StbRectPackSharp

StbRectPackSharp is C# port of the stb_rect_pack.h, which is C library to pack rectangles on atlas.

Adding Reference

There are two ways of referencing StbRectPackSharp in the project:

1. Through nuget: https://www.nuget.org/packages/StbRectPackSharp/

2. As submodule:

   a. git submodule add https://github.com/rds1983/StbRectPackSharp.git

   b. Now there are two options:

   • Add src/StbRectPackSharp.csproj to the solution

   • Include *.cs from folder "src" directly in the project. In this case, it might make sense to add STBSHARP_INTERNAL build compilation symbol to the project, so StbRectPackSharp classes would become internal.

Usage

StbRectPackSharp exposes API similar to stb_rect_pack.h.

Also it has utility class Packer.

Sample usage code

    // Create packer with size 256x256
    Packer packer = new Packer(256, 256);
    
    // Pack a few rectangles
    // data1, data2, data3 are arbitrary user objects that will be stored within instances of PackRectangle class
    // PackRect returns either object of PackerRectangle class(packing was succesful) or null(no more place)
    packer.PackRect(10, 10, data1);
    packer.PackRect(15, 10, data2);
    packer.PackRect(2, 2, data3);
    
    // Enumerate packed rectangles
    foreach(PackerRectangle packRect in packer.PackRectangles)
    {
      // ...
    }

If there's no more space to fit the new rectangle, then PackRect method will return null.

It could be addressed by creating newer and bigger Packer.

I.e.

    PackerRectangle pr = packer.PackRect(800, 600, data4);
    
    // If pr is null, it means there's no place for the new rect
    // Double the size of the packer until the new rectangle will fit
    while(pr == null)
    {
      Packer newPacker = new Packer(packer.Width * 2, packer.Height * 2);
      
      // Place existing rectangles
      foreach(PackerRectangle existingRect in packer.PackRectangles)
      {
        newPacker.PackRect(existingRect.Width, existingRect.Height, existingRect.Data);
      }
      
      // Now dispose old packer and assign new one
      packer.Dispose();
      packer = newPacker;
      
      // Try to fit the rectangle again
      pr = packer.PackRect(800, 600, data4);
    }

See also sample VisualizePacking that uses above code.

License

Public Domain

Credits

https://github.com/nothings/stb