Fix lookuptable

.gitmodules

@@ -0,0 +1,3 @@
+[submodule "extern/argh"]
+	path = extern/argh
+	url = https://github.com/adishavit/argh.git

CMakeLists.txt

@@ -1,15 +1,22 @@
+cmake_minimum_required(VERSION 3.20)
+
 project(
   contour-creator
   LANGUAGES CXX)    
   
-find_package(GDAL CONFIG REQUIRED)
-
 add_executable(${PROJECT_NAME}
 	src/HeightMap.cpp src/CellMap.cpp src/main.cpp
 )
+
+# Argh is a simple argrument parser
+add_subdirectory(extern/argh)
+target_link_libraries(${PROJECT_NAME} PRIVATE argh)
+
+# Gdal is used for geodata IO
+find_package(GDAL CONFIG REQUIRED)
+target_link_libraries(${PROJECT_NAME} PRIVATE GDAL::GDAL)
+
 find_package(OpenMP)
 if(OpenMP_CXX_FOUND)
     target_link_libraries(${PROJECT_NAME} PUBLIC OpenMP::OpenMP_CXX)
 endif()
-
-target_link_libraries(${PROJECT_NAME} GDAL::GDAL)

build&run.sh

@@ -3,4 +3,4 @@ rm -rf build
 mkdir build
 cmake -DCMAKE_BUILD_TYPE=Debug -B build
 cmake --build build --parallel 
-build/contour-creator 'example_files/crop.tif'
+build/contour-creator --interval=1 --blur example_files/crop.tif

src/main.cpp

@@ -1,4 +1,6 @@
 #include "contour_creator.hh"
+#include <algorithm>
+#include <array>
 #include <gdal/ogr_api.h>
 #include "ogrsf_frmts.h"
 #include <gdal/ogr_core.h>
@@ -6,12 +8,15 @@
 #include <gdal/ogr_geometry.h>
 #include <iostream>
 #include <ostream>
+#include <sys/types.h>
+#include <tuple>
 #include <vector>
 #include <cstdint>
 #include <gdal/gdal.h>
 #include "gdal/gdal_priv.h"
 #include <gdal/gdal_frmts.h>
 #include <omp.h>
+#include "argh.h"
 
 std::vector<Point> produce_cellmap(HeightMap* heightmap, float z)
 {
@@ -32,11 +37,21 @@ std::vector<Point> produce_cellmap(HeightMap* heightmap, float z)
     return points;
 }
 
+bool is_in(int value, std::array<int, 8> array)
+{
+    return std::binary_search(array.begin(), array.end(), value);
+}
+
 std::vector<std::vector<Point>> create_lines(HeightMap* heightmap, int interval)
 {
     int num_contours = (heightmap->max - heightmap->min)/interval;
     std::vector<std::vector<Point>> vector_contours;
 
+    std::array<int,8> north{4, 5,6,7,8,9,10,11};
+    std::array<int,8> south{1,2,5,6,9,10,13,14};
+    std::array<int,8> east{2,3,4,5,10,11,12,13};
+    std::array<int,8> west{1,3,5,7,8,10,12,14};
+
     #pragma omp parallel
     {
         std::vector<std::vector<Point>> vec_private;
@@ -50,39 +65,44 @@ std::vector<std::vector<Point>> create_lines(HeightMap* heightmap, int interval)
             int points_allocated = 0;
             x = points[0].x;
             y = points[0].y;
+            int current_case = points[0].mscase;
             points[0].allocated = true;
             line.push_back(points[0]);
             for (int j = 0; j < points.size(); j++){
                 for (int k = 0; k < points.size(); k++){
                     Point* candidate = &points[k];
                     if (!candidate->allocated) {
-                        if (candidate->x == x +1 && candidate->y == y) {
+                        if (candidate->x == x +1 && candidate->y == y /*&& is_in(current_case, east)*/) {
                             candidate->allocated = true;
                             x = candidate->x;
                             y = candidate->y;
+                            current_case = candidate->mscase;
                             line.push_back(*candidate);
                             points_allocated++;
                             break;
                         }
-                        else if (candidate->x == x -1 && candidate->y == y) {
+                        else if (candidate->x == x -1 && candidate->y == y /*&& is_in(current_case, west)*/) {
                             x = candidate->x;
                             y = candidate->y;
+                            current_case = candidate->mscase;
                             candidate->allocated = true;
                             line.push_back(*candidate);
                             points_allocated++;
                             break;
                         }
-                        else if (candidate->x == x && candidate->y == y + 1) {
+                        else if (candidate->x == x && candidate->y == y + 1 /*&& is_in(current_case, north)*/) {
                             x = candidate->x;
                             y = candidate->y;
+                            current_case = candidate->mscase;
                             candidate->allocated = true;
                             line.push_back(*candidate);
                             points_allocated++;
                             break;
                         }
-                        else if (candidate->x == x && candidate->y == y - 1) {
+                        else if (candidate->x == x && candidate->y == y - 1 /*&& is_in(current_case, south)*/) {
                             x = candidate->x;
                             y = candidate->y;
+                            current_case = candidate->mscase;
                             candidate->allocated = true;
                             line.push_back(*candidate);
                             points_allocated++;
@@ -100,8 +120,10 @@ std::vector<std::vector<Point>> create_lines(HeightMap* heightmap, int interval)
                         if (!candidate->allocated)
                         {
                             line.push_back(*candidate);
+                            candidate->allocated = true;
                             x = candidate->x;
                             y = candidate->y;
+                            current_case = candidate->mscase;
                             points_allocated++;
                             break;
                         }
@@ -129,20 +151,35 @@ std::tuple<double, double> local_to_projected(double* geotransform, int x, int y
 constexpr std::tuple<double, double, double, double> marching_squares_lookup(int mcase)
 {
     switch (mcase) {
-        case 1: return {0, 0.5, 0.5, 0};
-        case 2: return {1, 0.5, 0.5, 0};
-        case 3: return {0, 0.5, 1, 0.5};
-        case 4: return {0.5, 1, 1, 0.5};
-        case 5: return {0, 0, 0, 0}; //FIXME
-        case 6: return {0.5, 1, 0.5, 0};
-        case 7: return {0, 0.5, 0.5, 1};
-        case 8: return {0, 0.5, 0.5, 1};
-        case 9: return {0.5, 1, 0.5, 0};
-        case 10: return {0, 0, 0, 0}; //FIXME
-        case 11: return {0.5, 1, 1, 0.5};
-        case 12: return {0, 0.5, 1, 0.5};
-        case 13: return {0.5, 0, 1, 0.5};
-        case 14: return {0, 0.5, 0.5, 0};
+        case 1:
+            return {0, 0.5, 0.5, 0};
+        case 14:
+            return {0.5, 0, 0, 0.5};
+        case 2: 
+            return {0.5, 0, 1, 0.5};
+        case 13:
+            return {1, 0.5, 0.5, 0};
+        case 3:
+            return {0, 0.5, 1, 0.5};
+        case 12:
+            return {1, 0.5, 0, 0.5};
+        case 4:
+            return {0.5, 1, 1, 0.5};
+        case 11:
+            return {1, 0.5, 0.5, 1};
+        case 5: 
+        case 10:
+            return {0, 0, 0, 0}; //FIXME
+        case 6: 
+            return {0.5, 1, 0.5, 0};
+        case 9:
+            return {0.5, 0, 0.5, 1};
+        case 7: 
+            return {0, 0.5, 0.5, 1};
+        case 8:
+            return {0.5, 0.5, 0, 0.5};
+
+        
     };
 }
 void write_output_file(std::vector<std::vector<Point>> all_points, const char *filepath, HeightMap* heightmap)
@@ -200,13 +237,40 @@ void write_output_file(std::vector<std::vector<Point>> all_points, const char *f
 
         std::vector<Point> points = all_points[j];
         
+        bool left_to_right = true;
+        
+        if ((points[0].y - points[1].y) < 0)
+            left_to_right = true;
+        else
+            left_to_right = false;
+
         for (int k = 0; k < points.size(); k++)
         {
+            bool left_to_right = true;
+        
+            if ((points[k].x - points[k-1].x) < 0)
+                left_to_right = false;
+            bool top_to_bottom = true;
+            if ((points[k].y - points[k-1].y) < 0)
+                left_to_right = false;
+
+
+
             int x_raw = points[k].x;
             int y_raw = points[k].y;
             auto [x, y] = local_to_projected(heightmap->geotransform, x_raw, y_raw);
-            //auto [x_bl, y_bl, x_tr, y_tr] = marching_squares_lookup(*(cellmap->cells + i) );
-            geometry->setPoint(geometry->getNumPoints(),x ,y );
+
+            auto [x1, y1, x2, y2] = marching_squares_lookup(points[k].mscase);
+            
+            if (left_to_right or !top_to_bottom)
+            {
+                geometry->setPoint(geometry->getNumPoints(),x + (x1/6) ,y + (y1/6));
+                geometry->setPoint(geometry->getNumPoints(),x + (x2/6) ,y + (y2/6));
+            }
+            else {
+                geometry->setPoint(geometry->getNumPoints(),x + (x2/6) ,y + (y2/6));
+                geometry->setPoint(geometry->getNumPoints(),x + (x1/6) ,y + (y1/6));
+            }
         }
 
         if ( feature->SetGeometry(geometry) != OGRERR_NONE)
@@ -227,14 +291,34 @@ void write_output_file(std::vector<std::vector<Point>> all_points, const char *f
 
 int main(int argc, const char* argv[])
 {
-    const char* filepath = argv[1];
-    HeightMap map(filepath); 
+    argh::parser cmdl(argv);
 
-    std::cout << "x: " << map.width << "    y: " << map.height << "\n";
-    std::cout << "max: " << map.max << "    min: " << map.min << "\n";
+    if (cmdl[{ "-h", "--help" }])
+    {
+        std::cout << "Usage:\n"
+            << "contour_creator [OPTIONS] <input_file>\n"
+            << "-o; --output <FILENAME.geojson> - File to write output to (Default: contours.geojson)\n"
+            << "-i; --interval <int> - Set the interval between contours (Default: 5)\n"
+            << "-b; --blur - Blur the image\n"
+            << "--stats - Print statistical information about the heightmap\n";
+            exit(0);
+    }
+    int interval;
+    cmdl({"-i", "--interval"}, 5) >> interval;
+    if (interval <= 0)
+        std::cerr << "Interval must be valid positive integer!" << "\n";
     
-    map.blur(0.8);
+    std::string output_file;
+    cmdl({"-o", "--output"}, "contours.geojson") >> output_file;
 
-    auto lines = create_lines(&map, 5);
-    write_output_file(lines, "out.geojson", &map);
+    std::string input_file;
+    cmdl(1) >> input_file;
+    
+
+    HeightMap map(input_file.c_str());
+    if (cmdl[{"-b", "--blur"}])
+        map.blur(0.8);
+    auto lines = create_lines(&map, interval);
+    write_output_file(lines, output_file.c_str(), &map);
+    std::cout << "Contours written to " << output_file << " 🗺️\n";
 }