# Chroma

Super-fast, lightweight and efficient wallpaper daemon for Wayland compositors
with multi-monitor & hotplugging support. Born from my woes with Hyprpaper,
swaybg and most ironically _SWWW_ (now called AWWW for some awful reason), which
turned out to be NOT a solution to my Wayland wallpaper woes. Smaller, faster,
cleaner and somehow still more feature-rich...

## Features

Chroma combines simplicity with powerful performance optimizations and
comprehensive monitor management. Here's what makes Chroma stand out:

### Core Functionality

- **Memory-efficient**: Smart caching and resource management
  - **Optimized rendering**: VBO dirty flagging and reduced GPU overhead
- **Multi-monitor support**: Automatically detects and manages wallpapers for
  all connected displays
  - **Configurable scaling modes**: Fill, fit, stretch, and center options per
    monitor
- **Hotplugging**: Dynamically handles monitor connection/disconnection events
- **Per-output configuration**: Set different wallpapers and settings for each
  monitor
  - **Global and per-output settings**: Override defaults for specific monitors
  - **Performance tuning**: Adjustable downsampling limits and quality
    thresholds
- **Multiple image formats**: Supports JPEG, PNG, BMP, TGA, PSD, GIF, HDR, PIC,
  PPM, PGM
- **EGL/OpenGL rendering**: Hardware-accelerated wallpaper rendering
- **Configuration file support**: Easy setup with INI-style config files
- **Signal handling**: Graceful shutdown and configuration reload (SIGHUP)
- **Intelligent downsampling**: Automatically reduces large image resolution to
  save memory (up to 94% memory savings for 8K images)
- **Advanced filtering**: Nearest, linear, bilinear, and trilinear filtering
  options

## Usage

### Requirements

#### Dependencies

- **Wayland**: wayland-client, wayland-egl
- **Graphics**: EGL, OpenGL
- **System**: glibc, libm, libdl

#### Development Dependencies

- GCC or Clang compiler
- Make
- pkg-config
- Wayland development headers
- EGL/OpenGL development headers

### Building

#### Quick Build

```bash
# Check dependencies
make check-deps

# Build the daemon
make

# Or build debug version
make debug
```

### Installation

```bash
# Install to /usr/local (default)
sudo make install

# Install to /usr
sudo make PREFIX=/usr install

# Create systemd service file
make systemd-service

# Create sample configuration
make sample-config
```

### Configuration

#### Configuration File

Chroma looks for configuration files in this order:

1. `~/.config/chroma/chroma.conf`
2. `$XDG_CONFIG_HOME/chroma/chroma.conf`
3. `./chroma.conf` (current directory)

#### Sample Configuration

```ini
# Default wallpaper for outputs without specific mapping
default_image = ~/.config/chroma/default.jpg

# Output-specific wallpapers
# Format: output.OUTPUT_NAME = /path/to/image.jpg
output.DP-1 = ~/Pictures/monitor1.jpg
output.DP-2 = ~/Pictures/monitor2.png
output.HDMI-A-1 = ~/Pictures/hdmi_wallpaper.jpg
```

### Finding Output Names

Use `wlr-randr` or similar tools to find your output names:

```bash
wlr-randr
```

### Command Line Options

```plaintext
Usage: chroma [OPTIONS]

Options:
  -c, --config FILE    Configuration file path
  -d, --daemon         Run as daemon
  -v, --verbose        Verbose logging
  -h, --help          Show help
  --version           Show version information

Examples:
  chroma -c ~/.config/chroma/chroma.conf
  chroma --daemon
```

### Running Manually

```bash
# Run in foreground
chroma

# Run as daemon
chroma --daemon

# Use custom config
chroma -c /path/to/config.conf
```

### Systemd Service

```bash
# Enable and start the service
systemctl --user enable chroma.service
systemctl --user start chroma.service

# Check status
systemctl --user status chroma.service

# View logs
journalctl --user -u chroma.service -f

# Reload configuration
systemctl --user reload chroma.service
```

### Auto-start with Desktop Session

```bash
# Enable the service for auto-start
systemctl --user enable chroma.service

# The service will start automatically with your graphical session
```

### Supported Wayland Compositors

Chroma works with any Wayland compositor that supports:

- `wl_compositor` interface
- `wl_output` interface
- EGL window surface creation

Tested only on Hyprland.

## Development

### Building Debug Version

```bash
make debug
```

### Code Formatting

```bash
make format  # requires clang-format
```

### Static Analysis

```bash
make analyze  # requires cppcheck
```

## Contributing

1. Fork the repository
2. Create a feature branch
3. Make your changes
4. Test thoroughly
5. Submit a pull request

### Code Style

- C11 standard
- 2-space indentation
- No tabs (except for the Makefile, obviously)
- Function names: `chroma_function_name`
- Constants: `CHROMA_CONSTANT_NAME`

## License

<!--markdownlint-disable MD059 -->

This project is made available under Mozilla Public License (MPL) version 2.0.
See [LICENSE](LICENSE) for more details on the exact conditions. An online copy
is provided [here](https://www.mozilla.org/en-US/MPL/2.0/).

<!--markdownlint-enable MD059 -->