This code is hot garabage, but just testing things. Trying a really terrible way to do 'Updates' on the cells' statuses. Not really working but its a start of the checking the rules for the game.

src/cell.c

@@ -4,13 +4,17 @@
 Cell* CreateCell(int x, int y) {
     Cell* newCell = calloc(1, sizeof(Cell));
 
+    if (!newCell) {
+        printf("Faield to allocate cell\n");
+        return NULL;
+    }
+
     if (!newCell) {
 
         return NULL;
     }
 
-    newCell->Visited = 0;
+    newCell->Status = Dead;
-    newCell->Status = Alive;
     newCell->x = x;
     newCell->y = y;
 

src/cell.h

@@ -8,22 +8,27 @@ typedef enum {
     Dead
 } State;
 
-typedef struct cell {
+typedef struct {
-    struct cell* TopLeft;
-    struct cell* Top;
-    struct cell* TopRight;
-    struct cell* Left;
-    struct cell* Right;
-    struct cell* BottomLeft;
-    struct cell* Botttom;
-    struct cell* BottomRight;
-    State Status;
-    SDL_Rect Hitbox;
-    int Visited;
     int x;
     int y;
+} Point;
+
+typedef struct cell {
+    // Point TopLeft;
+    // Point Top;
+    // Point TopRight;
+    // Point Left;
+    // Point Right;
+    // Point BottomLeft;
+    // Point Botttom;
+    // Point BottomRight;
+    int living;
+    State Status;
+    int y;
+    int x;
 } Cell;
 
 Cell* CreateCell(int x, int y);
+void UpdateCell(Cell*);
 
 #endif

src/main.c

@@ -10,6 +10,7 @@
 #include <SDL2/SDL_video.h>
 #include <SDL2/SDL_image.h>
 #include <SDL2/SDL_ttf.h>
+#include <stdio.h>
 #include <stdlib.h>
 #include "cell.h"
 
@@ -18,6 +19,7 @@ const int SCREEN_HEIGHT = 720;
 const int CELL_SIZE = 15;
 const int MAX_X = SCREEN_WIDTH / CELL_SIZE - 1;
 const int MAX_Y = SCREEN_HEIGHT / CELL_SIZE - 1;
+int Start = 0;
 
 typedef struct {
     SDL_Window *window;
@@ -79,9 +81,16 @@ int main(int argc, char** argv) {
     }
 
     GlobalList = calloc(1, sizeof(CellList));
-    GlobalList->cells = calloc(GetIndex(MAX_X, MAX_Y, MAX_X), sizeof(Cell*));
+    GlobalList->cells = calloc(GetIndex(MAX_X, MAX_Y, MAX_X) + 1, sizeof(Cell*));
     GlobalList->capcity = GetIndex(MAX_X, MAX_Y, MAX_X);
-    GlobalList->size = 0;
+
+    for(int x = 0; x < MAX_X; x++) {
+      for(int y = 0; y < MAX_Y; y++) {
+        GlobalList->cells[GetIndex(x, y, MAX_X)] = CreateCell(x, y);
+      }
+    }
+
+    GlobalList->cells[GetIndex(MAX_X + 1, MAX_Y, MAX_X)] = NULL;
 
     SDL_Rect* rect = malloc(sizeof(SDL_Rect));
     rect->h = CELL_SIZE;
@@ -90,8 +99,7 @@ int main(int argc, char** argv) {
     // rect->y = 0;//MAX_Y * CELL_SIZE;
     // Cell* cell = CreateCell(*rect);
 
-    while(1){
+    while(!Start){
-
         HandleInput();
 
         SDL_Delay(128);
@@ -110,7 +118,68 @@ int main(int argc, char** argv) {
           rect->x = cell->x * CELL_SIZE;
           rect->y = cell->y * CELL_SIZE;
 
-          SDL_RenderFillRect(app.renderer, rect);
+          if (cell->Status == Alive) SDL_RenderFillRect(app.renderer, rect);
+        }
+
+        SDL_RenderPresent(app.renderer);
+    }
+
+    while(1){
+
+        HandleInput();
+
+        SDL_Delay(128);
+
+        SDL_SetRenderDrawColor(app.renderer, 0, 0, 0, 255);
+
+        SDL_RenderClear(app.renderer);
+
+        SDL_SetRenderDrawColor(app.renderer, 255, 255, 255, 255);
+
+        for(int i = 0; i < GlobalList->capcity; i++) {
+          // if (GlobalList->cells[i] == NULL) {
+          //     Cell* newCell = CreateCell(int x, int y)
+          // }
+
+          Cell* cell = GlobalList->cells[i];
+
+          if (!cell) continue;
+
+          int count = 0;
+
+          Cell* topLeft = GlobalList->cells[GetIndex(cell->x - 1, cell->y - 1, MAX_X)];
+          if (topLeft && topLeft->Status == Alive) count++;
+    // Point Top;
+          Cell* top = GlobalList->cells[GetIndex(cell->x, cell->y - 1, MAX_X)];
+          if (top && top->Status == Alive) count++;
+    // Point TopRight;
+          Cell* topRight = GlobalList->cells[GetIndex(cell->x + 1, cell->y - 1, MAX_X)];
+          if (topRight && topRight->Status == Alive) count++;
+    // Point Left;
+          Cell* left = GlobalList->cells[GetIndex(cell->x - 1, cell->y, MAX_X)];
+          if (left && left->Status == Alive) count++;
+    // Point Right;
+          Cell* right = GlobalList->cells[GetIndex(cell->x + 1, cell->y, MAX_X)];
+          if (right && right->Status == Alive) count++;
+    // Point BottomLeft;
+          Cell* bottomLeft = GlobalList->cells[GetIndex(cell->x + 1, cell->y - 1, MAX_X)];
+          if (bottomLeft && bottomLeft->Status == Alive) count++;
+    // Point Botttom;
+          Cell* bottom = GlobalList->cells[GetIndex(cell->x, cell->y + 1, MAX_X)];
+          if (bottom && bottom->Status == Alive) count++;
+    // Point BottomRight;
+          Cell* bottomRight = GlobalList->cells[GetIndex(cell->x - 1, cell->y - 1, MAX_X)];
+          if (bottomRight && bottomRight->Status == Alive) count++;
+
+          rect->x = cell->x * CELL_SIZE;
+          rect->y = cell->y * CELL_SIZE;
+
+          if (cell->Status == Alive) {
+            if (count < 2 || count > 3) cell->Status = Dead;
+          }
+          else if (cell->Status == Dead && count == 3) cell->Status = Alive;
+
+          if (cell->Status == Alive) SDL_RenderFillRect(app.renderer, rect);
         }
 
         // rect->x += CELL_SIZE;
@@ -139,13 +208,16 @@ void Thing(int x, int y) {
   x = x / CELL_SIZE;
   y = y /CELL_SIZE;
 
-  if (GlobalList->cells[GetIndex(x, y, MAX_X)] == NULL) {
+  GlobalList->cells[GetIndex(x, y, MAX_X)]->Status = Alive;
-    GlobalList->cells[GetIndex(x, y, MAX_X)] = CreateCell(x, y);
+
-    GlobalList->size++;
+  printf("Cell at [%d, %d] marked as Alive.\n", x, y);
-  }
+  // if (GlobalList->cells[GetIndex(x, y, MAX_X)] == NULL) {
-  else {
+  //   GlobalList->cells[GetIndex(x, y, MAX_X)] = CreateCell(x, y);
-    printf("Cell already at [%d, %d]\n", x, y);
+  //   GlobalList->size++;
-  }
+  // }
+  // else {
+  //   printf("Cell already at [%d, %d]\n", x, y);
+  // }
 }
 
 void HandleInput(void) {
@@ -159,6 +231,7 @@ void HandleInput(void) {
         if (event.button.button == SDL_BUTTON_RIGHT) exit(0);
         else Thing(event.button.x, event.button.y);
       case SDL_KEYDOWN:
+        if (event.key.keysym.sym == SDLK_s) Start = 1;
       default:
         break;
     }
@@ -166,6 +239,10 @@ void HandleInput(void) {
 }
 
 int GetIndex(int x, int y, int columns) {
+  if ( x < 0 || y < 0 || x > MAX_X || y > MAX_Y) {
+    return MAX_X + MAX_Y * MAX_X + 1;
+  }
+
   return x + y * columns;
 }