Task Hierarchy - Worms Armageddon 3.8.1

Overview

WA uses a hierarchical task/entity system. All game objects inherit from CTask, which forms a tree via parent/children pointers. Tasks communicate through a message passing system (see TaskMessage enum).

Class Hierarchy

CTask (base)                    vtable: 0x669F8C    ctor: 0x5625A0
├── CGameTask                   vtable: 0x6641F8    ctor: 0x4FED50
│   ├── CTaskWorm                                    ctor: 0x50BFB0
│   ├── CTaskOldWorm                                 ctor: 0x51FEB0
│   ├── CTaskMissile                                 ctor: 0x507D10
│   ├── CTaskArrow                                   ctor: 0x4FE130
│   ├── CTaskMine                                    ctor: 0x506660
│   ├── CTaskCanister                                ctor: 0x501A80
│   ├── CTaskCrate                                   ctor: 0x502490
│   ├── CTaskOilDrum                                 ctor: 0x504AF0
│   ├── CTaskCross                                   ctor: 0x5045C0
│   └── CTaskLand                                    ctor: 0x505440
├── CTaskFilter                                      ctor: 0x54F3D0
├── CTaskTeam                                        ctor: 0x555BB0
├── CTaskTurnGame                                    ctor: 0x55B280
├── CTaskAirStrike                                   ctor: 0x5553C0
├── CTaskDirt                                        ctor: 0x54EDC0
├── CTaskFlame                                       ctor: 0x54F0F0
├── CTaskFire                                        ctor: 0x54F4C0
├── CTaskGirder (was CTaskFireBall)                   ctor: 0x550890
├── CTaskGas                                         ctor: 0x554750
├── CTaskSmoke                                       ctor: 0x5551D0
├── CTaskCloud                                       ctor: 0x5482E0
├── CTaskSeaBubble                                   ctor: 0x554FE0
├── CTaskScoreBubble                                 ctor: 0x554CA0
├── CTaskCPU                                         ctor: 0x5485D0
└── CTaskSpriteAnimation                             ctor: 0x5466C0

Note: Not all tasks are confirmed to inherit from CGameTask. The hierarchy above needs further verification via Ghidra analysis of each constructor.

CTask vtable (0x669F8C)

Index	Offset	Address	Name (from wkJellyWorm)
0	0x00	0x562710	vtable0 (init?)
1	0x04	0x562620	Free
2	0x08	0x562F30	HandleMessage
3	0x0C	0x5613D0	unknown
4	0x10	0x5613D0	unknown (=vt3)
5	0x14	0x562FA0	unknown
6	0x18	0x563000	unknown
7	0x1C	0x563210	ProcessFrame

Note: wkJellyWorm says 7 methods but we see 8 entries. The 8th may be the start of CGameTask's extended vtable region, or the count was off by one.

CGameTask vtable (0x6641F8)

First 3 entries override CTask:

Index	Offset	Address	Name
0	0x00	0x4FF1C0	vtable0 override
1	0x04	0x4FEF10	Free override
2	0x08	0x4FF280	HandleMessage override
3	0x0C	0x5613D0	(inherited from CTask)
4	0x10	0x5613D0	(inherited from CTask)
5	0x14	0x562FA0	(inherited from CTask)
6	0x18	0x563000	(inherited from CTask)
7	0x1C	0x4FF720	CGameTask-specific
8	0x20	0x4FFED0	CGameTask-specific
9	0x24	0x500070	CGameTask-specific
10	0x28	0x500080	CGameTask-specific
11	0x2C	0x5000E0	CGameTask-specific
12	0x30	0x500380	CGameTask-specific
13	0x34	0x500360	CGameTask-specific
14	0x38	0x4FE060	CGameTask-specific
15	0x3C	0x500CC0	CGameTask-specific
16	0x40	0x592A50	CGameTask-specific
17	0x44	0x500090	CGameTask-specific
18	0x48	0x545780	CGameTask-specific
19	0x4C	0x4AA060	CGameTask-specific

CGameTask also has a secondary vtable at object offset 0xE8, pointing to 0x669CF8.

CTask memory layout (0x30 bytes)

Offset  Size  Field
0x00    4     vtable pointer
0x04    4     parent (CTask*)
0x08    4     unknown (set to 0x10 in ctor)
0x0C    4     children.max_size (init 0)
0x10    4     children.unk4 (init 0)
0x14    4     children.size
0x18    4     children.data_ptr (allocated 0x60 bytes, zeroed 0x40)
0x1C    4     children.hash_list
0x20    4     class_type (ClassType enum)
0x24    12    unknown padding

CGameTask memory layout (0xEC bytes)

Extends CTask at offset 0x00. Key fields discovered from constructor:

Offset  Size  Field
0x00    0x30  CTask base
0x20    4     class_type (set to 3 = GameCollisionTask in ctor)
0x2C    4     param_3 from ctor
0x30    4     param_3 (weapon id?)
0x38    4     param_4
0x3C    4     unknown
...
0x4C    4     = 0x10000 (Fixed 1.0)
0x50    4     = 0x100000 (Fixed 16.0)
0x54    4     = 0xCCCC (Fixed ~0.8)
0x58    4     = 0x10000 (Fixed 1.0)
0x5C    4     = 0
0x60    4     = 0x10000 (Fixed 1.0)
0x64    4     = 0x20000 (Fixed 2.0)
0x68    4     = 0xF333 (Fixed ~0.95)
...
0x84    4     pos_x (Fixed)
0x88    4     pos_y (Fixed)
0x8C    4     = 0x10000 (Fixed 1.0, scale?)
0x90    4     speed_x (Fixed)
0x94    4     speed_y (Fixed)
...
0xCC    4     = 0x10000 (Fixed 1.0)
0xD8    1     byte flag (init 0)
0xD9    1     byte flag (init 0)
0xE0    4     unknown (init 0)
0xE4    4     unknown (init 0)
0xDC    4     unknown (init 0)
0xE8    4     secondary vtable pointer -> 0x669CF8

Physics defaults from CGameTask constructor

Several fixed-point constants are set in the constructor, likely physics defaults:

0x10000 = 1.0 (appears at many offsets — scale factors, gravity?)
0x100000 = 16.0 (mass? terminal velocity?)
0xCCCC ≈ 0.8 (friction? damping?)
0x20000 = 2.0
0xF333 ≈ 0.95 (air resistance?)
0x3333 ≈ 0.2
0x4CCC ≈ 0.3
0xFEB8 ≈ 0.995
0x9999 ≈ 0.6
0x3AE1 ≈ 0.23
0xFC000000 = -67108864 (large negative, possibly a boundary?)