void MapEditor::Filter(int nFilteTimes, float filterPar)
{
ATLASSERT(nFilteTimes > 0);
for(int i = 0; i < nFilteTimes; ++i)
{
FilterHeightField(m_pMapData, m_height, filterPar);
}
m_isModified = true;
m_isDrawed = false;
}
void MakeTerrainFault(float* field,int size,int iterations,int maxDelta,int minDelta,int iterationsPerFilter,float filter)
{
int x1,y1,x2,y2,dx1,dy1,dx2,dy2,i,dHeight;
/*
Clear the height field
*/
for (i=0;i<size*size;i++)
{
field[i] = 0.0f;
}
for (i=0;i<iterations;i++)
{
/*
Calculate the dHeight for this iteration
(linear interpolation from maxDelta to minDelta
*/
dHeight = maxDelta - ((maxDelta-minDelta)*i)/iterations;
/*
Pick two random points on the field for the line
(make sure they're not identical)
*/
x1 = rand()%size;
y1 = rand()%size;
do
{
x2 = rand()%size;
y2 = rand()%size;
}while (x2==x1 && y2==y1);
/*
dx1,dy1 is a vector in the direction of the line
*/
dx1 = x2 - x1;
dy1 = y2 - y1;
for (x2 = 0;x2<size;x2++)
for (y2 = 0;y2<size;y2++)
{
/*
dx2,dy2 is a vector from x1,y1 to the candidate point
*/
dx2 = x2-x1;
dy2 = y2-y1;
/*
if z component of the cross product is 'up', then elevate this point
*/
if (dx2*dy1 - dx1*dy2 > 0)
{
field[x2+size*y2] += (float)(dHeight);
}
}
/*
Erode terrain
*/
if (iterationsPerFilter!=0 && (i%iterationsPerFilter)==0)
FilterHeightField(field,size,filter);
}
/*
Normalize terrain (height field values in the range 0-1)
*/
NormalizeTerrain(field,size);
}
//--------------------------------------------------------------
// Name: CTERRAIN::MakeTerrainFault - public
// Description: Create a height data set using the "Fault Formation"
// algorithm. Thanks a lot to Jason Shankel for this code!
// Arguments: -iSize: Desired size of the height map
// -iIterations: Number of detail passes to make
// -iMinDelta, iMaxDelta: the desired min/max heights
// -iIterationsPerFilter: Number of passes per filter
// -fFilter: Strength of the filter
// Return Value: A boolean value: -true: successful creation
// -false: unsuccessful creation
//--------------------------------------------------------------
bool CTERRAIN::MakeTerrainFault( int iSize, int iIterations, int iMinDelta, int iMaxDelta, float fFilter )
{
float* fTempBuffer;
int iCurrentIteration;
int iHeight;
int iRandX1, iRandZ1;
int iRandX2, iRandZ2;
int iDirX1, iDirZ1;
int iDirX2, iDirZ2;
int x, z;
int i;
if( m_heightData.m_ucpData )
UnloadHeightMap( );
m_iSize= iSize;
//allocate the memory for our height data
m_heightData.m_ucpData= new unsigned char [m_iSize*m_iSize];
fTempBuffer= new float [m_iSize*m_iSize];
//check to see if memory was successfully allocated
if( m_heightData.m_ucpData==NULL )
{
//something is seriously wrong here
g_log.Write( LOG_FAILURE, "Could not allocate memory for height map" );
return false;
}
//check to see if memory was successfully allocated
if( fTempBuffer==NULL )
{
//something is seriously wrong here
g_log.Write( LOG_FAILURE, "Could not allocate memory for height map" );
return false;
}
//clear the height fTempBuffer
for( i=0; i<m_iSize*m_iSize; i++ )
fTempBuffer[i]= 0;
for( iCurrentIteration=0; iCurrentIteration<iIterations; iCurrentIteration++ )
{
//calculate the height range (linear interpolation from iMaxDelta to
//iMinDelta) for this fault-pass
iHeight= iMaxDelta - ( ( iMaxDelta-iMinDelta )*iCurrentIteration )/iIterations;
//pick two points at random from the entire height map
iRandX1= rand( )%m_iSize;
iRandZ1= rand( )%m_iSize;
//check to make sure that the points are not the same
do
{
iRandX2= rand( )%m_iSize;
iRandZ2= rand( )%m_iSize;
} while ( iRandX2==iRandX1 && iRandZ2==iRandZ1 );
//iDirX1, iDirZ1 is a vector going the same direction as the line
iDirX1= iRandX2-iRandX1;
iDirZ1= iRandZ2-iRandZ1;
for( z=0; z<m_iSize; z++ )
{
for( x=0; x<m_iSize; x++ )
{
//iDirX2, iDirZ2 is a vector from iRandX1, iRandZ1 to the current point (in the loop)
iDirX2= x-iRandX1;
iDirZ2= z-iRandZ1;
//if the result of ( iDirX2*iDirZ1 - iDirX1*iDirZ2 ) is "up" (above 0),
//then raise this point by iHeight
if( ( iDirX2*iDirZ1 - iDirX1*iDirZ2 )>0 )
fTempBuffer[( z*m_iSize )+x]+= ( float )iHeight;
}
}
//erode terrain
FilterHeightField( fTempBuffer, fFilter );
}
//normalize the terrain for our purposes
NormalizeTerrain( fTempBuffer );
//transfer the terrain into our class's unsigned char height buffer
for( z=0; z<m_iSize; z++ )
{
for( x=0; x<m_iSize; x++ )
SetHeightAtPoint( ( unsigned char )fTempBuffer[( z*m_iSize )+x], x, z );
}
//delete temporary buffer
if( fTempBuffer )
{
//delete the data
delete[] fTempBuffer;
}
return true;
}
