summaryrefslogtreecommitdiffstats
path: root/apps/plugins/2048.c
blob: 1604b73c62e50d686b25d2e62fb170e02a42b61a (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
/***************************************************************************
 *             __________               __   ___.
 *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
 *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
 *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
 *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
 *                     \/            \/     \/    \/            \/
 * $Id$
 *
 * Copyright (C) 2014 Franklin Wei
 *
 * Clone of 2048 by Gabriele Cirulli
 *
 * Thanks to [Saint], saratoga, and gevaerts for answering all my n00b
 * questions :)
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
 * KIND, either express or implied.
 *
 ***************************************************************************/

/* TODO
 * Sounds!
 * Better animations!
 */

/* includes */

#include <plugin.h>

#include "lib/display_text.h"

#include "lib/helper.h"
#include "lib/highscore.h"
#include "lib/playback_control.h"
#include "lib/pluginlib_actions.h"
#include "lib/pluginlib_exit.h"

#include "pluginbitmaps/_2048_background.h"
#include "pluginbitmaps/_2048_tiles.h"

/* some constants */

static const int ANIM_SLEEPTIME = (HZ/20);
static const int NUM_STARTING_TILES = 2;
static const int VERT_SPACING = 4;
static const int WHAT_FONT = FONT_UI;
static const unsigned int WINNING_TILE = 2048;

/* must use macros for these */
#define GRID_SIZE 4
#define HISCORES_FILE PLUGIN_GAMES_DATA_DIR "/2048.score"
#define MIN_SPACE (BMPHEIGHT__2048_tiles * 0.134)
#define NUM_SCORES 5
#define RESUME_FILE PLUGIN_GAMES_DATA_DIR "/2048.save"
#define SPACES (GRID_SIZE * GRID_SIZE)

/* screen-specific configuration */

#if (LCD_WIDTH < LCD_HEIGHT) /* tall screens */
#  define TITLE_X 0
#  define TITLE_Y 0
#  define BASE_Y (BMPHEIGHT__2048_tiles*1.5)
#  define BASE_X (BMPHEIGHT__2048_tiles*.5-MIN_SPACE)
#  define SCORE_X 0
#  define SCORE_Y (max_numeral_height)
#  define BEST_SCORE_X 0
#  define BEST_SCORE_Y (2*max_numeral_height)
#else /* wide or square screens */
#  define TITLE_X 0
#  define TITLE_Y 0
#  define BASE_X (LCD_WIDTH-(GRID_SIZE*BMPHEIGHT__2048_tiles)-(((GRID_SIZE+1)*MIN_SPACE)))
#  define BASE_Y (BMPHEIGHT__2048_tiles*.5-MIN_SPACE)
#  define SCORE_X 0
#  define SCORE_Y (max_numeral_height)
#  define BEST_SCORE_X 0
#  define BEST_SCORE_Y (2*max_numeral_height)
#endif /* LCD_WIDTH < LCD_HEIGHT */

/* where to draw the background bitmap */
static const int BACKGROUND_X = (BASE_X-MIN_SPACE);
static const int BACKGROUND_Y = (BASE_Y-MIN_SPACE);

/* key mappings */
#define KEY_UP PLA_UP
#define KEY_DOWN PLA_DOWN
#define KEY_LEFT PLA_LEFT
#define KEY_RIGHT PLA_RIGHT
#define KEY_EXIT PLA_CANCEL
#define KEY_UNDO PLA_SELECT

/* notice how "color" is spelled :P */
#ifdef HAVE_LCD_COLOR

/* colors */

static const unsigned BACKGROUND = LCD_RGBPACK(0xfa, 0xf8, 0xef);
static const unsigned BOARD_BACKGROUND = LCD_RGBPACK(0xbb, 0xad, 0xa0);
static const unsigned TEXT_COLOR = LCD_RGBPACK(0x77, 0x6e, 0x65);

#endif

/* PLA data */
static const struct button_mapping *plugin_contexts[] = { pla_main_ctx };

/*** game data structures ***/

struct game_ctx_t {
    unsigned int grid[GRID_SIZE][GRID_SIZE]; /* 0 = empty */
    unsigned int score;
    unsigned int cksum;                      /* sum of grid, XORed by score */
    bool already_won;                        /* has the player gotten 2048 yet? */
} game_ctx;

static struct game_ctx_t *ctx = &game_ctx;

/*** temporary data ***/

static bool merged_grid[GRID_SIZE][GRID_SIZE];
static int old_grid[GRID_SIZE][GRID_SIZE];

static int max_numeral_height = -1;

#if LCD_DEPTH <= 1
static int max_numeral_width;
#endif

static bool loaded = false; /* has a save been loaded? */

/* the high score */
static unsigned int best_score;

static bool abnormal_exit = true;
static struct highscore highscores[NUM_SCORES];

/***************************** UTILITY FUNCTIONS *****************************/

static inline int rand_range(int min, int max)
{
    return rb->rand() % (max-min + 1) + min;
}

/* prepares for exit */
static void cleanup(void)
{
#ifdef HAVE_BACKLIGHT
    backlight_use_settings();
#endif
}

/* returns 2 or 4 */
static inline int rand_2_or_4(void)
{
    /* 1 in 10 chance of a four */
    if(rb->rand() % 10 == 0)
        return 4;
    else
        return 2;
}

/* displays the help text */
static bool do_help(void)
{

#ifdef HAVE_LCD_COLOR
    rb->lcd_set_foreground(LCD_WHITE);
    rb->lcd_set_background(LCD_BLACK);
#endif

    rb->lcd_setfont(FONT_UI);

    static char* help_text[]= {"2048", "", "Aim",
                               "", "Join", "the", "numbers", "to", "get", "to", "the", "2048", "tile!", "", "",
                               "How", "to", "Play", "",
                               "", "Use", "the", "directional", "keys", "to", "move", "the", "tiles.", "When",
                               "two", "tiles", "with", "the", "same", "number", "touch,", "they", "merge", "into", "one!"};

    struct style_text style[] = {
        {0,  TEXT_CENTER | TEXT_UNDERLINE},
        {2,  C_RED},
        {15, C_RED},
        {16, C_RED},
        {17, C_RED},
        LAST_STYLE_ITEM
    };

    return display_text(ARRAYLEN(help_text), help_text, style, NULL, true);
}

/*** tile movement logic ***/

/* this function performs the tile movement */
static inline void slide_internal(int startx, int starty,
                                  int stopx, int stopy,
                                  int dx, int dy,
                                  int lookx, int looky,
                                  bool update_best)
{
    unsigned int best_score_old = best_score;

    /* loop over the rows or columns, moving the tiles in the specified direction */
    for(int y = starty; y != stopy; y += dy)
    {
        for(int x = startx; x != stopx; x += dx)
        {
            if(ctx->grid[x + lookx][y + looky] == ctx->grid[x][y] &&
               ctx->grid[x][y]                                    &&
               !merged_grid[x + lookx][y + looky]                 &&
               !merged_grid[x][y]) /* merge these two tiles */
            {
                /* Each merged tile cannot be merged again */
                merged_grid[x + lookx][y + looky] = true;
                ctx->grid[x + lookx][y + looky] = 2 * ctx->grid[x][y];
                ctx->score += ctx->grid[x + lookx][y + looky];
                ctx->grid[x][y] = 0;
            }
            else if(ctx->grid[x + lookx][y + looky] == 0) /* Empty! */
            {
                ctx->grid[x + lookx][y + looky] = ctx->grid[x][y];
                ctx->grid[x][y] = 0;
            }
        }
    }
    if(ctx->score > best_score_old && update_best)
        best_score = ctx->score;
}

/* these functions move each tile 1 space in the direction specified via calls to slide_internal */

/* Up
   0
   1 ^ ^ ^ ^
   2 ^ ^ ^ ^
   3 ^ ^ ^ ^
   0 1 2 3
*/
static void up(bool update_best)
{
    slide_internal(0, 1,  /* start values */
                   GRID_SIZE, GRID_SIZE, /* stop values */
                   1, 1, /* delta values */
                   0, -1, /* lookahead values */
                   update_best);
}

/* Down
   0 v v v v
   1 v v v v
   2 v v v v
   3
   0 1 2 3
*/
static void down(bool update_best)
{
    slide_internal(0, GRID_SIZE-2,
                   GRID_SIZE, -1,
                   1, -1,
                   0, 1,
                   update_best);
}

/* Left
   0   < < <
   1   < < <
   2   < < <
   3   < < <
   0 1 2 3
*/
static void left(bool update_best)
{
    slide_internal(1, 0,
                   GRID_SIZE, GRID_SIZE,
                   1, 1,
                   -1, 0,
                   update_best);
}

/* Right
   0 > > >
   1 > > >
   2 > > >
   3 > > >
   0 1 2 3
*/
static void right(bool update_best)
{
    slide_internal(GRID_SIZE-2, 0, /* start */
                   -1, GRID_SIZE, /* stop */
                   -1, 1, /* delta */
                   1, 0, /* lookahead */
                   update_best);
}

/* copies old_grid to ctx->grid */
static inline void RESTORE_GRID(void)
{
    memcpy(&ctx->grid, &old_grid, sizeof(ctx->grid));
}

/* slightly modified base 2 logarithm, returns 1 when given zero, and log2(n) + 1 for anything else */
static inline int ilog2(int n)
{
    if(n == 0)
        return 1;
    int log = 0;
    while(n > 1)
    {
        n >>= 1;
        ++log;
    }
    return log + 1;
}

/* low-depth displays resort to text drawing, see the #else case below */

#if LCD_DEPTH > 1

/* draws game screen + updates LCD */
static void draw(void)
{
#ifdef HAVE_LCD_COLOR
    rb->lcd_set_background(BACKGROUND);
#endif

    rb->lcd_clear_display();

    /* draw the background */

    rb->lcd_bitmap(_2048_background,
                   BACKGROUND_X, BACKGROUND_Y,
                   BMPWIDTH__2048_background, BMPWIDTH__2048_background);

    /*
      grey_gray_bitmap(_2048_background, BACKGROUND_X, BACKGROUND_Y, BMPWIDTH__2048_background, BMPHEIGHT__2048_background);
    */

    /* draw the grid */

    for(int y = 0; y < GRID_SIZE; ++y)
    {
        for(int x = 0; x < GRID_SIZE; ++x)
        {
            rb->lcd_bitmap_part(_2048_tiles,                                                                                        /* source */
                                BMPWIDTH__2048_tiles - BMPHEIGHT__2048_tiles * ilog2(ctx->grid[x][y]), 0,                           /* source upper left corner */
                                STRIDE(SCREEN_MAIN, BMPWIDTH__2048_tiles, BMPHEIGHT__2048_tiles),                                   /* stride */
                                (BMPHEIGHT__2048_tiles + MIN_SPACE) * x + BASE_X, (BMPHEIGHT__2048_tiles + MIN_SPACE) * y + BASE_Y, /* dest upper-left corner */
                                BMPHEIGHT__2048_tiles, BMPHEIGHT__2048_tiles);                                                      /* size of the cut section */
        }
    }

    /* draw the title */
    char buf[32];

#ifdef HAVE_LCD_COLOR
    rb->lcd_set_foreground(TEXT_COLOR);
#endif

    rb->snprintf(buf, sizeof(buf), "%d", WINNING_TILE);

    /* check if the title will overlap the grid */
    int w, h;
    rb->lcd_setfont(FONT_UI);
    rb->font_getstringsize(buf, &w, &h, FONT_UI);
    bool draw_title = true;
    if(w + TITLE_X >= BACKGROUND_X && h + TITLE_Y >= BACKGROUND_Y)
    {
        /* if it goes into the grid, use the system font, which should be smaller */
        rb->lcd_setfont(FONT_SYSFIXED);
        rb->font_getstringsize(buf, &w, &h, FONT_SYSFIXED);
        if(w + TITLE_X >= BACKGROUND_X && h + TITLE_Y >= BACKGROUND_Y)
        {
            /* title can't fit, don't draw it */
            draw_title = false;
            h = 0;
        }
    }

    if(draw_title)
        rb->lcd_putsxy(TITLE_X, TITLE_Y, buf);

    int score_y = TITLE_Y + h + VERT_SPACING;

    /* draw the score */
    rb->snprintf(buf, sizeof(buf), "Score: %d", ctx->score);

#ifdef HAVE_LCD_COLOR
    rb->lcd_set_foreground(LCD_WHITE);
    rb->lcd_set_background(BOARD_BACKGROUND);
#endif

    rb->lcd_setfont(FONT_UI);
    rb->font_getstringsize(buf, &w, &h, FONT_UI);

    /* try making the score fit */
    if(w + SCORE_X >= BACKGROUND_X && h + SCORE_Y >= BACKGROUND_Y)
    {
        /* score overflows */
        /* first see if it fits with Score: and FONT_SYSFIXED */
        rb->lcd_setfont(FONT_SYSFIXED);
        rb->font_getstringsize(buf, &w, &h, FONT_SYSFIXED);
        if(w + SCORE_X < BACKGROUND_X)
            /* it fits, go and draw it */
            goto draw_lbl;

        /* now try with S: and FONT_UI */
        rb->snprintf(buf, sizeof(buf), "S: %d", ctx->score);
        rb->font_getstringsize(buf, &w, &h, FONT_UI);
        rb->lcd_setfont(FONT_UI);
        if(w + SCORE_X < BACKGROUND_X)
            goto draw_lbl;

        /* now try with S: and FONT_SYSFIXED */
        rb->snprintf(buf, sizeof(buf), "S: %d", ctx->score);
        rb->font_getstringsize(buf, &w, &h, FONT_SYSFIXED);
        rb->lcd_setfont(FONT_SYSFIXED);
        if(w + SCORE_X < BACKGROUND_X)
            goto draw_lbl;

        /* then try without Score: and FONT_UI */
        rb->snprintf(buf, sizeof(buf), "%d", ctx->score);
        rb->font_getstringsize(buf, &w, &h, FONT_UI);
        rb->lcd_setfont(FONT_UI);
        if(w + SCORE_X < BACKGROUND_X)
            goto draw_lbl;

        /* as a last resort, don't use Score: and use the system font */
        rb->snprintf(buf, sizeof(buf), "%d", ctx->score);
        rb->font_getstringsize(buf, &w, &h, FONT_SYSFIXED);
        rb->lcd_setfont(FONT_SYSFIXED);
        if(w + SCORE_X < BACKGROUND_X)
            goto draw_lbl;
        else
            goto skip_draw_score;
    }

draw_lbl:
    rb->lcd_putsxy(SCORE_X, score_y, buf);
    score_y += h + VERT_SPACING;

    /* draw the best score */
skip_draw_score:
    rb->snprintf(buf, sizeof(buf), "Best: %d", best_score);

#ifdef HAVE_LCD_COLOR
    rb->lcd_set_foreground(LCD_WHITE);
    rb->lcd_set_background(BOARD_BACKGROUND);
#endif

    rb->lcd_setfont(FONT_UI);
    rb->font_getstringsize(buf, &w, &h, FONT_UI);
    if(w + BEST_SCORE_X >= BACKGROUND_X && h + BEST_SCORE_Y >= BACKGROUND_Y)
    {
        /* score overflows */
        /* first see if it fits with Score: and FONT_SYSFIXED */
        rb->lcd_setfont(FONT_SYSFIXED);
        rb->font_getstringsize(buf, &w, &h, FONT_SYSFIXED);
        if(w + BEST_SCORE_X < BACKGROUND_X)
            /* it fits, go and draw it */
            goto draw_best;

        /* now try with S: and FONT_UI */
        rb->snprintf(buf, sizeof(buf), "B: %d", best_score);
        rb->font_getstringsize(buf, &w, &h, FONT_UI);
        rb->lcd_setfont(FONT_UI);
        if(w + BEST_SCORE_X < BACKGROUND_X)
            goto draw_best;

        /* now try with S: and FONT_SYSFIXED */
        rb->snprintf(buf, sizeof(buf), "B: %d", best_score);
        rb->font_getstringsize(buf, &w, &h, FONT_SYSFIXED);
        rb->lcd_setfont(FONT_SYSFIXED);
        if(w + BEST_SCORE_X < BACKGROUND_X)
            goto draw_best;

        /* then try without Score: and FONT_UI */
        rb->snprintf(buf, sizeof(buf), "%d", best_score);
        rb->font_getstringsize(buf, &w, &h, FONT_UI);
        rb->lcd_setfont(FONT_UI);
        if(w + BEST_SCORE_X < BACKGROUND_X)
            goto draw_best;

        /* as a last resort, don't use Score: and use the system font */
        rb->snprintf(buf, sizeof(buf), "%d", best_score);
        rb->font_getstringsize(buf, &w, &h, FONT_SYSFIXED);
        rb->lcd_setfont(FONT_SYSFIXED);
        if(w + BEST_SCORE_X < BACKGROUND_X)
            goto draw_best;
        else
            goto skip_draw_best;
    }
draw_best:
    rb->lcd_putsxy(BEST_SCORE_X, score_y, buf);

skip_draw_best:
    rb->lcd_update();

    /* revert the font */
    rb->lcd_setfont(WHAT_FONT);
}

#else /* LCD_DEPTH > 1 */

/* 1-bit display :( */
/* bitmaps are unreadable on these screens, so just resort to text-based drawing */
static void draw(void)
{
    rb->lcd_clear_display();

    /* Draw the grid */
    /* find the biggest tile */
    unsigned int biggest_tile = 0;
    for(int x = 0; x < GRID_SIZE; ++x)
    {
        for(int y = 0; y < GRID_SIZE; ++y)
            if(ctx->grid[x][y] > biggest_tile)
                biggest_tile = ctx->grid[x][y];
    }

    char buf[32];

    rb->snprintf(buf, 32, "%d", biggest_tile);

    int biggest_tile_width = rb->strlen(buf) * rb->font_get_width(rb->font_get(WHAT_FONT), '0') + MIN_SPACE;

    for(int y = 0; y < GRID_SIZE; ++y)
    {
        for(int x = 0; x < GRID_SIZE; ++x)
        {
            if(ctx->grid[x][y])
            {
                if(ctx->grid[x][y] > biggest_tile)
                    biggest_tile = ctx->grid[x][y];
                rb->snprintf(buf, 32, "%d", ctx->grid[x][y]);
                rb->lcd_putsxy(biggest_tile_width * x, y * max_numeral_height + max_numeral_height, buf);
            }
        }
    }

    /* Now draw the score, and the game title */
    rb->snprintf(buf, 32, "Score: %d", ctx->score);
    int buf_width, buf_height;
    rb->font_getstringsize(buf, &buf_width, &buf_height, WHAT_FONT);

    int score_leftmost = LCD_WIDTH - buf_width - 1;
    /* Check if there is enough space to display "Score: ", otherwise, only display the score */
    if(score_leftmost >= 0)
        rb->lcd_putsxy(score_leftmost, 0, buf);
    else
        rb->lcd_putsxy(score_leftmost, 0, buf + rb->strlen("Score: "));

    rb->snprintf(buf, 32, "%d", WINNING_TILE);
    rb->font_getstringsize(buf, &buf_width, &buf_height, WHAT_FONT);
    if(buf_width < score_leftmost)
        rb->lcd_putsxy(0, 0, buf);

    rb->lcd_update();
}

#endif /* LCD_DEPTH > 1 */

/* place a 2 or 4 in a random empty space */
static void place_random(void)
{
    int xpos[SPACES], ypos[SPACES];
    int back = 0;
    /* get the indexes of empty spaces */
    for(int y = 0; y < GRID_SIZE; ++y)
        for(int x = 0; x < GRID_SIZE; ++x)
        {
            if(!ctx->grid[x][y])
            {
                xpos[back] = x;
                ypos[back++] = y;
            }
        }

    if(!back)
        /* no empty spaces */
        return;

    int idx = rand_range(0, back - 1);
    ctx->grid[ xpos[idx] ][ ypos[idx] ] = rand_2_or_4();
}

/* checks for a win or loss */
static bool check_gameover(void)
{
    /* first, check for a loss */
    int oldscore = ctx->score;
    bool have_legal_move = false;

    memset(&merged_grid, 0, SPACES * sizeof(bool));
    up(false);
    if(memcmp(&old_grid, &ctx->grid, sizeof(ctx->grid)))
    {
        RESTORE_GRID();
        ctx->score = oldscore;
        have_legal_move = true;
    }
    RESTORE_GRID();

    memset(&merged_grid, 0, SPACES * sizeof(bool));
    down(false);
    if(memcmp(&old_grid, &ctx->grid, sizeof(ctx->grid)))
    {
        RESTORE_GRID();
        ctx->score = oldscore;
        have_legal_move = true;
    }
    RESTORE_GRID();

    memset(&merged_grid, 0, SPACES * sizeof(bool));
    left(false);
    if(memcmp(&old_grid, &ctx->grid, sizeof(ctx->grid)))
    {
        RESTORE_GRID();
        ctx->score = oldscore;
        have_legal_move = true;
    }
    RESTORE_GRID();

    memset(&merged_grid, 0, SPACES * sizeof(bool));
    right(false);
    if(memcmp(&old_grid, &ctx->grid, sizeof(ctx->grid)))
    {
        RESTORE_GRID();
        ctx->score = oldscore;
        have_legal_move = true;
    }
    ctx->score = oldscore;
    if(!have_legal_move)
    {
        /* no more legal moves */
        draw(); /* Shame the player */
        rb->splash(HZ*2, "Game Over!");
        return true;
    }

    for(int y = 0;y < GRID_SIZE; ++y)
    {
        for(int x = 0; x < GRID_SIZE; ++x)
        {
            if(ctx->grid[x][y] == WINNING_TILE && !ctx->already_won)
            {
                /* Let the user see the tile in its full glory... */
                draw();
                ctx->already_won = true;
                rb->splash(HZ*2,"You win!");
            }
        }
    }
    return false;
}

/* loads highscores from disk */
/* creates an empty structure if the file does not exist */
static void load_hs(void)
{
    if(rb->file_exists(HISCORES_FILE))
        highscore_load(HISCORES_FILE, highscores, NUM_SCORES);
    else
        memset(highscores, 0, sizeof(struct highscore) * NUM_SCORES);
}

/* initialize the data structures */
static void init_game(bool newgame)
{
    best_score = highscores[0].score;
    if(loaded && ctx->score > best_score)
        best_score = ctx->score;

    if(newgame)
    {
        /* initialize the game context */
        memset(ctx->grid, 0, sizeof(ctx->grid));
        for(int i = 0; i < NUM_STARTING_TILES; ++i)
        {
            place_random();
        }
        ctx->score = 0;
        ctx->already_won = false;
    }

    /* using the menu resets the font */
    /* set it again here */

    rb->lcd_setfont(WHAT_FONT);

    /* Now calculate font sizes */
    /* Now get the height of the font */
    rb->font_getstringsize("0123456789", NULL, &max_numeral_height, WHAT_FONT);
    max_numeral_height += VERT_SPACING;

#if LCD_DEPTH <= 1
    max_numeral_width = rb->font_get_width(rb->font_get(WHAT_FONT), '0');
#endif

#ifdef HAVE_BACKLIGHT
    backlight_ignore_timeout();
#endif
    draw();
}

/* save the current game state */
static void save_game(void)
{
    rb->splash(0, "Saving...");
    int fd = rb->open(RESUME_FILE, O_WRONLY|O_CREAT, 0666);
    if(fd < 0)
    {
        return;
    }

    /* calculate checksum */
    ctx->cksum = 0;

    for(int x = 0; x < GRID_SIZE; ++x)
        for(int y = 0; y < GRID_SIZE; ++y)
            ctx->cksum += ctx->grid[x][y];

    ctx->cksum ^= ctx->score;

    rb->write(fd, ctx, sizeof(struct game_ctx_t));
    rb->close(fd);
    rb->lcd_update();
}

/* loads a saved game, returns true on success */
static bool load_game(void)
{
    int success = 0;
    int fd = rb->open(RESUME_FILE, O_RDONLY);
    if(fd < 0)
    {
        rb->remove(RESUME_FILE);
        return false;
    }

    int numread = rb->read(fd, ctx, sizeof(struct game_ctx_t));

    /* verify checksum */
    unsigned int calc = 0;
    for(int x = 0; x < GRID_SIZE; ++x)
        for(int y = 0; y < GRID_SIZE; ++y)
            calc += ctx->grid[x][y];

    calc ^= ctx->score;

    if(numread == sizeof(struct game_ctx_t) && calc == ctx->cksum)
        ++success;

    rb->close(fd);
    rb->remove(RESUME_FILE);

    return (success > 0);
}

/* update the highscores with ctx->score */
static void hs_check_update(bool noshow)
{
    /* first, find the biggest tile to show as the level */
    unsigned int biggest = 0;
    for(int x = 0; x < GRID_SIZE; ++x)
    {
        for(int y = 0; y < GRID_SIZE; ++y)
        {
            if(ctx->grid[x][y] > biggest)
                biggest = ctx->grid[x][y];
        }
    }

    int hs_idx = highscore_update(ctx->score,biggest, "", highscores,NUM_SCORES);
    if(!noshow)
    {
        /* show the scores if there is a new high score */
        if(hs_idx >= 0)
        {
            rb->splashf(HZ*2, "New High Score: %d", ctx->score);
            rb->lcd_clear_display();
            highscore_show(hs_idx, highscores, NUM_SCORES, true);
        }
    }
    highscore_save(HISCORES_FILE, highscores, NUM_SCORES);
}

/* asks the user if they wish to quit */
static bool confirm_quit(void)
{
    const struct text_message prompt = { (const char*[]) {"Are you sure?", "This will clear your current game."}, 2};
    enum yesno_res response = rb->gui_syncyesno_run(&prompt, NULL, NULL);
    if(response == YESNO_NO)
        return false;
    else
        return true;
}

/* show the pause menu */
static int do_2048_pause_menu(void)
{
    int sel = 0;
    MENUITEM_STRINGLIST(menu,"2048 Menu", NULL,
                        "Resume Game",
                        "Start New Game",
                        "High Scores",
                        "Playback Control",
                        "Help",
                        "Quit without Saving",
                        "Quit");
    bool quit = false;
    while(!quit)
    {
        switch(rb->do_menu(&menu, &sel, NULL, false))
        {
        case 0:
            draw();
            return 0;
        case 1:
        {
            if(!confirm_quit())
                break;
            else
            {
                hs_check_update(false);
                return 1;
            }
        }
        case 2:
            highscore_show(-1, highscores, NUM_SCORES, true);
            break;
        case 3:
            playback_control(NULL);
            break;
        case 4:
            do_help();
            break;
        case 5: /* quit w/o saving */
        {
            if(!confirm_quit())
                break;
            else
            {
                return 2;
            }
        }
        case 6:
            return 3;
        }
    }
    return 0;
}

static void exit_handler(void)
{
    cleanup();
    if(abnormal_exit)
        save_game();
#ifdef HAVE_ADJUSTABLE_CPU_FREQ
    rb->cpu_boost(false); /* back to idle */
#endif
    return;
}

static bool check_hs;

/* main game loop */
static enum plugin_status do_game(bool newgame)
{
    init_game(newgame);
    rb_atexit(exit_handler);
    int made_move = 0;
    while(1)
    {
#ifdef HAVE_ADJUSTABLE_CPU_FREQ
        rb->cpu_boost(false); /* Save battery when idling */
#endif
        /* Wait for a button press */
        int button = pluginlib_getaction(-1, plugin_contexts, ARRAYLEN(plugin_contexts));
        made_move = 0;

        memset(&merged_grid, 0, SPACES*sizeof(bool));
        memcpy(&old_grid, &ctx->grid, sizeof(int)*SPACES);

        unsigned int grid_before_anim_step[GRID_SIZE][GRID_SIZE];

#ifdef HAVE_ADJUSTABLE_CPU_FREQ
        rb->cpu_boost(true); /* doing work now... */
#endif
        switch(button)
        {
        case KEY_UP:
            for(int i = 0; i < GRID_SIZE - 1; ++i)
            {
                memcpy(grid_before_anim_step, ctx->grid, sizeof(ctx->grid));
                up(true);
                if(memcmp(grid_before_anim_step, ctx->grid, sizeof(ctx->grid)))
                {
                    rb->sleep(ANIM_SLEEPTIME);
                    draw();
                }
            }
            made_move = 1;
            break;
        case KEY_DOWN:
            for(int i = 0; i < GRID_SIZE - 1; ++i)
            {
                memcpy(grid_before_anim_step, ctx->grid, sizeof(ctx->grid));
                down(true);
                if(memcmp(grid_before_anim_step, ctx->grid, sizeof(ctx->grid)))
                {
                    rb->sleep(ANIM_SLEEPTIME);
                    draw();
                }
            }
            made_move = 1;
            break;
        case KEY_LEFT:
            for(int i = 0; i < GRID_SIZE - 1; ++i)
            {
                memcpy(grid_before_anim_step, ctx->grid, sizeof(ctx->grid));
                left(true);
                if(memcmp(grid_before_anim_step, ctx->grid, sizeof(ctx->grid)))
                {
                    rb->sleep(ANIM_SLEEPTIME);
                    draw();
                }
            }
            made_move = 1;
            break;
        case KEY_RIGHT:
            for(int i = 0; i < GRID_SIZE - 1; ++i)
            {
                memcpy(grid_before_anim_step, ctx->grid, sizeof(ctx->grid));
                right(true);
                if(memcmp(grid_before_anim_step, ctx->grid, sizeof(ctx->grid)))
                {
                    rb->sleep(ANIM_SLEEPTIME);
                    draw();
                }
            }
            made_move = 1;
            break;
        case KEY_EXIT:
            switch(do_2048_pause_menu())
            {
            case 0: /* resume */
                break;
            case 1: /* new game */
                init_game(true);
                made_move = 1;
                continue;
            case 2: /* quit without saving */
                check_hs = true;
                rb->remove(RESUME_FILE);
                return PLUGIN_ERROR;
            case 3: /* save and quit */
                check_hs = false;
                save_game();
                return PLUGIN_ERROR;
            }
            break;
        default:
        {
            exit_on_usb(button); /* handle poweroff and USB events */
            break;
        }
        }

        if(made_move)
        {
            /* Check if any tiles moved, then add random */
            if(memcmp(&old_grid, ctx->grid, sizeof(ctx->grid)))
            {
                place_random();
            }
            memcpy(&old_grid, ctx->grid, sizeof(ctx->grid));
            if(check_gameover())
                return PLUGIN_OK;
            draw();
        }
#ifdef HAVE_ADJUSTABLE_CPU_FREQ
        rb->cpu_boost(false); /* back to idle */
#endif
        rb->yield();
    }
}

/* decide if this_item should be shown in the main menu */
/* used to hide resume option when there is no save */
static int mainmenu_cb(int action,
                       const struct menu_item_ex *this_item,
                       struct gui_synclist *this_list)
{
    (void)this_list;
    int idx = ((intptr_t)this_item);
    if(action == ACTION_REQUEST_MENUITEM && !loaded && (idx == 0 || idx == 5))
        return ACTION_EXIT_MENUITEM;
    return action;
}

/* show the main menu */
static enum plugin_status do_2048_menu(void)
{
    int sel = 0;
    loaded = load_game();
    MENUITEM_STRINGLIST(menu,
                        "2048 Menu",
                        mainmenu_cb,
                        "Resume Game",
                        "Start New Game",
                        "High Scores",
                        "Playback Control",
                        "Help",
                        "Quit without Saving",
                        "Quit");
    bool quit = false;
    while(!quit)
    {
        switch(rb->do_menu(&menu, &sel, NULL, false))
        {
        case 0: /* Start new game or resume a game */
        case 1:
        {
            if(sel == 1 && loaded)
            {
                if(!confirm_quit())
                    break;
            }
            enum plugin_status ret = do_game(sel == 1);
            switch(ret)
            {
            case PLUGIN_OK:
            {
                loaded = false;
                rb->remove(RESUME_FILE);
                hs_check_update(false);
                break;
            }
            case PLUGIN_USB_CONNECTED:
                save_game();
                /* Don't bother showing the high scores... */
                return ret;
            case PLUGIN_ERROR: /* exit without menu */
                if(check_hs)
                    hs_check_update(false);
                return PLUGIN_OK;
            default:
                break;
            }
            break;
        }
        case 2:
            highscore_show(-1, highscores, NUM_SCORES, true);
            break;
        case 3:
            playback_control(NULL);
            break;
        case 4:
            do_help();
            break;
        case 5:
            if(confirm_quit())
                return PLUGIN_OK;
        case 6:
            if(loaded)
                save_game();
            return PLUGIN_OK;
        default:
            break;
        }
    }
    return PLUGIN_OK;
}

/* plugin entry point */
enum plugin_status plugin_start(const void* param)
{
    (void)param;
    rb->srand(*rb->current_tick);
    load_hs();
    rb->lcd_setfont(WHAT_FONT);

    /* now start the game menu */
    enum plugin_status ret = do_2048_menu();

    highscore_save(HISCORES_FILE, highscores, NUM_SCORES);
    cleanup();

    abnormal_exit = false;

    return ret;
}