add Makefile

[lifeboot.git] / prototype.c

diff --git a/prototype.c b/prototype.c
index 5c6f052c91c37438d619d201c035459eb466cd19..c2979532ea5a29644ca492ebc360efef19daa1da 100644 (file)
--- a/prototype.c
+++ b/prototype.c
@@ -1,8 +1,8 @@
 #include <stdio.h>
 #include <stdlib.h>
-#include <unistd.h>
 #include <string.h>
 #include <time.h>
+#include <unistd.h>
 
 #define COLS 80
 #define ROWS 25
@@ -10,18 +10,14 @@
 #define DEAD ' '
 #define ALIVE '#'
 
-#define INIT_RATIO 10
+#define INIT_RATIO 4
 
 #define STR(x) _STR(x)
 #define _STR(x) #x
 
-static void clearscr() {
-  printf("\e[1;1H\e[2J");
-}
+static void clearscr() { printf("\e[1;1H\e[2J"); }
 
-static void print_row(char row[COLS]) {
-  printf("%." STR(COLS) "s\n", row);
-}
+static void print_row(char row[COLS]) { printf("%." STR(COLS) "s\n", row); }
 
 static void print_grid(char grid[COLS * ROWS]) {
   for (int i = 0; i < ROWS; i++)
@@ -37,22 +33,24 @@ static void init_grid(char grid[COLS * ROWS]) {
   }
 }
 
-static char get_state(char grid[COLS * ROWS], int idx) {
-  if (idx < 0 || idx >= COLS * ROWS)
+static char get_state(char grid[COLS * ROWS], int row, int col) {
+  if (row < 0 || row >= ROWS || col < 0 || col >= COLS)
     return DEAD;
 
-  return grid[idx];
+  return grid[row * COLS + col];
 }
 
 static int alive_neighbours(char grid[COLS * ROWS], int idx) {
+  int row = idx / COLS;
+  int col = idx % COLS;
   int neighbours = 0;
 
-  for (int i = -1; i <= 1; i++) /* row */
-    for (int j = -1; j <= 1; j++) /* col */
-      if (get_state(grid, idx + i * COLS + j) == ALIVE)
+  for (int i = -1; i <= 1; i++)
+    for (int j = -1; j <= 1; j++)
+      if (get_state(grid, row + i, col + j) == ALIVE)
         neighbours++;
 
-  if (get_state(grid, idx) == ALIVE)
+  if (get_state(grid, row, col) == ALIVE)
     neighbours--;
 
   return neighbours;
@@ -61,7 +59,7 @@ static int alive_neighbours(char grid[COLS * ROWS], int idx) {
 static char next_state(char grid[COLS * ROWS], int idx) {
   int n = alive_neighbours(grid, idx);
 
-  if (get_state(grid, idx) == ALIVE) {
+  if (get_state(grid, idx / COLS, idx % COLS) == ALIVE) {
     if (n < 2 || n > 3)
       return DEAD;
 
@@ -83,18 +81,17 @@ static void update_grid(char grid[COLS * ROWS]) {
   memcpy(grid, new, COLS * ROWS);
 }
 
-int main () {
+int main() {
   char grid[COLS * ROWS];
 
   srand(time(0));
   init_grid(grid);
 
-  for (;;) {
+  do {
     clearscr();
     print_grid(grid);
     update_grid(grid);
-    getchar();
-  }
+  } while (getchar() != 'q');
 
   return 0;
 }