void Garbrecht_GradientTowardsLower(const Array2D<T> &elevations, const Array2D<d8_flowdir_t> &flowdirs, garbrecht_flat_type &flats, Array2D<int32_t> &inc1){
int loops = 0;
int number_incremented = -1;
std::cerr<<"Setting up the inc1 matrix..."<<std::endl;
inc1.resize(elevations);
inc1.setAll(0);
while(number_incremented!=0){
number_incremented=0;
for(int i=0;i<(int)flats.size();i++){
bool increment_elevation=true;
int x=flats[i].x;
int y=flats[i].y;
for(int n=1;n<=8;n++){
if( elevations(x+dx[n],y+dy[n])<elevations(x,y) &&
flowdirs(x+dx[n],y+dy[n])!=NO_FLOW && !flowdirs.isNoData(x+dx[n],y+dy[n])
){
increment_elevation=false;
break;
}
else if(inc1(x+dx[n],y+dy[n])<loops &&
elevations(x+dx[n],y+dy[n])==elevations(x,y)
){
increment_elevation=false;
break;
}
}
if(increment_elevation){
inc1(x,y)++;
number_incremented++;
}
}
loops++;
}
}
void FindFlats(
const Array2D<T> &elevations,
Array2D<int8_t> &flats
){
flats.resize(elevations);
flats.setNoData(FLAT_NO_DATA);
ProgressBar progress;
progress.start( elevations.size() );
#pragma omp parallel for
for(int y=0;y<elevations.height();y++)
for(int x=0;x<elevations.width();x++){
if(elevations.isNoData(x,y)){
flats(x,y) = FLAT_NO_DATA;
continue;
}
if(elevations.isEdgeCell(x,y)){
flats(x,y) = NOT_A_FLAT;
continue;
}
//We'll now assume that the cell is a flat unless proven otherwise
flats(x,y) = IS_A_FLAT;
for(int n=1;n<=8;n++){
const int nx = x+dx[n];
const int ny = y+dy[n];
if(elevations(nx,ny)<elevations(x,y) || elevations.isNoData(nx,ny)){
flats(x,y) = NOT_A_FLAT;
break;
}
}
//We handled the base case just above the for loop
}
RDLOG_TIME_USE<<"Succeeded in = "<<progress.stop()<<" s";
}
static inline void TerrainProcessor(F func, const Array2D<T> &elevations, const float zscale, Array2D<float> &output){
if(elevations.getCellLengthX()!=elevations.getCellLengthY())
RDLOG_WARN<<"Cell X and Y dimensions are not equal!";
output.resize(elevations);
ProgressBar progress;
progress.start(elevations.size());
#pragma omp parallel for
for(int y=0;y<elevations.height();y++){
progress.update(y*elevations.width());
for(int x=0;x<elevations.width();x++)
if(elevations.isNoData(x,y))
output(x,y) = output.noData();
else
output(x,y) = func(elevations,x,y,zscale);
}
RDLOG_TIME_USE<<"Wall-time = "<<progress.stop();
}
void dinf_upslope_area(
const Array2D<T> &flowdirs,
Array2D<U> &area
){
Array2D<int8_t> dependency;
std::queue<GridCell> sources;
ProgressBar progress;
std::cerr<<"\nA D-infinity Upslope Area"<<std::endl;
std::cerr<<"C Tarboton, D.G. 1997. A new method for the determination of flow directions and upslope areas in grid digital elevation models. Water Resources Research. Vol. 33. pp 309-319."<<std::endl;
std::cerr<<"p Setting up the dependency matrix..."<<std::endl;
dependency.resize(flowdirs);
dependency.setAll(0);
std::cerr<<"p Setting up the area matrix..."<<std::endl;
area.resize(flowdirs);
area.setAll(0);
area.setNoData(dinf_NO_DATA);
bool has_cells_without_flow_directions=false;
std::cerr<<"p Calculating dependency matrix & setting noData() cells..."<<std::endl;
progress.start( flowdirs.size() );
///////////////////////
//Calculate the number of "dependencies" each cell has. That is, count the
//number of cells which flow into each cell.
#pragma omp parallel for reduction(|:has_cells_without_flow_directions)
for(int y=0;y<flowdirs.height();y++){
progress.update( y*flowdirs.width() );
for(int x=0;x<flowdirs.width();x++){
//If the flow direction of the cell is NoData, mark its area as NoData
if(flowdirs.isNoData(x,y)){
area(x,y) = area.noData();
dependency(x,y) = 9; //TODO: This is an unnecessary safety precaution. This prevents the cell from ever being enqueued (an unnecessary safe guard? TODO)
continue; //Only necessary if there are bugs below (TODO)
}
//If the cell has no flow direction, note that so we can warn the user
if(flowdirs(x,y)==NO_FLOW){
has_cells_without_flow_directions=true;
continue;
}
//TODO: More explanation of what's going on here
int n_high, n_low;
int nhx,nhy,nlx,nly;
where_do_i_flow(flowdirs(x,y),n_high,n_low);
nhx=x+dinf_dx[n_high];
nhy=y+dinf_dy[n_high];
if(n_low!=-1){
nlx = x+dinf_dx[n_low];
nly = y+dinf_dy[n_low];
}
if( n_low!=-1 && flowdirs.inGrid(nlx,nly) && flowdirs(nlx,nly)!=flowdirs.noData() )
dependency(nlx,nly)++;
if( flowdirs.inGrid(nhx,nhy) && flowdirs(nhx,nhy)!=flowdirs.noData() )
dependency(nhx,nhy)++;
}
}
std::cerr<<"t Succeeded in = "<<progress.stop()<<" s"<<std::endl;
if(has_cells_without_flow_directions)
std::cerr<<"W \033[91mNot all cells had defined flow directions! This implies that there will be digital dams!\033[39m"<<std::endl;
///////////////////////
//Find those cells which have no dependencies. These are the places to start
//the flow accumulation calculation.
std::cerr<<"p Locating source cells..."<<std::endl;
progress.start( flowdirs.size() );
for(int y=0;y<flowdirs.height();y++){
progress.update( y*flowdirs.width() );
for(int x=0;x<flowdirs.width();x++)
if(flowdirs(x,y)==flowdirs.noData())
continue;
else if(flowdirs(x,y)==NO_FLOW)
continue;
else if(dependency(x,y)==0)
sources.emplace(x,y);
}
std::cerr<<"t Source cells located in = "<<progress.stop()<<" s"<<std::endl;
///////////////////////
//Calculate the flow accumulation by "pouring" a cell's flow accumulation
//value into the cells below it, as indicated by the D-infinite flow routing
//method.
std::cerr<<"p Calculating up-slope areas..."<<std::endl;
progress.start( flowdirs.numDataCells() );
long int ccount=0;
while(sources.size()>0){
auto c = sources.front();
sources.pop();
progress.update(ccount++);
if(flowdirs.isNoData(c.x,c.y)) //TODO: This line shouldn't be necessary since NoData's do not get added below
continue;
area(c.x,c.y)+=1;
if(flowdirs(c.x,c.y)==NO_FLOW)
continue;
int n_high,n_low,nhx,nhy,nlx,nly;
where_do_i_flow(flowdirs(c.x,c.y),n_high,n_low);
nhx = c.x+dinf_dx[n_high];
nhy = c.y+dinf_dy[n_high];
float phigh,plow;
area_proportion(flowdirs(c.x,c.y), n_high, n_low, phigh, plow);
if(flowdirs.inGrid(nhx,nhy) && flowdirs(nhx,nhy)!=flowdirs.noData())
area(nhx,nhy)+=area(c.x,c.y)*phigh;
if(n_low!=-1){
nlx = c.x+dinf_dx[n_low];
nly = c.y+dinf_dy[n_low];
if(flowdirs.inGrid(nlx,nly) && flowdirs(nlx,nly)!=flowdirs.noData()){
area(nlx,nly)+=area(c.x,c.y)*plow;
if((--dependency(nlx,nly))==0)
sources.emplace(nlx,nly);
}
}
if( flowdirs.inGrid(nhx,nhy) && flowdirs(nhx,nhy)!=flowdirs.noData() && (--dependency(nhx,nhy))==0)
sources.emplace(nhx,nhy);
}
std::cerr<<"p Succeeded in = "<<progress.stop()<<" s"<<std::endl;
}
void FM_Freeman(
const Array2D<E> &elevations,
Array3D<float> &props,
const double xparam
){
RDLOG_ALG_NAME<<"Freeman (1991) Flow Accumulation (aka MFD, MD8)";
RDLOG_CITATION<<"Freeman, T.G., 1991. Calculating catchment area with divergent flow based on a regular grid. Computers & Geosciences 17, 413–422.";
RDLOG_CONFIG<<"p = "<<xparam;
props.setAll(NO_FLOW_GEN);
props.setNoData(NO_DATA_GEN);
ProgressBar progress;
progress.start(elevations.size());
#pragma omp parallel for collapse(2)
for(int y=0;y<elevations.height();y++)
for(int x=0;x<elevations.width();x++){
++progress;
if(elevations.isNoData(x,y)){
props(x,y,0) = NO_DATA_GEN;
continue;
}
if(elevations.isEdgeCell(x,y))
continue;
const E e = elevations(x,y);
double C = 0;
for(int n=1;n<=8;n++){
const int nx = x+dx[n];
const int ny = y+dy[n];
if(!elevations.inGrid(nx,ny))
continue;
if(elevations.isNoData(nx,ny)) //TODO: Don't I want water to drain this way?
continue;
const E ne = elevations(nx,ny);
if(ne<e){
const double rise = e-ne;
const double run = dr[n];
const double grad = rise/run;
const auto cval = std::pow(grad,xparam);
props(x,y,n) = cval;
C += cval;
}
}
if(C>0){
props(x,y,0) = HAS_FLOW_GEN;
C = 1/C; //TODO
for(int n=1;n<=8;n++){
auto &this_por = props(x,y,n);
if(this_por>0)
this_por *= C;
else
this_por = 0;
}
}
}
progress.stop();
}
