Add basic turbo support.

config.def.h

@@ -324,8 +324,9 @@ static const bool stdin_cmd_enable = false;
 // How far an axis must be tilted to result in a button press
 static const float axis_threshold = 0.5;
 
-// To figure out which joypad buttons to use, check jstest or similar.
-// SDL sometimes reverses the axes for some odd reason, but hey. :D
+// Describes speed of which turbo-enabled buttons toggle.
+static const unsigned turbo_period = 6;
+static const unsigned turbo_duty_cycle = 3;
 
 // Player 1
 static const struct retro_keybind retro_keybinds_1[] = {
@@ -347,6 +348,7 @@ static const struct retro_keybind retro_keybinds_1[] = {
    { true, RETRO_DEVICE_ID_JOYPAD_L3,        RETROK_UNKNOWN, NO_BTN,      AXIS_NONE },
    { true, RETRO_DEVICE_ID_JOYPAD_R3,        RETROK_UNKNOWN, NO_BTN,      AXIS_NONE },
 
+   { true, RARCH_TURBO_ENABLE,               RETROK_UNKNOWN, NO_BTN,      AXIS_NONE },
    { true, RARCH_ANALOG_LEFT_X_PLUS,         RETROK_UNKNOWN, NO_BTN,      AXIS_NONE },
    { true, RARCH_ANALOG_LEFT_X_MINUS,        RETROK_UNKNOWN, NO_BTN,      AXIS_NONE },
    { true, RARCH_ANALOG_LEFT_Y_PLUS,         RETROK_UNKNOWN, NO_BTN,      AXIS_NONE },
@@ -402,6 +404,7 @@ static const struct retro_keybind retro_keybinds_rest[] = {
    { true, RETRO_DEVICE_ID_JOYPAD_L3,        RETROK_UNKNOWN, NO_BTN, AXIS_NONE },
    { true, RETRO_DEVICE_ID_JOYPAD_R3,        RETROK_UNKNOWN, NO_BTN, AXIS_NONE },
 
+   { true, RARCH_TURBO_ENABLE,               RETROK_UNKNOWN, NO_BTN, AXIS_NONE },
    { true, RARCH_ANALOG_LEFT_X_PLUS,         RETROK_UNKNOWN, NO_BTN, AXIS_NONE },
    { true, RARCH_ANALOG_LEFT_X_MINUS,        RETROK_UNKNOWN, NO_BTN, AXIS_NONE },
    { true, RARCH_ANALOG_LEFT_Y_PLUS,         RETROK_UNKNOWN, NO_BTN, AXIS_NONE },

driver.h

@@ -40,12 +40,16 @@
 // Analog binds use RETRO_DEVICE_ANALOG, but we follow the same scheme internally
 // in RetroArch for simplicity,
 // so they are mapped into [16, 23].
-#define RARCH_FIRST_ANALOG_BIND 16
-#define RARCH_FIRST_META_KEY RARCH_ANALOG_BIND_LIST_END
+#define RARCH_FIRST_CUSTOM_BIND 16
+#define RARCH_FIRST_META_KEY RARCH_CUSTOM_BIND_LIST_END
 enum // RetroArch specific bind IDs.
 {
+   // Custom binds that extend the scope of RETRO_DEVICE_JOYPAD for RetroArch specifically.
+   // Turbo
+   RARCH_TURBO_ENABLE = RARCH_FIRST_CUSTOM_BIND, 
+
    // Analogs (RETRO_DEVICE_ANALOG)
-   RARCH_ANALOG_LEFT_X_PLUS = RARCH_FIRST_ANALOG_BIND,
+   RARCH_ANALOG_LEFT_X_PLUS,
    RARCH_ANALOG_LEFT_X_MINUS,
    RARCH_ANALOG_LEFT_Y_PLUS,
    RARCH_ANALOG_LEFT_Y_MINUS,
@@ -54,10 +58,10 @@ enum // RetroArch specific bind IDs.
    RARCH_ANALOG_RIGHT_Y_PLUS,
    RARCH_ANALOG_RIGHT_Y_MINUS,
 
-   RARCH_ANALOG_BIND_LIST_END,
+   RARCH_CUSTOM_BIND_LIST_END,
 
-   // Command binds.
-   RARCH_FAST_FORWARD_KEY = RARCH_ANALOG_BIND_LIST_END,
+   // Command binds. Not related to game input, only usable for port 0.
+   RARCH_FAST_FORWARD_KEY = RARCH_FIRST_META_KEY,
    RARCH_FAST_FORWARD_HOLD_KEY,
    RARCH_LOAD_STATE_KEY,
    RARCH_SAVE_STATE_KEY,

dynamic.c

@@ -365,7 +365,7 @@ static bool environment_cb(unsigned cmd, void *data)
             if (desc->device != RETRO_DEVICE_JOYPAD) // Ignore all others for now.
                continue;
 
-            if (desc->id >= RARCH_FIRST_ANALOG_BIND)
+            if (desc->id >= RARCH_FIRST_CUSTOM_BIND)
                continue;
 
             g_extern.system.input_desc_btn[desc->port][desc->id] = desc->description;
@@ -381,7 +381,7 @@ static bool environment_cb(unsigned cmd, void *data)
          RARCH_LOG("Environ SET_INPUT_DESCRIPTORS:\n");
          for (unsigned p = 0; p < MAX_PLAYERS; p++)
          {
-            for (unsigned id = 0; id < RARCH_FIRST_ANALOG_BIND; id++)
+            for (unsigned id = 0; id < RARCH_FIRST_CUSTOM_BIND; id++)
             {
                const char *desc = g_extern.system.input_desc_btn[p][id];
                if (desc)

general.h

@@ -156,6 +156,9 @@ struct settings
       unsigned device[MAX_PLAYERS];
 #endif
       bool netplay_client_swap_input;
+
+      unsigned turbo_period;
+      unsigned turbo_duty_cycle;
    } input;
 
    char libretro[PATH_MAX];
@@ -338,7 +341,7 @@ struct global
 
       bool force_nonblock;
 
-      const char *input_desc_btn[MAX_PLAYERS][RARCH_FIRST_ANALOG_BIND];
+      const char *input_desc_btn[MAX_PLAYERS][RARCH_FIRST_CUSTOM_BIND];
    } system;
 
    struct
@@ -422,6 +425,11 @@ struct global
    bool is_oneshot;
    bool is_slowmotion;
 
+   // Turbo support
+   bool turbo_frame_enable[MAX_PLAYERS];
+   uint16_t turbo_enable[MAX_PLAYERS];
+   unsigned turbo_count;
+
    // Autosave support.
    autosave_t *autosave[2];
 

retroarch.c

@@ -474,6 +474,22 @@ static void input_poll(void)
    input_poll_func();
 }
 
+// Turbo scheme: If turbo button is held, all buttons pressed except for D-pad will go into
+// a turbo mode. Until the button is released again, the input state will be modulated by a periodic pulse defined
+// by the configured duty cycle.
+static bool input_apply_turbo(unsigned port, unsigned id, bool res)
+{
+   if (res && g_extern.turbo_frame_enable[port])
+      g_extern.turbo_enable[port] |= (1 << id);
+   else if (!res)
+      g_extern.turbo_enable[port] &= ~(1 << id);
+
+   if (g_extern.turbo_enable[port] & (1 << id))
+      return res & ((g_extern.turbo_count % g_settings.input.turbo_period) < g_settings.input.turbo_duty_cycle);
+   else
+      return res;
+}
+
 static int16_t input_state(unsigned port, unsigned device, unsigned index, unsigned id)
 {
    device &= RETRO_DEVICE_MASK;
@@ -504,6 +520,10 @@ static int16_t input_state(unsigned port, unsigned device, unsigned index, unsig
    if (id < RARCH_FIRST_META_KEY || device == RETRO_DEVICE_KEYBOARD)
       res = input_input_state_func(binds, port, device, index, id);
 
+   // Don't allow turbo for D-pad.
+   if (device == RETRO_DEVICE_JOYPAD && (id < RETRO_DEVICE_ID_JOYPAD_UP || id > RETRO_DEVICE_ID_JOYPAD_RIGHT))
+      res = input_apply_turbo(port, id, res);
+
 #ifdef HAVE_BSV_MOVIE
    if (g_extern.bsv.movie && !g_extern.bsv.movie_playback)
       bsv_movie_set_input(g_extern.bsv.movie, res);
@@ -2261,6 +2281,26 @@ static void check_reset(void)
    old_state = new_state;
 }
 
+static void check_turbo(void)
+{
+   g_extern.turbo_count++;
+
+   static const struct retro_keybind *binds[MAX_PLAYERS] = {
+      g_settings.input.binds[0],
+      g_settings.input.binds[1],
+      g_settings.input.binds[2],
+      g_settings.input.binds[3],
+      g_settings.input.binds[4],
+      g_settings.input.binds[5],
+      g_settings.input.binds[6],
+      g_settings.input.binds[7],
+   };
+
+   for (unsigned i = 0; i < MAX_PLAYERS; i++)
+      g_extern.turbo_frame_enable[i] =
+         input_input_state_func(binds, i, RETRO_DEVICE_JOYPAD, 0, RARCH_TURBO_ENABLE);
+}
+
 #ifdef HAVE_XML
 static void check_shader_dir(void)
 {
@@ -2416,6 +2456,8 @@ static void do_state_checks(void)
    check_mute();
 #endif
 
+   check_turbo();
+
 #ifdef HAVE_NETPLAY
    if (!g_extern.netplay)
    {

retroarch.cfg

@@ -248,7 +248,7 @@
 # input_player1_l3_btn =
 # input_player1_r3_btn =
 
-# Axis for SNES DPAD. 
+# Axis for RetroArch D-Pad. 
 # Needs to be either '+' or '-' in the first character signaling either positive or negative direction of the axis, then the axis number. 
 # Do note that every other input option has the corresponding _btn and _axis binds as well; they are omitted here for clarity.
 # input_player1_left_axis =
@@ -256,7 +256,18 @@
 # input_player1_up_axis =
 # input_player1_down_axis =
 
+# Holding the turbo while pressing another button will let the button enter a turbo mode
+# where the button state is modulated with a periodic signal.
+# The modulation stops when the button itself (not turbo button) is released.
+# input_player1_turbo =
+
+# Describes the period and how long of that period a turbo-enabled button should behave.
+# Numbers are described in frames.
+# input_turbo_period = 6
+# input_turbo_duty_cycle = 3
+
 # This goes all the way to player 8 (*_player2_*, *_player3_*, etc), but omitted for clarity.
+# All input binds have corresponding binds for keyboard (none), joykeys (_btn) and joyaxes (_axis) as well.
 
 # Toggles fullscreen.
 # input_toggle_fullscreen = f

settings.c

@@ -221,6 +221,8 @@ void config_set_defaults(void)
 
    g_settings.input.axis_threshold = axis_threshold;
    g_settings.input.netplay_client_swap_input = netplay_client_swap_input;
+   g_settings.input.turbo_period = turbo_period;
+   g_settings.input.turbo_duty_cycle = turbo_duty_cycle;
    for (int i = 0; i < MAX_PLAYERS; i++)
       g_settings.input.joypad_map[i] = i;
 
@@ -494,6 +496,9 @@ bool config_load_file(const char *path)
    CONFIG_GET_INT(network_cmd_port, "network_cmd_port");
    CONFIG_GET_BOOL(stdin_cmd_enable, "stdin_cmd_enable");
 
+   CONFIG_GET_INT(input.turbo_period, "input_turbo_period");
+   CONFIG_GET_INT(input.turbo_duty_cycle, "input_duty_cycle");
+
    if (config_get_string(conf, "environment_variables",
             &g_extern.system.environment))
    {
@@ -567,6 +572,7 @@ struct bind_map
       DECLARE_BIND(player##P##_r2,        RETRO_DEVICE_ID_JOYPAD_R2), \
       DECLARE_BIND(player##P##_l3,        RETRO_DEVICE_ID_JOYPAD_L3), \
       DECLARE_BIND(player##P##_r3,        RETRO_DEVICE_ID_JOYPAD_R3), \
+      DECLARE_BIND(player##P##_turbo,     RARCH_TURBO_ENABLE), \
       DECLARE_BIND(player##P##_l_x_plus,  RARCH_ANALOG_LEFT_X_PLUS), \
       DECLARE_BIND(player##P##_l_x_minus, RARCH_ANALOG_LEFT_X_MINUS), \
       DECLARE_BIND(player##P##_l_y_plus,  RARCH_ANALOG_LEFT_Y_PLUS), \