWaterSurfaceAllHack(camera->play, &camera->play->colCtx, playerPosRot.pos.x, playerPosRot.pos.z,
+                                        waterY, &waterBox)) {
         // player's position is not within the x/z boundaries of a water box.
         *waterY = BGCHECK_Y_MIN;
         return -1;
@@ -722,7 +722,8 @@ f32 Camera_GetWaterSurface(Camera* camera, Vec3f* chkPos, s32* lightIndex) {
     playerPosRot = Actor_GetWorldPosShapeRot(&camera->player->actor);
     waterY = playerPosRot.pos.y;
 
-    if (!WaterBox_GetSurface1(camera->play, &camera->play->colCtx, chkPos->x, chkPos->z, &waterY, &waterBox)) {
+    if (!BgCheck_GetWaterSurfaceAllHack(camera->play, &camera->play->colCtx, chkPos->x, chkPos->z, &waterY,
+                                        &waterBox)) {
         // chkPos is not within the x/z boundaries of a water box.
         return BGCHECK_Y_MIN;
     }
diff --git a/src/code/z_play.c b/src/code/z_play.c
index ad0023e2d..acacb7174 100644
--- a/src/code/z_play.c
+++ b/src/code/z_play.c
@@ -1974,8 +1974,8 @@ s32 func_800C0DB4(PlayState* this, Vec3f* pos) {
 
     waterSurfacePos = *pos;
 
-    if (WaterBox_GetSurface1(this, &this->colCtx, waterSurfacePos.x, waterSurfacePos.z, &waterSurfacePos.y,
-                             &waterBox) == true &&
+    if (BgCheck_GetWaterSurfaceAllHack(this, &this->colCtx, waterSurfacePos.x, waterSurfacePos.z, &waterSurfacePos.y,
+                                       &waterBox) == true &&
         pos->y < waterSurfacePos.y &&
         BgCheck_EntityRaycastDown3(&this->colCtx, &poly, &bgId, &waterSurfacePos) != BGCHECK_Y_MIN) {
         return true;
diff --git a/src/overlays/actors/ovl_En_Bom_Chu/z_en_bom_chu.c b/src/overlays/actors/ovl_En_Bom_Chu/z_en_bom_chu.c
index c2ab0160d..1bb6a4f1d 100644
--- a/src/overlays/actors/ovl_En_Bom_Chu/z_en_bom_chu.c
+++ b/src/overlays/actors/ovl_En_Bom_Chu/z_en_bom_chu.c
@@ -465,8 +465,8 @@ void EnBomChu_Update(Actor* thisx, PlayState* play2) {
 
         waterY = this->actor.world.pos.y;
 
-        if (WaterBox_GetSurface1(play, &play->colCtx, this->actor.world.pos.x, this->actor.world.pos.z, &waterY,
-                                 &waterBox)) {
+        if (BgCheck_GetWaterSurfaceAllHack(play, &play->colCtx, this->actor.world.pos.x, this->actor.world.pos.z,
+                                           &waterY, &waterBox)) {
             this->actor.depthInWater = waterY - this->actor.world.pos.y;
 
             if (this->actor.depthInWater < 0.0f) {
diff --git a/src/overlays/actors/ovl_En_Fr/z_en_fr.c b/src/overlays/actors/ovl_En_Fr/z_en_fr.c
index 17889ad56..b413f3907 100644
--- a/src/overlays/actors/ovl_En_Fr/z_en_fr.c
+++ b/src/overlays/actors/ovl_En_Fr/z_en_fr.c
@@ -360,7 +360,7 @@ void EnFr_IsDivingIntoWater(EnFr* this, PlayState* play) {
     WaterBox* waterBox;
     f32 waterSurface;
 
-    if (WaterBox_GetSurfaceImpl(play, &play->colCtx, this->actor.world.pos.x, this->actor.world.pos.z, &waterSurface,
+    if (BgCheck_GetWaterSurface(play, &play->colCtx, this->actor.world.pos.x, this->actor.world.pos.z, &waterSurface,
                                 &waterBox)) {
         this->isBelowWaterSurfacePrevious = this->isBelowWaterSurfaceCurrent;
         this->isBelowWaterSurfaceCurrent = this->actor.world.pos.y <= waterSurface ? true : false;
diff --git a/src/overlays/actors/ovl_En_Goroiwa/z_en_goroiwa.c b/src/overlays/actors/ovl_En_Goroiwa/z_en_goroiwa.c
index f00a7b6de..0a571f115 100644
--- a/src/overlays/actors/ovl_En_Goroiwa/z_en_goroiwa.c
+++ b/src/overlays/actors/ovl_En_Goroiwa/z_en_goroiwa.c
@@ -436,7 +436,7 @@ s32 EnGoroiwa_MoveDownToNextWaypoint(EnGoroiwa* this, PlayState* play) {
         this->actor.world.pos.y = nextPointY - ((this->actor.world.pos.y - nextPointY) * 0.3f);
     }
     if (this->bounceCount == 0 &&
-        WaterBox_GetSurfaceImpl(play, &play->colCtx, this->actor.world.pos.x, this->actor.world.pos.z, &ySurface,
+        BgCheck_GetWaterSurface(play, &play->colCtx, this->actor.world.pos.x, this->actor.world.pos.z, &ySurface,
                                 &waterBox) &&
         this->actor.world.pos.y <= ySurface) {
         this->stateFlags |= ENGOROIWA_IN_WATER;
diff --git a/src/overlays/actors/ovl_En_Horse/z_en_horse.c b/src/overlays/actors/ovl_En_Horse/z_en_horse.c
index e2c9cb2c1..c817c5cb9 100644
--- a/src/overlays/actors/ovl_En_Horse/z_en_horse.c
+++ b/src/overlays/actors/ovl_En_Horse/z_en_horse.c
@@ -2861,7 +2861,7 @@ s32 EnHorse_CalcFloorHeight(EnHorse* this, PlayState* play, Vec3f* pos, Collisio
         return 1; // No floor
     }
 
-    if (WaterBox_GetSurfaceImpl(play, &play->colCtx, pos->x, pos->z, &waterY, &waterBox) == 1 &&
+    if (BgCheck_GetWaterSurface(play, &play->colCtx, pos->x, pos->z, &waterY, &waterBox) == true &&
         *floorHeight < waterY) {
         return 2; // Water
     }
@@ -2930,8 +2930,8 @@ void EnHorse_CheckFloors(EnHorse* this, PlayState* play) {
     WaterBox* waterBox;
     s32 pad;
 
-    if (WaterBox_GetSurfaceImpl(play, &play->colCtx, this->actor.world.pos.x, this->actor.world.pos.z, &waterHeight,
-                                &waterBox) == 1 &&
+    if (BgCheck_GetWaterSurface(play, &play->colCtx, this->actor.world.pos.x, this->actor.world.pos.z, &waterHeight,
+                                &waterBox) == true &&
         this->actor.floorHeight < waterHeight) {
         EnHorse_ObstructMovement(this, play, 1, galloping);
         return;
diff --git a/src/overlays/actors/ovl_En_Okuta/z_en_okuta.c b/src/overlays/actors/ovl_En_Okuta/z_en_okuta.c
index 938e7ebda..2284d9eab 100644
--- a/src/overlays/actors/ovl_En_Okuta/z_en_okuta.c
+++ b/src/overlays/actors/ovl_En_Okuta/z_en_okuta.c
@@ -148,8 +148,7 @@ void EnOkuta_Init(Actor* thisx, PlayState* play) {
         }
         thisx->floorHeight =
             BgCheck_EntityRaycastDown4(&play->colCtx, &thisx->floorPoly, &floorBgId, thisx, &thisx->world.pos);
-        //! @bug calls WaterBox_GetSurfaceImpl directly
-        if (!WaterBox_GetSurfaceImpl(play, &play->colCtx, thisx->world.pos.x, thisx->world.pos.z, &ySurface,
+        if (!BgCheck_GetWaterSurface(play, &play->colCtx, thisx->world.pos.x, thisx->world.pos.z, &ySurface,
                                      &outWaterBox) ||
             (ySurface <= thisx->floorHeight)) {
             Actor_Kill(thisx);
@@ -596,7 +595,7 @@ void EnOkuta_Update(Actor* thisx, PlayState* play2) {
     if (!(player->stateFlags1 & (PLAYER_STATE1_TALKING | PLAYER_STATE1_DEAD | PLAYER_STATE1_28 | PLAYER_STATE1_29))) {
         if (this->actor.params == 0) {
             EnOkuta_ColliderCheck(this, play);
-            if (!WaterBox_GetSurfaceImpl(play, &play->colCtx, this->actor.world.pos.x, this->actor.world.pos.z,
+            if (!BgCheck_GetWaterSurface(play, &play->colCtx, this->actor.world.pos.x, this->actor.world.pos.z,
                                          &ySurface, &outWaterBox) ||
                 (ySurface < this->actor.floorHeight)) {
                 if (this->actor.colChkInfo.health != 0) {
diff --git a/src/overlays/actors/ovl_En_Tite/z_en_tite.c b/src/overlays/actors/ovl_En_Tite/z_en_tite.c
index b61f66d3a..1085a9051 100644
--- a/src/overlays/actors/ovl_En_Tite/z_en_tite.c
+++ b/src/overlays/actors/ovl_En_Tite/z_en_tite.c
@@ -927,28 +927,28 @@ void EnTite_Update(Actor* thisx, PlayState* play) {
         if ((this->actor.params == TEKTITE_BLUE) && (thisx->bgCheckFlags & BGCHECKFLAG_WATER)) {
             floorPoly = thisx->floorPoly;
             if ((((play->gameplayFrames % 8) == 0) || (thisx->velocity.y < 0.0f)) &&
-                (WaterBox_GetSurfaceImpl(play, &play->colCtx, this->backRightFootPos.x, this->backRightFootPos.z,
+                (BgCheck_GetWaterSurface(play, &play->colCtx, this->backRightFootPos.x, this->backRightFootPos.z,
                                          &waterSurfaceY, &waterBox)) &&
                 (this->backRightFootPos.y <= waterSurfaceY)) {
                 this->backRightFootPos.y = waterSurfaceY;
                 EffectSsGRipple_Spawn(play, &this->backRightFootPos, 0, 220, 0);
             }
             if (((((play->gameplayFrames + 2) % 8) == 0) || (thisx->velocity.y < 0.0f)) &&
-                (WaterBox_GetSurfaceImpl(play, &play->colCtx, this->backLeftFootPos.x, this->backLeftFootPos.z,
+                (BgCheck_GetWaterSurface(play, &play->colCtx, this->backLeftFootPos.x, this->backLeftFootPos.z,
                                          &waterSurfaceY, &waterBox)) &&
                 (this->backLeftFootPos.y <= waterSurfaceY)) {
                 this->backLeftFootPos.y = waterSurfaceY;
                 EffectSsGRipple_Spawn(play, &this->backLeftFootPos, 0, 220, 0);
             }
             if (((((play->gameplayFrames + 4) % 8) == 0) || (thisx->velocity.y < 0.0f)) &&
-                (WaterBox_GetSurfaceImpl(play, &play->colCtx, this->frontLeftFootPos.x, this->frontLeftFootPos.z,
+                (BgCheck_GetWaterSurface(play, &play->colCtx, this->frontLeftFootPos.x, this->frontLeftFootPos.z,
                                          &waterSurfaceY, &waterBox)) &&
                 (this->frontLeftFootPos.y <= waterSurfaceY)) {
                 this->frontLeftFootPos.y = waterSurfaceY;
                 EffectSsGRipple_Spawn(play, &this->frontLeftFootPos, 0, 220, 0);
             }
             if (((((play->gameplayFrames + 1) % 8) == 0) || (thisx->velocity.y < 0.0f)) &&
-                (WaterBox_GetSurfaceImpl(play, &play->colCtx, this->frontRightFootPos.x, this->frontRightFootPos.z,
+                (BgCheck_GetWaterSurface(play, &play->colCtx, this->frontRightFootPos.x, this->frontRightFootPos.z,
                                          &waterSurfaceY, &waterBox)) &&
                 (this->frontRightFootPos.y <= waterSurfaceY)) {
                 this->frontRightFootPos.y = waterSurfaceY;
diff --git a/src/overlays/actors/ovl_En_Weiyer/z_en_weiyer.c b/src/overlays/actors/ovl_En_Weiyer/z_en_weiyer.c
index f7a2bfdc2..bc480f659 100644
--- a/src/overlays/actors/ovl_En_Weiyer/z_en_weiyer.c
+++ b/src/overlays/actors/ovl_En_Weiyer/z_en_weiyer.c
@@ -232,7 +232,7 @@ void EnWeiyer_InitInsideWaterBox(EnWeiyer* this, PlayState* play) {
     this->actor.floorHeight =
         BgCheck_EntityRaycastDown4(&play->colCtx, &this->actor.floorPoly, &bgId, &this->actor, &this->actor.world.pos);
 
-    if (!WaterBox_GetSurfaceImpl(play, &play->colCtx, this->actor.world.pos.x, this->actor.world.pos.z,
+    if (!BgCheck_GetWaterSurface(play, &play->colCtx, this->actor.world.pos.x, this->actor.world.pos.z,
                                  &this->actor.home.pos.y, &waterBox) ||
         ((this->actor.home.pos.y - 5.0f) <= this->actor.floorHeight)) {
         Actor_Kill(&this->actor);
diff --git a/src/overlays/actors/ovl_Obj_Syokudai/z_obj_syokudai.c b/src/overlays/actors/ovl_Obj_Syokudai/z_obj_syokudai.c
index 4f1c201cd..2134534e3 100644
--- a/src/overlays/actors/ovl_Obj_Syokudai/z_obj_syokudai.c
+++ b/src/overlays/actors/ovl_Obj_Syokudai/z_obj_syokudai.c
@@ -152,7 +152,7 @@ void ObjSyokudai_Update(Actor* thisx, PlayState* play2) {
     if (torchCount == 10) {
         torchCount = 24;
     }
-    if (WaterBox_GetSurfaceImpl(play, &play->colCtx, this->actor.world.pos.x, this->actor.world.pos.z, &waterSurface,
+    if (BgCheck_GetWaterSurface(play, &play->colCtx, this->actor.world.pos.x, this->actor.world.pos.z, &waterSurface,
                                 &dummy) &&
         ((waterSurface - this->actor.world.pos.y) > 52.0f)) {
         this->litTimer = 0;
diff --git a/src/overlays/actors/ovl_player_actor/z_player.c b/src/overlays/actors/ovl_player_actor/z_player.c
index 812a502f6..9ba6899e1 100644
--- a/src/overlays/actors/ovl_player_actor/z_player.c
+++ b/src/overlays/actors/ovl_player_actor/z_player.c
@@ -5823,10 +5823,10 @@ void func_8083AA10(Player* this, PlayState* play) {
     s32 sp5C;
     CollisionPoly* sp58;
     s32 sp54;
-    WaterBox* sp50;
+    WaterBox* waterBox;
     Vec3f sp44;
     f32 sp40;
-    f32 sp3C;
+    f32 waterSurfaceY;
 
     this->fallDistance = this->fallStartHeight - (s32)this->actor.world.pos.y;
 
@@ -5871,10 +5871,11 @@ void func_8083AA10(Player* this, PlayState* play) {
                         !(this->stateFlags1 & PLAYER_STATE1_CARRYING_ACTOR)) {
 
                         sp40 = func_808396F4(play, this, &D_8085451C, &sp44, &sp58, &sp54);
-                        sp3C = this->actor.world.pos.y;
+                        waterSurfaceY = this->actor.world.pos.y;
 
-                        if (WaterBox_GetSurface1(play, &play->colCtx, sp44.x, sp44.z, &sp3C, &sp50) &&
-                            ((sp3C - sp40) > 50.0f)) {
+                        if (BgCheck_GetWaterSurfaceAllHack(play, &play->colCtx, sp44.x, sp44.z, &waterSurfaceY,
+                                                           &waterBox) &&
+                            ((waterSurfaceY - sp40) > 50.0f)) {
                             func_808389E8(this, &gPlayerAnim_link_normal_run_jump_water_fall, 6.0f, play);
                             Player_SetupAction(play, this, Player_Action_80844A44, 0);
                             return;
@@ -6681,12 +6682,12 @@ void func_8083C8DC(Player* this, PlayState* play, s16 arg2) {
 }
 
 s32 Player_SetStartingMovement(PlayState* play, Player* this, f32 arg2) {
-    WaterBox* sp2C;
+    WaterBox* waterBox;
     f32 sp28;
 
     sp28 = this->actor.world.pos.y;
-    if (WaterBox_GetSurface1(play, &play->colCtx, this->actor.world.pos.x, this->actor.world.pos.z, &sp28, &sp2C) !=
-        0) {
+    if (BgCheck_GetWaterSurfaceAllHack(play, &play->colCtx, this->actor.world.pos.x, this->actor.world.pos.z, &sp28,
+                                       &waterBox)) {
         sp28 -= this->actor.world.pos.y;
         if (this->ageProperties->unk_24 <= sp28) {
             Player_SetupAction(play, this, Player_Action_8084D7C4, 0);
@@ -6817,24 +6818,24 @@ void func_8083CF5C(Player* this, PlayState* play) {
 
 s32 func_8083CFA8(PlayState* play, Player* this, f32 arg2, s32 splashScale) {
     f32 sp3C = fabsf(arg2);
-    WaterBox* sp38;
-    f32 sp34;
+    WaterBox* waterBox;
+    f32 waterSurfaceY;
     Vec3f splashPos;
     s32 splashType;
 
     if (sp3C > 2.0f) {
         splashPos.x = this->bodyPartsPos[PLAYER_BODYPART_WAIST].x;
         splashPos.z = this->bodyPartsPos[PLAYER_BODYPART_WAIST].z;
-        sp34 = this->actor.world.pos.y;
-        if (WaterBox_GetSurface1(play, &play->colCtx, splashPos.x, splashPos.z, &sp34, &sp38)) {
+        waterSurfaceY = this->actor.world.pos.y;
+        if (BgCheck_GetWaterSurfaceAllHack(play, &play->colCtx, splashPos.x, splashPos.z, &waterSurfaceY, &waterBox)) {
 #if OOT_VERSION < PAL_1_0
-            if ((sp34 - this->actor.world.pos.y) < 80.0f)
+            if ((waterSurfaceY - this->actor.world.pos.y) < 80.0f)
 #else
-            if ((sp34 - this->actor.world.pos.y) < 100.0f)
+            if ((waterSurfaceY - this->actor.world.pos.y) < 100.0f)
 #endif
             {
                 splashType = (sp3C <= 10.0f) ? 0 : 1;
-                splashPos.y = sp34;
+                splashPos.y = waterSurfaceY;
                 EffectSsGSplash_Spawn(play, &splashPos, NULL, NULL, splashType, splashScale);
                 return 1;
             }
diff --git a/src/overlays/effects/ovl_Effect_Ss_Bubble/z_eff_ss_bubble.c b/src/overlays/effects/ovl_Effect_Ss_Bubble/z_eff_ss_bubble.c
index bf25e04fe..26d05493b 100644
--- a/src/overlays/effects/ovl_Effect_Ss_Bubble/z_eff_ss_bubble.c
+++ b/src/overlays/effects/ovl_Effect_Ss_Bubble/z_eff_ss_bubble.c
@@ -71,7 +71,7 @@ void EffectSsBubble_Update(PlayState* play, u32 index, EffectSs* this) {
     f32 waterSurfaceY = this->pos.y;
 
     // kill bubble if it's out of range of a water box
-    if (!WaterBox_GetSurface1(play, &play->colCtx, this->pos.x, this->pos.z, &waterSurfaceY, &waterBox)) {
+    if (!BgCheck_GetWaterSurfaceAllHack(play, &play->colCtx, this->pos.x, this->pos.z, &waterSurfaceY, &waterBox)) {
         this->life = -1;
         return;
     }
diff --git a/src/overlays/effects/ovl_Effect_Ss_G_Ripple/z_eff_ss_g_ripple.c b/src/overlays/effects/ovl_Effect_Ss_G_Ripple/z_eff_ss_g_ripple.c
index 8822faadb..049b95fed 100644
--- a/src/overlays/effects/ovl_Effect_Ss_G_Ripple/z_eff_ss_g_ripple.c
+++ b/src/overlays/effects/ovl_Effect_Ss_G_Ripple/z_eff_ss_g_ripple.c
@@ -63,7 +63,7 @@ u32 EffectSsGRipple_Init(PlayState* play, u32 index, EffectSs* this, void* initP
     this->rEnvColorG = 255;
     this->rEnvColorB = 255;
     this->rEnvColorA = 255;
-    this->rWaterBoxNum = WaterBox_GetSurface2(play, &play->colCtx, &initParams->pos, 3.0f, &waterBox);
+    this->rWaterBoxNum = BgCheck_FindWaterBox(play, &play->colCtx, &initParams->pos, 3.0f, &waterBox);
 
     return 1;
 }