File size: 3,556 Bytes
ed63829 | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 | # Engine Initialization Chain
## Overview
WA.exe initializes the engine through a chain of constructor calls that build
the DDGame monolith and its subsystems. The top-level entry is
`ConstructDDGameWrapper` which allocates DDGame and wires up all subsystems.
## Call Chain
```
WinMain / CRT startup (0x5D8B6C)
└─ ConstructDDGameWrapper (0x56DEF0)
├─ Allocates DDGameWrapper (vtable 0x66A30C)
├─ DDGame__Constructor (0x56E220)
│ ├─ Allocates 0x98B8 bytes for DDGame
│ ├─ DDDisplay__Init (0x569D00)
│ │ └─ Sets display mode, dimensions, palette, HWND
│ ├─ GfxHandler x2 (vtable 0x66B280, 0x19C bytes each)
│ ├─ Task state machines x5 (vtable 0x664118)
│ └─ Game state pointer at DDGame+0x24
├─ PCLandscape__Constructor (0x57ACB0)
│ ├─ vtable 0x66B208, parent = DDGame
│ ├─ Allocates terrain buffer (0x60000 bytes) at +0x8E8
│ ├─ Creates WaterEffect object (vtable 0x66B268) at +0xC8
│ ├─ Creates LandscapeShader (vtable 0x66B1DC) at +0x93C
│ └─ Loads Water.dir, Level.dir from data\Gfx\
├─ DSSound__Constructor (0x573D50)
│ ├─ vtable 0x66AF20
│ ├─ Master volume = Fixed(0x10000) = 1.0 at +0x8A4
│ └─ 500 sound channel slots
└─ OpenGLCPU__Constructor (0x5A0850) [conditional]
├─ vtable 0x6774C0, 0x48 bytes
├─ Width at +0x10, Height at +0x24
└─ OpenGL__Init (0x59F000) stores HDC/HGLRC in DDDisplay
```
## DDGameWrapper Layout
DDGameWrapper is a thin wrapper (~0x500 bytes) around DDGame:
| Offset | Field | Notes |
|--------|--------------------|------------------------------------|
| 0x000 | vtable | 0x66A30C |
| 0x488 | DDGame ptr | Allocated 0x98B8-byte object |
| 0x48C | DDGame secondary | Optional 0x2C-byte struct |
| 0x4C0 | GfxHandler 0 | 0x19C bytes, vtable 0x66B280 |
| 0x4C4 | GfxHandler 1 | Optional |
| 0x4C8 | GfxMode | Graphics mode flag |
| 0x4CC | PCLandscape | Pointer to landscape subsystem |
## DDGame Key Offsets
DDGame is a ~39KB (0x98B8 bytes) monolithic object. Known landmark fields:
| Offset | Field | Notes |
|--------|--------------------|------------------------------------|
| 0x0024 | game_state | Global game state pointer |
| 0x0028 | param | Constructor parameter |
| 0x11B0 | task_ptrs[5] | 5 task state machine pointers |
| 0x3548 | display_mode | Display mode pointer |
| 0x354C | display_width | Screen width |
| 0x3560 | display_center_x | Screen center X |
| 0x3564 | display_center_y | Screen center Y |
| 0x3578 | hwnd | Window handle |
| 0x358D | palette | 256-color palette (0x400 bytes) |
| 0x3D98 | gfx_objects[4] | Graphics object pointers |
## Ghidra Offset Convention
Ghidra's decompiler shows DWORD-indexed offsets for struct access:
- `param_1[0x122]` → byte offset 0x122 * 4 = **0x488**
- `param_1[0x133]` → byte offset 0x133 * 4 = **0x4CC**
- Always multiply DWORD index by 4 to get the true byte offset.
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