Package micycle.pgs

Class PGS_Coloring

java.lang.Object
micycle.pgs.PGS_Coloring
public final class PGS_Coloring extends Object
Minimal colorings of meshes (or mesh-like shapes). It ensures that no two adjacent faces share the same color while also minimizing the total number of colors used.

This class differentiates between "conforming meshes" and "non-conforming meshes".

Conforming Meshes : Consist of adjacent cells that share edges and every pair of shared edges are identical, meaning they have the same coordinates. An example of a conforming mesh is a triangulation.
Non-Conforming Meshes : Consist of adjacent cells that share edges (i.e. edges may overlap) but adjacent edges do not necessarily have identical start and end coordinates.

For a non-conforming mesh, a pre-processing step called "noding" is required to split edges before coloring.
Since:
1.2.0
Author:
Michael Carleton

  • Nested Class Summary

    Nested Classes
    Modifier and Type
    Class
    Description
    static enum 
    PGS_Coloring.ColoringAlgorithm
    Specifies the algorithm/heuristic used by the underlying graph coloring process to find an approximate minimal coloring for mesh faces.

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    static long
    SEED
     

  • Method Summary

    Modifier and Type
    Method
    Description
    static Map<processing.core.PShape,Integer>
    colorMesh(Collection<processing.core.PShape> shapes, PGS_Coloring.ColoringAlgorithm coloringAlgorithm)
    Computes a coloring of the given mesh shape, returning a color class for each mesh face.
    static processing.core.PShape
    colorMesh(processing.core.PShape meshShape, int[] colorPalette)
    Computes a coloring of the given mesh shape using the default coloring algorithm (DBLAC) and applies the provided palette to its faces.
    static Map<processing.core.PShape,Integer>
    colorMesh(processing.core.PShape meshShape, PGS_Coloring.ColoringAlgorithm coloringAlgorithm)
    Computes a coloring of the given mesh shape, returning a color class for each mesh face.
    static processing.core.PShape
    colorMesh(processing.core.PShape shape, PGS_Coloring.ColoringAlgorithm coloringAlgorithm, int[] colorPalette)
    Computes a coloring of the given mesh shape and colors its faces using the colors provided.
    static processing.core.PShape
    colorMesh(processing.core.PShape shape, PGS_Coloring.ColoringAlgorithm coloringAlgorithm, String[] colorPalette)
    Computes a coloring of the given mesh shape and colors its faces using the colors provided.
    static processing.core.PShape
    colorNonMesh(processing.core.PShape meshShape, int[] colorPalette)
    Colors a non-conforming mesh-like PShape using the default coloring algorithm (DBLAC) and the provided palette.
    static Map<processing.core.PShape,Integer>
    colorNonMesh(processing.core.PShape shape, PGS_Coloring.ColoringAlgorithm coloringAlgorithm)
    Computes a coloring of the given non-conforming mesh shape, returning a color class for each face of the pre-processed (noded) mesh.
    static processing.core.PShape
    colorNonMesh(processing.core.PShape shape, PGS_Coloring.ColoringAlgorithm coloringAlgorithm, int[] colorPalette)
    Computes a coloring of the given non-conforming mesh shape and colors the faces of its noded representation using the colors provided.
    static processing.core.PShape
    colorNonMesh(processing.core.PShape shape, PGS_Coloring.ColoringAlgorithm coloringAlgorithm, String[] colorPalette)
    Computes a coloring of the given non-conforming mesh shape and colors the faces of its noded representation using the colors provided.

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

  • Field Details

    • SEED

      public static long SEED

  • Method Details

    • colorMesh

      public static Map<processing.core.PShape,Integer> colorMesh(processing.core.PShape meshShape, PGS_Coloring.ColoringAlgorithm coloringAlgorithm)
      Computes a coloring of the given mesh shape, returning a color class for each mesh face.
      Parameters:
      meshShape - a GROUP PShape, whose children constitute the faces of a conforming mesh
      coloringAlgorithm - coloring algorithm used to color the mesh
      Returns:
      a color-class map; a mapping of each mesh face (PShape) -> color class (integer)

    • colorMesh

      public static Map<processing.core.PShape,Integer> colorMesh(Collection<processing.core.PShape> shapes, PGS_Coloring.ColoringAlgorithm coloringAlgorithm)
      Computes a coloring of the given mesh shape, returning a color class for each mesh face.
      Parameters:
      shapes - a collection of shapes that constitute the faces of a conforming mesh
      coloringAlgorithm - coloring algorithm used to color the mesh
      Returns:
      a color-class map; a mapping of each mesh face (PShape) -> color class (integer)

    • colorMesh

      public static processing.core.PShape colorMesh(processing.core.PShape meshShape, int[] colorPalette)
      Computes a coloring of the given mesh shape using the default coloring algorithm (DBLAC) and applies the provided palette to its faces.

      This method mutates the fill colour of the input meshShape by setting the fill of each child face PShape. If the computed number of required colors exceeds the palette length.

      Parameters:
      meshShape - a GROUP PShape whose children constitute the faces of a conforming mesh
      colorPalette - the colors with which to color the mesh
      Returns:
      the input meshShape (whose faces have now been colored)
      See Also:

    • colorNonMesh

      public static processing.core.PShape colorNonMesh(processing.core.PShape meshShape, int[] colorPalette)
      Colors a non-conforming mesh-like PShape using the default coloring algorithm (DBLAC) and the provided palette.

      Unlike colorMesh(), this method is intended for inputs whose faces do not form a conforming planar mesh (e.g., adjacent faces may overlap, have T-junctions, or otherwise fail to share fully noded boundaries). The input is first converted to a noded (conforming) representation and the resulting faces are then colored.

      Parameters:
      meshShape - a GROUP PShape whose children are faces of a non-conforming mesh-like planar subdivision
      colorPalette - palette of colors used to fill the resulting noded faces
      Returns:
      a noded (conforming) GROUP PShape derived from meshShape, with its faces colored
      Since:
      2.2
      See Also:

    • colorMesh

      public static processing.core.PShape colorMesh(processing.core.PShape shape, PGS_Coloring.ColoringAlgorithm coloringAlgorithm, int[] colorPalette)
      Computes a coloring of the given mesh shape and colors its faces using the colors provided. This method mutates the fill colour of the input shape.
      Parameters:
      shape - a GROUP PShape, whose children constitute the faces of a conforming mesh
      coloringAlgorithm - coloring algorithm used to color the mesh
      colorPalette - the (integer) colors with which to color the mesh
      Returns:
      the input shape (whose faces have now been colored)

    • colorMesh

      public static processing.core.PShape colorMesh(processing.core.PShape shape, PGS_Coloring.ColoringAlgorithm coloringAlgorithm, String[] colorPalette)
      Computes a coloring of the given mesh shape and colors its faces using the colors provided. This method mutates the fill colour of the input shape.
      Parameters:
      shape - a GROUP PShape, whose children constitute the faces of a conforming mesh
      coloringAlgorithm - coloring algorithm used to color the mesh
      colorPalette - the string colors (e.g. "#FFFFFF", or "cba5e8") with which to color the mesh
      Returns:
      the input shape (whose faces have now been colored)

    • colorNonMesh

      public static Map<processing.core.PShape,Integer> colorNonMesh(processing.core.PShape shape, PGS_Coloring.ColoringAlgorithm coloringAlgorithm)
      Computes a coloring of the given non-conforming mesh shape, returning a color class for each face of the pre-processed (noded) mesh.
      Parameters:
      shape - a GROUP PShape, whose children constitute the faces of a non-conforming mesh
      coloringAlgorithm - coloring algorithm used to color the mesh
      Returns:
      a color-class map; a mapping of each noded mesh face (PShape) -> color class (integer)

    • colorNonMesh

      public static processing.core.PShape colorNonMesh(processing.core.PShape shape, PGS_Coloring.ColoringAlgorithm coloringAlgorithm, int[] colorPalette)
      Computes a coloring of the given non-conforming mesh shape and colors the faces of its noded representation using the colors provided.
      Parameters:
      shape - a GROUP PShape, whose children constitute the faces of a non-conforming mesh
      coloringAlgorithm - coloring algorithm used to color the mesh
      colorPalette - the (integer) colors with which to color the mesh
      Returns:
      noded representation of the input shape (whose faces have now been colored)

    • colorNonMesh

      public static processing.core.PShape colorNonMesh(processing.core.PShape shape, PGS_Coloring.ColoringAlgorithm coloringAlgorithm, String[] colorPalette)
      Computes a coloring of the given non-conforming mesh shape and colors the faces of its noded representation using the colors provided.
      Parameters:
      shape - a GROUP PShape, whose children constitute the faces of a non-conforming mesh
      coloringAlgorithm - coloring algorithm used to color the mesh
      colorPalette - the string colors (e.g. "#FFFFFF", or "cba5e8") with which to color the mesh
      Returns:
      noded representation of the input shape (whose faces have now been colored)