journeymap.api.v2.client.util

Class PolygonHelper

java.lang.Object

journeymap.api.v2.client.util.PolygonHelper

public class PolygonHelper
extends java.lang.Object

Utility class related to Polygons.

Constructor Summary

Constructors

Constructor and Description
PolygonHelper()

Method Summary

Modifier and Type	Method and Description
static java.util.List<MapPolygonWithHoles>	classifyAndGroup(java.util.List<MapPolygon> polygons) Given an arbitrary list of polygons, determine which are hulls and holes and which holes are associated with which hulls.
static MapPolygon	createBlockRect(net.minecraft.core.BlockPos corner1, net.minecraft.core.BlockPos corner2) Creates a polygon for the block coords, starting with the lower-left (southwest) corner and going counter-clockwise.
static MapPolygon	createChunkPolygon(int chunkX, int y, int chunkZ) Creates a polygon for the chunk coords, starting with the lower-left (southwest) corner and going counter-clockwise.
static MapPolygon	createChunkPolygonForWorldCoords(int x, int y, int z) Creates a polygon for the chunk containing worldCoords, starting with the lower-left (southwest) corner and going counter-clockwise.
static java.awt.geom.Area	createChunksArea(java.util.Collection<net.minecraft.world.level.ChunkPos> chunks) Given a collection of chunks, creates an Area that covers them.
static java.util.List<MapPolygonWithHoles>	createChunksPolygon(java.util.Collection<net.minecraft.world.level.ChunkPos> chunks, int y) Given a collection of chunks, creates one or more MapPolygonWithHoles that covers them.
static java.util.List<MapPolygonWithHoles>	createPolygonFromArea(java.awt.geom.Area area, int y) Creates a set of MapPolygonWithHoles from the given Area (XZ block coords) and the given Y coord.
static java.awt.geom.Area	toArea(MapPolygon polygon) Converts a MapPolygon into an Area (keeping XZ coords only).

Methods inherited from class java.lang.Object

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

Constructor Detail

PolygonHelper

public PolygonHelper()

Method Detail

createChunkPolygonForWorldCoords

public static MapPolygon createChunkPolygonForWorldCoords(int x,
                                                          int y,
                                                          int z)

Creates a polygon for the chunk containing worldCoords, starting with the lower-left (southwest) corner and going counter-clockwise.

Parameters:

x - world X

y - world Y

z - world Z

Returns:

a polygon for the surrounding chunk

createChunkPolygon

public static MapPolygon createChunkPolygon(int chunkX,
                                            int y,
                                            int chunkZ)

Creates a polygon for the chunk coords, starting with the lower-left (southwest) corner and going counter-clockwise.

Parameters:

chunkX - chunk x

y - block y

chunkZ - chunk z

Returns:

polygon

createBlockRect

public static MapPolygon createBlockRect(net.minecraft.core.BlockPos corner1,
                                         net.minecraft.core.BlockPos corner2)

Creates a polygon for the block coords, starting with the lower-left (southwest) corner and going counter-clockwise. The supplied coordinates don't need to be in order, just opposite.

Parameters:

corner1 - One corner of the desired rectangle

corner2 - The opposite corner

Returns:

polygon

createChunksArea

@Nonnull
public static java.awt.geom.Area createChunksArea(@Nonnull
                                                           java.util.Collection<net.minecraft.world.level.ChunkPos> chunks)

Given a collection of chunks, creates an Area that covers them.

Parameters:

chunks - The set of chunks.

Returns:

An Area of the corresponding block coordinates.

createChunksPolygon

@Nonnull
public static java.util.List<MapPolygonWithHoles> createChunksPolygon(@Nonnull
                                                                               java.util.Collection<net.minecraft.world.level.ChunkPos> chunks,
                                                                               int y)

Given a collection of chunks, creates one or more MapPolygonWithHoles that covers them. (Just a convenience wrapper for the Area-based methods.)

Parameters:

chunks - The set of chunks.

y - The y-coordinate for the resulting polygons.

Returns:

One or more polygons that cover the specified chunks.

toArea

@Nonnull
public static java.awt.geom.Area toArea(@Nonnull
                                                 MapPolygon polygon)

Converts a MapPolygon into an Area (keeping XZ coords only).

Parameters:

polygon - The polygon.

Returns:

The corresponding area.

createPolygonFromArea

@Nonnull
public static java.util.List<MapPolygonWithHoles> createPolygonFromArea(@Nonnull
                                                                                 java.awt.geom.Area area,
                                                                                 int y)

Creates a set of MapPolygonWithHoles from the given Area (XZ block coords) and the given Y coord.

Note that this includes some point-simplification that currently only works if the area is only made up of rectangular subregions -- i.e. all lines are perfectly horizontal or vertical. If you do have diagonal lines this is mostly harmless; just might leave more points than are strictly required.

Parameters:

area - The area to cover.

y - The y-coordinate.

Returns:

The polygons.

classifyAndGroup

@Nonnull
public static java.util.List<MapPolygonWithHoles> classifyAndGroup(@Nonnull
                                                                            java.util.List<MapPolygon> polygons)

Given an arbitrary list of polygons, determine which are hulls and holes and which holes are associated with which hulls.

Assumes that hulls use CCW point winding and holes use CW point winding, which seems to be consistent with createPolygonFromArea(java.awt.geom.Area, int).

Each hole is grouped with the innermost hull that fully contains it. A hole that no hull contains but that intersects one or more hulls (possible only for arbitrary input, not for the normalized Area contours createPolygonFromArea(java.awt.geom.Area, int) emits) falls back to the first hull it intersects; a hole that touches no hull is dropped. The innermost-owner result is independent of contour order when the hulls strictly nest, as they do for normalized Area contours; for overlapping or equal-area hulls that both contain a hole the first candidate wins.

Parameters:

polygons - The input list of MapPolygons.

Returns:

The resulting list of MapPolygonWithHoles.