Added Game of Life

4 files changed, 152 insertions, 0 deletions

diff --git a/src/constants.h b/src/constants.h
new file mode 100644
index 0000000..bb73900
--- /dev/null
+++ b/src/constants.h
@@ -0,0 +1,3 @@
+const int SCREEN_WIDTH = 640;
+const int SCREEN_HEIGHT = 480;
+const int SCALE_FACTOR = 2;
\ No newline at end of file
diff --git a/src/game.h b/src/game.h
new file mode 100644
index 0000000..5f14541
--- /dev/null
+++ b/src/game.h
@@ -0,0 +1,47 @@
+#include <array>
+#include <random>
+#include "screen.h"
+
+using Array2D = std::array<std::array<int, SCREEN_HEIGHT>, SCREEN_WIDTH>;
+
+// Two-dimensional array of ints
+struct Game {
+    Array2D display {};
+    Array2D swap {};
+};
+
+// random number generator function:
+int zeroOrOne() {
+    std::random_device rd;
+    std::mt19937 gen(rd());
+    std::uniform_int_distribution<> dis(0, 1);
+    return dis(gen);
+}
+
+// function to check if the cell will be alive or dead in the next generation
+bool isAlive(Array2D &game, int x, int y) {
+    int alive = 0;
+
+    // left test
+    if (x > 0 && game[x - 1][y] == 1) alive++;
+    // right test
+    if (x < SCREEN_WIDTH && game[x + 1][y] == 1) alive++;
+    // top test
+    if (y > 0 && game[x][y - 1] == 1) alive++;
+    // bottom test
+    if (y < SCREEN_HEIGHT && game[x][y + 1] == 1) alive++;
+    // top left test
+    if (x > 0 && y > 0 && game[x - 1][y - 1] == 1) alive++;
+    // top right test
+    if (x < SCREEN_WIDTH && y > 0 && game[x + 1][y - 1] == 1) alive++;
+    // bottom left test
+    if (x > 0 && y < SCREEN_HEIGHT && game[x - 1][y + 1] == 1) alive++;
+    // bottom right test
+    if (x < SCREEN_WIDTH && y < SCREEN_HEIGHT && game[x + 1][y + 1] == 1) alive++;
+
+    // if the cell is alive and has 2 or 3 neighbors, it stays alive or
+    // if the cell is dead and has exactly 3 neighbors, it comes to life
+    if ((game[x][y] == 1 && (alive == 2 || alive == 3)) || (game[x][y] == 0 && alive == 3)) return true;
+        // otherwise, the cell dies
+    else return false;
+}
diff --git a/src/gameOfLife.cpp b/src/gameOfLife.cpp
new file mode 100644
index 0000000..976d4ae
--- /dev/null
+++ b/src/gameOfLife.cpp
@@ -0,0 +1,40 @@
+#include "game.h"
+
+int main() {
+    Game game;
+    GameScreen screen;
+
+    // create random points
+    for (auto &row : game.display) {
+        std::generate(row.begin(), row.end(), zeroOrOne);
+    }
+
+    // game loop
+   for(;;) {
+        // check for alive cells
+        for (int i = 0; i < SCREEN_WIDTH; ++i) {
+            for (int j = 0; j < SCREEN_HEIGHT; ++j) {
+                // check if the cell will be alive or dead in the next generation
+                game.swap[i][j] = isAlive(game.display, i, j) ? 1 : 0;
+            }
+        }
+
+        // draw
+        for (int i = 0; i < SCREEN_WIDTH; ++i) {
+            for (int j = 0; j < SCREEN_HEIGHT; ++j) {
+                if (game.swap[i][j] == 1) {
+                    screen.drawPixel(i, j);
+                }
+            }
+        }
+
+        // swap buffers
+        std::copy(game.swap.begin(), game.swap.end(), game.display.begin());
+
+        // display to screen
+        screen.update();
+        SDL_Delay(20);
+        screen.input();
+        screen.clearPixels();
+    }
+}
diff --git a/src/screen.h b/src/screen.h
new file mode 100644
index 0000000..9aa242d
--- /dev/null
+++ b/src/screen.h
@@ -0,0 +1,62 @@
+#include <SDL2/SDL.h>
+#include <cstdlib>
+#include <iostream>
+#include <vector>
+#include <algorithm>
+#include "constants.h"
+
+// Game Screen Class -> Uses SDL2
+class GameScreen {
+    SDL_Window *window{};
+    SDL_Renderer *renderer{};
+    SDL_bool done;
+    std::vector<SDL_FPoint> points;
+    std::vector<SDL_Color> colors;
+    SDL_Event event{};
+
+public:
+    GameScreen() {
+        SDL_Init(SDL_INIT_VIDEO);
+        SDL_CreateWindowAndRenderer(SCREEN_WIDTH * SCALE_FACTOR,
+                                    SCREEN_HEIGHT * SCALE_FACTOR,
+                                    0, &window, &renderer);
+        SDL_SetWindowTitle(window, "Game of Life");
+        SDL_RenderSetScale(renderer, SCALE_FACTOR, SCALE_FACTOR);
+        done = SDL_FALSE;
+    }
+
+    void drawPixel(double xm, double ym, uint8_t r = 255, uint8_t g = 255, uint8_t b = 255, uint8_t a = 255) {
+        points.push_back({static_cast<float>(xm), static_cast<float>(ym)});
+        colors.push_back({r, g, b, a});
+    }
+
+    void clearPixels() {
+        points.clear();
+    }
+
+    void update() {
+        SDL_SetRenderDrawColor(renderer, 0, 0, 0, 255);
+        SDL_RenderClear(renderer);
+
+        for (long unsigned int i = 0; i < points.size(); ++i) {
+            SDL_SetRenderDrawColor(renderer, colors[i].r, colors[i].g, colors[i].b, colors[i].a);
+            SDL_RenderDrawPointF(renderer, points[i].x, points[i].y);
+        }
+
+        SDL_RenderPresent(renderer);
+    }
+
+    void input() {
+        while (SDL_PollEvent(&event)) {
+            switch (event.type) {
+                case SDL_QUIT:
+                    done = SDL_TRUE;
+                    SDL_Quit();
+                    exit(0);
+                    break;
+                default:
+                    break;
+            }
+        }
+    }
+};