// Sets only flowDir only where there is a positive slope
// Returns number of cells which are flat
int setPosDir(linearpart<float>& elevDEM, linearpart<short>& flowDir)
{
double dxA = elevDEM.getdxA();
double dyA = elevDEM.getdyA();
int nx = elevDEM.getnx();
int ny = elevDEM.getny();
int numFlat = 0;
double tempdxc, tempdyc;
fact = new double*[ny]; // initialize 2d array by Nazmus 2/16
for(int m = 0; m<ny; m++)
fact[m] = new double[9];
for (int m = 0; m<ny; m++) {
for (int k = 1; k <= 8; k++) {
elevDEM.getdxdyc(m, tempdxc, tempdyc);
fact[m][k] = (double) (1./sqrt(d1[k]*d1[k]*tempdxc*tempdxc + d2[k]*d2[k]*tempdyc*tempdyc));
}
}
for (int j = 0; j < ny; j++) {
for (int i=0; i < nx; i++) {
//FlowDir is nodata if it is on the border OR elevDEM has no data
if (elevDEM.isNodata(i,j) || !elevDEM.hasAccess(i-1,j) || !elevDEM.hasAccess(i+1,j) ||
!elevDEM.hasAccess(i,j-1) || !elevDEM.hasAccess(i,j+1)) {
//do nothing
continue;
}
//Check if cell is "contaminated" (neighbors have no data)
// set flowDir to noData if contaminated
bool contaminated = false;
for (int k=1; k<=8; k++) {
int in=i+d1[k];
int jn=j+d2[k];
if (elevDEM.isNodata(in,jn)) {
contaminated = true;
break;
}
}
if (contaminated) {
flowDir.setToNodata(i,j);
} else {
// If cell is not contaminated,
flowDir.setData(i, j, 0);
setFlow(i,j, flowDir, elevDEM);
if (flowDir.getData(i,j) == 0) {
numFlat++;
}
}
}
}
return numFlat;
}
long setPosDirDinf(linearpart<float>& elevDEM, linearpart<float>& flowDir, linearpart<float>& slope, int useflowfile) {
double dxA = elevDEM.getdxA();
double dyA = elevDEM.getdyA();
long nx = elevDEM.getnx();
long ny = elevDEM.getny();
float tempFloat;
double tempdxc, tempdyc;
int i, j, k, in, jn, con;
long numFlat = 0;
tempFloat = 0;
for (j = 0; j < ny; j++) {
for (i = 0; i < nx; i++) {
//FlowDir is nodata if it is on the border OR elevDEM has no data
if (elevDEM.isNodata(i, j) || !elevDEM.hasAccess(i - 1, j) || !elevDEM.hasAccess(i + 1, j) ||
!elevDEM.hasAccess(i, j - 1) || !elevDEM.hasAccess(i, j + 1)) {
//do nothing
} else {
//Check if cell is "contaminated" (neighbors have no data)
// set flowDir to noData if contaminated
con = 0;
for (k = 1; k <= 8 && con != -1; k++) {
in = i + d1[k];
jn = j + d2[k];
if (elevDEM.isNodata(in, jn)) con = -1;
}
if (con == -1)
flowDir.setToNodata(i, j);
//If cell is not contaminated,
else {
tempFloat = -1.;
flowDir.setData(i, j, tempFloat); //set to -1
elevDEM.getdxdyc(j, tempdxc, tempdyc);
float DXX[3] = {0, tempdxc, tempdyc}; //tardemlib.cpp ln 1291
float DD = sqrt(tempdxc * tempdxc + tempdyc * tempdyc); //tardemlib.cpp ln 1293
SET2(j, i, DXX, DD, elevDEM, flowDir, slope); //i=y in function form old code j is x switched on purpose
// Use SET2 from serial code here modified to get what it has as felevg.d from elevDEM partition
// Modify to return 0 if there is a 0 slope. Modify SET2 to output flowDIR as no data (do nothing
// if verified initialization to nodata) and
// slope as 0 if a positive slope is not found
//setFlow( i,j, flowDir, elevDEM, area, useflowfile);
if (flowDir.getData(i, j, tempFloat) == -1)
numFlat++;
}
}
}
}
return numFlat;
}
//Calculate the slope information of flowDir to slope
void calcSlope(linearpart<short>& flowDir, linearpart<float>& elevDEM, linearpart<float>& slope)
{
int nx = elevDEM.getnx();
int ny = elevDEM.getny();
for (int j=0; j < ny; j++) {
for (int i=0; i < nx; i++) {
// If i,j is on the border or flowDir has no data, set slope(i,j) to slopeNoData
if (flowDir.isNodata(i,j) || !flowDir.hasAccess(i-1,j) || !flowDir.hasAccess(i+1,j) ||
!flowDir.hasAccess(i,j-1) || !flowDir.hasAccess(i,j+1)) {
slope.setToNodata(i, j);
} else {
short flowDirection = flowDir.getData(i,j);
int in = i + d1[flowDirection];
int jn = j + d2[flowDirection];
float elevDiff = elevDEM.getData(i,j) - elevDEM.getData(in,jn);
slope.setData(i,j, elevDiff*fact[j][flowDirection]);
}
}
}
}
int markPits(T& elevDEM, linearpart<float>& flowDir, std::vector<std::vector<node>>&islands, SparsePartition<short>& inc)
{
int nx = flowDir.getnx();
int ny = flowDir.getny();
int numPits = 0;
//There are pits remaining - set direction to no data
for (auto& island : islands) {
for (node flat : island) {
bool skip = false;
for (int k=1; k<=8; k++) {
if (dontCross(k, flat.x, flat.y, flowDir)==0) {
int jn = flat.y + d2[k];
int in = flat.x + d1[k];
if (!flowDir.hasAccess(in, jn))
continue;
auto elevDiff = elevDEM.getData(flat.x, flat.y) - elevDEM.getData(in, jn);
float flow = flowDir.getData(in, jn);
// Adjacent cell drains and is equal or lower in elevation so this is a low boundary
if (elevDiff >= 0 && flow == -1) {
skip = true;
break;
} else if (flow == -1) {
// If neighbor is in flat
// FIXME: check if this is correct
if (inc.getData(in,jn) >= 0){ // && inc.getData(in,jn)<st) {
skip = true;
break;
}
}
}
}
// mark pit
if (!skip) {
numPits++;
flowDir.setToNodata(flat.x, flat.y);
}
}
}
return numPits;
}
void flowTowardsLower(T& elev, linearpart<float>& flowDir, std::vector<std::vector<node>>&islands, SparsePartition<short>& inc)
{
long nx = flowDir.getnx();
long ny = flowDir.getny();
std::vector<node> lowBoundaries;
// Find low boundaries.
for(auto& island : islands) {
for(node flat : island) {
float flatElev = elev.getData(flat.x, flat.y);
for (int k = 1; k <= 8; k++) {
if (dontCross(k, flat.x, flat.y, flowDir) == 0) {
int in = flat.x + d1[k];
int jn = flat.y + d2[k];
if (!flowDir.hasAccess(in, jn))
continue;
auto elevDiff = flatElev - elev.getData(in,jn);
float flow = flowDir.getData(in, jn);
bool edgeDrain = flowDir.isNodata(in, jn);
// Adjacent cell drains and is equal or lower in elevation so this is a low boundary
if ((elevDiff >= 0 && flow >= 0.0) || edgeDrain) {
lowBoundaries.push_back(flat);
inc.setData(flat.x, flat.y, -1);
// No need to check the other neighbors
break;
}
}
}
}
}
size_t numInc = propagateIncrements(flowDir, inc, lowBoundaries);
// Not all grid cells were resolved - pits remain
// Remaining grid cells are unresolvable pits
if (numInc > 0)
{
markPits(elev, flowDir, islands, inc);
}
}
void setFlow2(int i, int j, linearpart<short>& flowDir, T& elev, SparsePartition<int>& inc)
{
/* This function sets directions based upon secondary elevations for
assignment of flow directions across flats according to Garbrecht and Martz
scheme. There are two possibilities:
A. The neighbor is outside the flat set
B. The neighbor is in the flat set.
In the case of A the input elevations are used and if a draining neighbor is found it is selected.
Case B requires slope to be positive. Remaining flats are removed by iterating this process
*/
int nx = flowDir.getnx();
int ny = flowDir.getny();
const short order[8]= {1,3,5,7,2,4,6,8};
float slopeMax = 0;
for (short k : order) {
int in = i+d1[k];
int jn = j+d2[k];
if (!flowDir.hasAccess(in, jn))
continue;
if (inc.getData(in, jn) > 0) {
// Neighbor is in flat
float slope = fact[j][k]*(inc.getData(i, j) - inc.getData(in, jn));
if (slope > slopeMax) {
flowDir.setData(i, j, k);
slopeMax = slope;
}
} else {
// Neighbor is not in flat
auto ed = elev.getData(i, j) - elev.getData(in, jn);
if (ed >= 0) {
// Found a way out - this is outlet
flowDir.setData(i, j, k);
break;
}
}
}
}
void flowFromHigher(T& elev, linearpart<float>& flowDir, std::vector<std::vector<node>>&islands, SparsePartition<short>& inc)
{
long nx = flowDir.getnx();
long ny = flowDir.getny();
// Find high boundaries
for (auto& island : islands) {
std::vector<node> highBoundaries;
for (node flat : island) {
float flatElev = elev.getData(flat.x, flat.y);
bool highBoundary = false;
for (int k = 1; k <= 8; k++) {
if (dontCross(k, flat.x, flat.y, flowDir) == 0) {
int in = flat.x + d1[k];
int jn = flat.y + d2[k];
if (!flowDir.hasAccess(in, jn))
continue;
auto elevDiff = flatElev - elev.getData(in, jn);
if (elevDiff < 0) {
// Adjacent cell has higher elevation so this is a high boundary
highBoundary = true;
break;
}
}
}
if (highBoundary) {
inc.setData(flat.x, flat.y, -1);
highBoundaries.push_back(flat);
}
}
propagateIncrements(flowDir, inc, highBoundaries);
}
}