//---------------------------------------------------------
bool SG_Get_Crossing(TSG_Point &Crossing, const TSG_Point &a1, const TSG_Point &a2, const TSG_Point &b1, const TSG_Point &b2, bool bExactMatch)
{
//-----------------------------------------------------
if( bExactMatch
&& ( (M_GET_MAX(a1.x, a2.x) < M_GET_MIN(b1.x, b2.x))
|| (M_GET_MIN(a1.x, a2.x) > M_GET_MAX(b1.x, b2.x))
|| (M_GET_MAX(a1.y, a2.y) < M_GET_MIN(b1.y, b2.y))
|| (M_GET_MIN(a1.y, a2.y) > M_GET_MAX(b1.y, b2.y)) ) )
{
return( false );
}
//-----------------------------------------------------
if( (a1.x == b1.x && a1.y == b1.y) || (a1.x == b2.x && a1.y == b2.y) )
{
Crossing = a1;
return( true );
}
if( (a2.x == b1.x && a2.y == b1.y) || (a2.x == b2.x && a2.y == b2.y) )
{
Crossing = a2;
return( true );
}
//-----------------------------------------------------
double lambda, div, a_dx, a_dy, b_dx, b_dy;
a_dx = a2.x - a1.x;
a_dy = a2.y - a1.y;
b_dx = b2.x - b1.x;
b_dy = b2.y - b1.y;
if( (div = a_dx * b_dy - b_dx * a_dy) != 0.0 )
{
lambda = ((b1.x - a1.x) * b_dy - b_dx * (b1.y - a1.y)) / div;
Crossing.x = a1.x + lambda * a_dx;
Crossing.y = a1.y + lambda * a_dy;
if( !bExactMatch )
{
return( true );
}
else if( 0.0 <= lambda && lambda <= 1.0 )
{
lambda = ((b1.x - a1.x) * a_dy - a_dx * (b1.y - a1.y)) / div;
if( 0.0 <= lambda && lambda <= 1.0 )
{
return( true );
}
}
}
return( false );
}
bool CGrid_Proximity_Buffer::On_Execute(void){
CSG_Grid *pSource, *pDistance, *pAlloc, *pBuffer;
double dBufDist, dDist, cellSize;
int x, y, i, j, imin, imax, jmin, jmax, iBufDist, alloc, ival;
pSource = Parameters("SOURCE")->asGrid();
pDistance = Parameters("DISTANCE")->asGrid();
pAlloc = Parameters("ALLOC")->asGrid();
pBuffer = Parameters("BUFFER")->asGrid();
ival = Parameters("IVAL")->asInt();
cellSize = pSource->Get_Cellsize();
dBufDist = Parameters("DIST")->asDouble() / cellSize;
iBufDist = (int) (dBufDist + 2.0);
dBufDist = pow(dBufDist, 2);
pDistance->Assign_NoData();
pAlloc->Assign_NoData();
pBuffer->Assign_NoData();
for(y=0; y<Get_NY() && Set_Progress(y); y++)
{
for(x=0; x<Get_NX(); x++)
{
if( !pSource->is_NoData(x, y) )
{
alloc = pSource->asInt(x, y);
pAlloc->Set_Value(x, y, alloc);
pDistance->Set_Value(x, y, 0.0);
imin = M_GET_MAX(0, x-iBufDist);
imax = M_GET_MIN(x+iBufDist, Get_NX());
jmin = M_GET_MAX(0, y-iBufDist);
jmax = M_GET_MIN(y+iBufDist, Get_NY());
for(i=imin; i<imax; i++)
{
for(j=jmin; j<jmax; j++)
{
if( pSource->is_NoData(i, j) )
{
dDist= (x-i)*(x-i)+(y-j)*(y-j);
if( dDist <= dBufDist && (pDistance->is_NoData(i, j) || pDistance->asDouble(i, j) > dDist) )
{
pDistance->Set_Value(i, j, dDist);
pAlloc->Set_Value(i, j, alloc);
}
}
}//for
}//for
}//if
}//for
}//for
for(y=0; y<Get_NY() && Set_Progress(y); y++)
{
for(x=0; x<Get_NX(); x++)
{
if( !pDistance->is_NoData(x, y) )
{
dDist = sqrt(pDistance->asDouble(x, y)) * cellSize;
pDistance->Set_Value(x, y, dDist);
i = 0;
while( i< dDist )
i += ival;
pBuffer->Set_Value(x, y, i);
}
}
}
return( true );
}