Project Context

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trigger: always_on
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## Project Context

You are working with a disassembled Windows 95 release of "My Teacher is an Alien" (1997), a point-and-click game developed by 7th Level.

- Original codebase: C++
- Compiler: Microsoft Visual C++ 4 (already set up)
- Many classes and methods have been partially identified and renamed.
- Several functions still have unknown ownership (class/function mapping is incomplete).
- Decompiled code exists, but it may be incorrect or mislabeled.

IMPORTANT: The assembly output and the extracted strings are the *only* source of truth. Decompiled code can be a good hint, but is NOT authoritative.

The demo assembly is in `code` and the full game assembly is in `code-full`. For the reimplemented code, `src` is the full game (primary) and `src-demo` is the demo.

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## Absolute Rules (Do Not Violate)

- DO NOT remove or modify existing functions or classes, especially those identified by a comment header containing a function address.
- DO NOT remove existing code.
- DO NOT change calling conventions (class methods must remain __thiscall; do not explicitly specify it).
- DO NOT add:
  - inline assembly
  - dummy variables
  - don't add internal class functions, excepts you have evidence from the assembly
  - vtable fields or manual vtable handling
  - unions or substructures
  - .c files
- DO NOT show the final code once you finish.
- If you are out of ideas, stop. do not break any rules.
- Do not use this-> in the code. Use the class name instead.

### Other important rules
- Do NOT add explit try/catch/finally. The compiler added SEH in a number of functions, when some conditions are met. Check the exceptions.md file for more details.
- If possible, use high level fields to access the members of the class. If you do not know the name, use generic names like field_0, field_4, etc (until we have a better name).
- In some cases, some you can try to inline small functions if you have evidence in the assembly (add the code directly in the .h and the compiler will inline it if possible).

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## Your Task

Before starting:
1. Review all existing files.
2. Determine whether the target function belongs to an existing class.
3. If the function already exists, ensure it is properly used, not declared as extern.
4. Ensure naming is reasonable and consistent.

You may stop once assembly similarity is >= 90%.
If you give up, still provide the best possible implementation.

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## Workflow

### Locating a Function

To implement a function at a specific address (e.g. 0x418C70):

grep -r -i 418C70 code-full

Always use -i to ensure case-insensitive matches.

IMPORTANT: the assembly produced the compiler is saved `out/*.asm` but this is NOT the original implementation, but file produced by compiler directly from the C code. Use `binary-comp` commands to compare them. Same with the TEACHER.map file, this is *only* for the reimplemented code, not the original assembly.

### Compiling & Comparing Assembly

After implementing code in a file (e.g. Class::Name):

binary-comp compare --config config/binary-comp.json --target full Class::Name code-full/FUN_418C70.disassembled.txt

This shows compiler errors or the generated instruction diff.

## Required Files & Documentation

- src/map  
  Sorted address lists showing which functions are adjacent in the binary.

- code-full/strings.txt  
  Address-to-string mappings. Always review when strings appear.

- docs/game.txt  
  Gameplay description; useful for understanding puzzles and logic.

- docs/exceptions.md  
  Explains how MSVC compiles exceptions. Required reading if exception patterns are suspected.

- data/demo/mis  
  Game script files used to understand parsed data and class responsibilities.

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## Implementation Requirements

### Function Structure

- Define the class at the top of the file.
- Add this header before every reimplemented function:

/* Function start: 0x1234.. */

- Sort functions by address within each file.
  - MSVC emits functions in source order.
  - Ordering helps detect incorrect class ownership.

### Accuracy Constraints

- Preserve:
  - Local variable order
  - Field offsets
  - Stack layout
  - Jump types and order (jmp, jne, etc.)
- Assembly output must match stack usage as closely as possible.
- Keep code high-level, but faithful.

### Strings & Standard Functions

- Include full string literals as constants (no pointer aliases).
- If decompiled code calls _strcpy, use strcpy from the proper header.
- Standard functions (e.g. fsetpos) must be reviewed carefully to infer field types and meanings.
- You may use memcpy or strcpy only if they improve assembly matching via compiler inlining.

### External Functions

- If a function is referenced but not implemented (e.g. FUN_00123456), declare it as extern.
- Do not guess implementations.
- If ShowError is referenced, use the existing implementation.

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## Special Cases & Patterns

- Pattern:

local_X = unaff_FS_OFFSET;
local_u = 0xffffffff;

This usually indicates a SEH.

- The code will be compiled but not linked.
- Do not modify compiler flags in bin/compile.bat.

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## Important Notes

- ShowError is effectively no-return, but the compiler currently cannot optimize it as such.
- Do not use attributes or workarounds.
- This will be fixed later.

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## Final Reminder

If similarity is >= 90%, stop.
If you are stuck, stop.
Never break the rules above.