The user can now click to create a cell anywhere. Terrible main loop for drawing the cells but good enough for quick and dirty testing.

src/cell.c

@@ -1,7 +1,7 @@
 #include "cell.h"
 #include <stdlib.h>
 
-Cell* CreateCell(SDL_Rect rect) {
+Cell* CreateCell(int x, int y) {
     Cell* newCell = calloc(1, sizeof(Cell));
 
     if (!newCell) {
@@ -9,8 +9,10 @@ Cell* CreateCell(SDL_Rect rect) {
         return NULL;
     }
 
+    newCell->Visited = 0;
     newCell->Status = Alive;
-    newCell->Hitbox = rect;
+    newCell->x = x;
+    newCell->y = y;
 
     return newCell;
 }

src/cell.h

@@ -19,8 +19,11 @@ typedef struct cell {
     struct cell* BottomRight;
     State Status;
     SDL_Rect Hitbox;
+    int Visited;
+    int x;
+    int y;
 } Cell;
 
-Cell* CreateCell(SDL_Rect);
+Cell* CreateCell(int x, int y);
 
 #endif

src/main.c

@@ -2,6 +2,7 @@
 #include <SDL2/SDL_events.h>
 #include <SDL2/SDL_hints.h>
 #include <SDL2/SDL_keycode.h>
+#include <SDL2/SDL_mouse.h>
 #include <SDL2/SDL_rect.h>
 #include <SDL2/SDL_render.h>
 #include <SDL2/SDL_thread.h>
@@ -24,11 +25,20 @@ typedef struct {
     TTF_Font* font;
 }   App;
 
+typedef struct {
+  Cell** cells;
+  int size;
+  unsigned int capcity;
+} CellList;
+
+CellList* GlobalList;
+
 App app;
 
 void Cleanup(void);
 void HandleInput(void);
 int GetIndex(int x, int y, int columns);
+int GetNotSoRandomNumber(int);
 
 int main(int argc, char** argv) {
     memset(&app, 0, sizeof(app));
@@ -68,12 +78,17 @@ int main(int argc, char** argv) {
         return -1;
     }
 
+    GlobalList = calloc(1, sizeof(CellList));
+    GlobalList->cells = calloc(GetIndex(MAX_X, MAX_Y, MAX_X), sizeof(Cell*));
+    GlobalList->capcity = GetIndex(MAX_X, MAX_Y, MAX_X);
+    GlobalList->size = 0;
+
     SDL_Rect* rect = malloc(sizeof(SDL_Rect));
     rect->h = CELL_SIZE;
     rect->w = CELL_SIZE;
-    rect->x = 0;//MAX_X * CELL_SIZE;
-    rect->y = 0;//MAX_Y * CELL_SIZE;
-    Cell* cell = CreateCell(*rect);
+    // rect->x = 0;//MAX_X * CELL_SIZE;
+    // rect->y = 0;//MAX_Y * CELL_SIZE;
+    // Cell* cell = CreateCell(*rect);
 
     while(1){
 
@@ -87,18 +102,29 @@ int main(int argc, char** argv) {
 
         SDL_SetRenderDrawColor(app.renderer, 255, 255, 255, 255);
 
-        rect->x += CELL_SIZE;
-        rect->y += CELL_SIZE;
+        for(int i = 0; i < GlobalList->capcity; i++) {
+          if (GlobalList->cells[i] == NULL) continue;
 
-        if (rect->x / CELL_SIZE > MAX_X) rect->x = 0;
-        if (rect->y / CELL_SIZE > MAX_Y) rect->y = 0;
+          Cell* cell = GlobalList->cells[i];
+
+          rect->x = cell->x * CELL_SIZE;
+          rect->y = cell->y * CELL_SIZE;
 
           SDL_RenderFillRect(app.renderer, rect);
+        }
+
+        // rect->x += CELL_SIZE;
+        // rect->y += CELL_SIZE;
+
+        // if (rect->x / CELL_SIZE > MAX_X) rect->x = 0;
+        // if (rect->y / CELL_SIZE > MAX_Y) rect->y = 0;
+
+        // SDL_RenderFillRect(app.renderer, rect);
 
         SDL_RenderPresent(app.renderer);
     }
 
-    free(cell);
+    //free(cell);
 }
 
 void Cleanup(void) {
@@ -109,6 +135,19 @@ void Cleanup(void) {
     SDL_Quit();
 }
 
+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)] = CreateCell(x, y);
+    GlobalList->size++;
+  }
+  else {
+    printf("Cell already at [%d, %d]\n", x, y);
+  }
+}
+
 void HandleInput(void) {
   SDL_Event event;
   while(SDL_PollEvent(&event)) {
@@ -117,7 +156,8 @@ void HandleInput(void) {
         exit(0);
         break;
       case SDL_MOUSEBUTTONDOWN:
-        exit(0);
+        if (event.button.button == SDL_BUTTON_RIGHT) exit(0);
+        else Thing(event.button.x, event.button.y);
       case SDL_KEYDOWN:
       default:
         break;
@@ -128,3 +168,7 @@ void HandleInput(void) {
 int GetIndex(int x, int y, int columns) {
   return x + y * columns;
 }
+
+int GetNotSoRandomNumber(int max) {
+  return rand() % (max + 1);
+}