houmain/rect_pack

A library for packing rectangles to one or more sprite sheets/atlases with optional constraints.

Multi-sheet rectangle packing

A C++17 library for packing rectangles to one or more sprite sheets/atlases with optional constraints.

It is part of the spright project and utilizing Sean T. Barrett's Skyline and Jukka Jylänki's MaxRects packing algorithm implementations.

Simply pass your sheet constraints and the rectangle sizes to the pack function. It will return one or more sheets with rectangle positions. The id can be used to correlate in- and output (there are no rectangles for sizes which did not fit).

For now the header may serve as documentation:

rect_pack.h

#include <vector>

namespace rect_pack {

enum class Method {
  Best,
  Best_Skyline,
  Best_MaxRects,
  Skyline_BottomLeft,
  Skyline_BestFit,
  MaxRects_BestShortSideFit,
  MaxRects_BestLongSideFit,
  MaxRects_BestAreaFit,
  MaxRects_BottomLeftRule,
  MaxRects_ContactPointRule
};

struct Size {
  int id;
  int width;
  int height;
};

struct Rect {
  int id;
  int x;
  int y;
  int width;
  int height;
  bool rotated;
};

struct Sheet {
  int width;
  int height;
  std::vector<Rect> rects;
};

struct Settings {
  Method method;
  int max_sheets;
  bool power_of_two;
  bool square;
  bool allow_rotate;
  int align_width;
  int border_padding;
  int over_allocate;
  int min_width;
  int min_height;
  int max_width;
  int max_height;
};

std::vector<Sheet> pack(Settings settings, std::vector<Size> sizes);

} // namespace