2016-04-20 08:41:22 +10:00

80 lines
2.7 KiB
C#

// ClassicalSharp copyright 2014-2016 UnknownShadow200 | Licensed under MIT
using System;
using ClassicalSharp.GraphicsAPI;
using OpenTK;
namespace ClassicalSharp.Renderers {
public static class ChunkSorter {
public static void UpdateSortOrder( Game game, ChunkUpdater updater ) {
Vector3 cameraPos = game.CurrentCameraPos;
Vector3I newChunkPos = Vector3I.Floor( cameraPos );
newChunkPos.X = (newChunkPos.X & ~0x0F) + 8;
newChunkPos.Y = (newChunkPos.Y & ~0x0F) + 8;
newChunkPos.Z = (newChunkPos.Z & ~0x0F) + 8;
if( newChunkPos == updater.chunkPos ) return;
ChunkInfo[] chunks = game.MapRenderer.chunks;
int[] distances = updater.distances;
updater.chunkPos = newChunkPos;
for( int i = 0; i < distances.Length; i++ ) {
ChunkInfo info = chunks[i];
distances[i] = Utils.DistanceSquared( info.CentreX, info.CentreY, info.CentreZ,
updater.chunkPos.X, updater.chunkPos.Y, updater.chunkPos.Z );
}
// NOTE: Over 5x faster compared to normal comparison of IComparer<ChunkInfo>.Compare
if( distances.Length > 1 )
QuickSort( distances, chunks, 0, chunks.Length - 1 );
Vector3I pPos = newChunkPos;
for( int i = 0; i < chunks.Length; i++ ) {
ChunkInfo info = chunks[i];
int dX1 = (info.CentreX - 8) - pPos.X, dX2 = (info.CentreX + 8) - pPos.X;
int dY1 = (info.CentreY - 8) - pPos.Y, dY2 = (info.CentreY + 8) - pPos.Y;
int dZ1 = (info.CentreZ - 8) - pPos.Z, dZ2 = (info.CentreZ + 8) - pPos.Z;
// Back face culling: make sure that the chunk is definitely entirely back facing.
info.DrawLeft = !(dX1 <= 0 && dX2 <= 0);
info.DrawRight = !(dX1 >= 0 && dX2 >= 0);
info.DrawFront = !(dZ1 <= 0 && dZ2 <= 0);
info.DrawBack = !(dZ1 >= 0 && dZ2 >= 0);
info.DrawBottom = !(dY1 <= 0 && dY2 <= 0);
info.DrawTop = !(dY1 >= 0 && dY2 >= 0);
}
updater.RecalcBooleans( false );
//SimpleOcclusionCulling();
}
static void QuickSort( int[] keys, ChunkInfo[] values, int left, int right ) {
while( left < right ) {
int i = left, j = right;
int pivot = keys[(i + j) / 2];
// partition the list
while( i <= j ) {
while( pivot > keys[i] ) i++;
while( pivot < keys[j] ) j--;
if( i <= j ) {
int key = keys[i]; keys[i] = keys[j]; keys[j] = key;
ChunkInfo value = values[i]; values[i] = values[j]; values[j] = value;
i++; j--;
}
}
// recurse into the smaller subset
if( j - left <= right - i ) {
if( left < j )
QuickSort( keys, values, left, j );
left = i;
} else {
if( i < right )
QuickSort( keys, values, i, right );
right = j;
}
}
}
}
}