void d8_flow_directions(
const Array2D<T> &elevations,
Array2D<U> &flowdirs
){
ProgressBar progress;
std::cerr<<"A D8 Flow Directions"<<std::endl;
std::cerr<<"C TODO"<<std::endl;
std::cerr<<"p Setting up the flow directions matrix..."<<std::endl;
flowdirs.resize(elevations);
flowdirs.setAll(NO_FLOW);
flowdirs.setNoData(FLOWDIR_NO_DATA);
std::cerr<<"p Calculating D8 flow directions..."<<std::endl;
progress.start( elevations.width()*elevations.height() );
#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(x,y)==elevations.noData())
flowdirs(x,y) = flowdirs.noData();
else
flowdirs(x,y) = d8_FlowDir(elevations,x,y);
}
std::cerr<<"t Succeeded in = "<<progress.stop()<<" s"<<std::endl;
}
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 Garbrecht_GradientAwayFromHigher(const Array2D<T> &elevations, const Array2D<d8_flowdir_t> &flowdirs, garbrecht_flat_type &flats, Array2D<int32_t> &inc2){
int loops = 0;
int number_incremented = 0;
std::cerr<<"Setting up the inc2 matrix..."<<std::endl;
inc2.resize(elevations);
inc2.setAll(0);
while(number_incremented<(int)flats.size()){
for(int i=0;i<(int)flats.size();i++){
int x=flats[i].x;
int y=flats[i].y;
if(inc2(x,y)>0){
inc2(x,y)++;
continue;
}
}
for(int i=0;i<(int)flats.size();i++){
bool has_higher=false,has_lower=false;
int x=flats[i].x;
int y=flats[i].y;
if(inc2(x,y)>0) continue;
for(int n=1;n<=8;n++){
if( !has_higher &&
(elevations(x+dx[n],y+dy[n])>elevations(x,y) ||
inc2(x+dx[n],y+dy[n])==2)
)
has_higher=true;
else if( !has_lower &&
elevations(x+dx[n],y+dy[n])<elevations(x,y)
)
has_lower=true;
}
if(has_higher && !has_lower){
inc2(x,y)++;
number_incremented++;
}
}
loops++;
}
}
void dinf_flow_directions(const Array2D<T> &elevations, Array2D<float> &flowdirs){
ProgressBar progress;
std::cerr<<"\nA Dinf Flow Directions"<<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 Dinf flow directions matrix..."<<std::endl;
flowdirs.resize(elevations);
flowdirs.setNoData(dinf_NO_DATA);
flowdirs.setAll(NO_FLOW);
std::cerr<<"p Calculating Dinf flow directions..."<<std::endl;
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(x,y)==elevations.noData())
flowdirs(x,y) = flowdirs.noData();
else
flowdirs(x,y) = dinf_FlowDir(elevations,x,y);
}
std::cerr<<"t Succeeded in = "<<progress.stop()<<" s"<<std::endl;
}
void Zhou2015Labels(
Array2D<elev_t> &dem,
Array2D<label_t> &labels,
std::vector<std::map<label_t, elev_t> > &my_graph,
uint8_t edge,
bool flipH,
bool flipV
){
std::queue<GridCellZ<elev_t> > traceQueue;
std::queue<GridCellZ<elev_t> > depressionQue;
label_t current_label = 2;
labels.setAll(0);
GridCellZ_pq<elev_t> priorityQueue;
for(int32_t x=0;x<dem.width();x++){
const int height = dem.height()-1;
priorityQueue.emplace(x,0, dem(x,0 ));
priorityQueue.emplace(x,height,dem(x,height));
}
for(int32_t y=1;y<dem.height()-1;y++){
const int width = dem.width()-1;
priorityQueue.emplace(0, y,dem(0, y));
priorityQueue.emplace(width,y,dem(width,y));
}
while (!priorityQueue.empty()){
GridCellZ<elev_t> c = priorityQueue.top();
priorityQueue.pop();
auto my_label = labels(c.x,c.y) = GetNewLabelZhou(c.x,c.y,current_label,edge,dem,labels);
for(int n=1;n<=8;n++){
int nx = c.x+dx[n];
int ny = c.y+dy[n];
if (!dem.inGrid(nx,ny))
continue;
WatershedsMeet(my_label,labels(nx,ny),dem(c.x,c.y),dem(nx,ny),my_graph);
if(labels(nx,ny)!=0)
continue;
labels(nx,ny) = labels(c.x,c.y);
if(dem(nx,ny)<=c.z){ //Depression cell
dem(nx,ny) = c.z;
depressionQue.emplace(nx,ny,c.z);
ProcessPit_onepass(dem,labels,depressionQue,traceQueue,priorityQueue,my_graph);
} else { //Slope cell
traceQueue.emplace(nx,ny,dem(nx,ny));
}
ProcessTraceQue_onepass(dem,labels,traceQueue,priorityQueue,my_graph);
}
}
//Connect the DEM's outside edges to Special Watershed 1. This requires
//knowing whether the tile has been flipped toe snure that we connect the
//correct edges.
if( ((edge & GRID_TOP) && !flipV) || ((edge & GRID_BOTTOM) && flipV) )
for(int32_t x=0;x<labels.width();x++)
WatershedsMeet(labels(x,0),(label_t)1,dem(x,0),dem(x,0),my_graph);
if( ((edge & GRID_BOTTOM) && !flipV) || ((edge & GRID_TOP) && flipV) ){
int bottom_row = labels.height()-1;
for(int32_t x=0;x<labels.width();x++)
WatershedsMeet(labels(x,bottom_row),(label_t)1,dem(x,bottom_row),dem(x,bottom_row),my_graph);
}
if( ((edge & GRID_LEFT) && !flipH) || ((edge & GRID_RIGHT) && flipH) )
for(int32_t y=0;y<labels.height();y++)
WatershedsMeet(labels(0,y),(label_t)1,dem(0,y),dem(0,y),my_graph);
if( ((edge & GRID_RIGHT) && !flipH) || ((edge & GRID_LEFT) && flipH) ){
int right_col = labels.width()-1;
for(int32_t y=0;y<labels.height();y++)
WatershedsMeet(labels(right_col,y),(label_t)1,dem(right_col,y),dem(right_col,y),my_graph);
}
my_graph.resize(current_label);
}
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;
}
