Fix/reimplement input flushing

This fixes:

- menu toggle erratically not working on Android
- stray input going to libretro core when resuming content
- bound keys triggering as soon as they're bound on Android
- menu key repeat also repeating keys which should not be repeated
- issues caused by relying on timeouts for flushing

Architectural changes:

- menu_ctx_driver_t::input_postprocess now takes state and old_state
  (this allows getting rid of menu_handle_t::trigger_state)

Related changes:

- remove some no-op input_postprocess handlers (same effect as NULL)
- menu_iterate now uses the parameters passed to it, instead of
  polling menu_input
- menu_input is now merged into meta_input_keys_pressed

driver.h

@@ -481,10 +481,9 @@ typedef struct driver
 #endif
    bool stdin_claimed;
    bool block_hotkey;
-   unsigned block_hotkey_until;
    bool block_input;
    bool block_libretro_input;
-   unsigned block_libretro_input_until;
+   bool flushing_input;
    bool nonblock_state;
 
    /* Opaque handles to currently running window.

frontend/menu/disp/glui.c

@@ -344,13 +344,6 @@ static void glui_free(void *data)
    g_extern.core_info = NULL;
 }
 
-static int glui_input_postprocess(uint64_t old_state)
-{
-   (void)old_state;
-
-   return 0;
-}
-
 static GLuint glui_png_texture_load(const char * file_name)
 {
    struct texture_image ti = {0};
@@ -404,7 +397,7 @@ menu_ctx_driver_t menu_ctx_glui = {
    NULL,
    NULL,
    NULL,
-   glui_input_postprocess,
+   NULL,
    NULL,
    NULL,
    NULL,

frontend/menu/disp/lakka.c

@@ -984,10 +984,10 @@ static void lakka_free(void *data)
    g_extern.core_info = NULL;
 }
 
-static int lakka_input_postprocess(uint64_t old_state)
+static int lakka_input_postprocess(retro_input_t state, retro_input_t old_state)
 {
-   if ((driver.menu && driver.menu->trigger_state
-            & (1ULL << RARCH_MENU_TOGGLE)) &&
+   retro_input_t trigger_state = state & ~old_state;
+   if ((driver.menu && check_enter_menu_func(trigger_state)) &&
          g_extern.main_is_init &&
          !g_extern.libretro_dummy)
       global_alpha = 0;

frontend/menu/disp/menu_display.h

@@ -18,7 +18,7 @@ typedef struct menu_ctx_driver
    void  (*populate_entries)(void*, const char *, const char *,
          unsigned);
    void  (*iterate)(void*, unsigned);
-   int   (*input_postprocess)(uint64_t);
+   int   (*input_postprocess)(uint64_t, uint64_t);
    void  (*navigation_clear)(void *);
    void  (*navigation_decrement)(void *);
    void  (*navigation_increment)(void *);

frontend/menu/disp/rgui.c

@@ -447,11 +447,6 @@ static void rgui_free(void *data)
       free((uint8_t*)menu->font);
 }
 
-static int rgui_input_postprocess(uint64_t old_state)
-{
-   return 0;
-}
-
 void rgui_set_texture(void *data)
 {
    menu_handle_t *menu = (menu_handle_t*)data;
@@ -473,7 +468,7 @@ menu_ctx_driver_t menu_ctx_rgui = {
    NULL,
    NULL,
    NULL,
-   rgui_input_postprocess,
+   NULL,
    NULL,
    NULL,
    NULL,

frontend/menu/menu_common.c

@@ -103,8 +103,6 @@ bool load_menu_content(void)
    /* redraw menu frame */
    if (driver.menu)
    {
-      driver.menu->old_input_state = driver.menu->trigger_state = 0;
-      driver.menu->do_held = false;
       driver.menu->msg_force = true;
    }
 
@@ -172,9 +170,6 @@ void *menu_init(const void *data)
    menu_entries_push_list(menu, menu->selection_buf,
          "", "mainmenu", 0);
 
-   menu->trigger_state = 0;
-   menu->old_input_state = 0;
-   menu->do_held = false;
    menu->current_pad = 0;
 
    update_libretro_info(&g_extern.menu.info);
@@ -302,8 +297,14 @@ bool menu_iterate(retro_input_t input,
    unsigned action = MENU_ACTION_NOOP;
    static bool initial_held = true;
    static bool first_held = false;
-   uint64_t input_state = 0;
    int32_t ret = 0;
+   static const retro_input_t input_repeat =
+      (1ULL << RETRO_DEVICE_ID_JOYPAD_UP)
+      | (1ULL << RETRO_DEVICE_ID_JOYPAD_DOWN)
+      | (1ULL << RETRO_DEVICE_ID_JOYPAD_LEFT)
+      | (1ULL << RETRO_DEVICE_ID_JOYPAD_RIGHT)
+      | (1ULL << RETRO_DEVICE_ID_JOYPAD_L)
+      | (1ULL << RETRO_DEVICE_ID_JOYPAD_R);
 
    if (!driver.menu)
       return false;
@@ -316,9 +317,7 @@ bool menu_iterate(retro_input_t input,
 
    driver.retro_ctx.poll_cb();
 
-   input_state = menu_input();
-
-   if (driver.menu->do_held)
+   if (input & input_repeat)
    {
       if (!first_held)
       {
@@ -330,7 +329,7 @@ bool menu_iterate(retro_input_t input,
       if (driver.menu->delay_count >= driver.menu->delay_timer)
       {
          first_held = false;
-         driver.menu->trigger_state = input_state;
+         trigger_input |= input & input_repeat;
          driver.menu->scroll_accel = min(driver.menu->scroll_accel + 1, 64);
       }
 
@@ -344,15 +343,14 @@ bool menu_iterate(retro_input_t input,
    }
 
    driver.menu->delay_count++;
-   driver.menu->old_input_state = input_state;
 
    if (driver.block_input)
-      driver.menu->trigger_state = 0;
+      trigger_input = 0;
 
    /* don't run anything first frame, only capture held inputs
     * for old_input_state.
     */
-   action = input_frame(driver.menu->trigger_state);
+   action = input_frame(trigger_input);
 
    if (driver.menu_ctx && driver.menu_ctx->backend
          && driver.menu_ctx->backend->iterate) 
@@ -362,7 +360,7 @@ bool menu_iterate(retro_input_t input,
    draw_frame(false);
 
    if (driver.menu_ctx && driver.menu_ctx->input_postprocess)
-      driver.menu_ctx->input_postprocess(driver.menu->old_input_state);
+      driver.menu_ctx->input_postprocess(input, old_input);
 
 #if 0
    /* Go back to Main Menu when exiting */

frontend/menu/menu_driver.h

@@ -67,18 +67,6 @@ struct menu_bind_state
 
 typedef struct
 {
-   /* Keys down last frame. Used for trigger_state */
-   uint64_t old_input_state;
-
-   /* New keys pressed down this frame */
-   uint64_t trigger_state;
-
-   /* Whether any repeating keys are being held down, */
-   /* and key repeat should be handled */
-   /* TODO: should be a mask of keys we are repeating, */
-   /* instead of repeating all keys being held down. */
-   bool do_held;
-
    /* Used for key repeat */
    unsigned delay_timer;
    unsigned delay_count;

frontend/menu/menu_input_line_cb.c

@@ -56,7 +56,7 @@ static void menu_key_end_line(void *data)
    menu->keyboard.label_setting = NULL;
 
    /* Avoid triggering states on pressing return. */
-   menu->old_input_state = -1ULL;
+   driver.flushing_input = true;
 }
 
 static void menu_search_callback(void *userdata, const char *str)
@@ -298,43 +298,6 @@ bool menu_custom_bind_keyboard_cb(void *data, unsigned code)
    return menu->binds.begin <= menu->binds.last;
 }
 
-uint64_t menu_input(void)
-{
-   unsigned i;
-   retro_input_t input_state = 0;
-   static const struct retro_keybind *binds[] = { g_settings.input.binds[0] };
-
-   if (!driver.menu)
-      return 0;
-
-   input_push_analog_dpad((struct retro_keybind*)binds[0],
-         (g_settings.input.analog_dpad_mode[0] == ANALOG_DPAD_NONE) ?
-         ANALOG_DPAD_LSTICK : g_settings.input.analog_dpad_mode[0]);
-
-   for (i = 0; i < MAX_PLAYERS; i++)
-      input_push_analog_dpad(g_settings.input.autoconf_binds[i],
-            g_settings.input.analog_dpad_mode[i]);
-
-   input_state = input_keys_pressed(0, RARCH_FIRST_CUSTOM_BIND, binds);
-
-   input_pop_analog_dpad((struct retro_keybind*)binds[0]);
-   for (i = 0; i < MAX_PLAYERS; i++)
-      input_pop_analog_dpad(g_settings.input.autoconf_binds[i]);
-
-   driver.menu->trigger_state = input_state & ~driver.menu->old_input_state;
-
-   driver.menu->do_held = (input_state & (
-            (1ULL << RETRO_DEVICE_ID_JOYPAD_UP)
-            | (1ULL << RETRO_DEVICE_ID_JOYPAD_DOWN)
-            | (1ULL << RETRO_DEVICE_ID_JOYPAD_LEFT)
-            | (1ULL << RETRO_DEVICE_ID_JOYPAD_RIGHT)
-            | (1ULL << RETRO_DEVICE_ID_JOYPAD_L)
-            | (1ULL << RETRO_DEVICE_ID_JOYPAD_R)
-            ));
-
-   return input_state;
-}
-
 int menu_input_bind_iterate(void *data)
 {
    char msg[PATH_MAX];
@@ -358,22 +321,22 @@ int menu_input_bind_iterate(void *data)
          && driver.menu_ctx->render_messagebox)
       driver.menu_ctx->render_messagebox(msg);
 
+   driver.block_input = true;
    menu_poll_bind_state(&binds);
 
-   driver.block_hotkey_until = g_extern.frame_count + (15);
-
    if ((binds.skip && !menu->binds.skip) ||
          menu_poll_find_trigger(&menu->binds, &binds))
    {
+      driver.block_input = false;
+
+      /* Avoid new binds triggering things right away. */
+      driver.flushing_input = true;
+
       binds.begin++;
       if (binds.begin <= binds.last)
          binds.target++;
       else
          return 1;
-
-      /* Avoid new binds triggering things right away. */
-      menu->trigger_state = 0;
-      menu->old_input_state = -1ULL;
    }
    menu->binds = binds;
 
@@ -416,14 +379,11 @@ int menu_input_bind_iterate_keyboard(void *data)
       timed_out = true;
    }
 
-   driver.block_hotkey_until = g_extern.frame_count + (15);
-
    /* binds.begin is updated in keyboard_press callback. */
    if (menu->binds.begin > menu->binds.last)
    {
       /* Avoid new binds triggering things right away. */
-      menu->trigger_state = 0;
-      menu->old_input_state = -1ULL;
+      driver.flushing_input = true;
 
       /* We won't be getting any key events, so just cancel early. */
       if (timed_out)

frontend/menu/menu_input_line_cb.h

@@ -42,6 +42,4 @@ int menu_input_bind_iterate(void *data);
 
 int menu_input_bind_iterate_keyboard(void *data);
 
-uint64_t menu_input(void);
-
 #endif

input/android_input.c

@@ -503,9 +503,7 @@ static int android_input_get_id(android_input_t *android, AInputEvent *event)
 
 static bool pause_key_pressed(void)
 {
-   retro_input_t old_input = 0;
-   retro_input_t input = meta_input_keys_pressed(RARCH_PAUSE_TOGGLE, RARCH_PAUSE_TOGGLE+1, &old_input);
-   return BIND_PRESSED(input, RARCH_PAUSE_TOGGLE);
+   return driver.input->key_pressed(driver.input_data, RARCH_PAUSE_TOGGLE);
 }
 
 /* Handle all events. If our activity is in pause state,

input/input_common.c

@@ -1625,6 +1625,10 @@ retro_input_t input_keys_pressed(unsigned key,
  * from the specified key up until the last queryable key
  * (key_end).
  *
+ * Because this function keeps a copy of the old input state,
+ * it should only be called once per frame (currently in
+ * rarch_main_iterate);
+ *
  * TODO: In case RARCH_BIND_LIST_END starts exceeding 64,
  * and you need a bitmask of more than 64 entries, don't
  * use this function.
@@ -1634,20 +1638,29 @@ retro_input_t meta_input_keys_pressed(unsigned key,
       unsigned key_end, retro_input_t *old_state)
 {
    static retro_input_t old_ret = 0;
+   static const struct retro_keybind *binds[] = { g_settings.input.binds[0] };
    retro_input_t ret = 0;
    *old_state = old_ret;
+   int i;
 
 #ifdef RARCH_INTERNAL
    rarch_check_block_hotkey(driver.input->key_pressed(driver.input_data,
             RARCH_ENABLE_HOTKEY));
 #endif
 
+   input_push_analog_dpad((struct retro_keybind*)binds[0],
+         (g_settings.input.analog_dpad_mode[0] == ANALOG_DPAD_NONE) ?
+         ANALOG_DPAD_LSTICK : g_settings.input.analog_dpad_mode[0]);
+
+   for (i = 0; i < MAX_PLAYERS; i++)
+      input_push_analog_dpad(g_settings.input.autoconf_binds[i],
+            g_settings.input.analog_dpad_mode[i]);
+
    for (; key < key_end; key++)
    {
       bool state = false;
 
-      if (!driver.block_hotkey
-            && g_extern.frame_count > driver.block_hotkey_until)
+      if (!driver.block_hotkey)
          state = driver.input->key_pressed(driver.input_data, key);
 
 #ifdef HAVE_OVERLAY
@@ -1663,6 +1676,10 @@ retro_input_t meta_input_keys_pressed(unsigned key,
          ret |= (1ULL << key);
    }
 
+   input_pop_analog_dpad((struct retro_keybind*)binds[0]);
+   for (i = 0; i < MAX_PLAYERS; i++)
+      input_pop_analog_dpad(g_settings.input.autoconf_binds[i]);
+
    old_ret = ret;
 
    return ret;

libretro_version_1.c

@@ -183,8 +183,7 @@ static int16_t input_state(unsigned port, unsigned device,
 
    if (!driver.block_libretro_input &&
          ((id < RARCH_FIRST_META_KEY ||
-            device == RETRO_DEVICE_KEYBOARD) &&
-         (g_extern.frame_count > driver.block_libretro_input_until))
+            device == RETRO_DEVICE_KEYBOARD))
          )
       res = driver.input->input_state(driver.input_data, binds, port,
             device, index, id);
@@ -203,6 +202,35 @@ static int16_t input_state(unsigned port, unsigned device,
    }
 #endif
 
+   {
+      /* Last frame input_state was called. */
+      static unsigned flush_frame = 0;
+      /* Last frame which had input. */
+      static unsigned flush_frame_input = 0;
+
+      if (driver.flushing_input)
+      {
+         if (flush_frame != g_extern.frame_count &&
+            flush_frame != flush_frame_input)
+         {
+            /* At least one entire frame has passed with no input. */
+            driver.flushing_input = false;
+            flush_frame = flush_frame_input = 0;
+         }
+         else
+         {
+            flush_frame = g_extern.frame_count;
+            if (res)
+            {
+               flush_frame_input = g_extern.frame_count;
+               res = 0;
+            }
+         }
+      }
+      else
+         flush_frame = flush_frame_input = 0;
+   }
+
    /* Don't allow turbo for D-pad. */
    if (device == RETRO_DEVICE_JOYPAD && (id < RETRO_DEVICE_ID_JOYPAD_UP ||
             id > RETRO_DEVICE_ID_JOYPAD_RIGHT))

retroarch.c

@@ -2838,7 +2838,9 @@ void rarch_main_set_state(unsigned cmd)
 
          rarch_main_command(RARCH_CMD_AUDIO_START);
 
-         driver.block_libretro_input_until = g_extern.frame_count + (5);
+         /* Prevent stray input from going to libretro core */
+         driver.flushing_input = true;
+
          /* Restore libretro keyboard callback. */
          g_extern.system.key_event = g_extern.frontend_key_event;
          break;
@@ -3226,9 +3228,17 @@ bool rarch_main_iterate(void)
 {
    unsigned i;
    retro_input_t old_input, trigger_input;
-   retro_input_t input = meta_input_keys_pressed(RARCH_FIRST_META_KEY,
+   retro_input_t input = meta_input_keys_pressed(0,
          RARCH_BIND_LIST_END, &old_input);
 
+   if (driver.flushing_input)
+   {
+      if (input)
+         input = 0;
+      else
+         driver.flushing_input = false;
+   }
+
    trigger_input = input & ~old_input;
 
    /* Time to drop? */