2016-07-07 17:42:26 +10:00

364 lines
13 KiB
C#

// ClassicalSharp copyright 2014-2016 UnknownShadow200 | Licensed under MIT
//#define DEBUG_OCCLUSION
using System;
using ClassicalSharp.GraphicsAPI;
using ClassicalSharp.Map;
using OpenTK;
namespace ClassicalSharp {
/// <summary> Class responsible for converting a 16x16x16 into an optimised mesh of vertices. </summary>
/// <remarks> This class is heavily optimised and as such may suffer from slightly unreadable code. </remarks>
public unsafe partial class ChunkMeshBuilder {
int X, Y, Z;
float x1, y1, z1, x2, y2, z2;
byte curBlock;
BlockInfo info;
World map;
WorldEnv env;
Game game;
IGraphicsApi graphics;
const int chunkSize = 16, extChunkSize = 18;
const int chunkSize2 = 16 * 16, extChunkSize2 = 18 * 18;
const int chunkSize3 = 16 * 16 * 16, extChunkSize3 = 18 * 18 * 18;
public ChunkMeshBuilder( Game game ) {
this.game = game;
graphics = game.Graphics;
info = game.BlockInfo;
game.Events.TerrainAtlasChanged += TerrainAtlasChanged;
}
internal int width, length, height, clipLevel;
int maxX, maxY, maxZ;
byte* chunk, counts;
bool BuildChunk( int x1, int y1, int z1 ) {
PreStretchTiles( x1, y1, z1 );
byte* chunkPtr = stackalloc byte[extChunkSize3]; chunk = chunkPtr;
byte* countsPtr = stackalloc byte[chunkSize3 * Side.Sides]; counts = countsPtr;
MemUtils.memset( (IntPtr)chunkPtr, 0, 0, extChunkSize3 );
if( ReadChunkData( x1, y1, z1 ) ) return false;
MemUtils.memset( (IntPtr)countsPtr, 1, 0, chunkSize3 * Side.Sides );
Stretch( x1, y1, z1 );
PostStretchTiles( x1, y1, z1 );
int xMax = Math.Min( width, x1 + chunkSize );
int yMax = Math.Min( height, y1 + chunkSize );
int zMax = Math.Min( length, z1 + chunkSize );
for( int y = y1, yy = 0; y < yMax; y++, yy++ ) {
for( int z = z1, zz = 0; z < zMax; z++, zz++ ) {
int chunkIndex = (yy + 1) * extChunkSize2 + (zz + 1) * extChunkSize + (0 + 1);
for( int x = x1, xx = 0; x < xMax; x++, xx++ ) {
curBlock = chunk[chunkIndex];
if( !info.IsAir[curBlock] ) {
int index = ((yy << 8) | (zz << 4) | xx) * Side.Sides;
RenderTile( index, x, y, z );
}
chunkIndex++;
}
}
}
return true;
}
bool ReadChunkData( int x1, int y1, int z1 ) {
bool allAir = true, allSolid = true;
fixed( byte* mapPtr = map.blocks ) {
for( int yy = -1; yy < 17; yy++ ) {
int y = yy + y1;
if( y < 0 ) continue;
if( y > maxY ) break;
for( int zz = -1; zz < 17; zz++ ) {
int z = zz + z1;
if( z < 0 ) continue;
if( z > maxZ ) break;
int index = (y * length + z) * width + (x1 - 1 - 1);
int chunkIndex = (yy + 1) * extChunkSize2 + (zz + 1) * extChunkSize + (-1 + 1) - 1;
for( int xx = -1; xx < 17; xx++ ) {
int x = xx + x1;
index++;
chunkIndex++;
if( x < 0 ) continue;
if( x > maxX ) break;
byte rawBlock = mapPtr[index];
if( rawBlock == Block.StillWater ) rawBlock = Block.Water;
if( rawBlock == Block.StillLava ) rawBlock = Block.Lava;
allAir = allAir && rawBlock == 0;
allSolid = allSolid && info.IsOpaque[rawBlock];
chunk[chunkIndex] = rawBlock;
}
}
}
if( x1 == 0 || y1 == 0 || z1 == 0 || x1 + chunkSize >= width ||
y1 + chunkSize >= height || z1 + chunkSize >= length ) allSolid = false;
if( allAir || allSolid ) return true;
map.HeightmapHint( x1 - 1, z1 - 1, mapPtr );
return false;
}
}
public void GetDrawInfo( int x, int y, int z, ref ChunkPartInfo[] nParts, ref ChunkPartInfo[] tParts ) {
if( !BuildChunk( x, y, z ) ) return;
for( int i = 0; i < arraysCount; i++ ) {
SetPartInfo( normalParts[i], i, ref nParts );
SetPartInfo( translucentParts[i], i, ref tParts );
}
#if OCCLUSION
// , ref byte occlusionFlags
if( normalParts != null || translucentParts != null )
occlusionFlags = (byte)ComputeOcclusion();
#endif
}
void SetPartInfo( DrawInfo part, int i, ref ChunkPartInfo[] parts ) {
if( part.iCount == 0 ) return;
ChunkPartInfo info;
int vertCount = (part.iCount / 6 * 4) + 2;
info.VbId = graphics.CreateVb( part.vertices, VertexFormat.P3fT2fC4b, vertCount );
info.IndicesCount = part.iCount;
info.LeftCount = (ushort)part.vCount.left; info.RightCount = (ushort)part.vCount.right;
info.FrontCount = (ushort)part.vCount.front; info.BackCount = (ushort)part.vCount.back;
info.BottomCount = (ushort)part.vCount.bottom; info.TopCount = (ushort)part.vCount.top;
info.SpriteCount = part.spriteCount;
info.LeftIndex = info.SpriteCount;
info.RightIndex = info.LeftIndex + info.LeftCount;
info.FrontIndex = info.RightIndex + info.RightCount;
info.BackIndex = info.FrontIndex + info.FrontCount;
info.BottomIndex = info.BackIndex + info.BackCount;
info.TopIndex = info.BottomIndex + info.BottomCount;
// Lazy initalize part arrays so we can save time in MapRenderer for chunks that only contain 1 or 2 part types.
if( parts == null )
parts = new ChunkPartInfo[arraysCount];
parts[i] = info;
}
void Stretch( int x1, int y1, int z1 ) {
int xMax = Math.Min( width, x1 + chunkSize );
int yMax = Math.Min( height, y1 + chunkSize );
int zMax = Math.Min( length, z1 + chunkSize );
#if OCCLUSION
int flags = ComputeOcclusion();
#endif
#if DEBUG_OCCLUSION
FastColour col = new FastColour( 60, 60, 60, 255 );
if( (flags & 1) != 0 ) col.R = 255; // x
if( (flags & 4) != 0 ) col.G = 255; // y
if( (flags & 2) != 0 ) col.B = 255; // z
map.Sunlight = map.Shadowlight = col;
map.SunlightXSide = map.ShadowlightXSide = col;
map.SunlightZSide = map.ShadowlightZSide = col;
map.SunlightYBottom = map.ShadowlightYBottom = col;
#endif
byte[] hidden = game.BlockInfo.hidden;
for( int y = y1, yy = 0; y < yMax; y++, yy++ ) {
for( int z = z1, zz = 0; z < zMax; z++, zz++ ) {
int cIndex = (yy + 1) * extChunkSize2 + (zz + 1) * extChunkSize + (-1 + 1);
for( int x = x1, xx = 0; x < xMax; x++, xx++ ) {
cIndex++;
byte rawBlock = chunk[cIndex];
if( info.IsAir[rawBlock] ) continue;
int index = ((yy << 8) + (zz << 4) + xx) * Side.Sides;
// Sprites only use one face to indicate stretching count, so we can take a shortcut here.
// Note that sprites are not drawn with any of the DrawXFace, they are drawn using DrawSprite.
if( info.IsSprite[rawBlock] ) {
index += Side.Top;
if( counts[index] != 0 ) {
X = x; Y = y; Z = z;
AddSpriteVertices( rawBlock );
counts[index] = 1;
}
} else {
X = x; Y = y; Z = z;
fullBright = info.FullBright[rawBlock];
int tileIdx = rawBlock << 8;
// All of these function calls are inlined as they can be called tens of millions to hundreds of millions of times.
if( counts[index] == 0 || (x == 0 && Y < clipLevel) ||
(x != 0 && (hidden[tileIdx + chunk[cIndex - 1]] & (1 << Side.Left)) != 0 ) ) {
counts[index] = 0;
} else {
int count = StretchZ( zz, index, X, Y, Z, cIndex, rawBlock, Side.Left );
AddVertices( rawBlock, count, Side.Left ); counts[index] = (byte)count;
}
index++;
if( counts[index] == 0 || (x == maxX && Y < clipLevel) ||
(x != maxX && (hidden[tileIdx + chunk[cIndex + 1]] & (1 << Side.Right)) != 0 ) ) {
counts[index] = 0;
} else {
int count = StretchZ( zz, index, X, Y, Z, cIndex, rawBlock, Side.Right );
AddVertices( rawBlock, count, Side.Right ); counts[index] = (byte)count;
}
index++;
if( counts[index] == 0 || (z == 0 && Y < clipLevel) ||
(z != 0 && (hidden[tileIdx + chunk[cIndex - 18]] & (1 << Side.Front)) != 0 ) ) {
counts[index] = 0;
} else {
int count = StretchX( xx, index, X, Y, Z, cIndex, rawBlock, Side.Front );
AddVertices( rawBlock, count, Side.Front ); counts[index] = (byte)count;
}
index++;
if( counts[index] == 0 || (z == maxZ && Y < clipLevel) ||
(z != maxZ && (hidden[tileIdx + chunk[cIndex + 18]] & (1 << Side.Back)) != 0 ) ) {
counts[index] = 0;
} else {
int count = StretchX( xx, index, X, Y, Z, cIndex, rawBlock, Side.Back );
AddVertices( rawBlock, count, Side.Back ); counts[index] = (byte)count;
}
index++;
if( counts[index] == 0 || y == 0 ||
(hidden[tileIdx + chunk[cIndex - 324]] & (1 << Side.Bottom)) != 0 ) {
counts[index] = 0;
} else {
int count = StretchX( xx, index, X, Y, Z, cIndex, rawBlock, Side.Bottom );
AddVertices( rawBlock, count, Side.Bottom ); counts[index] = (byte)count;
}
index++;
if( counts[index] == 0 ||
(hidden[tileIdx + chunk[cIndex + 324]] & (1 << Side.Top)) != 0 ) {
counts[index] = 0;
} else if( rawBlock < Block.Water || rawBlock > Block.StillLava ) {
int count = StretchX( xx, index, X, Y, Z, cIndex, rawBlock, Side.Top );
AddVertices( rawBlock, count, Side.Top ); counts[index] = (byte)count;
} else {
int count = StretchXLiquid( xx, index, X, Y, Z, cIndex, rawBlock );
if( count > 0 ) AddVertices( rawBlock, count, Side.Top );
counts[index] = (byte)count;
}
}
}
}
}
}
int StretchXLiquid( int xx, int countIndex, int x, int y, int z, int chunkIndex, byte block ) {
if( OccludedLiquid( chunkIndex ) ) return 0;
int count = 1;
x++;
chunkIndex++;
countIndex += Side.Sides;
int max = chunkSize - xx;
while( count < max && x < width && CanStretch( block, chunkIndex, x, y, z, Side.Top )
&& !OccludedLiquid( chunkIndex ) ) {
counts[countIndex] = 0;
count++;
x++;
chunkIndex++;
countIndex += Side.Sides;
}
return count;
}
int StretchX( int xx, int countIndex, int x, int y, int z, int chunkIndex, byte block, int face ) {
int count = 1;
x++;
chunkIndex++;
countIndex += Side.Sides;
int max = chunkSize - xx;
bool stretchTile = (info.CanStretch[block] & (1 << face)) != 0;
while( count < max && x < width && stretchTile && CanStretch( block, chunkIndex, x, y, z, face ) ) {
counts[countIndex] = 0;
count++;
x++;
chunkIndex++;
countIndex += Side.Sides;
}
return count;
}
int StretchZ( int zz, int countIndex, int x, int y, int z, int chunkIndex, byte block, int face ) {
int count = 1;
z++;
chunkIndex += extChunkSize;
countIndex += chunkSize * Side.Sides;
int max = chunkSize - zz;
bool stretchTile = (info.CanStretch[block] & (1 << face)) != 0;
while( count < max && z < length && stretchTile && CanStretch( block, chunkIndex, x, y, z, face ) ) {
counts[countIndex] = 0;
count++;
z++;
chunkIndex += extChunkSize;
countIndex += chunkSize * Side.Sides;
}
return count;
}
int[] offsets = { -1, 1, -extChunkSize, extChunkSize, -extChunkSize2, extChunkSize2 };
bool CanStretch( byte initialTile, int chunkIndex, int x, int y, int z, int face ) {
byte rawBlock = chunk[chunkIndex];
return rawBlock == initialTile && !info.IsFaceHidden( rawBlock, chunk[chunkIndex + offsets[face]], face )
&& (fullBright || IsLit( X, Y, Z, face, initialTile ) == IsLit( x, y, z, face, rawBlock ) );
}
bool OccludedLiquid( int chunkIndex ) {
return info.IsOpaque[chunk[chunkIndex + 324]] && !info.IsAir[chunk[chunkIndex + 324 - 18]] &&
!info.IsAir[chunk[chunkIndex + 324 - 1]] && !info.IsAir[chunk[chunkIndex + 324 + 1]] &&
!info.IsAir[chunk[chunkIndex + 324 + 18]];
}
bool IsLit( int x, int y, int z, int face, byte type ) {
int offset = (info.LightOffset[type] >> face) & 1;
switch( face ) {
case Side.Left:
return x < offset || y > map.heightmap[(z * width) + (x - offset)];
case Side.Right:
return x > (maxX - offset) || y > map.heightmap[(z * width) + (x + offset)];
case Side.Front:
return z < offset || y > map.heightmap[((z - offset) * width) + x];
case Side.Back:
return z > (maxZ - offset) || y > map.heightmap[((z + offset) * width) + x];
case Side.Bottom:
return y <= 0 || (y - 1 - offset) >= (map.heightmap[(z * width) + x]);
case Side.Top:
return y >= maxY || (y - offset) >= (map.heightmap[(z * width) + x]);
}
return true;
}
public void OnNewMapLoaded() {
map = game.World;
env = game.World.Env;
width = map.Width;
height = map.Height;
length = map.Length;
clipLevel = Math.Max( 0, game.World.Env.SidesHeight );
maxX = width - 1;
maxY = height - 1;
maxZ = length - 1;
}
}
public struct ChunkPartInfo {
public int VbId, IndicesCount, SpriteCount;
public int LeftIndex, RightIndex, FrontIndex,
BackIndex, BottomIndex, TopIndex;
public ushort LeftCount, RightCount, FrontCount,
BackCount, BottomCount, TopCount;
}
}