rewrite without using ncursesHEADmain

1 files changed, 70 insertions, 41 deletions

diff --git a/2048_clean.c b/2048_clean.c
index ac58325..79a474b 100644
--- a/2048_clean.c
+++ b/2048_clean.c
@@ -1,24 +1,69 @@
-#include <ncurses.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <termios.h>
 #include <time.h>
 #include <unistd.h>
 
-#define waddstr_(text) waddstr(main_window, text)
-#define waddch_(ch) waddch(main_window, ch)
-#define wprintw_(format, data) wprintw(main_window, format, data)
-#define newline waddch_('\n')
+#define waddstr_(text) printf("%s", text)
+#define waddch_(ch) putchar(ch)
+#define wprintw_(format, data) printf(format, data)
+#define newline printf("\r\n")
 
 #define repeat(i, n) for (int i = 0; i < n; ++i)
 
 #define get_tile_at(k) (grid + y * ((x + size) % (size + 1) + k * x) + (size + 1 - y) * i)
 
-WINDOW *main_window;
-char *message = "\0";
-int size, num_rows, num_columns, new_tile_pos, num_empty_slots, changed, last_empty_tile_index, *last_non_empty_tile,
-    *this_tile, grid_buf[128], *grid = grid_buf;
+#define CLEAR_SCREEN "\033[2J\033[H"
+#define HIDE_CURSOR "\033[?25l"
+#define SHOW_CURSOR "\033[?25h"
 
-void draw_frame_1() {
+int size, new_tile_pos, num_empty_slots, changed, last_empty_tile_index, *last_non_empty_tile, *this_tile,
+    grid_buf[128], *grid = grid_buf, did_restore_from_alt_buffer, did_disable_raw_mode;
+
+void restore_from_alt_buffer(void) {
+    if (did_restore_from_alt_buffer++)
+        return;
+    printf("\033[?1049l");
+}
+
+void switch_to_alt_buffer(void) {
+    atexit(restore_from_alt_buffer);
+    printf("\033[?1049h");
+}
+
+struct termios original_termios;
+
+void disable_raw_mode(void) {
+    if (did_disable_raw_mode++)
+        return;
+    tcsetattr(STDIN_FILENO, TCSAFLUSH, &original_termios);
+    printf(SHOW_CURSOR);
+}
+
+void enable_raw_mode(void) {
+    tcgetattr(STDIN_FILENO, &original_termios);
+    atexit(disable_raw_mode);
+
+    struct termios raw = original_termios;
+    raw.c_iflag &= ~(BRKINT | ICRNL | INPCK | ISTRIP | IXON);
+    raw.c_oflag &= ~(OPOST);
+    raw.c_cflag |= (CS8);
+    raw.c_lflag &= ~(ECHO | ICANON | IEXTEN | ISIG);
+    raw.c_cc[VMIN] = 0;
+    raw.c_cc[VTIME] = 1;
+
+    tcsetattr(STDIN_FILENO, TCSAFLUSH, &raw);
+    printf(HIDE_CURSOR);
+}
+
+char get_key(void) {
+    char c;
+    while (read(STDIN_FILENO, &c, 1) != 1)
+        ;
+    return c;
+}
+
+void draw_frame_1(void) {
     waddch_('+');
     repeat(i, 8 * size - 1) {
         waddch_('-');
@@ -27,19 +72,18 @@ void draw_frame_1() {
     newline;
 }
 
-void draw_frame_2() {
+void draw_frame_2(void) {
     waddch_('|');
     repeat(i, size) {
-        repeat(j, 8) {
+        repeat(j, 7) {
             waddch_(32);
         }
-        waddch_('\b');
         waddch_('|');
     }
     newline;
 }
 
-void show_grid() {
+void show_grid(void) {
     draw_frame_1();
     repeat(i, size) {
         draw_frame_2();
@@ -62,10 +106,9 @@ void show_grid() {
         if (i < size - 1) {
             waddch_('|');
             repeat(j, size) {
-                repeat(j, 8) {
+                repeat(j, 7) {
                     waddch_('-');
                 }
-                waddch_('\b');
                 if (j < size - 1) {
                     waddch_('+');
                 }
@@ -113,7 +156,7 @@ int move_grid(int x, int y, int do_change) {
     return !changed;
 }
 
-void put_new_tile() {
+void put_new_tile(void) {
     num_empty_slots = 0;
     repeat(i, size * size) {
         if (!grid[i]) {
@@ -134,34 +177,25 @@ void put_new_tile() {
 int main(int argc, char **argv) {
     srand(time(0));
 
-    initscr();
-    cbreak();
-    noecho();
-    curs_set(0);
-    getmaxyx(stdscr, num_rows, num_columns);
+    switch_to_alt_buffer();
+    enable_raw_mode();
 
     size = argc > 1 ? (*argv[1] - '0') : 4;
     if (size <= 1 || size > 8) {
-        message = "\1Invalid size given.\n";
-        goto quit;
-    }
-
-    main_window = newwin(0, 0, (num_rows - 4 * size) / 2, (num_columns - 8 * size) / 2);
-    if (!main_window) {
-        message = "\1Terminal too small.\n";
-        goto quit;
+        fputs("invalid board size\n", stderr);
+        return 1;
     }
 
     put_new_tile();
     put_new_tile();
 
     while (1) {
-        wclear(main_window);
+        printf(CLEAR_SCREEN);
         show_grid();
         waddstr_("  h,j,k,l: move         q: quit");
-        wrefresh(main_window);
+        fflush(stdout);
 
-        switch (wgetch(main_window)) {
+        switch (get_key()) {
         case 'q':
             goto quit;
 
@@ -183,7 +217,6 @@ int main(int argc, char **argv) {
                 put_new_tile();
             }
             if (move_grid(1, 1, 0) & move_grid(-1, 1, 0) & move_grid(1, size, 0) & move_grid(-1, size, 0)) {
-                message = "\0Game over.\n";
                 goto quit;
             }
             usleep(2048 * 8);
@@ -192,11 +225,7 @@ int main(int argc, char **argv) {
     }
 
 quit:
-    if (main_window) {
-        delwin(main_window);
-    }
-    endwin();
-
-    fputs(message + 1, stderr);
-    return *message;
+    disable_raw_mode();
+    restore_from_alt_buffer();
+    printf(CLEAR_SCREEN);
 }