From a68cf346b7a23f4d83f903fd7859008beb47e6f1 Mon Sep 17 00:00:00 2001
From: Bixilon <bixilon@bixilon.de>
Date: Thu, 6 Oct 2022 20:20:08 +0200
Subject: [PATCH] light: fix neighbour propagation

---
 .../data/world/chunk/light/SectionLight.kt    | 25 +++++++++----------
 1 file changed, 12 insertions(+), 13 deletions(-)

diff --git a/src/main/java/de/bixilon/minosoft/data/world/chunk/light/SectionLight.kt b/src/main/java/de/bixilon/minosoft/data/world/chunk/light/SectionLight.kt
index 92754e37e..a3729d916 100644
--- a/src/main/java/de/bixilon/minosoft/data/world/chunk/light/SectionLight.kt
+++ b/src/main/java/de/bixilon/minosoft/data/world/chunk/light/SectionLight.kt
@@ -210,7 +210,6 @@ class SectionLight(
     }
 
     fun calculate() {
-        // ToDo: skylight
         update = true
         val blocks = section.blocks
 
@@ -261,12 +260,12 @@ class SectionLight(
             for (y in 0 until ProtocolDefinition.SECTION_HEIGHT_Y) {
                 val totalY = baseY + y
                 neighbours[Directions.O_WEST]?.light?.get(ProtocolDefinition.SECTION_MAX_Z, y, z)?.toInt()?.let { light ->
-                    (light and BLOCK_LIGHT_MASK).let { if (it > 1) traceBlockIncrease(0, y, z, it - 1, Directions.EAST) }
-                    (light and SKY_LIGHT_MASK shr 4).let { if (it > 1) traceSkylightIncrease(0, y, z, it - 1, Directions.EAST, totalY) }
+                    (light and BLOCK_LIGHT_MASK).let { if (it > 1) traceBlockIncrease(0, y, z, it - 1, Directions.WEST) }
+                    (light and SKY_LIGHT_MASK shr 4).let { if (it > 1) traceSkylightIncrease(0, y, z, it - 1, Directions.WEST, totalY) }
                 }
                 neighbours[Directions.O_EAST]?.light?.get(0, y, z)?.toInt()?.let { light ->
-                    (light and BLOCK_LIGHT_MASK).let { if (it > 1) traceBlockIncrease(ProtocolDefinition.SECTION_MAX_X, y, z, it - 1, Directions.WEST) }
-                    (light and SKY_LIGHT_MASK shr 4).let { if (it > 1) traceSkylightIncrease(ProtocolDefinition.SECTION_MAX_X, y, z, it - 1, Directions.WEST, totalY) }
+                    (light and BLOCK_LIGHT_MASK).let { if (it > 1) traceBlockIncrease(ProtocolDefinition.SECTION_MAX_X, y, z, it - 1, Directions.EAST) }
+                    (light and SKY_LIGHT_MASK shr 4).let { if (it > 1) traceSkylightIncrease(ProtocolDefinition.SECTION_MAX_X, y, z, it - 1, Directions.EAST, totalY) }
                 }
             }
         }
@@ -276,12 +275,12 @@ class SectionLight(
         for (y in 0 until ProtocolDefinition.SECTION_HEIGHT_Y) {
             val totalY = baseY + y
             neighbours[Directions.O_NORTH]?.light?.get(x, y, ProtocolDefinition.SECTION_MAX_Z)?.toInt()?.let { light ->
-                (light and BLOCK_LIGHT_MASK).let { if (it > 1) traceBlockIncrease(x, y, 0, it - 1, Directions.SOUTH) }
-                (light and SKY_LIGHT_MASK shr 4).let { if (it > 1) traceSkylightIncrease(x, y, 0, it - 1, Directions.SOUTH, totalY) }
+                (light and BLOCK_LIGHT_MASK).let { if (it > 1) traceBlockIncrease(x, y, 0, it - 1, Directions.NORTH) }
+                (light and SKY_LIGHT_MASK shr 4).let { if (it > 1) traceSkylightIncrease(x, y, 0, it - 1, Directions.NORTH, totalY) }
             }
             neighbours[Directions.O_SOUTH]?.light?.get(x, y, 0)?.toInt()?.let { light ->
-                (light and BLOCK_LIGHT_MASK).let { if (it > 1) traceBlockIncrease(x, y, ProtocolDefinition.SECTION_MAX_Z, it - 1, Directions.NORTH) }
-                (light and SKY_LIGHT_MASK shr 4).let { if (it > 1) traceSkylightIncrease(x, y, ProtocolDefinition.SECTION_MAX_Z, it - 1, Directions.NORTH, totalY) }
+                (light and BLOCK_LIGHT_MASK).let { if (it > 1) traceBlockIncrease(x, y, ProtocolDefinition.SECTION_MAX_Z, it - 1, Directions.SOUTH) }
+                (light and SKY_LIGHT_MASK shr 4).let { if (it > 1) traceSkylightIncrease(x, y, ProtocolDefinition.SECTION_MAX_Z, it - 1, Directions.SOUTH, totalY) }
             }
         }
     }
@@ -289,12 +288,12 @@ class SectionLight(
     private fun propagateY(neighbours: Array<ChunkSection?>, x: Int, baseY: Int) {
         for (z in 0 until ProtocolDefinition.SECTION_WIDTH_Z) {
             neighbours[Directions.O_DOWN]?.light?.get(x, ProtocolDefinition.SECTION_MAX_Y, z)?.toInt()?.let { light ->
-                (light and BLOCK_LIGHT_MASK).let { if (it > 1) traceBlockIncrease(x, 0, z, it - 1, Directions.UP) }
-                (light and SKY_LIGHT_MASK shr 4).let { if (it > 1) traceSkylightIncrease(x, 0, z, it - 1, Directions.UP, baseY + 0) } // ToDo: Is that possible?
+                (light and BLOCK_LIGHT_MASK).let { if (it > 1) traceBlockIncrease(x, 0, z, it - 1, Directions.DOWN) }
+                (light and SKY_LIGHT_MASK shr 4).let { if (it > 1) traceSkylightIncrease(x, 0, z, it - 1, Directions.DOWN, baseY + 0) } // ToDo: Is that possible?
             }
             neighbours[Directions.O_UP]?.light?.get(x, 0, z)?.toInt()?.let { light ->
-                (light and BLOCK_LIGHT_MASK).let { if (it > 1) traceBlockIncrease(x, ProtocolDefinition.SECTION_MAX_Y, z, it - 1, Directions.DOWN) }
-                (light and SKY_LIGHT_MASK shr 4).let { if (it > 1) traceSkylightIncrease(x, ProtocolDefinition.SECTION_MAX_Y, z, it - 1, Directions.DOWN, baseY + ProtocolDefinition.SECTION_MAX_Y) }
+                (light and BLOCK_LIGHT_MASK).let { if (it > 1) traceBlockIncrease(x, ProtocolDefinition.SECTION_MAX_Y, z, it - 1, Directions.UP) }
+                (light and SKY_LIGHT_MASK shr 4).let { if (it > 1) traceSkylightIncrease(x, ProtocolDefinition.SECTION_MAX_Y, z, it - 1, Directions.UP, baseY + ProtocolDefinition.SECTION_MAX_Y) }
             }
         }
     }