# NodGL Documentation

**NodGL** is ModuOS's powerful graphics library for creating games and graphical applications!

## 📚 Documentation

### For Beginners
Start here if you're new to graphics programming:

1. **[Getting Started](Getting-Started.md)** - Your first NodGL program
2. **[Drawing Shapes](Drawing-Shapes.md)** - Rectangles, circles, lines, and more
3. **[Using Textures](Using-Textures.md)** - Images, sprites, and backbuffers
4. **[Handling Input](Handling-Input.md)** - Mouse and keyboard controls
5. **[Simple Examples](Simple-Examples.md)** - Complete programs to learn from

### Game Development
Want to make games? Check out **[Blit Engine](../Blit-Engine.md)** - a complete game framework built on NodGL!

Blit Engine is located in `EXTERNAL/Blit/` and includes:
- Complete 2D game framework
- Entity/sprite management
- BlitStudio visual editor
- Example games

### Advanced Topics
For experienced developers:

- **[NodGL API Reference](../NodGL-API.md)** - Complete function documentation
- **[Performance Tips](Performance-Tips.md)** - Make your programs faster
- **[3D Graphics](3D-Graphics.md)** - Basic 3D rendering techniques

## 🎮 What Can You Make?

- **Games** - Platformers, shooters, puzzle games
- **Graphics demos** - Fractals, animations, visualizations
- **GUI applications** - Calculators, paint programs, file browsers
- **Educational programs** - Interactive tutorials, simulations

## 🚀 Quick Start

```c
#include "NodGL.h"
#include "libc.h"

int md_main(long argc, char **argv) {
    // Create graphics device
    NodGL_Device device;
    NodGL_Context ctx;
    NodGL_CreateDevice(NodGL_FEATURE_LEVEL_1_0, &device, &ctx, NULL);
    
    // Clear screen to blue
    NodGL_ClearContext(ctx, NodGL_CLEAR_COLOR, 0xFF0000FF, 1.0f, 0);
    
    // Draw a red square
    NodGL_FillRectContext(ctx, 100, 100, 200, 200, 0xFFFF0000);
    
    // Show it
    NodGL_PresentContext(ctx, 1);
    
    // Wait
    for (volatile int i = 0; i < 5000000; i++);
    
    // Cleanup
    NodGL_ReleaseDevice(device);
    return 0;
}
```

## 💡 Key Concepts

### Device & Context
- **Device** - Represents your graphics hardware
- **Context** - Where you issue drawing commands

### Colors
Colors use ARGB format: `0xAARRGGBB`
- `0xFFFF0000` = Red
- `0xFF00FF00` = Green
- `0xFF0000FF` = Blue

### Frame Loop
Most programs follow this pattern:
```c
while (running) {
    // 1. Handle input
    // 2. Update game logic
    // 3. Clear screen
    // 4. Draw everything
    // 5. Present frame
}
```

## 🎯 Learning Path

**Absolute Beginner** (no graphics experience):
1. Read [Getting Started](Getting-Started.md)
2. Type out Example 1 from [Simple Examples](Simple-Examples.md)
3. Modify the colors and positions
4. Try [Drawing Shapes](Drawing-Shapes.md)

**Some C Experience**:
1. Skim [Getting Started](Getting-Started.md)
2. Read [Handling Input](Handling-Input.md)
3. Build the Pong game from [Simple Examples](Simple-Examples.md)
4. Start with the [Game Engine](Game-Engine.md)

**Experienced Programmer**:
1. Check [NodGL API Reference](../NodGL-API.md)
2. Look at [Game Engine](Game-Engine.md) source code
3. Read [Performance Tips](Performance-Tips.md)
4. Build something awesome!

## 📖 Additional Resources

- **Source Code** - All examples are in `/userland/` directory
- **Header File** - `NodGL.h` has all function signatures
- **Library** - `lib_NodGL.c` contains the implementation

## 🤝 Community

Share your NodGL creations! Check out what others have made:
- Snake game (`snakegfx.c`)
- Minesweeper (`minesgfx.c`)
- Calculator (`calcgfx.c`)
- Paint program (`paintgfx.c`)

## ⚡ Features

- **Hardware Acceleration** - Uses GPU when available
- **Simple API** - Easy to learn, hard to mess up
- **Fast** - Optimized for performance
- **Flexible** - From simple shapes to complex 3D
- **Well Documented** - Lots of examples and guides

Start your journey: [Getting Started →](Getting-Started.md)