core/src/ru/deadsoftware/cavedroid/game/world/GameWorldGenerator.kt

   1 package ru.deadsoftware.cavedroid.game.world
   2
   3 import com.badlogic.gdx.utils.TimeUtils
   4 import ru.deadsoftware.cavedroid.game.GameItems
   5 import kotlin.math.abs
   6 import kotlin.random.Random
   7
   8 object GameWorldGenerator {
   9
  10     private fun generateHeights(width: Int, min: Int, max: Int, random: Random) = IntArray(width).apply {
  11         set(0, (min + max) / 2)
  12         for (x in 1 until width) {
  13             val previous = get(x - 1)
  14             var d = random.nextInt(-5, 6).let { if (it !in -4..4) it / abs(it) else 0 }
  15
  16             if (previous + d !in min..max) { d = -d }
  17             if (lastIndex - x < abs(get(0) - previous) * 3) {
  18                 d = get(0).compareTo(previous).let { if (it != 0) it / abs(it) else 0 }
  19             }
  20
  21             set(x, get(x - 1) + d)
  22         }
  23     }
  24
  25     /**
  26      * Generates world of given width and height with given seed
  27      * @param width world width
  28      * @param height world height
  29      * @param seed seed for random number generator
  30      * @return pair of foreground and background layers
  31      */
  32     fun generate(width: Int, height: Int, seed: Long = TimeUtils.millis()): Pair<Array<IntArray>, Array<IntArray>> {
  33         val random = Random(seed)
  34         val foreMap = Array(width) { IntArray(height) }
  35         val backMap = Array(width) { IntArray(width) }
  36         val heightsMap = generateHeights(width, height / 2, height * 3 / 4, random)
  37
  38         for (x in 0 until width) {
  39             val xHeight = heightsMap[x]
  40
  41             foreMap[x][xHeight] = GameItems.getBlockId("grass")
  42             foreMap[x][height - 1] = GameItems.getBlockId("bedrock")
  43             backMap[x][xHeight] = GameItems.getBlockId("grass")
  44             backMap[x][height - 1] = GameItems.getBlockId("bedrock")
  45
  46             for (y in xHeight + 1 until height - 1) {
  47                 foreMap[x][y] = when {
  48                     y < xHeight + random.nextInt(5, 8) -> GameItems.getBlockId("dirt")
  49                     else -> GameItems.getBlockId("stone")
  50                 }
  51                 backMap[x][y] = foreMap[x][y]
  52             }
  53         }
  54         return Pair(foreMap, backMap)
  55     }
  56
  57 }