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

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