diff --git a/asm/object/fireballChain.s b/asm/object/fireballChain.s
deleted file mode 100644
index dfda3925..00000000
--- a/asm/object/fireballChain.s
+++ /dev/null
@@ -1,61 +0,0 @@
-	.include "asm/macros.inc"
-
-	.include "constants/constants.inc"
-
-	.syntax unified
-
-	.text
-
-
-	thumb_func_start FireballChain
-FireballChain: @ 0x0809F8A4
-	push {r4, r5, r6, r7, lr}
-	mov r7, r8
-	push {r7}
-	adds r6, r0, #0
-	ldr r0, _0809F904 @ =gEntCount
-	ldrb r0, [r0]
-	cmp r0, #0x42
-	bhi _0809F8FC
-	movs r5, #0
-_0809F8B6:
-	movs r0, #0x1d
-	bl CreateProjectile
-	adds r4, r0, #0
-	cmp r5, #0
-	bne _0809F8C6
-	mov r8, r4
-	adds r7, r4, #0
-_0809F8C6:
-	strb r5, [r4, #0xa]
-	mov r0, r8
-	str r0, [r4, #0x50]
-	str r7, [r4, #0x54]
-	adds r0, r6, #0
-	adds r1, r4, #0
-	bl CopyPosition
-	adds r1, r4, #0
-	adds r1, #0x68
-	adds r3, r5, #1
-	movs r2, #7
-_0809F8DE:
-	ldrh r0, [r6, #0x2e]
-	strh r0, [r1]
-	adds r1, #2
-	ldrh r0, [r6, #0x32]
-	strh r0, [r1]
-	adds r1, #2
-	subs r2, #1
-	cmp r2, #0
-	bge _0809F8DE
-	adds r7, r4, #0
-	adds r5, r3, #0
-	cmp r5, #4
-	ble _0809F8B6
-	bl DeleteThisEntity
-_0809F8FC:
-	pop {r3}
-	mov r8, r3
-	pop {r4, r5, r6, r7, pc}
-	.align 2, 0
-_0809F904: .4byte gEntCount
diff --git a/include/collision.h b/include/collision.h
new file mode 100644
index 00000000..d57258a6
--- /dev/null
+++ b/include/collision.h
@@ -0,0 +1,33 @@
+
+#ifndef COLLISION_H
+#define COLLISION_H
+
+#include "global.h"
+#include "entity.h"
+
+/** Collisions. */
+typedef enum {
+    COL_NONE = 0x0,
+    COL_NORTH_WEST = 0x2,
+    COL_NORTH_EAST = 0x4,
+    COL_NORTH_FULL = 0x6,
+    COL_NORTH_ANY = 0xe,
+    COL_SOUTH_WEST = 0x20,
+    COL_SOUTH_EAST = 0x40,
+    COL_SOUTH_FULL = 0x60,
+    COL_SOUTH_ANY = 0xe0,
+    COL_WEST_SOUTH = 0x200,
+    COL_WEST_NORTH = 0x400,
+    COL_WEST_FULL = 0x600,
+    COL_WEST_ANY = 0xe00,
+    COL_EAST_SOUTH = 0x2000,
+    COL_EAST_NORTH = 0x4000,
+    COL_EAST_FULL = 0x6000,
+    COL_EAST_ANY = 0xe000,
+} Collisions;
+
+bool32 IsTileCollision(const u8*, s32, s32, u32);
+void CalculateEntityTileCollisions(Entity*, u32, u32);
+bool32 ProcessMovementInternal(Entity*, s32, s32, u32);
+
+#endif
diff --git a/include/projectile/winder.h b/include/projectile/winder.h
new file mode 100644
index 00000000..1fe479ff
--- /dev/null
+++ b/include/projectile/winder.h
@@ -0,0 +1,12 @@
+#ifndef PROJECTILE_WINDER_H
+#define PROJECTILE_WINDER_H
+#include "enemy.h"
+
+#define WINDER_NUM_SEGMENTS 8
+
+typedef struct {
+    Entity base;
+    s16 positions[2 * WINDER_NUM_SEGMENTS];
+} WinderEntity;
+
+#endif
diff --git a/linker.ld b/linker.ld
index 51a80d79..a0f8b4c0 100644
--- a/linker.ld
+++ b/linker.ld
@@ -787,7 +787,7 @@ SECTIONS {
         src/object/objectA2.o(.text);
         src/object/cloud.o(.text);
         src/object/minishLight.o(.text);
-        asm/object/fireballChain.o(.text);
+        src/object/fireballChain.o(.text);
         src/object/objectA6.o(.text);
         src/object/objectA7.o(.text);
         src/object/objectA8.o(.text);
diff --git a/src/enemy/bobomb.c b/src/enemy/bobomb.c
index 7e214b63..5ff23ab7 100644
--- a/src/enemy/bobomb.c
+++ b/src/enemy/bobomb.c
@@ -6,6 +6,7 @@
  */
 
 #include "asm.h"
+#include "collision.h"
 #include "sound.h"
 #include "enemy.h"
 #include "object.h"
@@ -160,7 +161,7 @@ void sub_0802C91C(Entity* this) {
     GetNextFrame(this);
     ProcessMovement0(this);
     if (this->field_0x82.HALF.LO) {
-        if (this->collisions) {
+        if (this->collisions != COL_NONE) {
             sub_0800417E(this, this->collisions);
             InitializeAnimation(this, (this->direction >> 4) | 2);
         }
@@ -173,7 +174,7 @@ void sub_0802C91C(Entity* this) {
             sub_0802CC18(this);
         }
     } else {
-        if (this->collisions) {
+        if (this->collisions != COL_NONE) {
             sub_0800417E(this, this->collisions);
             InitializeAnimation(this, this->direction >> 4);
         }
diff --git a/src/enemy/cloudPiranha.c b/src/enemy/cloudPiranha.c
index 6922958c..e1075af3 100644
--- a/src/enemy/cloudPiranha.c
+++ b/src/enemy/cloudPiranha.c
@@ -7,6 +7,7 @@
 
 #define NENT_DEPRECATED
 #include "global.h"
+#include "collision.h"
 #include "enemy.h"
 #include "functions.h"
 #include "coord.h"
@@ -259,7 +260,7 @@ void sub_080387F0(CloudPiranhaEntity* this) {
         if ((iVar4 == 0xf) || (iVar4 == 0x2a)) {
             super->direction = (super->direction + 0x10) & 0x1f;
         } else {
-            if (super->collisions != 0) {
+            if (super->collisions != COL_NONE) {
                 sub_0800417E(super, super->collisions);
             }
         }
diff --git a/src/enemy/flyingPot.c b/src/enemy/flyingPot.c
index abba834c..1736979d 100644
--- a/src/enemy/flyingPot.c
+++ b/src/enemy/flyingPot.c
@@ -5,6 +5,7 @@
  * @brief Flying pot enemy
  */
 #define NENT_DEPRECATED
+#include "collision.h"
 #include "functions.h"
 #include "enemy.h"
 #include "player.h"
@@ -234,7 +235,7 @@ void FlyingPot_Action4(FlyingPotEntity* this) {
 void FlyingPot_Action5(FlyingPotEntity* this) {
     ProcessMovement2(super);
 
-    if (super->collisions != 0) {
+    if (super->collisions != COL_NONE) {
         sub_08037408(this);
     }
 }
diff --git a/src/enemy/flyingSkull.c b/src/enemy/flyingSkull.c
index 262781bb..85ebe162 100644
--- a/src/enemy/flyingSkull.c
+++ b/src/enemy/flyingSkull.c
@@ -1,4 +1,5 @@
 #define NENT_DEPRECATED
+#include "collision.h"
 #include "entity.h"
 #include "enemy.h"
 #include "functions.h"
@@ -159,7 +160,7 @@ void sub_08039ECC(FlyingSkullEntity* this) {
 void sub_08039EE4(FlyingSkullEntity* this) {
     super->subAction = 1;
     COLLISION_OFF(super);
-    super->collisions = 0;
+    super->collisions = COL_NONE;
     super->hitbox = (Hitbox*)&gUnk_080FD340;
     gPlayerEntity.animationState;
     this->unk_0x76 = gPlayerEntity.animationState;
@@ -175,7 +176,7 @@ void sub_08039F4C(FlyingSkullEntity* this) {
 
 void sub_08039F78(FlyingSkullEntity* this) {
     super->spritePriority.b1 = 1;
-    if (super->z.HALF.HI == 0 || super->collisions) {
+    if (super->z.HALF.HI == 0 || (super->collisions != COL_NONE)) {
         sub_0803A0E0(this);
     }
 }
@@ -222,7 +223,7 @@ void sub_0803A09C(FlyingSkullEntity* this) {
     GetNextFrame(super);
     ProcessMovement2(super);
 
-    if (super->collisions) {
+    if (super->collisions != COL_NONE) {
         sub_0803A0E0(this);
     }
 }
diff --git a/src/enemy/moldorm.c b/src/enemy/moldorm.c
index 7a5ab69c..a73135cd 100644
--- a/src/enemy/moldorm.c
+++ b/src/enemy/moldorm.c
@@ -6,6 +6,7 @@
  */
 
 #include "enemy.h"
+#include "collision.h"
 #include "functions.h"
 
 void sub_08022EAC(Entity*);
@@ -103,7 +104,7 @@ void sub_08022D40(Entity* this) {
         sub_08022F14(this);
         ProcessMovement0(this);
 
-        if (this->collisions) {
+        if (this->collisions != COL_NONE) {
             sub_0800417E(this, this->collisions);
             this->animationState = ((this->direction + 2) & 0x1c) >> 2;
             this->frameIndex = this->animationState;
diff --git a/src/enemy/mulldozer.c b/src/enemy/mulldozer.c
index 6a6a79de..1550c4d1 100644
--- a/src/enemy/mulldozer.c
+++ b/src/enemy/mulldozer.c
@@ -7,6 +7,7 @@
 
 #define NENT_DEPRECATED
 #include "global.h"
+#include "collision.h"
 #include "enemy.h"
 #include "functions.h"
 
@@ -63,11 +64,11 @@ void sub_08032CAC(MulldozerEntity* this) {
             case 2:
             case 3:
                 super->action = 6;
-                super->actionDelay = super->type != 0 ? 0x5a : 200;
+                super->actionDelay = (super->type != 0) ? 0x5a : 200;
                 super->field_0xf = 2;
                 this->unk_80 = 3;
                 super->direction = super->knockbackDirection;
-                super->direction = (super->direction + ((Random() & 0x40) != 0 ? 4 : 0x1c));
+                super->direction += ((Random() & 0x40) != 0) ? 4 : 0x1c;
                 super->direction &= 0x1f;
                 super->speed = 0;
                 break;
@@ -102,7 +103,7 @@ void Mulldozer_Action1(MulldozerEntity* this) {
     if (--super->actionDelay == 0) {
         sub_080330C0(this);
     } else {
-        if (sub_08033364(this) != 0) {
+        if (sub_08033364(this)) {
             sub_08033100(this);
         }
     }
@@ -200,7 +201,7 @@ void sub_08032F48(MulldozerEntity* this) {
 }
 
 void sub_08032F64(MulldozerEntity* this) {
-    if (super->collisions != 0) {
+    if (super->collisions != COL_NONE) {
         sub_0800417E(super, super->collisions);
         super->animationState = super->direction >> 2;
         sub_08032F24(this);
diff --git a/src/enemy/octorokBoss.c b/src/enemy/octorokBoss.c
index 49ca9525..c5b944f7 100644
--- a/src/enemy/octorokBoss.c
+++ b/src/enemy/octorokBoss.c
@@ -6,6 +6,7 @@
  */
 #define NENT_DEPRECATED
 #include "enemy/octorokBoss.h"
+#include "collision.h"
 #include "functions.h"
 #include "game.h"
 #include "object.h"
@@ -639,14 +640,15 @@ void OctorokBoss_Action1_ChargeAttack(OctorokBossEntity* this) {
 
     if (this->timer == 0) {
         ProcessMovement0(super);
-        knockbackCondition = 0;
+        knockbackCondition = FALSE;
         if ((super->direction != 0) && (super->direction != 0x10)) {
-            knockbackCondition = ((u32)super->collisions & 0xee00) != 0;
+            knockbackCondition = ((super->collisions & (COL_EAST_ANY | COL_WEST_ANY)) != COL_NONE);
         }
-        if (((super->direction != 0x18) && (super->direction != 8)) && ((super->collisions & 0xee) != 0)) {
-            knockbackCondition = 1;
+        if (((super->direction != 0x18) && (super->direction != 8)) &&
+            (super->collisions & (COL_NORTH_ANY | COL_SOUTH_ANY))) {
+            knockbackCondition = TRUE;
         }
-        if (knockbackCondition != 0) {
+        if (knockbackCondition) {
             super->knockbackDuration = 0x20;
             super->knockbackSpeed = 0x200;
             super->knockbackDirection = super->direction ^ 0x10;
@@ -911,7 +913,7 @@ void OctorokBoss_Burning(OctorokBossEntity* this) {
 void OctorokBoss_Burning_SubAction0(OctorokBossEntity* this) {
     super->subAction = 1;
     super->speed = 0x200;
-    super->collisions = 0;
+    super->collisions = COL_NONE;
     super->direction = (u8)(-this->angle.HALF.HI ^ 0x80U) >> 3;
     this->timer = 0x78;
     this->angularSpeed.HWORD = 0x180;
@@ -922,13 +924,13 @@ void OctorokBoss_Burning_SubAction0(OctorokBossEntity* this) {
 
 void OctorokBoss_Burning_SubAction1(OctorokBossEntity* this) {
     ProcessMovement0(super);
-    if (super->collisions != 0) {
+    if (super->collisions != COL_NONE) {
         super->subAction = 2;
         this->heap->targetAngle = this->angle.HALF.HI;
-        if ((super->collisions & 0xee00) != 0) {
+        if ((super->collisions & (COL_EAST_ANY | COL_WEST_ANY)) != COL_NONE) {
             this->heap->targetAngle = -this->heap->targetAngle;
         }
-        if ((super->collisions & 0xee) != 0) {
+        if ((super->collisions & (COL_NORTH_ANY | COL_SOUTH_ANY)) != COL_NONE) {
             this->heap->targetAngle = -this->heap->targetAngle ^ 0x80;
         }
         super->knockbackDuration = 0x18;
@@ -951,10 +953,10 @@ void OctorokBoss_Burning_SubAction2(OctorokBossEntity* this) {
     if ((u32)(this->heap->targetAngle - this->angle.HALF.HI + 7) < 0xf) {
         super->subAction = 1;
         super->direction = ((u8) - this->angle.HALF.HI ^ 0x80) >> 3;
-        super->collisions = 0;
+        super->collisions = COL_NONE;
         ProcessMovement0(super);
     } else {
-        if ((u8)(this->heap->targetAngle - this->angle.HALF.HI) >= 0x81) {
+        if ((u8)(this->heap->targetAngle - this->angle.HALF.HI) > 0x80) {
             this->angle.HWORD -= this->angularSpeed.HWORD;
         } else {
             this->angle.HWORD += this->angularSpeed.HWORD;
@@ -1161,7 +1163,7 @@ void OctorokBoss_StartRegularAttack(OctorokBossEntity* this) {
             super->subAction = ACTION1_SUBACTION2;
             super->speed = 0x200;
             this->timer = 0x3c;
-            super->collisions = 0;
+            super->collisions = COL_NONE;
             this->heap->unk_0 = 4;
             SoundReq(SFX_159);
             return;
diff --git a/src/enemy/pesto.c b/src/enemy/pesto.c
index f7f8baf1..7882e8e8 100644
--- a/src/enemy/pesto.c
+++ b/src/enemy/pesto.c
@@ -6,6 +6,7 @@
  */
 
 #include "enemy.h"
+#include "collision.h"
 #include "object.h"
 #include "game.h"
 #include "functions.h"
@@ -525,7 +526,7 @@ void sub_080244E8(Entity* this) {
 void sub_08024940(Entity* this) {
     u32 random = Random() & 0x70;
 
-    if (this->collisions != 0) {
+    if (this->collisions != COL_NONE) {
         sub_0800417E(this, this->collisions);
         sub_080249F4(this);
     }
diff --git a/src/enemy/puffstool.c b/src/enemy/puffstool.c
index 18838cf6..76f4858b 100644
--- a/src/enemy/puffstool.c
+++ b/src/enemy/puffstool.c
@@ -6,6 +6,7 @@
  */
 
 #include "enemy.h"
+#include "collision.h"
 #include "object.h"
 #include "functions.h"
 
@@ -156,7 +157,7 @@ void sub_08025230(Entity* this) {
         this->direction = sub_08025C60(this);
     }
 
-    if (this->collisions != 0) {
+    if (this->collisions != COL_NONE) {
         if (--this->field_0xf == 0) {
             sub_0800417E(this, this->collisions);
         }
diff --git a/src/enemy/scissorsBeetle.c b/src/enemy/scissorsBeetle.c
index 28ce9d57..29fddd38 100644
--- a/src/enemy/scissorsBeetle.c
+++ b/src/enemy/scissorsBeetle.c
@@ -1,4 +1,5 @@
 #define NENT_DEPRECATED
+#include "collision.h"
 #include "entity.h"
 #include "enemy.h"
 #include "functions.h"
@@ -92,7 +93,7 @@ void sub_080389E8(ScissorsBeetleEntity* this) {
         sub_08038C2C((ScissorsBeetleEntity*)child);
     } else if (super->actionDelay) {
         super->actionDelay--;
-    } else if (super->collisions) {
+    } else if (super->collisions != COL_NONE) {
         super->actionDelay = 0xc;
         if ((child->animationState & 1) == 0) {
             child->animationState += Random() & 0x20 ? 1 : 7;
diff --git a/src/enemy/spark.c b/src/enemy/spark.c
index f6f9325d..7a977440 100644
--- a/src/enemy/spark.c
+++ b/src/enemy/spark.c
@@ -5,6 +5,7 @@
  * @brief Spark enemy
  */
 
+#include "collision.h"
 #include "enemy.h"
 #include "object.h"
 #include "functions.h"
@@ -40,7 +41,6 @@ void Spark_OnCollision(Entity* this) {
 }
 
 void Spark_OnGrabbed(Entity* this) {
-    /* ... */
 }
 
 void sub_0802B33C(Entity* this) {
@@ -57,7 +57,7 @@ void sub_0802B35C(Entity* this) {
     GetNextFrame(this);
     ProcessMovement0(this);
     is_head = this->type == 0;
-    if (this->collisions == 0) {
+    if (this->collisions == COL_NONE) {
         if (--this->field_0xf == 0) {
             this->field_0xf = 0x78;
 
@@ -68,49 +68,49 @@ void sub_0802B35C(Entity* this) {
         this->field_0xf = 0x78;
         switch (DirectionRound(this->direction)) {
             case DirectionNorth:
-                if (this->collisions & 0xe) {
+                if ((this->collisions & COL_NORTH_ANY) != COL_NONE) {
                     this->direction = is_head ? DirectionWest : DirectionEast;
                 } else {
-                    if ((this->collisions & 0xe000) == 0x4000 && is_head) {
+                    if (((this->collisions & COL_EAST_ANY) == COL_EAST_NORTH) && is_head) {
                         this->direction = DirectionEast;
                     }
-                    if ((this->collisions & 0xe00) == 0x400 && !is_head) {
+                    if (((this->collisions & COL_WEST_ANY) == COL_WEST_NORTH) && !is_head) {
                         this->direction = DirectionWest;
                     }
                 }
                 break;
             case DirectionSouth:
-                if (this->collisions & 0xe0) {
+                if ((this->collisions & COL_SOUTH_ANY) != COL_NONE) {
                     this->direction = is_head ? DirectionEast : DirectionWest;
                 } else {
-                    if ((this->collisions & 0xe000) == 0x2000 && !is_head) {
+                    if (((this->collisions & COL_EAST_ANY) == COL_EAST_SOUTH) && !is_head) {
                         this->direction = DirectionEast;
                     }
-                    if ((this->collisions & 0xe00) == 0x200 && is_head) {
+                    if (((this->collisions & COL_WEST_ANY) == COL_WEST_SOUTH) && is_head) {
                         this->direction = DirectionWest;
                     }
                 }
                 break;
             case DirectionWest:
-                if (this->collisions & 0xe00) {
+                if ((this->collisions & COL_WEST_ANY) != COL_NONE) {
                     this->direction = is_head ? DirectionSouth : DirectionNorth;
                 } else {
-                    if ((this->collisions & 0xe) == 4 && is_head) {
+                    if (((this->collisions & COL_NORTH_ANY) == COL_NORTH_EAST) && is_head) {
                         this->direction = DirectionNorth;
                     }
-                    if ((this->collisions & 0xe0) == 0x40 && !is_head) {
+                    if (((this->collisions & COL_SOUTH_ANY) == COL_SOUTH_EAST) && !is_head) {
                         this->direction = DirectionSouth;
                     }
                 }
                 break;
             case DirectionEast:
-                if (this->collisions & 0xe000) {
+                if ((this->collisions & COL_EAST_ANY) != COL_NONE) {
                     this->direction = is_head ? DirectionNorth : DirectionSouth;
                 } else {
-                    if ((this->collisions & 0xe) == 2 && !is_head) {
+                    if (((this->collisions & COL_NORTH_ANY) == COL_NORTH_WEST) && !is_head) {
                         this->direction = DirectionNorth;
                     }
-                    if ((this->collisions & 0xe0) == 0x20 && is_head) {
+                    if (((this->collisions & COL_SOUTH_ANY) == COL_SOUTH_WEST) && is_head) {
                         this->direction = DirectionSouth;
                     }
                 }
diff --git a/src/enemy/stalfos.c b/src/enemy/stalfos.c
index 61512e7e..31086dc1 100644
--- a/src/enemy/stalfos.c
+++ b/src/enemy/stalfos.c
@@ -7,6 +7,7 @@
 
 #define NENT_DEPRECATED
 #include "global.h"
+#include "collision.h"
 #include "enemy.h"
 #include "functions.h"
 
@@ -366,7 +367,7 @@ void sub_0803992C(StalfosEntity* this) {
     super->direction = super->animationState << 3;
     this->unk_78 = (u16)gUnk_080CF900[Random() & 0xf];
     CalculateEntityTileCollisions(super, super->direction, 0);
-    if ((gUnk_080CF910[super->animationState] & super->collisions) != 0) {
+    if ((gUnk_080CF910[super->animationState] & super->collisions) != COL_NONE) {
         InitAnimationForceUpdate(super, super->animationState);
     } else {
         InitAnimationForceUpdate(super, super->animationState + 4);
diff --git a/src/enemy/tektite.c b/src/enemy/tektite.c
index db461a94..776f08e5 100644
--- a/src/enemy/tektite.c
+++ b/src/enemy/tektite.c
@@ -5,6 +5,7 @@
  * @brief Tektite enemy
  */
 
+#include "collision.h"
 #include "enemy.h"
 #include "functions.h"
 
@@ -135,7 +136,7 @@ void sub_0802F300(Entity* this) {
         this->field_0xf = 0;
         InitializeAnimation(this, 3);
         return;
-    } else if (this->collisions != 0) {
+    } else if (this->collisions != COL_NONE) {
         sub_0800417E(this, this->collisions);
     } else if ((GetTileUnderEntity(this) & 0xf0) == 0x50) {
         this->direction = (this->direction + 0x10) & 0x1f;
diff --git a/src/enemy/tektiteGolden.c b/src/enemy/tektiteGolden.c
index af71db25..f8862aa8 100644
--- a/src/enemy/tektiteGolden.c
+++ b/src/enemy/tektiteGolden.c
@@ -5,6 +5,7 @@
  * @brief Golden Tektite enemy
  */
 
+#include "collision.h"
 #include "enemy.h"
 #include "functions.h"
 
@@ -114,7 +115,7 @@ void sub_08038048(Entity* this) {
         this->actionDelay = 0x14;
         InitializeAnimation(this, 3);
         return;
-    } else if (this->collisions != 0) {
+    } else if (this->collisions != COL_NONE) {
         sub_0800417E(this, this->collisions);
     } else if ((GetTileUnderEntity(this) & 0xf0) == 0x50) {
         this->direction = (this->direction + 0x10) & 0x1f;
diff --git a/src/enemy/wisp.c b/src/enemy/wisp.c
index 213453c2..73f82457 100644
--- a/src/enemy/wisp.c
+++ b/src/enemy/wisp.c
@@ -5,6 +5,7 @@
  * @brief Wisp enemy
  */
 
+#include "collision.h"
 #include "enemy.h"
 #include "save.h"
 #include "object.h"
@@ -102,7 +103,7 @@ void sub_08033674(Entity* this) {
 void sub_080336A8(Entity* this) {
     if (--this->actionDelay == 0) {
         sub_08033744(this);
-    } else if (this->collisions != 0) {
+    } else if (this->collisions != COL_NONE) {
         sub_0800417E(this, this->collisions);
     }
     ProcessMovement0(this);
diff --git a/src/enemy/wizzrobeWind.c b/src/enemy/wizzrobeWind.c
index 4ea7da19..4fce3d5a 100644
--- a/src/enemy/wizzrobeWind.c
+++ b/src/enemy/wizzrobeWind.c
@@ -7,6 +7,7 @@
 
 #define NENT_DEPRECATED
 #include "global.h"
+#include "collision.h"
 #include "enemy.h"
 #include "enemy/wizzrobe.h"
 #include "functions.h"
@@ -262,7 +263,7 @@ void sub_0802F9C8(WizzrobeEntity* this) {
         } else {
             if (super->type2 != 0) {
                 ProcessMovement0(super);
-                if (super->collisions != 0) {
+                if (super->collisions != COL_NONE) {
                     super->flags &= 0x7f;
                     this->timer1 = 0x28;
                 }
diff --git a/src/movement.c b/src/movement.c
index 8fee2b1f..1e54b3c5 100644
--- a/src/movement.c
+++ b/src/movement.c
@@ -1,4 +1,5 @@
 #include "global.h"
+#include "collision.h"
 #include "entity.h"
 #include "room.h"
 #include "area.h"
@@ -9,30 +10,6 @@
 #include "transitions.h"
 #include "functions.h"
 
-/** Collisions. */
-typedef enum {
-    COL_NONE = 0x0,
-    COL_NORTH_WEST = 0x2,
-    COL_NORTH_EAST = 0x4,
-    COL_NORTH_FULL = 0x6,
-    COL_NORTH_ANY = 0xe,
-    COL_SOUTH_WEST = 0x20,
-    COL_SOUTH_EAST = 0x40,
-    COL_SOUTH_FULL = 0x60,
-    COL_SOUTH_ANY = 0xe0,
-    COL_WEST_SOUTH = 0x200,
-    COL_WEST_NORTH = 0x400,
-    COL_WEST_FULL = 0x600,
-    COL_WEST_ANY = 0xe00,
-    COL_EAST_SOUTH = 0x2000,
-    COL_EAST_NORTH = 0x4000,
-    COL_EAST_FULL = 0x6000,
-    COL_EAST_ANY = 0xe000,
-} Collisions;
-
-bool32 IsTileCollision(const u8*, s32, s32, u32);
-void CalculateEntityTileCollisions(Entity*, u32, u32);
-bool32 ProcessMovementInternal(Entity*, s32, s32, u32);
 bool32 sub_080AF0C8(Entity*);
 
 /** The type of the movement/collision? that is done. */
@@ -112,7 +89,8 @@ bool32 TileCollisionFunction2(s32 x, s32 y) {
         0b1111111111111110,
         0b1111111111111111,
         */
-        32768, 49152, 57344, 61440, 63488, 64512, 65024, 65280, 65408, 65472, 65504, 65520, 65528, 65532, 65534, 65535,
+        0x8000, 0xC000, 0xE000, 0xF000, 0xF800, 0xFC00, 0xFE00, 0xFF00,
+        0xFF80, 0xFFC0, 0xFFE0, 0xFFF0, 0xFFF8, 0xFFFC, 0xFFFE, 0xFFFF,
     };
 
     return gUnk_08133918[y & 0xf] >> (x & 0xf) & 1;
@@ -122,24 +100,24 @@ bool32 TileCollisionFunction2(s32 x, s32 y) {
 bool32 TileCollisionFunction3(s32 x, s32 y) {
     static const u16 gUnk_08133938[] = {
         /*
-        0b1,
-        0b11,
-        0b111,
-        0b1111,
-        0b11111,
-        0b111111,
-        0b1111111,
-        0b11111111,
-        0b111111111,
-        0b1111111111,
-        0b11111111111,
-        0b111111111111,
-        0b1111111111111,
-        0b11111111111111,
-        0b111111111111111,
+        0b0000000000000001,
+        0b0000000000000011,
+        0b0000000000000111,
+        0b0000000000001111,
+        0b0000000000011111,
+        0b0000000000111111,
+        0b0000000001111111,
+        0b0000000011111111,
+        0b0000000111111111,
+        0b0000001111111111,
+        0b0000011111111111,
+        0b0000111111111111,
+        0b0001111111111111,
+        0b0011111111111111,
+        0b0111111111111111,
         0b1111111111111111,
         */
-        1, 3, 7, 15, 31, 63, 127, 255, 511, 1023, 2047, 4095, 8191, 16383, 32767, 65535,
+        0x1, 0x3, 0x7, 0xF, 0x1F, 0x3F, 0x7F, 0xFF, 0x1FF, 0x3FF, 0x7FF, 0xFFF, 0x1FFF, 0x3FFF, 0x7FFF, 0xFFFF,
     };
     return gUnk_08133938[y & 0xf] >> (x & 0xf) & 1;
 }
@@ -165,7 +143,8 @@ bool32 TileCollisionFunction4(s32 x, s32 y) {
         0b1100000000000000,
         0b1000000000000000,
         */
-        65535, 65534, 65532, 65528, 65520, 65504, 65472, 65408, 65280, 65024, 64512, 63488, 61440, 57344, 49152, 32768,
+        0xFFFF, 0xFFFE, 0xFFFC, 0xFFF8, 0xFFF0, 0xFFE0, 0xFFC0, 0xFF80,
+        0xFF00, 0xFE00, 0xFC00, 0xF800, 0xF000, 0xE000, 0xC000, 0x8000,
     };
     return gUnk_08133958[y & 0xf] >> (x & 0xf) & 1;
 }
@@ -175,23 +154,23 @@ bool32 TileCollisionFunction5(s32 x, s32 y) {
     static const u16 gUnk_08133978[] = {
         /*
         0b1111111111111111,
-        0b111111111111111,
-        0b11111111111111,
-        0b1111111111111,
-        0b111111111111,
-        0b11111111111,
-        0b1111111111,
-        0b111111111,
-        0b11111111,
-        0b1111111,
-        0b111111,
-        0b11111,
-        0b1111,
-        0b111,
-        0b11,
-        0b1,
+        0b0111111111111111,
+        0b0011111111111111,
+        0b0001111111111111,
+        0b0000111111111111,
+        0b0000011111111111,
+        0b0000001111111111,
+        0b0000000111111111,
+        0b0000000011111111,
+        0b0000000001111111,
+        0b0000000000111111,
+        0b0000000000011111,
+        0b0000000000001111,
+        0b0000000000000111,
+        0b0000000000000011,
+        0b0000000000000001,
         */
-        65535, 32767, 16383, 8191, 4095, 2047, 1023, 511, 255, 127, 63, 31, 15, 7, 3, 1,
+        0xFFFF, 0x7FFF, 0x3FFF, 0x1FFF, 0xFFF, 0x7FF, 0x3FF, 0x1FF, 0xFF, 0x7F, 0x3F, 0x1F, 0xF, 0x7, 0x3, 0x1,
     };
     return gUnk_08133978[y & 0xf] >> (x & 0xf) & 1;
 }
@@ -210,14 +189,14 @@ bool32 TileCollisionFunction6(s32 x, s32 y) {
         0b1111111111111111,
         0b1111111111111111,
         0b1111111111111111,
-        0b0,
-        0b0,
-        0b0,
-        0b0,
-        0b0,
-        0b0,
+        0b0000000000000000,
+        0b0000000000000000,
+        0b0000000000000000,
+        0b0000000000000000,
+        0b0000000000000000,
+        0b0000000000000000,
         */
-        65535, 65535, 65535, 65535, 65535, 65535, 65535, 65535, 65535, 65535, 0, 0, 0, 0, 0, 0,
+        0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
     };
 
     return gUnk_08133998[y & 0xf] >> (x & 0xf) & 1;
@@ -227,12 +206,12 @@ bool32 TileCollisionFunction6(s32 x, s32 y) {
 bool32 TileCollisionFunction7(s32 x, s32 y) {
     static const u16 gUnk_081339B8[] = {
         /*
-        0b0,
-        0b0,
-        0b0,
-        0b0,
-        0b0,
-        0b0,
+        0b0000000000000000,
+        0b0000000000000000,
+        0b0000000000000000,
+        0b0000000000000000,
+        0b0000000000000000,
+        0b0000000000000000,
         0b1111111111111111,
         0b1111111111111111,
         0b1111111111111111,
@@ -244,7 +223,7 @@ bool32 TileCollisionFunction7(s32 x, s32 y) {
         0b1111111111111111,
         0b1111111111111111,
         */
-        0, 0, 0, 0, 0, 0, 65535, 65535, 65535, 65535, 65535, 65535, 65535, 65535, 65535, 65535,
+        0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF,
     };
     return gUnk_081339B8[y & 0xf] >> (x & 0xf) & 1;
 }
@@ -270,7 +249,8 @@ bool32 TileCollisionFunction8(s32 x, s32 y) {
         0b1111111111000000,
         0b1111111111000000,
         */
-        65472, 65472, 65472, 65472, 65472, 65472, 65472, 65472, 65472, 65472, 65472, 65472, 65472, 65472, 65472, 65472,
+        0xFFC0, 0xFFC0, 0xFFC0, 0xFFC0, 0xFFC0, 0xFFC0, 0xFFC0, 0xFFC0,
+        0xFFC0, 0xFFC0, 0xFFC0, 0xFFC0, 0xFFC0, 0xFFC0, 0xFFC0, 0xFFC0,
     };
     return gUnk_081339D8[y & 0xf] >> (x & 0xf) & 1;
 }
@@ -279,24 +259,24 @@ bool32 TileCollisionFunction8(s32 x, s32 y) {
 bool32 TileCollisionFunction9(s32 x, s32 y) {
     static const u16 gUnk_081339F8[] = {
         /*
-        0b1111111111,
-        0b1111111111,
-        0b1111111111,
-        0b1111111111,
-        0b1111111111,
-        0b1111111111,
-        0b1111111111,
-        0b1111111111,
-        0b1111111111,
-        0b1111111111,
-        0b1111111111,
-        0b1111111111,
-        0b1111111111,
-        0b1111111111,
-        0b1111111111,
-        0b1111111111,
+        0b[000001111111111,
+        0b0000001111111111,
+        0b0000001111111111,
+        0b0000001111111111,
+        0b0000001111111111,
+        0b0000001111111111,
+        0b0000001111111111,
+        0b0000001111111111,
+        0b0000001111111111,
+        0b0000001111111111,
+        0b0000001111111111,
+        0b0000001111111111,
+        0b0000001111111111,
+        0b0000001111111111,
+        0b0000001111111111,
+        0b0000001111111111,
         */
-        1023, 1023, 1023, 1023, 1023, 1023, 1023, 1023, 1023, 1023, 1023, 1023, 1023, 1023, 1023, 1023,
+        0x3FF, 0x3FF, 0x3FF, 0x3FF, 0x3FF, 0x3FF, 0x3FF, 0x3FF, 0x3FF, 0x3FF, 0x3FF, 0x3FF, 0x3FF, 0x3FF, 0x3FF, 0x3FF,
     };
     return gUnk_081339F8[y & 0xf] >> (x & 0xf) & 1;
 }
diff --git a/src/npc/dog.c b/src/npc/dog.c
index e54e6477..d63a8c4d 100644
--- a/src/npc/dog.c
+++ b/src/npc/dog.c
@@ -1,4 +1,5 @@
 #include "entity.h"
+#include "collision.h"
 #include "functions.h"
 #include "npc.h"
 #include "item.h"
@@ -143,17 +144,17 @@ void sub_08069D54(Entity* this) {
 
             if (this->x.HALF.HI < this->field_0x6e.HWORD) {
                 this->x.HALF.HI = this->field_0x6e.HWORD + 1;
-                collisions = 0xe00;
+                collisions = COL_WEST_ANY;
             } else if (this->x.HALF.HI > this->field_0x6c.HWORD) {
                 this->x.HALF.HI = this->field_0x6c.HWORD - 1;
-                collisions = 0xe000;
+                collisions = COL_EAST_ANY;
             }
             if (this->y.HALF.HI < this->field_0x70.HALF_U.LO) {
                 this->y.HALF.HI = this->field_0x70.HALF_U.LO + 1;
-                collisions = 0xe;
+                collisions = COL_NORTH_ANY;
             } else if (this->y.HALF.HI > this->field_0x70.HALF_U.HI) {
                 this->y.HALF.HI = this->field_0x70.HALF_U.HI - 1;
-                collisions = 0xe0;
+                collisions = COL_SOUTH_ANY;
             }
             sub_0800417E(this, collisions);
             sub_08069F6C(this);
diff --git a/src/object/fireballChain.c b/src/object/fireballChain.c
new file mode 100644
index 00000000..ac5322b7
--- /dev/null
+++ b/src/object/fireballChain.c
@@ -0,0 +1,41 @@
+#define NENT_DEPRECATED
+#include "global.h"
+#include "entity.h"
+#include "functions.h"
+#include "projectile.h"
+#include "projectile/winder.h"
+
+void FireballChain(Entity* thisx) {
+    WinderEntity* newSegment;
+    Entity* parent;
+    Entity* child;
+    s32 i;
+    s32 j;
+
+    if (gEntCount > 0x42) {
+        return;
+    }
+
+    for (i = 0; i < 5; i++) {
+        u16* tmp;
+
+        newSegment = (WinderEntity*)CreateProjectile(WINDER);
+        if (i == 0) {
+            child = parent = &newSegment->base;
+        }
+
+        newSegment->base.type = i;
+        newSegment->base.parent = parent;
+        newSegment->base.child = child;
+        CopyPosition(thisx, &newSegment->base);
+
+        for (j = 0, tmp = newSegment->positions; j < WINDER_NUM_SEGMENTS; j++) {
+            *tmp++ = thisx->x.HALF.HI;
+            *tmp++ = thisx->y.HALF.HI;
+        }
+
+        child = &newSegment->base;
+    }
+
+    DeleteThisEntity();
+}
diff --git a/src/object/mazaalBossObject.c b/src/object/mazaalBossObject.c
index 27f42ffb..adc3ab6d 100644
--- a/src/object/mazaalBossObject.c
+++ b/src/object/mazaalBossObject.c
@@ -80,7 +80,7 @@ void MazaalBossObject_Action0(MazaalBossObjectEntity* this) {
         gRoomControls.camera_target = super;
         sub_080809D4();
     } else {
-        super->action = 1;
+        super->action = MAZAAL_BOSS_OBJECT_ACTION_1;
         super->actionDelay = 30;
         super->frameIndex = gRoomTransition.field_0x38;
         super->spritePriority.b0 = 7;
diff --git a/src/object/playerClone.c b/src/object/playerClone.c
index b8a94abc..cabbd7c9 100644
--- a/src/object/playerClone.c
+++ b/src/object/playerClone.c
@@ -1,5 +1,6 @@
 #define NENT_DEPRECATED
 #include "entity.h"
+#include "collision.h"
 #include "room.h"
 #include "asm.h"
 #include "sound.h"
@@ -49,7 +50,12 @@ void PlayerClone_Init(PlayerCloneEntity* this) {
     SoundReq(SFX_112);
 }
 
-const u16 PlayerCloneCollisions[] = { 0x2206, 0x6044, 0x4460, 0x622 };
+const u16 PlayerCloneCollisions[] = {
+    COL_NORTH_FULL | COL_WEST_SOUTH | COL_EAST_SOUTH,
+    COL_NORTH_EAST | COL_SOUTH_EAST | COL_EAST_FULL,
+    COL_SOUTH_FULL | COL_WEST_NORTH | COL_EAST_NORTH,
+    COL_NORTH_WEST | COL_SOUTH_WEST | COL_WEST_FULL,
+};
 
 void PlayerClone_Action1(PlayerCloneEntity* this) {
     static const Hitbox PlayerCloneHitbox = { 0, -3, { 5, 3, 3, 5 }, 6, 6 };
@@ -104,7 +110,8 @@ void PlayerClone_Action2(PlayerCloneEntity* this) {
             super->y.HALF.HI = gPlayerEntity.y.HALF.HI + this->unk7a;
             sub_08084CAC(this);
             sub_080085B0(super);
-            if ((super->collisions & 0x6666) != 0x6666) {
+            if ((super->collisions & (COL_NORTH_FULL | COL_SOUTH_FULL | COL_EAST_FULL | COL_WEST_FULL)) !=
+                (COL_NORTH_FULL | COL_SOUTH_FULL | COL_EAST_FULL | COL_WEST_FULL)) {
                 for (index = 0; index <= 3; index++) {
                     if (PlayerCloneCollisions[index] == (PlayerCloneCollisions[index] & super->collisions)) {
                         break;
diff --git a/src/object/smallIceBlock.c b/src/object/smallIceBlock.c
index 11994ed5..63c4c5a6 100644
--- a/src/object/smallIceBlock.c
+++ b/src/object/smallIceBlock.c
@@ -7,6 +7,7 @@
 
 #define NENT_DEPRECATED
 #include "global.h"
+#include "collision.h"
 #include "object.h"
 #include "functions.h"
 #include "hitbox.h"
@@ -204,7 +205,7 @@ bool32 sub_0809953C(SmallIceBlockEntity* this) {
 
     uVar3 = sub_0800442E(super);
     if (uVar3 != 0) {
-        return 0;
+        return FALSE;
     }
     ProcessMovement2(super);
     sub_0800445C(super);
@@ -216,17 +217,17 @@ bool32 sub_0809953C(SmallIceBlockEntity* this) {
     }
     switch (super->direction >> 3) {
         case 0:
-            if ((super->collisions & 0xe) == 0) {
-                return 0;
+            if ((super->collisions & COL_NORTH_ANY) == COL_NONE) {
+                return FALSE;
             }
             if ((u32)(super->y.HALF.HI & 0xf) - 7 < 3) {
                 super->y.HALF.HI = (super->y.HALF.HI & 0xfff0) + 8;
-                return 1;
+                return TRUE;
             }
             sub_0809969C(this);
             break;
         case 1:
-            if ((super->collisions & 0xe000) == 0) {
+            if ((super->collisions & COL_EAST_ANY) == COL_NONE) {
                 return FALSE;
             }
             if ((u32)(super->x.HALF.HI & 0xf) - 7 < 3) {
@@ -236,7 +237,7 @@ bool32 sub_0809953C(SmallIceBlockEntity* this) {
             sub_0809969C(this);
             break;
         case 2:
-            if ((super->collisions & 0xe0) == 0) {
+            if ((super->collisions & COL_SOUTH_ANY) == COL_NONE) {
                 return FALSE;
             }
             if ((u32)(super->y.HALF.HI & 0xf) - 7 < 3) {
@@ -246,7 +247,7 @@ bool32 sub_0809953C(SmallIceBlockEntity* this) {
             sub_0809969C(this);
             break;
         default:
-            if ((super->collisions & 0xe00) != 0) {
+            if ((super->collisions & COL_WEST_ANY) != COL_NONE) {
                 if ((u32)(super->x.HALF.HI & 0xf) - 7 < 3) {
                     super->x.HALF.HI = (super->x.HALF.HI & 0xfff0) + 8;
                     return TRUE;
diff --git a/src/player.c b/src/player.c
index 60257988..9f1c93eb 100644
--- a/src/player.c
+++ b/src/player.c
@@ -6,6 +6,7 @@
  */
 
 #include "global.h"
+#include "collision.h"
 #include "asm.h"
 #include "sound.h"
 #include "entity.h"
@@ -3018,7 +3019,7 @@ static void sub_080739EC(Entity* this) {
     if ((gPlayerState.jump_status & 0xC0) != 0) {
         gPlayerState.field_0xd = this->direction;
         if (gPlayerState.jump_status & 0x80)
-            this->collisions = 0;
+            this->collisions = COL_NONE;
         v = GRAVITY_RATE;
     } else {
         if ((u16)sub_0806F854(this, 0, -12)) {
@@ -3414,7 +3415,7 @@ void SurfaceAction_7(Entity* this) {
 
 void SurfaceAction_MinishDoorFront(Entity* this) {
     if ((this->y.HALF.HI & 0xF) <= 0xD) {
-        this->collisions = 0x6600;
+        this->collisions = COL_EAST_FULL | COL_WEST_FULL;
         hide(this);
     } else {
         EnablePlayerDraw(this);
@@ -3423,7 +3424,7 @@ void SurfaceAction_MinishDoorFront(Entity* this) {
 
 void SurfaceAction_MinishDoorBack(Entity* this) {
     if ((this->y.HALF.HI & 0xF) > 1) {
-        this->collisions = 0x6600;
+        this->collisions = COL_EAST_FULL | COL_WEST_FULL;
         hide(this);
     } else {
         EnablePlayerDraw(this);
@@ -3432,7 +3433,7 @@ void SurfaceAction_MinishDoorBack(Entity* this) {
 
 void SurfaceAction_A(Entity* this) {
     if ((this->x.HALF.HI & 0xF) < 12) {
-        this->collisions = 0x66;
+        this->collisions = COL_NORTH_FULL | COL_SOUTH_FULL;
         hide(this);
     } else {
         EnablePlayerDraw(this);
@@ -3441,7 +3442,7 @@ void SurfaceAction_A(Entity* this) {
 
 void SurfaceAction_B(Entity* this) {
     if ((this->x.HALF.HI & 0xF) > 4) {
-        this->collisions = 0x66;
+        this->collisions = COL_NORTH_FULL | COL_SOUTH_FULL;
         hide(this);
     } else {
         EnablePlayerDraw(this);
diff --git a/src/projectile/arrowProjectile.c b/src/projectile/arrowProjectile.c
index 91567d8b..755ee6f8 100644
--- a/src/projectile/arrowProjectile.c
+++ b/src/projectile/arrowProjectile.c
@@ -1,4 +1,5 @@
 #include "entity.h"
+#include "collision.h"
 #include "enemy.h"
 #include "functions.h"
 #include "object.h"
@@ -66,7 +67,7 @@ void ArrowProjectile_Action1(Entity* this) {
 }
 
 void ArrowProjectile_Action2(Entity* this) {
-    if (this->collisions != 0) {
+    if (this->collisions != COL_NONE) {
         this->action = 3;
         COLLISION_OFF(this);
         this->actionDelay = 0x20;
diff --git a/src/projectile/boneProjectile.c b/src/projectile/boneProjectile.c
index 3f9858a9..429a94c9 100644
--- a/src/projectile/boneProjectile.c
+++ b/src/projectile/boneProjectile.c
@@ -1,4 +1,5 @@
 #include "entity.h"
+#include "collision.h"
 #include "enemy.h"
 #include "functions.h"
 
@@ -25,15 +26,15 @@ void sub_080A81C4(Entity* this) {
 
 void BoneProjectile_Init(Entity* this) {
     this->action = 1;
-    this->actionDelay = 0x3c;
-    this->z.HALF.HI = 0xfffe;
+    this->actionDelay = 60;
+    this->z.HALF.HI = -2;
     InitializeAnimation(this, 0);
 }
 
 void BoneProjectile_Action1(Entity* this) {
     GetNextFrame(this);
     ProcessMovement3(this);
-    if (this->collisions == 0) {
+    if (this->collisions == COL_NONE) {
         if (IsProjectileOffScreen(this)) {
             DeleteEntity(this);
         } else {
diff --git a/src/projectile/cannonballProjectile.c b/src/projectile/cannonballProjectile.c
index acf5ccd7..18e79a67 100644
--- a/src/projectile/cannonballProjectile.c
+++ b/src/projectile/cannonballProjectile.c
@@ -1,4 +1,5 @@
 #include "entity.h"
+#include "collision.h"
 #include "enemy.h"
 #include "functions.h"
 
@@ -49,7 +50,7 @@ void CannonballProjectile_Action1(Entity* this) {
 void CannonballProjectile_Action2(Entity* this) {
     GetNextFrame(this);
     ProcessMovement3(this);
-    if ((sub_080AB634(this) == 0) && (this->collisions != 0)) {
+    if ((sub_080AB634(this) == 0) && (this->collisions != COL_NONE)) {
         CreateFx(this, FX_DEATH, 0);
         DeleteThisEntity();
     }
diff --git a/src/projectile/dekuSeedProjectile.c b/src/projectile/dekuSeedProjectile.c
index 94eb1e59..86fce52a 100644
--- a/src/projectile/dekuSeedProjectile.c
+++ b/src/projectile/dekuSeedProjectile.c
@@ -91,7 +91,7 @@ void DekuSeedProjectile_Action2(Entity* this) {
             COLLISION_ON(this);
         }
     } else {
-        sub_0800417E(this, (u32)this->collisions);
+        sub_0800417E(this, this->collisions);
         sub_08016AD2(this);
         InitializeAnimation(this, 0x19);
         sub_080A86A0(this);
diff --git a/src/projectile/lakituLightning.c b/src/projectile/lakituLightning.c
index 1f366e0f..171be05c 100644
--- a/src/projectile/lakituLightning.c
+++ b/src/projectile/lakituLightning.c
@@ -1,4 +1,5 @@
 #include "entity.h"
+#include "collision.h"
 #include "enemy.h"
 #include "functions.h"
 
@@ -32,7 +33,7 @@ void LakituLightning_Init(Entity* this) {
 void LakituLightning_Action1(Entity* this) {
     GetNextFrame(this);
     ProcessMovement3(this);
-    if ((this->collisions != 0) || (--this->actionDelay == 0)) {
+    if ((this->collisions != COL_NONE) || (--this->actionDelay == 0)) {
         CreateFx(this, FX_BLUE_EFC, 0);
         DeleteThisEntity();
     }
diff --git a/src/projectile/octorokBossProjectile.c b/src/projectile/octorokBossProjectile.c
index 659f748c..54ac6c32 100644
--- a/src/projectile/octorokBossProjectile.c
+++ b/src/projectile/octorokBossProjectile.c
@@ -1,4 +1,5 @@
 #include "entity.h"
+#include "collision.h"
 #include "enemy.h"
 #include "functions.h"
 #include "projectile.h"
@@ -114,10 +115,10 @@ void OctorokBossProjectile_Action1(Entity* this) {
             this->field_0x78.HWORD--;
             LinearMoveAngle(this, this->speed, this->direction);
             CalculateEntityTileCollisions(this, this->direction >> 3, 0);
-            if ((this->collisions & 0xee00) != 0) {
+            if ((this->collisions & (COL_WEST_ANY | COL_EAST_ANY)) != COL_NONE) {
                 this->direction = -this->direction;
             }
-            if ((this->collisions & 0xee) != 0) {
+            if ((this->collisions & (COL_NORTH_ANY | COL_SOUTH_ANY)) != COL_NONE) {
                 this->direction = -this->direction ^ 0x80;
             }
             if (this->direction == this->field_0xf) {
@@ -151,7 +152,7 @@ void OctorokBossProjectile_Action1(Entity* this) {
             GetNextFrame(this);
             if (GravityUpdate(this, 0x1800) != 0) {
                 CalculateEntityTileCollisions(this, this->direction >> 3, 0);
-                if (this->collisions == 0) {
+                if (this->collisions == COL_NONE) {
                     LinearMoveAngle(this, (s32)this->speed, (u32)this->direction);
                 } else {
                     OctorokBossProjectile_Action2(this);
diff --git a/src/projectile/torchTrapProjectile.c b/src/projectile/torchTrapProjectile.c
index 5ff167c0..38503e89 100644
--- a/src/projectile/torchTrapProjectile.c
+++ b/src/projectile/torchTrapProjectile.c
@@ -1,4 +1,5 @@
 #include "entity.h"
+#include "collision.h"
 #include "enemy.h"
 #include "functions.h"
 
@@ -39,7 +40,7 @@ void TorchTrapProjectile_Action1(Entity* this) {
 void TorchTrapProjectile_Action2(Entity* this) {
     GetNextFrame(this);
     ProcessMovement3(this);
-    if (this->collisions != 0) {
+    if (this->collisions != COL_NONE) {
         DeleteThisEntity();
     }
     if (IsProjectileOffScreen(this)) {
diff --git a/src/projectile/v3ElectricProjectile.c b/src/projectile/v3ElectricProjectile.c
index c52258cd..77308f1e 100644
--- a/src/projectile/v3ElectricProjectile.c
+++ b/src/projectile/v3ElectricProjectile.c
@@ -1,4 +1,5 @@
 #include "entity.h"
+#include "collision.h"
 #include "enemy.h"
 #include "player.h"
 #include "coord.h"
@@ -96,7 +97,7 @@ void V3ElectricProjectile_Action2(Entity* this) {
         this->z.HALF.HI += 3;
     }
     ProcessMovement3(this);
-    if (this->collisions != 0) {
+    if (this->collisions != COL_NONE) {
         DeleteThisEntity();
     }
     GetNextFrame(this);
diff --git a/src/projectile/v3HandProjectile.c b/src/projectile/v3HandProjectile.c
index 4d4c55bf..ce11e1ef 100644
--- a/src/projectile/v3HandProjectile.c
+++ b/src/projectile/v3HandProjectile.c
@@ -1,4 +1,5 @@
 #include "entity.h"
+#include "collision.h"
 #include "enemy.h"
 #include "player.h"
 #include "functions.h"
@@ -20,7 +21,7 @@ void V3HandProjectile_OnTick(Entity* this) {
         this->z.HALF.HI += 2;
     }
     ProcessMovement3(this);
-    if (this->collisions != 0) {
+    if (this->collisions != COL_NONE) {
         DeleteThisEntity();
     }
     GetNextFrame(this);
diff --git a/src/projectile/v3TennisBallProjectile.c b/src/projectile/v3TennisBallProjectile.c
index 455f67af..c487be01 100644
--- a/src/projectile/v3TennisBallProjectile.c
+++ b/src/projectile/v3TennisBallProjectile.c
@@ -1,4 +1,5 @@
 #include "entity.h"
+#include "collision.h"
 #include "enemy.h"
 #include "functions.h"
 
@@ -62,7 +63,7 @@ void V3TennisBallProjectile_Action1(Entity* this) {
 
 void V3TennisBallProjectile_Action2(Entity* this) {
     ProcessMovement3(this);
-    if (this->collisions != 0) {
+    if (this->collisions != COL_NONE) {
         DeleteThisEntity();
     }
     GetNextFrame(this);
@@ -78,28 +79,28 @@ bool32 sub_080ACB40(Entity* this) {
     Entity* tmp = ((Entity**)(r1_grandparent->myHeap))[7]->child;
 
     if (tmp != this && child == tmp->child) {
-        return 0;
+        return FALSE;
     }
 
     tmp = ((Entity**)(r1_grandparent->myHeap))[8]->child;
 
     if (tmp != this && child == tmp->child) {
-        return 0;
+        return FALSE;
     }
 
     tmp = ((Entity**)(r1_grandparent->myHeap))[9]->child;
 
     if (tmp != this && child == tmp->child) {
-        return 0;
+        return FALSE;
     }
 
     tmp = ((Entity**)(r1_grandparent->myHeap))[10]->child;
 
     if (tmp != this && child == tmp->child) {
-        return 0;
+        return FALSE;
     }
 
-    return 1;
+    return TRUE;
 }
 
 void sub_080ACB90(Entity* this) {
diff --git a/src/projectile/winder.c b/src/projectile/winder.c
index ae1cb901..d15ce8a0 100644
--- a/src/projectile/winder.c
+++ b/src/projectile/winder.c
@@ -1,118 +1,133 @@
+#define NENT_DEPRECATED
+#include "collision.h"
 #include "entity.h"
 #include "asm.h"
 #include "functions.h"
 #include "common.h"
 #include "projectile.h"
+#include "projectile/winder.h"
 
-extern void (*const Winder_Actions[])(Entity*);
 extern s16 gUnk_080B4488[];
-static const u8 gUnk_0812A6BC[];
-static const u16 gUnk_0812A6C4[];
 
-void sub_080AB9DC(Entity*);
-bool32 sub_080AB9FC(Entity* this, u32 param_1);
+typedef enum {
+    /* 0 */ WINDER_TYPE_HEAD,
+    /* 4 */ WINDER_TYPE_TAIL = 4,
+} WinderType;
 
-void Winder(Entity* this) {
-    Winder_Actions[this->action](this);
-    sub_080AB9DC(this);
+void Winder_Init(WinderEntity* this);
+void Winder_Move(WinderEntity* this);
+
+void Winder_SetPositions(WinderEntity*);
+bool32 Winder_CheckForRailings(WinderEntity* this, u32 dir);
+
+void Winder(Entity* thisx) {
+    static void (*const Winder_Actions[])(WinderEntity*) = {
+        Winder_Init,
+        Winder_Move,
+    };
+    WinderEntity* this = (WinderEntity*)thisx;
+
+    Winder_Actions[super->action](this);
+    Winder_SetPositions(this);
 }
 
-void Winder_Init(Entity* this) {
-    Entity* entity;
-    u16* puVar3;
-    s32 index;
+void Winder_Init(WinderEntity* this) {
+    Entity* nextSegment;
+    u16* posPtr;
+    s32 i;
 
-    this->action += 1;
-    this->speed = 0x140;
-    this->z.WORD = 0;
-    if (this->type == 0) {
-        this->direction = Random() & 0x18;
-        this->parent = this;
+    super->action++;
+    super->speed = 0x140;
+    super->z.WORD = 0;
+    if (super->type == 0) {
+        super->direction = Random() & 0x18;
+        super->parent = super;
     }
-    InitializeAnimation(this, 0);
-    if (this->type < 4) {
-        entity = CreateProjectile(WINDER);
-        entity->type = this->type + 1;
-        entity->parent = this->parent;
-        entity->child = this;
-        CopyPosition(this, entity);
+    InitializeAnimation(super, 0);
+    if (super->type < WINDER_TYPE_TAIL) {
+        nextSegment = CreateProjectile(WINDER);
+        nextSegment->type = super->type + 1;
+        nextSegment->parent = super->parent;
+        nextSegment->child = super;
+        CopyPosition(super, nextSegment);
     }
 
-    puVar3 = &this->field_0x68.HWORD;
-    for (index = 7; index >= 0; --index) {
-        *puVar3 = this->x.HALF.HI;
-        puVar3 += 1;
-        *puVar3 = this->y.HALF.HI;
-        puVar3 += 1;
+    posPtr = this->positions;
+    for (i = 0; i < WINDER_NUM_SEGMENTS; i++) {
+        *posPtr++ = super->x.HALF.HI;
+        *posPtr++ = super->y.HALF.HI;
     }
 }
 
-void sub_080AB950(Entity* this) {
-    if (this->type == 0) {
+void Winder_Move(WinderEntity* this) {
+    static const u8 nextDirections[][2] = {
+        { DirectionEast, DirectionWest },
+        { DirectionNorth, DirectionSouth },
+        { DirectionEast, DirectionWest },
+        { DirectionNorth, DirectionSouth },
+    };
+    static const u16 collisionChecks[] = { COL_NORTH_ANY, COL_EAST_ANY, COL_SOUTH_ANY, COL_WEST_ANY };
+
+    if (super->type == WINDER_TYPE_HEAD) {
         u8 dir;
-        ProcessMovement0(this);
-        dir = this->direction >> 3;
-        if (((gUnk_0812A6C4)[dir] & this->collisions) || sub_080AB9FC(this, this->direction)) {
-            this->direction = gUnk_0812A6BC[(Random() & 0x1) + (dir << 1)];
+
+        ProcessMovement0(super);
+
+        dir = super->direction >> 3;
+        if ((collisionChecks[dir] & super->collisions) || Winder_CheckForRailings(this, super->direction)) {
+            super->direction = nextDirections[dir][Random() & 0x1];
         }
     } else {
-        Entity* child;
+        WinderEntity* child;
 
-        if (this->parent == NULL) {
+        if (super->parent == NULL) {
             DeleteThisEntity();
         }
 
-        if (this->parent->next == NULL) {
+        if (super->parent->next == NULL) {
             DeleteThisEntity();
         }
 
-        child = this->child;
-        if (child && child->next) {
-            this->x.HALF.HI = child->field_0x68.HWORD;
-            this->y.HALF.HI = child->field_0x6a.HWORD;
+        child = (WinderEntity*)super->child;
+        if ((child != NULL) && (child->base.next != NULL)) {
+            super->x.HALF.HI = child->positions[0];
+            super->y.HALF.HI = child->positions[1];
         } else {
             DeleteThisEntity();
         }
     }
 
-    GetNextFrame(this);
+    GetNextFrame(super);
 }
 
-void sub_080AB9DC(Entity* this) {
-    MemCopy(&this->field_0x6c, &this->field_0x68, 0x1c);
-    this->cutsceneBeh.HWORD = this->x.HALF.HI;
-    this->field_0x86.HWORD = this->y.HALF.HI;
+void Winder_SetPositions(WinderEntity* this) {
+    //! @bug Undefined behaviour for source and destination to overlap in a memcpy. In this case it is okay because the
+    //! copy will always be sequential, incremental and in chunks of <= 4 bytes, so it will copy the contents of
+    //! positions[0] and positions[1] to positions[2] and positions[3], then that of positions[2] and positions[3] to
+    //! positions[4] and positions[5], and so on. A safer way to do this would be a manual loop as in Winder_Move.
+    MemCopy(&this->positions[2], &this->positions[0], sizeof(u16) * (ARRAY_COUNT(this->positions) - 2));
+
+    this->positions[2 * (WINDER_NUM_SEGMENTS - 1)] = super->x.HALF.HI;
+    this->positions[2 * (WINDER_NUM_SEGMENTS - 1) + 1] = super->y.HALF.HI;
 }
 
-bool32 sub_080AB9FC(Entity* this, u32 dir) {
+bool32 Winder_CheckForRailings(WinderEntity* this, u32 dir) {
+    u32 tile;
     u32 val;
-    LayerStruct* layer = GetLayerByIndex(this->collisionLayer);
-    u32 tmp;
-    val = (((this->x.HALF.HI - gRoomControls.origin_x) >> 4) & 0x3f) |
-          ((((this->y.HALF.HI - gRoomControls.origin_y) >> 4) & 0x3f) << 6);
-    val += gUnk_080B4488[dir >> 3];
-    tmp = layer->collisionData[val];
-    if (tmp <= 0x1f) {
-        return 0;
+    LayerStruct* layer = GetLayerByIndex(super->collisionLayer);
+    u32 collisionData;
+
+    tile = TILE(super->x.HALF.HI, super->y.HALF.HI);
+    tile += gUnk_080B4488[dir >> 3];
+    collisionData = layer->collisionData[tile];
+
+    if (collisionData <= 0x1F) {
+        return FALSE;
     }
 
-    if (tmp > 0x3f) {
-        return 0;
+    if (collisionData > 0x3F) {
+        return FALSE;
     }
 
-    return 1;
+    return TRUE;
 }
-
-void (*const Winder_Actions[])(Entity*) = {
-    Winder_Init,
-    sub_080AB950,
-};
-const u8 gUnk_0812A6BC[] = {
-    8, 24, 0, 16, 8, 24, 0, 16,
-};
-const u16 gUnk_0812A6C4[] = {
-    0xe,
-    0xe000,
-    0xe0,
-    0xe00,
-};