Improve basic example.

Author: abellgithub

CMakeLists.txt

@@ -23,7 +23,11 @@ add_subdirectory(test)
 
 #examples
 #add_executable(triangulate-geojson examples/triangulate_geojson.cpp include/delaunator.cpp)
-#add_executable(basic examples/basic.cpp include/delaunator.cpp)
+add_executable(basic examples/basic.cpp include/delaunator.cpp)
+target_include_directories(basic
+    PRIVATE
+        include
+)
 
 #set(CPACK_PROJECT_NAME ${PROJECT_NAME})
 #set(CPACK_PROJECT_VERSION ${PROJECT_VERSION})

examples/basic.cpp

@@ -1,22 +1,45 @@
 #include <delaunator.hpp>
-#include <cstdio>
+#include <iostream>
+#include <string>
 
 int main() {
+    using namespace delaunator;
+
     /* x0, y0, x1, y1, ... */
-    std::vector<double> coords = {-1, 1, 1, 1, 1, -1, -1, -1};
+    std::vector<double> coords = {-3, 1, -1, 1, 1, 1, 3, 1,
+                                  3, -1, 1, -1, -1, -1, -3, -1};
 
     //triangulation happens here
-    delaunator::Delaunator d(coords);
-
-    for(std::size_t i = 0; i < d.triangles.size(); i+=3) {
-        printf(
-            "Triangle points: [[%f, %f], [%f, %f], [%f, %f]]\n",
-            d.coords[2 * d.triangles[i]],        //tx0
-            d.coords[2 * d.triangles[i] + 1],    //ty0
-            d.coords[2 * d.triangles[i + 1]],    //tx1
-            d.coords[2 * d.triangles[i + 1] + 1],//ty1
-            d.coords[2 * d.triangles[i + 2]],    //tx2
-            d.coords[2 * d.triangles[i + 2] + 1] //ty2
-        );
+    Delaunator d(coords);
+
+    auto xcoord = [&d](size_t tri, int coord) -> double
+    {
+        size_t index = d.triangles[tri + coord];
+        return d.coords[2 * index];
+    };
+
+    auto ycoord = [&d](size_t tri, int coord) -> double
+    {
+        size_t index = d.triangles[tri + coord];
+        return d.coords[2 * index + 1];
+    };
+
+    for (std::size_t i = 0; i < d.triangles.size(); i += 3) {
+        std::cout << "Triangle " << (i / 3) << " points: [[" <<
+            xcoord(i, 0) << ", " << ycoord(i, 0) << "], [" <<
+            xcoord(i, 1) << ", " << ycoord(i, 1) << "], [" <<
+            xcoord(i, 2) << ", " << ycoord(i, 2) << "]]\n";
+    }
+
+    auto adjTriangle = [&d](size_t edge) -> std::string
+    {
+        size_t adj = d.halfedges[edge];
+        return adj == INVALID_INDEX ? "None" : std::to_string(adj / 3);
+    };
+
+    for (std::size_t i = 0; i < d.triangles.size(); i += 3)
+    {
+        std::cerr << "Adjacent triangles for triangle number " << (i / 3) << ": " <<
+            adjTriangle(i) << ", " << adjTriangle(i + 1) << " and " << adjTriangle(i + 2) << "\n";
     }
 }