game: play talk sfx when TV appears at spatial volume

Instead of only playing the talk sfx when adult gets glued to the
TV, always play it when the TV appears.

Also scale the volume with the inverse square of the distance
from the TV.

1 files changed, 20 insertions, 5 deletions

diff --git a/src/game.c b/src/game.c
index 2b46001..a9ffb67 100644
--- a/src/game.c
+++ b/src/game.c
@@ -400,6 +400,19 @@ static void reset_virus(virus_t *virus)
 }
 
 
+/* return a 0-1 volume based on entity's distance from the adult */
+static float entity_volume(game_t *game, entity_any_t *entity)
+{
+	float	volume;
+	v2f_t	delta;
+
+	delta = v2f_sub(&game->adult->entity.position, &entity->position);
+	volume = 1.f - ((1.f / 2.8284f) * v2f_length(&delta));
+
+	return (volume * volume);
+}
+
+
 /* returns 1 if entity started flashing, 0 if already flashing */
 static int flash_entity(game_t *game, entity_any_t *any, unsigned count)
 {
@@ -817,6 +830,13 @@ static void update_entities(play_t *play, game_t *game)
 		game->tv->entity.position.y = randf();
 		entity_update_x(game, &game->tv->entity);
 		stage_set_active(game->tv->entity.node, 1);
+
+		/* shifted because rand() tends to have more activity in the upper bits,
+		 * but this could be more careful about avoiding repetition by randomizing
+		 * a 0-9 list every time it stepped through said list. TODO
+		 */
+		sfx_play(&sfx.tv_talk[(rand() >> 8) % NELEMS(sfx.tv_talk)],
+			 entity_volume(game, &game->tv->entity));
 	}
 
 	if (game->adult->captivated && randf() > (1.f - GAME_MAGA_CHANCE) && !stage_get_active(game->maga->entity.node)) {
@@ -991,11 +1011,6 @@ static ix2_search_status_t adult_search(void *cb_context, ix2_object_t *ix2_obje
 	case ENTITY_TYPE_TV:
 		game->adult->captivated = 1;
 		sfx_play(&sfx.adult_captivated, 1.f);
-		/* shifted because rand() tends to have more activity in the upper bits,
-		 * but this could be more careful about avoiding repetition by randomizing
-		 * a 0-9 list every time it stepped through said list. TODO
-		 */
-		sfx_play(&sfx.tv_talk[(rand() >> 8) % NELEMS(sfx.tv_talk)], 1.f);
 
 		return IX2_SEARCH_STOP_HIT;