void TerrainLattice::CalcGeoMipmapLod(float x,float y)
{
Terrain* pTerrain = m_pCachedTerrains[m_CurrentTerrainIndex[0]].pTerrain;
int blockCountX = (pTerrain->GetWidthVertices()-1) / pTerrain->GetMaximumVisibleBlockSize();
float blockSize = m_TerrainWidth/blockCountX;
int terrainCountX = (int)x / (int)m_TerrainWidth;
int terrainCountY = (int)y / (int)m_TerrainHeight;
x = x - terrainCountX * (int)m_TerrainWidth;
y = y - terrainCountY * (int)m_TerrainHeight;
int centerChunkIdxX = (int)(x / blockSize) + blockCountX;
int centerChunkIdxY = (int)(y / blockSize) + blockCountX;
int lodBounds[8];
int halfWidth = m_Level0ChunkCount / 2;
lodBounds[0] = centerChunkIdxX - halfWidth;
lodBounds[1] = centerChunkIdxX + halfWidth;
lodBounds[2] = centerChunkIdxY - halfWidth;
lodBounds[3] = centerChunkIdxY + halfWidth;
halfWidth = m_Level1ChunkCount / 2;
lodBounds[4] = lodBounds[0] - halfWidth;
lodBounds[5] = lodBounds[1] + halfWidth;
lodBounds[6] = lodBounds[2] - halfWidth;
lodBounds[7] = lodBounds[3] + halfWidth;
const int leftFlag = 0x01;
const int rightFlag = 0x02;
const int topFlag = 0x04;
const int bottomFlag = 0x08;
//calc lod for each block in each terrain
for (int dir = 0; dir < 9 ; dir++)
{
TerrainTileCacheMap_type::iterator iter = m_pCachedTerrains.find(m_CurrentTerrainIndex[dir]);
if(iter != m_pCachedTerrains.end())
{
int startBlockIdxX = 0;
int startBlockIdxY = 0;
Terrain* pTerrain = (*iter).second.pTerrain;
if(dir == DIR_CENTER)
{
startBlockIdxX = blockCountX;
startBlockIdxY = blockCountX;
}
else if(dir == DIR_NORTH)
{
startBlockIdxX = blockCountX;
startBlockIdxY = blockCountX * 2;
}
else if(dir == DIR_NORTHEAST)
{
startBlockIdxX = blockCountX * 2;
startBlockIdxY = blockCountX * 2;
}
else if(dir == DIR_EAST)
{
startBlockIdxX = blockCountX * 2;
startBlockIdxY = blockCountX;
}
else if(dir == DIR_SOUTHEAST)
{
startBlockIdxX = blockCountX * 2;
startBlockIdxY = 0;
}
else if(dir == DIR_SOUTH)
{
startBlockIdxX = blockCountX;
startBlockIdxY = 0;
}
else if(dir == DIR_SOUTHWEST)
{
startBlockIdxX = 0;
startBlockIdxY = 0;
}
else if(dir == DIR_WEST)
{
startBlockIdxX = 0;
startBlockIdxY = blockCountX;
}
else if(dir == DIR_NORTHWEST)
{
startBlockIdxX = 0;
startBlockIdxY = blockCountX * 2;
}
for(int i=0;i<blockCountX;i++)
{
for(int j=0;j<blockCountX;j++)
{
int blockX = startBlockIdxX + j;
int blockY = startBlockIdxY + i;
int level = CalcBlockLod(lodBounds,blockX,blockY,3);
int blockType = 0;
int leftBlock = CalcBlockLod(lodBounds,blockX-1,blockY,3);
if(leftBlock > level)
blockType |= leftFlag;
int rightBlock = CalcBlockLod(lodBounds,blockX+1,blockY,3);
if(rightBlock > level)
blockType |= rightFlag;
int topBlock = CalcBlockLod(lodBounds,blockX,blockY-1,3);
if(topBlock > level)
blockType |= topFlag;
int bottomBlock = CalcBlockLod(lodBounds,blockX,blockY+1,3);
if(bottomBlock > level)
blockType |= bottomFlag;
GeoMipmapChunkType chunkType;
switch (blockType)
{
case leftFlag|rightFlag|topFlag|bottomFlag:
chunkType = gmc_surrounded;
break;
case topFlag | leftFlag:
chunkType = gmc_topLeft;
break;
case leftFlag:
chunkType = gmc_left;
break;
case bottomFlag | leftFlag:
chunkType = gmc_bottomLeft;
break;
case bottomFlag:
chunkType = gmc_bottom;
break;
case bottomFlag | rightFlag:
chunkType = gmc_bottomRight;
break;
case rightFlag:
chunkType = gmc_right;
break;
case topFlag | rightFlag:
chunkType = gmc_topRight;
break;
case topFlag:
chunkType = gmc_top;
break;
default:
chunkType = gmc_normal;
break;
}
pTerrain->SetBlockLod(i,j,level,chunkType);
}
}
}
}
}
