update linedrawing for lineslopes >1

Author: Joeperdefloep

include/richdem/methods/catchment_delineation_generic.hpp

@@ -49,23 +49,43 @@ std::queue<GridCell> queue_from_linepoints(
   int deltay     = y1-y0;
   float error    = 0;
   float deltaerr = (float)deltay/(float)deltax;
+  std::cout << "linedrawing deltaerr:" << deltaerr << std::endl;
 
   if (deltaerr<0)
     deltaerr = -deltaerr;
 
   RDLOG_MISC<<"Line slope is "<<deltaerr;
-  int y=y0;
-  for(int x=x0;x<=x1;x++){
-    expansion.push(GridCell(x,y));
-    upslope_cells(x,y)=2;
-    error+=deltaerr;
-    if (error>=0.5) {
-      expansion.push(GridCell(x+1,y));
-      upslope_cells(x+1,y) = 2;
-      y                   += sgn(deltay);
-      error               -= 1;
+  //if the slope is larger than 1, loop over y?
+  if (deltaerr<1){ 
+    int y=y0;
+    for(int x=x0;x<=x1;x++){
+      expansion.push(GridCell(x,y));
+      upslope_cells(x,y)=2;
+      error+=deltaerr;
+      if (error>=0.5) {
+        expansion.push(GridCell(x+1,y));
+        upslope_cells(x+1,y) = 2;
+        y                   += sgn(deltay);
+        error               -= 1;
+      }
     }
-  }
+} else {
+  // deltaerr >1
+  deltaerr = std::abs((float)deltax/(float)deltay);
+  int x=x0;
+    for(int y=y0;y<=y1;y++){
+      expansion.push(GridCell(x,y));
+      upslope_cells(x,y)=2;
+      std::cout<< "(" << x << "," << y << ")\n";
+      error+=deltaerr;
+      if (error>=0.5) {
+        expansion.push(GridCell(x,y+1));
+        upslope_cells(x,y+1) = 2;
+        y                   += sgn(deltay);
+        error               -= 1;
+      }
+    }
+}
 
   return expansion;
 }

tests/richdem_unittests

@@ -505,7 +505,7 @@ TEST_CASE("Checking Catchment Delineation Generic"){
   SUBCASE("line"){
     int x0=0;
     int y0=0;
-    int x1=2;
+    int x1=0;
     int y1=4;
 
     std::queue<GridCell> q_expected;
@@ -515,24 +515,29 @@ TEST_CASE("Checking Catchment Delineation Generic"){
     q_expected.emplace(0,3);
     q_expected.emplace(0,4);
 
-    const Array2D<uint8_t> upslope_e = {
+    Array2D<uint8_t> upslope_e = {
       {2, 0, 0, 0, 0, 0},
       {2, 0, 0, 0, 0, 0},
       {2, 0, 0, 0, 0, 0},
       {2, 0, 0, 0, 0, 0},
       {2, 0, 0, 0, 0, 0},
+      {0, 0, 0, 0, 0, 0},
     };
+    upslope_e.setNoData(0);
     Array2D<uint8_t> upslope(upslope_e,0);
+    upslope.setNoData(0);
 
-    // upslope_e.printAll();
+    // printAll not working, because we need to cast to unsigned() from uint8_t
     std::queue<GridCell> q = queue_from_linepoints(x0,y0,x1,y1,upslope);
     for (int y = 0; y< upslope.width(); y++){
       for (int x = 0; x<upslope.height(); x++){
         std::cout << unsigned(upslope(x,y)) << " ";
       }
       std::cout << std::endl;
     }
-    // REQUIRE_EQ(q, q_expected);
+
+    CHECK(upslope.height() == upslope_e.height());
+    CHECK(upslope.width() == upslope_e.width());
     CHECK(upslope == upslope_e);
   }
 
@@ -561,12 +566,6 @@ TEST_CASE("Checking Catchment Delineation Generic"){
     result.setNoData(0);
     expected.setNoData(0); //the function sets nodata to 0
 
-    for (int y = 0; y< result.width(); y++){
-      for (int x = 0; x<result.height(); x++){
-        std::cout << unsigned(result(x,y)) << " ";
-      }
-      std::cout << std::endl;
-    }
     upslope_cells_mflow(expansion, dem, result);
     CHECK(result == expected);
   }