# Decimal Day Progress Watchface - Implementation Plan

**Note:** This watchface implements French Revolutionary/Decimal Time, not "metric time" which is a different concept.

## Concept Overview

Create a joke/novelty Garmin watchface that displays time as a decimal day progress meter instead of traditional 12/24 hour format.

### Key Features
- **10 equal divisions** on the watchface (instead of 12 hours)
- **Single hand** showing day progress as a decimal (0-10)
- **Analog display** with tick marks at each decimal position
- **Optional digital readout** showing exact decimal time

### Time Mapping
- Midnight (00:00) → 0.0
- 6:00 AM → 2.5
- Noon (12:00) → 5.0
- 6:00 PM → 7.5
- Midnight (24:00) → 10.0 (wraps to 0)

## Technical Implementation

### Project Structure
```
MetricWatchFace/
├── manifest.xml                    # App metadata and device compatibility
├── monkey.jungle                   # Build configuration
├── resources/
│   ├── drawables/
│   │   └── drawables.xml          # Layout definitions
│   ├── strings/
│   │   └── strings.xml            # Localization
│   └── settings/
│       └── settings.xml           # User settings (if needed)
└── source/
    ├── DecimalWatchFaceApp.mc     # Application entry point
    └── DecimalWatchFaceView.mc    # Main watchface view logic
```

### Core Calculation

**Decimal Time Formula:**
```
decimalTime = (currentHour + currentMinute/60.0 + currentSecond/3600.0) / 24.0 * 10.0
```

**Hand Angle Calculation:**
```
handAngle = (decimalTime / 10.0) * 360.0 - 90.0  // -90 to start at top (12 o'clock position)
```

### Drawing Components

1. **Watchface Circle**
   - Use `drawCircle()` or `drawArc()` for outline
   - Draw 10 tick marks at 36° intervals (360°/10)

2. **Decimal Markers**
   - Place numbers 0-9 around the perimeter
   - Position 0 at top (traditional 12 o'clock position)
   - Position 5 at bottom (traditional 6 o'clock position)

3. **Progress Hand**
   - Use `fillPolygon()` to draw a triangle/arrow hand
   - Calculate hand coordinates using trigonometry
   - Rotate based on current decimal time

4. **Digital Display** (optional)
   - Show exact decimal time (e.g., "3.47")
   - Position at center or bottom of face

### Key Methods

**DecimalWatchFaceView.mc:**
- `initialize()` - Set up initial state
- `onUpdate(dc)` - Main rendering method (called periodically)
- `computeDecimalTime()` - Calculate current decimal time
- `drawWatchFace(dc)` - Draw the analog face and markers
- `drawHand(dc, decimalTime)` - Draw the progress hand
- `drawDigitalTime(dc, decimalTime)` - Optional digital display

### Device Compatibility

Target devices:
- Fenix series (5, 6, 7)
- Forerunner series (245, 645, 945)
- Vivoactive series (3, 4)
- Other modern Garmin watches with Connect IQ support

Considerations:
- Handle different screen sizes/resolutions
- Support both round and semi-round displays
- Test with MIP and AMOLED displays

## Implementation Steps

1. **Project Setup**
   - Create manifest.xml with app metadata
   - Set up basic directory structure
   - Create application entry point

2. **Core Logic**
   - Implement decimal time calculation
   - Add time update handling
   - Create view class structure

3. **Rendering**
   - Draw watchface circle and divisions
   - Add decimal markers (0-9)
   - Implement hand rotation logic
   - Add digital display

4. **Testing & Refinement**
   - Test in simulator
   - Verify calculations at key times
   - Optimize drawing performance
   - Test on actual device if available

## Future Enhancements (Optional)

- Add date display
- Include battery indicator
- Show step count or other metrics
- Customizable colors via settings
- Alternative hand styles
- Animation effects

## References

- Garmin Connect IQ SDK Documentation
- Swiss Railway Clock example (analog implementation)
- Monkey C API reference for graphics primitives