Changing Centroid Finding Algorithm

.vscode/c_cpp_properties.json

@@ -0,0 +1,16 @@
+{
+    "configurations": [
+        {
+            "name": "Linux",
+            "includePath": [
+                "${workspaceFolder}/**"
+            ],
+            "defines": [],
+            "compilerPath": "/usr/bin/gcc",
+            "cStandard": "gnu17",
+            "cppStandard": "gnu++14",
+            "intelliSenseMode": "linux-gcc-x64"
+        }
+    ],
+    "version": 4
+}

.vscode/settings.json

@@ -47,6 +47,22 @@
         "streambuf": "cpp",
         "cinttypes": "cpp",
         "typeinfo": "cpp",
-        "files.eol": "\n"
+        "files.eol": "\n",
+        "bitset": "cpp",
+        "chrono": "cpp",
+        "complex": "cpp",
+        "condition_variable": "cpp",
+        "cstring": "cpp",
+        "ctime": "cpp",
+        "set": "cpp",
+        "ratio": "cpp",
+        "regex": "cpp",
+        "future": "cpp",
+        "iomanip": "cpp",
+        "mutex": "cpp",
+        "shared_mutex": "cpp",
+        "thread": "cpp",
+        "variant": "cpp",
+        "list": "cpp"
     }
 }

src/centroiders.hpp

@@ -24,8 +24,10 @@ class DummyCentroidAlgorithm: public CentroidAlgorithm {
 
 class CenterOfGravityAlgorithm : public CentroidAlgorithm {
     public:
-        CenterOfGravityAlgorithm() { };
+        CenterOfGravityAlgorithm(int subdivisions) : subdivisions(subdivisions) { };
         Stars Go(unsigned char *image, int imageWidth, int imageHeight) const override;
+    private:
+        int subdivisions;
 };
 
 class IterativeWeightedCenterOfGravityAlgorithm : public CentroidAlgorithm {

src/io.cpp

@@ -268,7 +268,8 @@ CentroidAlgorithm *DummyCentroidAlgorithmPrompt() {
 }
 
 CentroidAlgorithm *CoGCentroidAlgorithmPrompt() {
-    return new CenterOfGravityAlgorithm();
+    int subdivisions = Prompt<int>("How many subdivisions to use");
+    return new CenterOfGravityAlgorithm(subdivisions);
 }
 
 CentroidAlgorithm *IWCoGCentroidAlgorithmPrompt() {

test/centroid.cpp

@@ -0,0 +1,56 @@
+#include <catch.hpp>
+
+#include <math.h>
+#include <iostream>
+
+namespace lost {
+    int RowOrColumn(long i, int leftover, int div);
+    int FindSubdivision(long i, int imageWidth, int imageHeight, int subdivisions);
+    int StartOfSubdivision(int i, int leftover, int div);
+}
+
+
+TEST_CASE("Testing Start and End Rows") {
+    int row = 0;
+    int horizontalLeftover = 5;
+    int horizontalDiv = 10;
+    CHECK(lost::StartOfSubdivision(row, horizontalLeftover, horizontalDiv) == 0);
+    CHECK(lost::StartOfSubdivision(row + 1, horizontalLeftover, horizontalDiv) == 11);
+}
+
+TEST_CASE("Testing Start and End Columns") {
+    int col = 0;
+    int verticalLeftover = 5;
+    int verticalDiv = 10;
+    CHECK(lost::StartOfSubdivision(col, verticalLeftover, verticalDiv) == 0);
+    CHECK(lost::StartOfSubdivision(col + 1, verticalLeftover, verticalDiv) == 11);
+}
+
+TEST_CASE("Correct Row: 4th Row") {
+    CHECK(lost::RowOrColumn(33795 / 1024, 1024 % 100, 1024 / 100) == 3);
+}
+
+TEST_CASE("Correct Row: 27th Row") {
+    CHECK(lost::RowOrColumn((24 * 1024 * 11 + 10 * 2 * 1024 + 20) / 1024, 1024 % 100, 1024 / 100) == 26);
+}
+
+TEST_CASE("Correct Row: Last Row 1") {
+    CHECK(lost::RowOrColumn((1024 * 1024 - 1) / 1024, 1024 % 100, 1024 / 100) == 99);
+}
+
+TEST_CASE("Correct Box: Last Subdivision") {
+    CHECK(lost::FindSubdivision(1024 * 1024 - 1, 1024, 1024, 1024) == 1024 * 1024 - 1);
+}
+
+TEST_CASE("Testing Inverse Conjecture") {
+    int size = 1024;
+    int subdivisions = 10;
+    int leftover = size % subdivisions;
+    int div = size / subdivisions;
+    for(int i = 0; i < subdivisions; i++) {
+        int x = lost::StartOfSubdivision(i, leftover, div);
+        CHECK(lost::RowOrColumn(x, leftover, div) == i);
+        CHECK(lost::StartOfSubdivision(lost::RowOrColumn(x, leftover, div), leftover, div) == x);
+    }
+}
+