# Game Boy Development Progress

## Recent Achievements (November 2025)

### 🎯 KidLisp Compiler - Complete with Splash Screen ✅
**Date:** November 18, 2025

Built a complete KidLisp → Game Boy ROM compiler with custom splash screens!

**Syntax:**
```kidlisp
wipe black
ink white
line 50 50 100 100
box 10 10 70 70
circle 80 80 30
melody "ceg"
```

**Features:**
- Simple command-per-line format (no s-expressions)
- Graphics commands: `wipe`, `ink`, `line`, `box`, `circle`
- Custom splash screen for every ROM with:
  - AESTHETIC.COMPUTER branding
  - ROM name display
  - Source code listing (auto-truncated)
  - 1px progress bar animation (160 frames)
  - Auto-start (no button press needed)
- Music: `melody "notes"` with direct sound register control
- Full pipeline: `.lisp` → C → GBDK → `.gb` ROM
- Integrated build system
- Browser testing: `ac gameboy~romname`

**Technical:**
- Compiler: Node.js (`kidlisp-to-gb.mjs`)
- Graphics: GBDK drawing.h (line, box, circle primitives)
- Color inversion mapping: KidLisp black → GB WHITE (0), KidLisp white → GB BLACK (3)
- Scene transition: Background tile map clearing critical for text→graphics mode
- Music: Direct GB sound registers (NR10-NR14, Channel 1 square wave)
- Output: 32KB DMG ROM

**Critical Bug Fix:**
- **Problem**: White screen after splash instead of KidLisp graphics
- **Cause**: gprintf() uses background tile map, conflicts with drawing.h functions
- **Solution**: Clear BG tile map with `fill_bkg_rect(0, 0, 20, 18, 0)` after splash
- **Pattern learned from**: GBDK examples (hblank_copy, dscan, galaxy)

**Files:**
- `compiler/kidlisp-to-gb.mjs` - Main compiler
- `examples/linetest.lisp` - Simple line test
- `examples/boxtest.lisp` - Box drawing test
- `examples/shapes.lisp` - Combined shapes demo
- `examples/lines.lisp` - Grid pattern demo
- `KIDLISP-COMPILER.md` - Documentation

**Dependencies:**
- GBDK with drawing.h (line, box, circle)
- RGBDS (already in Dockerfile)
- Replaced hUGEDriver with custom sound system

### 🎵 Melody ROM Development ✅
- **Status**: COMPLETE - Fully functional Game Boy ROM
- **Features**:
  - Hardware-accurate 4-channel audio system
  - Real-time animation synchronized to music
  - Custom sprite graphics (melody notes, staff lines) 
  - Interactive melody visualization
  - Works on real hardware and emulators

### 🛠️ Build System & Tooling ✅
- **Auto-launch integration**: ROMs automatically trigger `ac gameboy~melody` after build
- **Cross-platform builds**: Fish and Bash scripts for Linux/macOS/Windows
- **GBDK integration**: Full C development workflow
- **Sprite generation**: Automated sprite compilation pipeline

### 🎯 VSCode Extension Integration ✅ 
- **Implemented Option E**: Extension now connects as WebSocket client to session server
- **Published v1.194.0**: Live on VS Code Marketplace
- **Eliminates initialization delays**: Panel loads directly with piece URL
- **Robust ac command**: Shows connection status, works in all environments

### 🎨 Graphics & Animation System ✅
- **Sprite management**: Efficient tile loading and animation
- **VBlank synchronization**: Smooth 60 FPS animation
- **Hardware optimization**: Uses Game Boy's native capabilities
- **Visual feedback**: Real-time response to audio channels

## Current Status

### ✅ Completed
1. **Melody ROM** - Full interactive music visualization
2. **Build toolchain** - Automated compilation and testing  
3. **VSCode integration** - Seamless development workflow
4. **Audio system** - 4-channel Game Boy sound
5. **Graphics pipeline** - Sprite rendering and animation
6. **ac command robustness** - WebSocket-based architecture

### 🔄 Active Development
- KidLisp compiler fully functional with splash screens
- All graphics primitives working (line, box, circle)
- Custom sound system operational
- Scene transition bugs resolved

### 🎯 Next Phase: Advanced KidLisp Features
- More graphics primitives (filled shapes, pixels, text)
- Input handling (buttons, movement)
- Sprite support
- Background scrolling
- Advanced sound (multiple channels, effects)

## Architecture Insights

### Audio-Visual Synchronization
The melody ROM demonstrates perfect sync between Game Boy's 4-channel audio and visual animation through:
- VBlank interrupt handling
- Hardware register monitoring  
- Efficient sprite management
- Real-time channel visualization

### Development Workflow
```
Edit C code → Build (build.sh) → Auto-launch (ac gameboy~melody) → VSCode panel opens → Test on hardware
```

This creates a seamless edit-compile-test cycle for Game Boy development.

## Files Structure
```
kidlisp-gameboy/
├── src/melody_main.c           # Main ROM logic
├── src/melody_sprites.c        # Sprite definitions  
├── src/melody_audio.c          # Audio system
├── build.sh                    # Build automation
├── melody.gb                   # Final ROM output
└── PROGRESS.md                 # This file
```

## Key Learnings

1. **Hardware constraints drive optimization** - Game Boy's limitations force elegant solutions
2. **VBlank is critical** - All graphics updates must respect 60 FPS timing
3. **WebSocket architecture** - Direct extension communication is superior to CLI workarounds  
4. **Build automation** - Seamless tooling makes iteration fast and enjoyable

## Future Roadmap

### Short Term
- [ ] KidLisp parser implementation
- [ ] Basic graphics primitives compiler
- [ ] Live coding integration

### Long Term  
- [ ] Advanced Game Boy features (scrolling, sprites, etc.)
- [ ] Multi-ROM project support
- [ ] Hardware debugging tools
- [ ] Community ROM sharing platform

---

**Last Updated**: November 18, 2025  
**Status**: KidLisp compiler complete with splash screens, all core features working