Major rewrite. Abstracting graphics code completely and allowing new extensions via a consistent drawing interface

Makefile

@@ -1,14 +1,27 @@
-CC	   ?= gcc
+CC	    := clang
-CFLAGS += -Wall -Wextra
+CFLAGS  += -O2 -Wall -Wextra
-DEFS	= -DVT100_COMPATIBLE
+LFLAGS  +=
-LIBS	= 
+DEFINES := -DVT100
 
-all: 2048
+PROGRAM := 2048
+C_FILES := $(wildcard src/*.c)
+O_FILES := $(addprefix obj/,$(notdir $(C_FILES:.c=.o)))
 
-2048: src/2048_engine.c src/2048_rewrite.c
+all: curses
-	$(CC) $(DEFS) src/2048_engine.c src/2048_rewrite.c -o 2048 $(LIBS)
+
+curses: $(O_FILES)
+	$(CC) $(filter-out obj/gfx%.o, $(O_FILES)) obj/gfx_curses.o -o $(PROGRAM) -lcurses
+
+vt100: $(O_FILES)
+	$(CC) $(filter-out obj/gfx%.o, $(O_FILES)) obj/gfx_terminal.o -o $(PROGRAM)
+
+obj/%.o: src/%.c
+	$(CC) $(DEFINES) $(CFLAGS) -c -o $@ $<
+
+remake: clean all
 
 clean:
+	rm -f obj/*
 	rm -f 2048
 
-.PHONY: clean
+.PHONY: clean remake

src/2048_engine.h

@@ -1,62 +0,0 @@
-#ifndef _2048_ENGINE
-#define _2048_ENGINE
-
-#include <stdio.h>
-
-#define CONSTRAINT_GRID_MIN 4
-#define CONSTRAINT_GRID_MAX 20
-#define DEFAULT_GRID_HEIGHT 4
-#define DEFAULT_GRID_WIDTH 4
-#define DEFAULT_GOAL 2048
-#define DEFAULT_SPAWN_VALUE 2
-#define DEFAULT_SPAWN_RATE 1
-#define DEFAULT_COLOR_TOGGLE 0
-#define DEFAULT_ANIMATE_TOGGLE 1
-
-#define fatal(msg)\
-    do {\
-        fprintf(stderr, "line %d: %s\n", __LINE__, msg);\
-        abort();\
-    } while (0)
-
-typedef enum {
-    dir_left  = 'h',
-    dir_right = 'l',
-    dir_up    = 'k',
-    dir_down  = 'j'
-} direction;
-
-struct gameoptions {
-    size_t grid_height;
-    size_t grid_width;
-    long goal;
-    long spawn_value;
-    int spawn_rate;
-    int enable_color;
-    int animate;
-};
-
-struct gamestate {
-    /* Game state */
-    long **grid;
-    size_t gridsize;
-    int moved;
-    long score;
-    long score_high;
-    long score_last;
-    size_t print_width;
-    size_t blocks_in_play;
-    /* Options */
-    struct gameoptions *opts;
-};
-
-struct gameoptions* parse_options(struct gameoptions*, int, char**);
-void gravitate(struct gamestate*, direction, void (*callback)(struct gamestate*));
-void merge(struct gamestate*, direction, void (*callback)(struct gamestate*));
-int end_condition(struct gamestate *);
-void random_block(struct gamestate *);
-int  gamestate_tick(struct gamestate*, direction, void (*callback)(struct gamestate*));
-void gamestate_clear(struct gamestate*);
-struct gamestate*   gamestate_init(struct gameoptions *);
-struct gameoptions* gameoptions_default(void);
-#endif

src/2048_rewrite.c

@@ -1,191 +0,0 @@
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include "2048_engine.h"
-
-/* Need to alter termios settings before actually cross-platform. */
-/* It will be something like this, maybe switch to using a time.h sleep
- * method to get by os dependence, too? */
-#if (defined _WIN32 || defined __WIN64)
-#include <windows.h>
-#define syssleep(s) Sleep(s)
-#elif defined __unix__
-#include <unistd.h>
-#define syssleep(s) usleep((s) * 1000)
-#else 
-#error "Unsupported os: no sleep function"
-#endif
-
-#ifdef HAVE_CURSES
-#include <ncurses.h>
-#else
-#include <termios.h>
-#endif
-
-#define iterate(x, expr)\
-    do {\
-        size_t i;\
-        for (i = 0; i < x; ++i) { expr; }\
-    } while (0)
-
-#ifdef HAVE_CURSES  /* PLATFORM/OUTPUT DEPENDENT */
-void draw_screen(struct gamestate *g)
-{
-    static WINDOW *gamewin;
-    static size_t wh;
-    static size_t ww;
-
-    if (!gamewin) {
-        wh = g->opts->grid_height * (g->print_width + 2) + 3;
-        ww = g->opts->grid_width * (g->print_width + 2) + 1;
-        gamewin = newwin(wh, ww, 1, 1);
-        keypad(gamewin, TRUE);
-    }
-
-    if (g->score_last)
-        mvwprintw(gamewin, 0, 0, "SCORE: %d (+%d)\n", g->score, g->score_last);
-    else
-        mvwprintw(gamewin, 0, 0, "SCORE: %d\n", g->score);
-
-    mvwprintw(gamewin, 1, 0, "HISCR: %d\n", g->score_high);
-
-    iterate(g->opts->grid_width*(g->print_width + 2) + 1, waddch(gamewin, '-')); 
-    size_t x, y, xps = 0, yps = 3;
-    for (y = 0; y < g->opts->grid_height; y++, xps = 0, yps++) {
-        mvwprintw(gamewin, yps, xps++, "|");
-        for (x = 0; x < g->opts->grid_width; x++) {
-            if (g->grid[x][y]) {
-                mvwprintw(gamewin, yps, xps, "%*d", g->print_width, g->grid[x][y]);
-                mvwprintw(gamewin, yps, xps + g->print_width, " |");
-            }
-            else {
-                iterate(g->print_width + 1, waddch(gamewin, ' '));
-                waddch(gamewin, '|');
-            }
-            xps += (g->print_width + 2);
-        }
-    }
-    iterate(g->opts->grid_height*(g->print_width + 2) + 1, waddch(gamewin, '-')); 
-    wrefresh(gamewin);
-}
-
-void drawstate_init(void)
-{
-    initscr();
-    cbreak();
-    noecho();
-    curs_set(FALSE);
-    refresh();
-}
-
-void drawstate_clear(void)
-{
-    endwin();
-}
-
-int get_keypress(void)
-{
-    return getch();
-}
-
-#else /* vt100 and standard shared functions */
-
-/* Search for windows, blocking, non newline getchar */
-/* Could bypass termios that way */
-struct termios sattr;
-void drawstate_clear()
-{
-    tcsetattr(STDIN_FILENO, TCSANOW, &sattr);
-}
-
-void drawstate_init(void)
-{
-    tcgetattr(STDIN_FILENO, &sattr);
-
-    struct termios tattr;
-    tcgetattr(STDIN_FILENO, &tattr);
-    tattr.c_lflag &= ~(ICANON | ECHO);
-    tcsetattr(STDOUT_FILENO, TCSANOW, &tattr);
-}
-
-/* Need to check input queue, and remove all queued values on each getc to get
- * by any caught chars during any sleeps which may occur. This is easy in the
- * ncurses version (check until ERR), but requires extra tweaking here */
-int get_keypress(void)
-{
-    return fgetc(stdin);
-}
-
-void draw_screen(struct gamestate *g)
-{
-    /* Clear the screen each draw if we are able to */
-
-    /* Check for windows clear screen */
-#ifdef VT100_COMPATIBLE
-    printf("\033[2J\033[H");
-#endif
-    char *scr = g->score_last ? "SCORE: %d (+%d)\n" : "SCORE: %d\n";
-    printf(scr, g->score, g->score_last);
-    printf("HISCR: %ld\n", g->score_high);
-
-    // alter this grid_size + 1 to match abitrary grid size
-    iterate((g->print_width + 2) * g->opts->grid_width + 1, printf("-"));
-    printf("\n");
-    size_t x, y;
-    for (y = 0; y < g->opts->grid_height; y++) {
-        printf("|");
-        for (x = 0; x < g->opts->grid_width; x++) {
-            if (g->grid[x][y])
-                printf("%*ld |", g->print_width, g->grid[x][y]);
-            else
-                printf("%*s |", g->print_width, "");
-        }
-        printf("\n");
-    }
-
-    iterate((g->print_width + 2) * g->opts->grid_width + 1, printf("-"));
-    printf("\n\n");
-}
-#endif /* PLATFORM/OUTPUT DEPENDENT */
-
-void ddraw(struct gamestate *g)
-{
-    draw_screen(g);
-    syssleep(40);
-}
-
-int main(int argc, char **argv)
-{
-    struct gameoptions *o = gameoptions_default();
-    struct gamestate *g = gamestate_init(parse_options(o, argc, argv));
-
-    drawstate_init();
-
-    while (1) {
-        draw_screen(g);
-
-        /* abstract getting keypress */
-        int ch;
-        do {
-            ch = get_keypress();
-            if (ch == 'q') { goto endloop; }
-        } while (strchr("hjkl", ch) == NULL);
-
-        gamestate_tick(g, ch, g->opts->animate ? ddraw : NULL);
-
-        int e;
-        if ((e = end_condition(g))) {
-            drawstate_clear();
-            gamestate_clear(g);
-            printf(e > 0 ? "You win\n" : "You lose\n");
-            goto endloop;
-        }
-
-        random_block(g);
-    }
-
-endloop:
-    drawstate_clear();
-    gamestate_clear(g);
-    return 0;
-}

src/engine.c

@@ -1,11 +1,14 @@
 #include <stdlib.h>
 #include <time.h>
-#include "2048_engine.h"
+#include "engine.h"
 
 /* Utilize block counter to improve some of the functions so they can run
  * quicker */
 
-void gravitate(struct gamestate *g, direction d, void (*callback)(struct gamestate *g))
+/* This function will move all blocks in the given game the given direction.
+ * The callback function is called after each single move. It can be used to
+ * animate the movement of the board. */
+static void gravitate(struct gfx_state *s, struct gamestate *g, int d, void (*callback)(struct gfx_state *s, struct gamestate *g))
 {
 
 #define swap_if_space(xoff, yoff)\
@@ -18,7 +21,7 @@ void gravitate(struct gamestate *g, direction d, void (*callback)(struct gamesta
         }\
     } while (0)
 
-    size_t x, y;
+    int x, y;
     int done = 0;
 
     if (d == dir_left) {
@@ -30,7 +33,7 @@ void gravitate(struct gamestate *g, direction d, void (*callback)(struct gamesta
                 }
             }
             if (callback)
-                callback(g);
+                callback(s, g);
         }
     }
     else if (d == dir_right) {
@@ -42,7 +45,7 @@ void gravitate(struct gamestate *g, direction d, void (*callback)(struct gamesta
                 }
             }
             if (callback)
-                callback(g);
+                callback(s, g);
         }
     }
     else if (d == dir_down) {
@@ -54,7 +57,7 @@ void gravitate(struct gamestate *g, direction d, void (*callback)(struct gamesta
                 }
             }
             if (callback)
-                callback(g);
+                callback(s, g);
         }
     }
     else if (d == dir_up) {
@@ -66,7 +69,7 @@ void gravitate(struct gamestate *g, direction d, void (*callback)(struct gamesta
                 }
             }
             if (callback)
-                callback(g);
+                callback(s, g);
         }
     }
     else {
@@ -77,7 +80,16 @@ void gravitate(struct gamestate *g, direction d, void (*callback)(struct gamesta
 #undef swap_if_space
 }
 
-void merge(struct gamestate *g, direction d, void (*callback)(struct gamestate *g))
+/* The merge function will combine adjacent blocks with the same value for
+ * the given direction. Note, left and right merges will merge in a different
+ * order, so they are not identical in all cases.
+ *
+ * Consider 2 2 2 0
+ *
+ * Right merging: 4 0 2 0
+ * Left merging:  2 0 4 0
+ */
+static void merge(struct gfx_state *s, struct gamestate *g, int d, void (*callback)(struct gfx_state *s, struct gamestate *g))
 {
 
 #define merge_if_equal(xoff, yoff)\
@@ -92,7 +104,7 @@ void merge(struct gamestate *g, direction d, void (*callback)(struct gamestate *
         }\
     } while (0)
 
-    size_t x, y;
+    int x, y;
     g->score_last = 0;
 
     if (d == dir_left) {
@@ -129,28 +141,21 @@ void merge(struct gamestate *g, direction d, void (*callback)(struct gamestate *
     }
 
     if (callback)
-        callback(g);
+        callback(s, g);
 
 #undef merge_if_equal
 }
 
-/* Return -1 on lose condition, 1 on win condition, 0 on
+/* Scan the current board and determine if an end outcome has been reached.
- * haven't ended */
+ * -1 indicates a lose condition, 1 indicates a win condition, 0 indicates
-int end_condition(struct gamestate *g)
+ *  end has not yet been reached. */
+int gamestate_end_condition(struct gamestate *g)
 {
     int ret = -1;
-    size_t blocks_counted = 0;
+    //size_t blocks_counted = 0;
 
-    size_t x, y;
+    for (int x = 0; x < g->opts->grid_width; ++x) {
-    for (x = 0; x < g->opts->grid_width; ++x) {
+        for (int y = 0; y < g->opts->grid_height; ++y) {
-        for (y = 0; y < g->opts->grid_height; ++y) {
-            if (g->grid[x][y]) {
-                blocks_counted++;
-                if (g->grid[x][y] >= g->opts->goal)
-                    return 1;
-                else if (blocks_counted >= g->blocks_in_play)
-                    return ret;
-            }
             if (g->grid[x][y] >= g->opts->goal)
                 return 1;
             if (!g->grid[x][y] || ((x + 1 < g->opts->grid_width) &&
@@ -164,10 +169,8 @@ int end_condition(struct gamestate *g)
     return ret;
 }
 
-/* Find a better method for getting a random square. It would be useful to keep
+/* Place a random block into the current grid */
- * track of how many blocks are in play, which we can query here, end_condition
+void gamestate_new_block(struct gamestate *g)
- * to improve them. */
-void random_block(struct gamestate *g)
 {
     /* pick random square, if it is full, then move forward until we find
      * an empty square. This is biased */
@@ -186,7 +189,7 @@ void random_block(struct gamestate *g)
      */
 
     /* Error here */
-#ifdef NULLO
+#ifdef SKIP
     size_t block_position = (size_t)rand() % (
             g->opts->grid_width * g->opts->grid_height - g->blocks_in_play);
 
@@ -208,13 +211,17 @@ void random_block(struct gamestate *g)
 
 /* This returns the number of digits in the base10 rep of n. The ceiling is
  * taken so this will be one greater than required */
-static int clog10(unsigned int n)
+static int digits_ceiling(unsigned int n)
 {
     int l = 0;
     while (n) n /= 10, ++l;
     return l + 1;
 }
 
+/* Return NULL if we couldn't allocate space for the gamestate. The opt
+ * argument can be passed directly via gameoptions_default i.e
+ * *o = gamestate_init(gameoptions_default) is valid, as the delete function
+ * will find the pointer to the gameoptions and delete the data accordingly. */
 struct gamestate* gamestate_init(struct gameoptions *opt)
 {
     if (!opt) return NULL;
@@ -223,146 +230,58 @@ struct gamestate* gamestate_init(struct gameoptions *opt)
     if (!g) goto gamestate_alloc_fail;
     g->gridsize = opt->grid_width * opt->grid_height;
 
-    long *grid_back = calloc(g->gridsize, sizeof(long));
+    g->grid_data_ptr = calloc(g->gridsize, sizeof(long));
-    if (!grid_back) goto grid_back_alloc_fail;
+    if (!g->grid_data_ptr) goto grid_data_alloc_fail;
 
     g->grid = malloc(opt->grid_height * sizeof(long*));
     if (!g->grid) goto grid_alloc_fail;
 
     /* Switch to two allocation version */
-    size_t i;
     long **iterator = g->grid;
-    for (i = 0; i < g->gridsize; i += opt->grid_width)
+    for (int i = 0; i < g->gridsize; i += opt->grid_width)
-        *iterator++ = &grid_back[i];
+        *iterator++ = &g->grid_data_ptr[i];
 
     g->moved = 0;
     g->score = 0;
     g->score_high = 0;
     g->score_last = 0;
-    g->print_width = clog10(opt->goal);
+    g->print_width = digits_ceiling(opt->goal);
     g->blocks_in_play = 0;
     g->opts = opt;
 
     /* Initial 3 random blocks */
-    random_block(g);
+    gamestate_new_block(g);
-    random_block(g);
+    gamestate_new_block(g);
-    random_block(g);
+    gamestate_new_block(g);
     return g;
 
 grid_alloc_fail:
-    free(grid_back);
+    free(g->grid_data_ptr);
-grid_back_alloc_fail:
+grid_data_alloc_fail:
     free(g);
 gamestate_alloc_fail:
     return NULL;
 }
 
-struct gameoptions* gameoptions_default(void)
+/* A tick is a gravitate, merge then gravitate all in the same direction.
-{
+ * the moved variable is set to 0 initially and if the gravitate of merge
-    struct gameoptions *opt = malloc(sizeof(struct gameoptions));
+ * functions modify it, we can determine which action to take. */
-    if (!opt) return NULL;
+int gamestate_tick(struct gfx_state *s, struct gamestate *g, int d, void (*callback)(struct gfx_state*, struct gamestate*))
-
-    opt->grid_height = DEFAULT_GRID_HEIGHT;
-    opt->grid_width = DEFAULT_GRID_WIDTH;
-    opt->goal = DEFAULT_GOAL;
-    opt->spawn_value = DEFAULT_SPAWN_VALUE;
-    opt->spawn_rate = DEFAULT_SPAWN_RATE;
-    opt->enable_color = DEFAULT_COLOR_TOGGLE;
-    opt->animate = DEFAULT_ANIMATE_TOGGLE;
-
-    return opt;
-}
-
-int gamestate_tick(struct gamestate *g, direction d, void (*callback)(struct gamestate*))
 {
     /* Reset move. Altered by gravitate and merge if we do move */
     g->moved = 0;
-    gravitate(g, d, callback);
+    printf("%d\n", d);
-    merge(g, d, callback);
+    gravitate(s, g, d, callback);
-    gravitate(g, d, callback);
+    merge(s, g, d, callback);
+    gravitate(s, g, d, callback);
     return g->moved;
 }
 
+/* Free all data associated with the gamestate */
 void gamestate_clear(struct gamestate *g)
 {
-    free(g->opts);
+    gameoptions_destroy(g->opts);
-    free(g->grid[0]);   /* Free grid data */
+    free(g->grid_data_ptr);   /* Free grid data */
     free(g->grid);      /* Free pointers to data slots */
     free(g);
 }
-
-/* The following may be moved into own file */
-void reset_highscore(void)
-{
-    printf("Are you sure you want to reset your highscores? (Y)es/(N)o: ");
-
-    int response;
-    if ((response = getchar()) == 'y' || response == 'Y') {
-        printf("Resetting highscore...\n");
-    }
-}
-
-void print_usage(void)
-{
-    printf(
-    "usage: 2048 [-cCaArh] [-g <goal>] [-b <rate>] [-s <size>]\n"
-    "\n"
-    "controls\n"
-    "   hjkl        movement keys\n"
-    "   q           quit current game\n"
-    "\n"
-    "options\n"
-    "   -s <size>   set the grid side lengths\n"
-    "   -b <rate>   set the block spawn rate\n"
-    "   -g <goal>   set a new goal (default 2048)\n"
-    "   -a          enable animations (default)\n"
-    "   -A          disable animations\n"
-    "   -c          enable color support\n"
-    "   -C          disable color support (default)\n"
-    );
-}
-
-#include <getopt.h>
-
-struct gameoptions* parse_options(struct gameoptions *opt, int argc, char **argv)
-{
-    int c;
-    while ((c = getopt(argc, argv, "aArcChg:s:b:")) != -1) {
-        switch (c) {
-        case 'a':
-            opt->animate = 1;
-            break;
-        case 'A':
-            opt->animate = 0;
-            break;
-        case 'c':
-            opt->enable_color = 1;
-            break;
-        case 'C':
-            opt->enable_color = 0;
-            break;
-        case 'g':
-            opt->goal = strtol(optarg, NULL, 10);
-            break;
-        case 's':;
-            /* Stick with square for now */
-            int optint = strtol(optarg, NULL, 10);
-            if (optint < CONSTRAINT_GRID_MAX && optint > CONSTRAINT_GRID_MIN) {
-                opt->grid_height = optint;
-                opt->grid_width = optint;
-            }
-            break;
-        case 'b':
-            opt->spawn_rate = strtol(optarg, NULL, 10);
-            break;
-        case 'r':
-            reset_highscore();
-            exit(0);
-        case 'h':
-            print_usage();
-            exit(0);
-        }
-    }
-
-    return opt;
-}

src/engine.h

@@ -0,0 +1,43 @@
+#ifndef ENGINE_H
+#define ENGINE_H
+
+#include <stdio.h>
+#include "gfx.h"
+#include "options.h"
+
+#define fatal(msg)\
+    do {\
+        fprintf(stderr, "line %d: %s\n", __LINE__, msg);\
+        abort();\
+    } while (0)
+
+struct gamestate {
+    /* Game state */
+    long *grid_data_ptr;
+    long **grid;
+    int gridsize;
+    int moved;
+    long score;
+    long score_high;
+    long score_last;
+    int print_width;
+    int blocks_in_play;
+    /* Variable command line options */
+    struct gameoptions *opts;
+};
+
+enum {
+    dir_invalid,
+    dir_down,
+    dir_left,
+    dir_right,
+    dir_up
+};
+
+int gamestate_end_condition(struct gamestate*);
+void gamestate_new_block(struct gamestate*);
+int  gamestate_tick(struct gfx_state*, struct gamestate*, int, void (*callback)(struct gfx_state*, struct gamestate*));
+void gamestate_clear(struct gamestate*);
+struct gamestate* gamestate_init(struct gameoptions *);
+
+#endif

src/gfx.h

@@ -0,0 +1,30 @@
+#ifndef GFX_H
+#define GFX_H
+
+#include "engine.h"
+
+/* These can be defined by an implemenation if special codes are used
+ * to represent some keys. e.g. KEY_LEFT in ncurses */
+#define GFX_RIGHT_EXTRA
+#define GFX_LEFT_EXTRA
+#define GFX_DOWN_EXTRA
+#define GFX_UP_EXTRA
+
+struct gfx_state;
+
+/* Initialization of a graphics context */
+struct gfx_state* gfx_init(struct gamestate *);
+
+/* Drawing of a game_state onto a graphics context */
+void gfx_draw(struct gfx_state *, struct gamestate *);
+
+/* Blocking get character. Should not be buffered for best results */
+int gfx_getch(struct gfx_state *);
+
+/* Destruction of a graphics context */
+void gfx_destroy(struct gfx_state *);
+
+/* Sleep for a specifed millisecond period */
+void gfx_sleep(int ms);
+
+#endif

src/gfx_curses.c

@@ -0,0 +1,93 @@
+#include <stdlib.h>
+#include <ncurses.h>
+#include <unistd.h>
+#include "gfx.h"
+
+#define GFX_EXTRA_UP    case KEY_UP:
+#define GFX_EXTRA_DOWN  case KEY_DOWN:
+#define GFX_EXTRA_RIGHT case KEY_RIGHT:
+#define GFX_EXTRA_LEFT  case KEY_LEFT:
+
+#define iterate(n, expression)\
+    do {\
+        int i;\
+        for (i = 0; i < n; ++i) { expression; }\
+    } while (0)
+
+struct gfx_state {
+    WINDOW *window;
+    size_t window_height, window_width;
+};
+
+struct gfx_state* gfx_init(struct gamestate *g)
+{
+    initscr();
+    cbreak();
+    noecho();
+    curs_set(FALSE);
+    refresh();
+
+    struct gfx_state *s = malloc(sizeof(struct gfx_state));
+    s->window_height = g->opts->grid_height * (g->print_width + 2) + 3;
+    s->window_width  = g->opts->grid_width * (g->print_width + 2) + 1;
+    s->window = newwin(s->window_height, s->window_width, 1, 1);
+    keypad(s->window, TRUE);
+    return s;
+}
+
+void gfx_draw(struct gfx_state *s, struct gamestate *g)
+{
+    if (g->score_last)
+        mvwprintw(s->window, 0, 0, "Score: %d (+%d)\n", g->score, g->score_last);
+    else
+        mvwprintw(s->window, 0, 0, "Score: %d\n", g->score);
+
+    mvwprintw(s->window, 1, 0, "   Hi: %d\n", g->score_high);
+    iterate(g->opts->grid_width * (g->print_width + 2) + 1, waddch(s->window, '-'));
+
+    int x, y,
+        xpos = 0,
+        ypos = 3;
+
+    for (y = 0; y < g->opts->grid_height; ++y, ++ypos, xpos = 0) {
+        mvwprintw(s->window, ypos, xpos++, "|");
+
+        for (x = 0; x < g->opts->grid_width; ++x) {
+            if (g->grid[x][y]) {
+                mvwprintw(s->window, ypos, xpos, "%*d", g->print_width, g->grid[x][y]);
+                mvwprintw(s->window, ypos, xpos + g->print_width, " |");
+            }
+            else {
+                iterate(g->print_width + 1, waddch(s->window, ' '));
+                waddch(s->window, '|');
+            }
+
+            xpos += (g->print_width + 2);
+        }
+    }
+
+    iterate(g->opts->grid_height * (g->print_width + 2) + 1, waddch(s->window, '-'));
+    wrefresh(s->window);
+}
+
+int gfx_getch(struct gfx_state *s)
+{
+    int c = wgetch(s->window);
+
+    /* Flush buffer */
+    nodelay(s->window, TRUE);
+    while (wgetch(s->window) != ERR);
+    nodelay(s->window, FALSE);
+    return c;
+}
+
+void gfx_sleep(int ms)
+{
+    usleep(ms * 1000);
+}
+
+void gfx_destroy(struct gfx_state *s)
+{
+    free(s);
+    endwin();
+}

src/gfx_terminal.c

@@ -0,0 +1,72 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <termios.h>
+#include <unistd.h>
+#include "gfx.h"
+
+#define iterate(n, expression)\
+    do {\
+        int i;\
+        for (i = 0; i < n; ++i) { expression; }\
+    } while (0)
+
+struct gfx_state {
+    struct termios oldt, newt;
+};
+
+struct gfx_state* gfx_init(struct gamestate *g)
+{
+    struct gfx_state *s = malloc(sizeof(struct gfx_state));
+    tcgetattr(STDIN_FILENO, &s->oldt);
+    s->newt = s->oldt;
+    s->newt.c_lflag &= ~(ICANON | ECHO);
+    tcsetattr(STDIN_FILENO, TCSANOW, &s->newt);
+    return s;
+}
+
+void gfx_draw(struct gfx_state *s, struct gamestate *g)
+{
+#ifdef VT100
+    printf("\033[2J\033[H");
+#endif
+
+    if (g->score_last)
+        printf("Score: %ld (+%ld)\n", g->score, g->score_last);
+    else
+        printf("Score: %ld\n", g->score);
+
+    printf("   Hi: %ld\n", g->score_high);
+
+    iterate((g->print_width + 2) * g->opts->grid_width + 1, printf("-")); printf("\n");
+
+    int x, y;
+    for (y = 0; y < g->opts->grid_width; ++y) {
+        printf("|");
+
+        for (x = 0; x < g->opts->grid_width; ++x) {
+            if (g->grid[x][y])
+                printf("%*zd |", g->print_width, g->grid[x][y]);
+            else
+                printf("%*s |", g->print_width, "");
+        }
+        printf("\n");
+    }
+
+    iterate((g->print_width + 2) * g->opts->grid_width + 1, printf("-")); printf("\n\n");
+}
+
+int gfx_getch(struct gfx_state *s)
+{
+    return getchar();
+}
+
+void gfx_sleep(int ms)
+{
+    usleep(ms * 1000);
+}
+
+void gfx_destroy(struct gfx_state *t)
+{
+    tcsetattr(STDIN_FILENO, TCSANOW, &t->oldt);
+    free(t);
+}

src/main.c

@@ -0,0 +1,64 @@
+#include <stdio.h>
+#include <stdbool.h>
+#include "engine.h"
+#include "gfx.h"
+
+void draw_then_sleep(struct gfx_state *s, struct gamestate *g)
+{
+    gfx_draw(s, g);
+    gfx_sleep(40);
+}
+
+int main(int argc, char **argv)
+{
+    struct gameoptions *o = gameoptions_default();
+    struct gamestate *g   = gamestate_init(parse_options(o, argc, argv));
+    struct gfx_state *s   = gfx_init(g);
+
+    int game_running = true;
+    while (game_running) {
+        gfx_draw(s, g);
+
+get_new_key:;
+        int direction = dir_invalid;
+        switch (gfx_getch(s)) {
+            case 'h':
+            case 'a':
+                direction = dir_left;
+                break;
+            case 'l':
+            case 'd':
+                direction = dir_right;
+                break;
+            case 'j':
+            case 's':
+                direction = dir_down;
+                break;
+            case 'k':
+            case 'w':
+                direction = dir_up;
+                break;
+            case 'q':
+                game_running = false;
+                break;
+            default:
+                goto get_new_key;
+        }
+
+        /* Game will only end if 0 moves available */
+        if (game_running) {
+            if (gamestate_tick(s, g, direction, g->opts->animate ? draw_then_sleep : NULL))
+                gamestate_new_block(g);
+
+            if (gamestate_end_condition(g)) {
+                game_running = false;
+                goto game_end;
+            }
+        }
+    }
+
+game_end:
+    gfx_destroy(s);
+    gamestate_clear(g);
+    return 0;
+}

src/options.c

@@ -0,0 +1,88 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include "options.h"
+
+void print_usage(void)
+{
+    printf(
+    "usage: 2048 [-cCaArh] [-g <goal>] [-b <rate>] [-s <size>]\n"
+    "\n"
+    "controls\n"
+    "   hjkl        movement keys\n"
+    "   q           quit current game\n"
+    "\n"
+    "options\n"
+    "   -s <size>   set the grid side lengths\n"
+    "   -b <rate>   set the block spawn rate\n"
+    "   -g <goal>   set a new goal (default 2048)\n"
+    "   -a          enable animations (default)\n"
+    "   -A          disable animations\n"
+    "   -c          enable color support\n"
+    "   -C          disable color support (default)\n"
+    );
+}
+
+
+/* Initial game options */
+struct gameoptions* gameoptions_default(void)
+{
+    struct gameoptions *opt = malloc(sizeof(struct gameoptions));
+    if (!opt) return NULL;
+
+    opt->grid_height = DEFAULT_GRID_HEIGHT;
+    opt->grid_width = DEFAULT_GRID_WIDTH;
+    opt->goal = DEFAULT_GOAL;
+    opt->spawn_value = DEFAULT_SPAWN_VALUE;
+    opt->spawn_rate = DEFAULT_SPAWN_RATE;
+    opt->enable_color = DEFAULT_COLOR_TOGGLE;
+    opt->animate = DEFAULT_ANIMATE_TOGGLE;
+
+    return opt;
+}
+
+void gameoptions_destroy(struct gameoptions *opt)
+{
+    free(opt);
+}
+
+struct gameoptions* parse_options(struct gameoptions *opt, int argc, char **argv)
+{
+    int c;
+    while ((c = getopt(argc, argv, "aArcChg:s:b:")) != -1) {
+        switch (c) {
+        case 'a':
+            opt->animate = 1;
+            break;
+        case 'A':
+            opt->animate = 0;
+            break;
+        case 'c':
+            opt->enable_color = 1;
+            break;
+        case 'C':
+            opt->enable_color = 0;
+            break;
+        case 'g':
+            opt->goal = strtol(optarg, NULL, 10);
+            break;
+        case 's':;
+            /* Stick with square for now */
+            int optint = strtol(optarg, NULL, 10);
+            if (optint < CONSTRAINT_GRID_MAX && optint > CONSTRAINT_GRID_MIN) {
+                opt->grid_height = optint;
+                opt->grid_width = optint;
+            }
+            break;
+        case 'b':
+            opt->spawn_rate = strtol(optarg, NULL, 10);
+            break;
+        case 'r':
+            exit(0);
+        case 'h':
+            print_usage();
+            exit(0);
+        }
+    }
+
+    return opt;
+}

src/options.h

@@ -0,0 +1,31 @@
+#ifndef OPTIONS_H
+#define OPTIONS_H
+
+#include <getopt.h>
+
+#define CONSTRAINT_GRID_MIN 4
+#define CONSTRAINT_GRID_MAX 20
+#define DEFAULT_GRID_HEIGHT 4
+#define DEFAULT_GRID_WIDTH 4
+#define DEFAULT_GOAL 2048
+#define DEFAULT_SPAWN_VALUE 2
+#define DEFAULT_SPAWN_RATE 1
+#define DEFAULT_COLOR_TOGGLE 0
+#define DEFAULT_ANIMATE_TOGGLE 1
+
+struct gameoptions {
+    int grid_height;
+    int grid_width;
+    long goal;
+    long spawn_value;
+    int spawn_rate;
+    int enable_color;
+    int animate;
+};
+
+void print_usage(void);
+struct gameoptions* parse_options(struct gameoptions*, int, char**);
+struct gameoptions* gameoptions_default(void);
+void gameoptions_destroy(struct gameoptions *opt);
+
+#endif