Configurable rewind stuff.

config.def.h

@@ -146,6 +146,13 @@ static const bool audio_sync = true;
 // Defines the quality (and cpu reqirements) of samplerate conversion.
 #define SAMPLERATE_QUALITY SRC_LINEAR
 
+// Enables use of rewind. This will incur some memory footprint depending on the save state buffer.
+// This rewind only works when using bSNES core atm.
+static const bool rewind_enable = false;
+
+// The buffer size for the rewind buffer. This needs to be about 15-20MB per minute. Very game dependant.
+static const unsigned rewind_buffer_size = 20 << 20; // 20MiB
+
 
 
 

general.h

@@ -85,6 +85,9 @@ struct settings
    } input;
 
    char libsnes[256];
+
+   bool rewind_enable;
+   unsigned rewind_buffer_size;
 };
 
 enum ssnes_game_type

settings.c

@@ -124,6 +124,9 @@ static void set_defaults(void)
    g_settings.audio.sync = audio_sync;
    g_settings.audio.src_quality = SAMPLERATE_QUALITY;
 
+   g_settings.rewind_enable = rewind_enable;
+   g_settings.rewind_buffer_size = rewind_buffer_size;
+
    assert(sizeof(g_settings.input.binds[0]) >= sizeof(snes_keybinds_1));
    assert(sizeof(g_settings.input.binds[1]) >= sizeof(snes_keybinds_2));
    assert(sizeof(g_settings.input.binds[2]) >= sizeof(snes_keybinds_3));
@@ -372,6 +375,12 @@ static void parse_config_file(void)
       free(tmp_str);
    }
 
+   if (config_get_bool(conf, "rewind_enable", &tmp_bool))
+      g_settings.rewind_enable = true;
+
+   if (config_get_int(conf, "rewind_buffer_size", &tmp_int))
+      g_settings.rewind_buffer_size = tmp_int * 1000000;
+
    read_keybinds(conf);
 
    config_file_free(conf);
@@ -411,6 +420,7 @@ static const struct bind_map bind_maps[MAX_PLAYERS][MAX_BINDS - 1] = {
       DECLARE_BIND(toggle_fullscreen,     SSNES_FULLSCREEN_TOGGLE_KEY)
       DECLARE_BIND(rate_step_up,          SSNES_AUDIO_INPUT_RATE_PLUS)
       DECLARE_BIND(rate_step_down,        SSNES_AUDIO_INPUT_RATE_MINUS)
+      DECLARE_BIND(rewind,                SSNES_REWIND)
    },
    {
       DECLARE_BIND(player2_a,             SNES_DEVICE_ID_JOYPAD_A)
@@ -434,6 +444,7 @@ static const struct bind_map bind_maps[MAX_PLAYERS][MAX_BINDS - 1] = {
       DECLARE_BIND(toggle_fullscreen,     SSNES_FULLSCREEN_TOGGLE_KEY)
       DECLARE_BIND(rate_step_up,          SSNES_AUDIO_INPUT_RATE_PLUS)
       DECLARE_BIND(rate_step_down,        SSNES_AUDIO_INPUT_RATE_MINUS)
+      DECLARE_BIND(rewind,                SSNES_REWIND)
    },
    {
       DECLARE_BIND(player3_a,             SNES_DEVICE_ID_JOYPAD_A)
@@ -457,6 +468,7 @@ static const struct bind_map bind_maps[MAX_PLAYERS][MAX_BINDS - 1] = {
       DECLARE_BIND(toggle_fullscreen,     SSNES_FULLSCREEN_TOGGLE_KEY)
       DECLARE_BIND(rate_step_up,          SSNES_AUDIO_INPUT_RATE_PLUS)
       DECLARE_BIND(rate_step_down,        SSNES_AUDIO_INPUT_RATE_MINUS)
+      DECLARE_BIND(rewind,                SSNES_REWIND)
    },
    {
       DECLARE_BIND(player4_a,             SNES_DEVICE_ID_JOYPAD_A)
@@ -480,6 +492,7 @@ static const struct bind_map bind_maps[MAX_PLAYERS][MAX_BINDS - 1] = {
       DECLARE_BIND(toggle_fullscreen,     SSNES_FULLSCREEN_TOGGLE_KEY)
       DECLARE_BIND(rate_step_up,          SSNES_AUDIO_INPUT_RATE_PLUS)
       DECLARE_BIND(rate_step_down,        SSNES_AUDIO_INPUT_RATE_MINUS)
+      DECLARE_BIND(rewind,                SSNES_REWIND)
    },
    {
       DECLARE_BIND(player5_a,             SNES_DEVICE_ID_JOYPAD_A)
@@ -503,6 +516,7 @@ static const struct bind_map bind_maps[MAX_PLAYERS][MAX_BINDS - 1] = {
       DECLARE_BIND(toggle_fullscreen,     SSNES_FULLSCREEN_TOGGLE_KEY)
       DECLARE_BIND(rate_step_up,          SSNES_AUDIO_INPUT_RATE_PLUS)
       DECLARE_BIND(rate_step_down,        SSNES_AUDIO_INPUT_RATE_MINUS)
+      DECLARE_BIND(rewind,                SSNES_REWIND)
    },
 };
 

ssnes.c

@@ -643,10 +643,16 @@ static void deinit_msg_queue(void)
 
 static void init_rewind(void)
 {
-   size_t serial_size = snes_serialize_size();
+   if (g_settings.rewind_enable)
-   g_extern.state_buf = malloc(serial_size);
+   {
-   snes_serialize(g_extern.state_buf, serial_size);
+      size_t serial_size = snes_serialize_size();
-   g_extern.state_manager = state_manager_new(serial_size, 10 << 20, g_extern.state_buf);
+      g_extern.state_buf = malloc(serial_size);
+      snes_serialize(g_extern.state_buf, serial_size);
+      SSNES_LOG("Initing rewind buffer with size: %u MB\n", (unsigned)g_settings.rewind_buffer_size / 1000000);
+      g_extern.state_manager = state_manager_new(serial_size, g_settings.rewind_buffer_size, g_extern.state_buf);
+      if (!g_extern.state_manager)
+         SSNES_WARN("Failed to init rewind buffer. Rewinding will be disabled!\n");
+   }
 }
 
 static void deinit_rewind(void)

ssnes.cfg

@@ -190,3 +190,15 @@
 # Decrease/increase input sample rate on the fly. Amount to decrease/increase is defined by audio_rate_step.
 # input_rate_step_up = kp_plus
 # input_rate_step_down = kp_minus
+
+# Enable rewinding. This will take a performance hit when playing, so it is disabled by default.
+# Do note that rewinding will only work properly when using bSNES libsnes core atm.
+# rewind_enable = false
+
+# Rewinding buffer size in megabytes. Bigger rewinding buffer means you can rewind longer.
+# The buffer should be approx. 20MB per minute of buffer time.
+# rewind_buffer_size = 20
+
+# Hold button down to rewind. Rewinding must be enabled.
+# input_rewind = r
+