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section occlusion: work with just the index, not xyz
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This actually is a lot faster since there is no need to push xyz recursively (benchmark goes down from 23s to 12s, so 48% improvement).
This is time critical code, because occlusion is calculated on demand in the rendering thread and might cause stuttering when new chunks flow it (the meshing queue depends on it)
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@Bixilon
Bixilon committed Feb 13, 2025
1 parent 25d4ab6 commit b74d63a
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Showing 2 changed files with 29 additions and 28 deletions.
7 changes: 5 additions & 2 deletions ...ration-test/kotlin/de/bixilon/minosoft/data/world/container/block/SectionOcclusionTest.kt
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Original file line number Diff line number Diff line change
Expand Up @@ -16,12 +16,16 @@ package de.bixilon.minosoft.data.world.container.block
import de.bixilon.kutil.cast.CastUtil.unsafeCast
import de.bixilon.kutil.reflection.ReflectionUtil.forceSet
import de.bixilon.kutil.reflection.ReflectionUtil.getFieldOrNull
import de.bixilon.kutil.unit.UnitFormatter.formatNanos
import de.bixilon.minosoft.data.registries.blocks.GlassTest0
import de.bixilon.minosoft.data.registries.blocks.state.BlockState
import de.bixilon.minosoft.data.registries.blocks.types.stone.StoneTest0
import de.bixilon.minosoft.protocol.protocol.ProtocolDefinition
import de.bixilon.minosoft.test.ITUtil.allocate
import org.testng.Assert.assertEquals
import org.testng.annotations.Test
import kotlin.random.Random
import kotlin.time.measureTime

@Test(groups = ["occlusion"], dependsOnGroups = ["block"])
class SectionOcclusionTest {
Expand Down Expand Up @@ -91,7 +95,7 @@ class SectionOcclusionTest {
assertEquals(occlusion.occlusion, BooleanArray(15) { false })
}

/*
@Test(enabled = false)
fun benchmark() {
val occlusion = create()
val stone = StoneTest0.state
Expand All @@ -109,7 +113,6 @@ class SectionOcclusionTest {
}
println("Took: ${time.inWholeNanoseconds.formatNanos()}")
}
*/

// TODO: Test more possible cases
}
50 changes: 24 additions & 26 deletions src/main/java/de/bixilon/minosoft/data/world/container/block/SectionOcclusion.kt
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Original file line number Diff line number Diff line change
Expand Up @@ -58,8 +58,7 @@ class SectionOcclusion(
}
}

private inline fun ShortArray.setIfUnset(x: Int, y: Int, z: Int, id: Short): Boolean {
val index = y shl 8 or (z shl 4) or x
private inline fun ShortArray.setIfUnset(index: Int, region: Int): Boolean {
if (this[index] != EMPTY_REGION) {
return true
}
Expand All @@ -68,41 +67,36 @@ class SectionOcclusion(
this[index] = INVALID_REGION
return true
}
this[index] = id
this[index] = region.toShort()
return false
}

private fun startTrace(regions: ShortArray, x: Int, y: Int, z: Int, nextId: Short) {
if (regions.setIfUnset(x, y, z, nextId)) return
private fun startTrace(regions: ShortArray, index: Int) {
if (regions.setIfUnset(index, index)) return

// no need to trace negative coordinates initially
if (x < ProtocolDefinition.SECTION_MAX_X) trace(regions, x + 1, y, z, nextId)
if (z < ProtocolDefinition.SECTION_MAX_Z) trace(regions, x, y, z + 1, nextId)
if (y < ProtocolDefinition.SECTION_MAX_Y) trace(regions, x, y + 1, z, nextId)
if (index and 0x00F < (ProtocolDefinition.SECTION_MAX_X shl 0)) trace(regions, index + X, index)
if (index and 0x0F0 < (ProtocolDefinition.SECTION_MAX_Z shl 4)) trace(regions, index + Z, index)
if (index and 0xF00 < (ProtocolDefinition.SECTION_MAX_Y shl 8)) trace(regions, index + Y, index)
}

private fun trace(regions: ShortArray, x: Int, y: Int, z: Int, nextId: Short) {
if (regions.setIfUnset(x, y, z, nextId)) return
private fun trace(regions: ShortArray, index: Int, region: Int) {
if (regions.setIfUnset(index, region)) return

if (x > 0) trace(regions, x - 1, y, z, nextId)
if (x < ProtocolDefinition.SECTION_MAX_X) trace(regions, x + 1, y, z, nextId)
if (z > 0) trace(regions, x, y, z - 1, nextId)
if (z < ProtocolDefinition.SECTION_MAX_Z) trace(regions, x, y, z + 1, nextId)
if (y > 0) trace(regions, x, y - 1, z, nextId)
if (y < ProtocolDefinition.SECTION_MAX_Y) trace(regions, x, y + 1, z, nextId)
if (index and 0x00F > 0) trace(regions, index - X, region)
if (index and 0x00F < (ProtocolDefinition.SECTION_MAX_X shl 0)) trace(regions, index + X, region)
if (index and 0x0F0 > 0) trace(regions, index - Z, region)
if (index and 0x0F0 < (ProtocolDefinition.SECTION_MAX_Z shl 4)) trace(regions, index + Z, region)
if (index and 0xF00 > 0) trace(regions, index - Y, region)
if (index and 0xF00 < (ProtocolDefinition.SECTION_MAX_Y shl 8)) trace(regions, index + Y, region)
}

private fun floodFill(array: ShortArray): ShortArray {
// mark regions and check direct neighbours
Arrays.fill(array, EMPTY_REGION)

var next = EMPTY_REGION
for (y in 0 until ProtocolDefinition.SECTION_HEIGHT_Y) {
for (z in 0 until ProtocolDefinition.SECTION_WIDTH_Z) {
for (x in 0 until ProtocolDefinition.SECTION_WIDTH_X) {
startTrace(array, x, y, z, ++next)
}
}
for (index in 0 until ProtocolDefinition.BLOCKS_PER_SECTION) {
startTrace(array, index)
}

return array
Expand Down Expand Up @@ -140,7 +134,7 @@ class SectionOcclusion(
Axes.Z -> ProtocolDefinition.SECTION_MAX_Z shl 4
}
val pRegion = regions[index2].toInt()
if (pRegion > 0) {
if (pRegion > EMPTY_REGION) {
sideRegions[pDirection.ordinal].add(pRegion) // primitive
}
}
Expand Down Expand Up @@ -204,11 +198,15 @@ class SectionOcclusion(
}

companion object {
private const val EMPTY_REGION = 0.toShort()
private const val INVALID_REGION = (-1).toShort()
private const val EMPTY_REGION = (-1).toShort()
private const val INVALID_REGION = (-2).toShort()
private val EMPTY = BooleanArray(CubeDirections.CUBE_DIRECTION_COMBINATIONS)
private val ALLOCATOR = ShortAllocator()

private const val X = 0x001
private const val Y = 0x100
private const val Z = 0x010


fun BlockState?._isFullyOpaque(): Boolean {
if (this == null) {
Expand Down

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