refactor main, better neighbour check

1 files changed, 34 insertions, 28 deletions

diff --git a/labb1/src/life.cpp b/labb1/src/life.cpp
index 1f582f6..7233d79 100644
--- a/labb1/src/life.cpp
+++ b/labb1/src/life.cpp
@@ -8,6 +8,29 @@
 #include <string>
 
 /*
+ * Ask for a file and read it, storing the initial state in `grid`.
+ */
+void askAndReadFile(Grid<bool> &grid) {
+    std::string filepath;
+    std::cout << "file: ";
+    std::cin >> filepath;
+    std::ifstream input;
+    input.open(filepath);
+    int h, w;
+    input >> h >> w;
+    grid.resize(h, w);
+
+    for (int y = 0; y < grid.numRows(); y++) {
+        std::string line;
+        std::getline(input, line);
+        for (int x = 0; x < grid.numCols(); x++) {
+            grid.set(y, x, line[x] == 'X');
+        }
+    }
+    input.close();
+}
+
+/*
  * Print a representation of the grid.
  * Alive cells show as 'X', dead show as '-'.
  */
@@ -25,9 +48,9 @@ void printGrid(const Grid<bool> &grid) {
 }
 
 /*
- * Return 1 if (x, y) is in bounds and alive, otherwise 0.
+ * Return whether (x, y) is in bounds and alive.
  */
-int checkPoint(const Grid<bool> &grid, int y, int x) {
+bool checkPoint(const Grid<bool> &grid, int y, int x) {
     return grid.inBounds(y, x) && grid.get(y, x) ? 1 : 0;
 }
 
@@ -38,14 +61,14 @@ void simulate(Grid<bool> &grid) {
     Grid<bool> prevGrid(grid);
     for (int y = 0; y < grid.numRows(); y++) {
         for (int x = 0; x < grid.numCols(); x++) {
-            int numNeighbours = checkPoint(prevGrid, y-1, x-1) +
-                    checkPoint(prevGrid, y-1, x  ) +
-                    checkPoint(prevGrid, y-1, x+1) +
-                    checkPoint(prevGrid, y  , x-1) +
-                    checkPoint(prevGrid, y  , x+1) +
-                    checkPoint(prevGrid, y+1, x-1) +
-                    checkPoint(prevGrid, y+1, x  ) +
-                    checkPoint(prevGrid, y+1, x+1);
+            int numNeighbours = 0;
+            for (int dy = -1; dy <= 1; dy++) {
+                for (int dx = -1; dx <= 1; dx++) {
+                    if ((dx != 0 || dy != 0) && checkPoint(prevGrid, y+dy, x+dx)) {
+                        numNeighbours++;
+                    }
+                }
+            }
             if (numNeighbours < 2) {
                 grid.set(y, x, false);
             } else if (numNeighbours == 2) {
@@ -61,24 +84,7 @@ void simulate(Grid<bool> &grid) {
 
 int main() {
     Grid<bool> grid;
-
-    std::string filepath;
-    std::cout << "file: ";
-    std::cin >> filepath;
-    std::ifstream input;
-    input.open(filepath);
-    int h, w;
-    input >> h >> w;
-    grid.resize(h, w);
-
-    for (int y = 0; y < grid.numRows(); y++) {
-        std::string line;
-        std::getline(input, line);
-        for (int x = 0; x < grid.numCols(); x++) {
-            grid.set(y, x, line[x] == 'X');
-        }
-    }
-    input.close();
+    askAndReadFile(grid);
 
     char prompt;
     bool running = true;