Demo Record + Replay (#150) (#152)

* Added demo

* Added default demo file

src/core/args.c

@@ -5,19 +5,22 @@
 #include <stdlib.h>
 #include <time.h>
 #include "args.h"
-
+#include "demo.h"
+static unsigned long seed;
 void parse_args(int argc, char **argv)
 {
-    srand(time(NULL));
+    int demo_started = 0;
+    set_seed(time(NULL));
 
     while (1) {
         struct option long_options[] = {
             { "help", no_argument, NULL, 'h' },
             { "seed", required_argument, NULL, 's' },
+            { "play", optional_argument, NULL, 'r' },
+            { "record", optional_argument, NULL, 'w' },
             { 0, 0, 0, 0 }
         };
-        int c = getopt_long(argc, argv, "hs:", long_options, NULL);
-        unsigned long seed;
+        int c = getopt_long(argc, argv, "hs:r?w?", long_options, NULL);
 
         if (c == -1) {
             break;
@@ -29,7 +32,10 @@ void parse_args(int argc, char **argv)
                 ("hag, an ncurses procedurally-generated dungeon crawler.\n\n");
             printf("Usage: %s [options]\n", argv[0]);
             printf("-h, --help        Show this help message\n");
-            printf("-s, --seed <seed> RNG seed to use\n");
+            printf("-s, --seed   <seed> RNG seed to use\n");
+            printf("-r, --play   [file] demo file to replay\n");
+            printf("-w, --record [file] file to save demo to\n");
+            printf("\n\n--play and --record take an optional file - if these flags are used but no file is given, .demo.hag is used instead.\n");
             exit(EXIT_SUCCESS);
         case 's':
             seed = strtoul(optarg, NULL, 10);
@@ -39,10 +45,32 @@ void parse_args(int argc, char **argv)
                 exit(EXIT_FAILURE);
             }
 
-            srand(seed);
+            set_seed(seed);
+            break;
+        case 'r':
+            demo_start(DEMO_REPLAY, optarg);
+            demo_started = 1;
+            break;
+        case 'w':
+            demo_start(DEMO_RECORD, optarg);
+            demo_started = 1;
             break;
         default:
             exit(EXIT_FAILURE);
         }
     }
+    if (!demo_started) {
+        demo_start(DEMO_NONE, 0);
+    }
 }
+
+void set_seed(unsigned long s)
+{
+    seed = s;
+    srand(s);
+}
+
+unsigned long get_seed(void)
+{
+    return seed;
+}

src/core/args.h

@@ -1,4 +1,6 @@
 #ifndef ARGS_H
 #define ARGS_H
 void parse_args(int argc, char **argv);
+unsigned long get_seed(void);
+void set_seed(unsigned long seed);
 #endif

src/core/demo.c

@@ -0,0 +1,75 @@
+#include <stdio.h>
+#include <curses.h>
+#include <unistd.h>
+#include "demo.h"
+#include "args.h"
+
+static void demo_write_header(void);
+static void demo_read_header(void);
+
+static FILE* read_from = 0;
+static FILE* write_to = 0;
+
+void usleep(long); /* needed because headers are big sad */
+
+int demo_next(void)
+{
+    int move = 0;
+    if (read_from) {
+        fread(&move, sizeof(move), 1, read_from);
+        usleep(1000 /*ms to us*/ * 300 /*ms*/);
+    }
+    if (!move) {
+        move = getch();
+    }
+    if (write_to) {
+        fwrite(&move, sizeof(move), 1, write_to);
+    }
+    return move;
+}
+
+static void demo_read_header()
+{
+    int demo_version;
+    unsigned long s;
+    fread(&demo_version, sizeof(demo_version), 1, read_from);
+    fread(&s, sizeof(s), 1, read_from);
+    /* TODO: fail if demo version is wrong */
+    set_seed(s);
+}
+
+
+static void demo_write_header(void)
+{
+    unsigned long s = get_seed();
+    int demo_version = DEMO_VERSION;
+    fwrite(&demo_version, sizeof(demo_version), 1, write_to);
+    fwrite(&s, sizeof(s), 1, write_to);
+}
+
+void demo_start(int mode, char* fname)
+{
+    if (!fname) {
+        fname = DEMO_DEFAULT_FILE;
+    }
+    if (read_from) {
+        fclose(read_from);
+        read_from = 0;
+    }
+    if (write_to) {
+        fclose(write_to);
+        write_to = 0;
+    }
+    switch (mode) {
+    default:
+        break;
+    case DEMO_REPLAY:
+        read_from = fopen(fname, "r");
+        demo_read_header();
+        break;
+    case DEMO_RECORD:
+        write_to = fopen(fname, "w");
+        demo_write_header();
+        break;
+    }
+}

src/core/demo.h

@@ -0,0 +1,11 @@
+#ifndef DEMO_H
+#define DEMO_H
+int demo_next(void);
+void demo_start(int mode, char* fname);
+#define DEMO_NONE 0
+#define DEMO_REPLAY 1
+#define DEMO_RECORD 2
+#define DEMO_VERSION 0
+#define DEMO_DEFAULT_FILE ".demo.hag"
+/* TODO: do we need a demo_close? */
+#endif

src/core/main.c

@@ -6,6 +6,7 @@
 #include <unistd.h>
 #include <ctype.h>
 
+#include "demo.h"
 #include "args.h"
 #include "player.h"
 #include "colors.h"
@@ -126,7 +127,7 @@ int main(int argc, char **argv)
         xn = xp = player->x;
         yn = yp = player->y;
         ch = ERR;
-        if ((ch = repeat_act) || (ch = getch(), ch != ERR)) {
+        if ((ch = repeat_act) || (ch = demo_next(), ch != ERR)) {
             if (rand() % player->luck) {
                 switch (ch) {
                 case KEY_FIGHT: