.github/prompts/new-game-state.prompt.md
---
description: "Scaffold a new game state: creates the .hpp and .cpp boilerplate for a sago::GameStateInterface subclass in src/"
argument-hint: "State class name (e.g. HighScoreState, OptionsState)"
agent: "agent"
---
Scaffold a new game state for this project. The class name is: **$ARGUMENTS**
## What to do
1. Derive the filename: class name as-is (e.g. `HighScoreState` → `HighScoreState.hpp` / `HighScoreState.cpp`). Files go in `src/`.
2. Create `src/<ClassName>.hpp` using this exact pattern (based on existing states like [src/CollectionListState.hpp](../src/CollectionListState.hpp)):
```cpp
/*
===========================================================================
* Sago Multi Scrambler Puzzle
Copyright (C) 2022-2026 Poul Sander
...license header...
===========================================================================
*/
#pragma once
#include "sago/GameStateInterface.hpp"
class <ClassName> : public sago::GameStateInterface {
public:
<ClassName>();
<ClassName>(const <ClassName>& orig) = delete;
virtual ~<ClassName>();
bool IsActive() override;
void ProcessInput(const SDL_Event& event, bool& processed) override;
void Draw(SDL_Renderer* target) override;
void Update() override;
private:
bool isActive = true;
};
```
3. Create `src/<ClassName>.cpp` using this exact pattern (based on [src/CollectionListState.cpp](../src/CollectionListState.cpp)):
```cpp
/*
===========================================================================
* Sago Multi Scrambler Puzzle
Copyright (C) 2022-2026 Poul Sander
...license header...
===========================================================================
*/
#include "<ClassName>.hpp"
#include "sago_common.hpp"
#include "globals.hpp"
#include "SagoImGui.hpp"
<ClassName>::<ClassName>() {
}
<ClassName>::~<ClassName>() {
}
bool <ClassName>::IsActive() {
return isActive;
}
void <ClassName>::ProcessInput(const SDL_Event& event, bool& processed) {
ImGui_ImplSDL2_ProcessEvent(&event);
if (event.type == SDL_KEYDOWN) {
if (event.key.keysym.sym == SDLK_ESCAPE) {
isActive = false;
processed = true;
}
}
}
void <ClassName>::Draw(SDL_Renderer* target) {
// TODO: implement drawing
}
void <ClassName>::Update() {
// TODO: implement per-frame logic
}
```
4. **Do not** wire the state into `src/sago_multi_scrambler_puzzle2.cpp` unless the user explicitly asks — just create the two files.
5. After creating the files, print:
- The two file paths created
- A snippet showing how to launch the state from `main()`:
```cpp
#include "<ClassName>.hpp"
// ...
InitGame();
<ClassName> state;
RunGameState(state);
UninitGame();
```
## Key rules
- Always `#include "SagoImGui.hpp"` in the .cpp so `ImGui_ImplSDL2_ProcessEvent` is available — forgetting this is the most common compile error.
- Use tabs for indentation (matches the existing codebase style).
- `isActive = false` is the only way to exit a state (pops from the game loop in `RunGameState()`).
- Access renderer output size via `globalData.xsize` / `globalData.ysize` (not SDL_GetWindowSize).
- See [.github/copilot-instructions.md](../copilot-instructions.md) → "Adding a New Game State" for full context.