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 dinf_upslope_area_interval(const float_2d &flowdirs, grid_engine< boost::numeric::interval<T> > &area){
char_2d dependency;
std::queue<grid_cell> sources;
ProgressBar progress;
diagnostic_arg("The sources queue will require at most approximately %ldMB of RAM.\n",flowdirs.width()*flowdirs.height()*((long)sizeof(grid_cell))/1024/1024);
diagnostic("Setting up the dependency matrix...");
dependency.copyprops(flowdirs);
dependency.init(0);
diagnostic("succeeded.\n");
diagnostic("Setting up the area matrix...");
area.copyprops(flowdirs);
area.init((float)0);
area.no_data=dinf_NO_DATA;
diagnostic("succeeded.\n");
bool has_cells_without_flow_directions=false;
diagnostic("%%Calculating dependency matrix & setting no_data cells...\n");
progress.start( flowdirs.width()*flowdirs.height() );
#pragma omp parallel for reduction(|:has_cells_without_flow_directions)
for(int x=0;x<flowdirs.width();x++){
progress.update( x*flowdirs.height() );
for(int y=0;y<flowdirs.height();y++){
if(flowdirs(x,y)==flowdirs.no_data){
area(x,y)=area.no_data;
dependency(x,y)=9; //Note: This is an unnecessary safety precaution
continue;
}
if(flowdirs(x,y)==NO_FLOW){
has_cells_without_flow_directions=true;
continue;
}
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.in_grid(nlx,nly) && flowdirs(nlx,nly)!=flowdirs.no_data )
dependency(nlx,nly)++;
if( flowdirs.in_grid(nhx,nhy) && flowdirs(nhx,nhy)!=flowdirs.no_data )
dependency(nhx,nhy)++;
}
}
diagnostic_arg(SUCCEEDED_IN,progress.stop());
if(has_cells_without_flow_directions)
diagnostic("\033[91mNot all cells had defined flow directions! This implies that there will be digital dams!\033[39m\n");
diagnostic("%%Locating source cells...\n");
progress.start( flowdirs.width()*flowdirs.height() );
for(int x=0;x<flowdirs.width();x++){
progress.update( x*flowdirs.height() );
for(int y=0;y<flowdirs.height();y++)
if(flowdirs(x,y)==flowdirs.no_data)
continue;
else if(flowdirs(x,y)==NO_FLOW)
continue;
else if(dependency(x,y)==0)
sources.push(grid_cell(x,y));
}
diagnostic_arg(SUCCEEDED_IN,progress.stop());
diagnostic("%%Calculating up-slope areas...\n");
progress.start( flowdirs.data_cells );
long int ccount=0;
while(sources.size()>0){
grid_cell c=sources.front();
sources.pop();
ccount++;
progress.update(ccount);
if(flowdirs(c.x,c.y)==flowdirs.no_data) //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.in_grid(nhx,nhy) && flowdirs(nhx,nhy)!=flowdirs.no_data)
area(nhx,nhy)+=area(c.x,c.y)*(T)phigh;
if(n_low!=-1){
nlx=c.x+dinf_dx[n_low];
nly=c.y+dinf_dy[n_low];
if(flowdirs.in_grid(nlx,nly) && flowdirs(nlx,nly)!=flowdirs.no_data){
area(nlx,nly)+=area(c.x,c.y)*(T)plow;
if((--dependency(nlx,nly))==0)
sources.push(grid_cell(nlx,nly));
}
}
if( flowdirs.in_grid(nhx,nhy) && flowdirs(nhx,nhy)!=flowdirs.no_data && (--dependency(nhx,nhy))==0)
sources.push(grid_cell(nhx,nhy));
}
diagnostic_arg(SUCCEEDED_IN,progress.stop());
}
