bluegrass

Blue noise "textures," both original and pseudo-randomly editable, in pure Java.

You may want to use this code to generate areas of blue noise textures or blue noise point sets without any image dependencies or any need for visuals at all. This library has the currently-rare feature that any of the blue noise textures in a group of 64 can tile with any other textures from that group; I call this "omni-tiling." The getSeeded() and getSeededTriangular() methods in BlueNoise provide an aperiodic tiling of the 2D plane with varied blue noise, with the exact choices of what textures are used affected by a seed. See Alan Wolfe's blog for an introduction to blue noise, if you're lost here. Blue noise point sets are quite useful for placing objects and terrain features in natural ways, not to mention a primary use they have in dithering graphics.

This provides 64 uniform blue noise textures and 64 triangular-mapped blue noise textures, each 64x64, in code. You can use these as blue noise point samples by placing a point where a particular value is less than some threshold, where the lowest values equal -128 and all values are less than 128.

All the API docs are in the one file's class documentation, and are also in methods docs.

The code here is straightforward to use as a library, but it can be quite frustrating to copy the code into your own project by hand because of encoding issues. So, even though you could copy BlueNoise.java into your code, unless it goes just right... the encoding used by some large Strings could be wrong, and the blue noise textures would be incorrect. That's why I encourage using a dependency manager like Gradle or Maven here.

The current version is 0.2.2; it should be available on Maven Central using:

• Gradle: implementation "com.github.tommyettinger:bluegrass:0.2.2" (may need api instead of implementation).
• Maven:

<dependency>
  <groupId>com.github.tommyettinger</groupId>
  <artifactId>bluegrass</artifactId>
  <version>0.2.2</version>
</dependency>

If Maven Central isn't working, try JitPack.

Major changes are expected to be quite rare; if something is added, the rest will probably stay as it is. Some major changes applied in version 0.2.0, where the omni-tiling blue noise was added, and some smaller ones changed the triangular-mapped blue noise in 0.2.1 (improving its range of values). There is a 0.2.2 release, but it's exactly the same as 0.2.1 (there are only some tiny internal changes, like the Gradle version used within the library). Using 0.2.1 is fine, but because automated updates may encourage moving to 0.2.2, and because switching to 0.2.2 won't change anything, you can update if or when you want.