generalize dentata-snakes bounce logic into a util function

datapacks/omega-flowey/data/entity/functions/hostile/omega-flowey/attack/dentata-snakes/bullet/loop.mcfunction

@@ -5,7 +5,7 @@ data merge storage utils:damage { damage: 2.5 }
 function entity:utils/damage with storage utils:damage
 
 # Bounce if hit edge of arena
-execute unless entity @s[x=-21,dx=42,z=-3,dz=21] run function entity:hostile/omega-flowey/attack/dentata-snakes/bullet/loop/bounce
+execute unless entity @s[x=-21,dx=42,z=-3,dz=21] run function entity:hostile/omega-flowey/attack/dentata-snakes/bullet/loop/maybe_bounce
 
 # Move forward at defined `attack.speed.z` velocity
 execute store result storage utils:move z float 0.01 run scoreboard players get @s attack.speed.z

datapacks/omega-flowey/data/entity/functions/hostile/omega-flowey/attack/dentata-snakes/bullet/loop/after_bounce_as_bullet_head.mcfunction

@@ -0,0 +1,4 @@
+# If we bounced, play bounce sound
+# Only the bullet-head makes bounce sounds/shakes the player's screen (see `maybe_bounce.mcfunction`)
+playsound omega-flowey:attack.dentata-snakes.bounce hostile @a ~ ~ ~ 5 1
+execute as @a unless entity @s[team=!player,team=!dead,team=!spectator] at @s run function entity:utils/shake_screen

datapacks/omega-flowey/data/entity/functions/hostile/omega-flowey/attack/dentata-snakes/bullet/loop/maybe_bounce.mcfunction

@@ -0,0 +1,12 @@
+# Don't bounce if we've already escaped the arena (past top wall)
+execute if entity @s[x=-1000,dx=2000,y=30,dy=10,z=-4,dz=-1000,tag=can-escape-arena] run return 0
+
+# TODO(42): adjust arena bounds based on new animated java model (visually, it clips into the wall right now)
+data merge storage attack:dentata-snakes.bounce { x_negative_x: -21, x_negative_dx: 50 }
+data merge storage attack:dentata-snakes.bounce { x_positive_x: 21, x_positive_dx: -50 }
+data merge storage attack:dentata-snakes.bounce { z_negative_z: -3, z_negative_dz: 25 }
+data merge storage attack:dentata-snakes.bounce { z_positive_z: 18, z_positive_dz: -25 }
+data merge storage attack:dentata-snakes.bounce { y: 30, dy: 10 }
+data merge storage attack:dentata-snakes.bounce { command_after_bouncing: 'execute if entity @s[tag=attack-bullet-head] run function entity:hostile/omega-flowey/attack/dentata-snakes/bullet/loop/after_bounce_as_bullet_head' }
+
+function entity:utils/bounce with storage attack:dentata-snakes.bounce

datapacks/omega-flowey/data/entity/functions/utils/bounce.mcfunction

@@ -0,0 +1,36 @@
+## Reflects an entity's facing direction (yaw only) against the walls of a specified bounding box
+# i.e. (flips x-direction/z-direction as necessary)
+# ---
+# params:
+# * x_negative_x: x coordinate for the bounding box's safe region outside of the -X wall
+# * x_negative_dx: x width for the bounding box's safe region outside of the -X wall
+# * x_positive_x: x coordinate for the bounding box's safe region outside of the +X wall
+# * x_positive_dx: x width for the bounding box's safe region outside of the +X wall
+# * z_negative_z: z coordinate for the bounding box's safe region outside of the -Z wall
+# * z_negative_dz: z width for the bounding box's safe region outside of the -Z wall
+# * z_positive_z: z coordinate for the bounding box's safe region outside of the +Z wall
+# * z_positive_dz: z width for the bounding box's safe region outside of the +Z wall
+# * y/dy: generous y lower-bound + height for each bounding box
+#   (y/dy need to be generous because of target selectors being janky with volume selections)
+
+# Save initial yaw
+execute store result score @s util.bounce.yaw.initial run data get entity @s Rotation[0]
+scoreboard players operation @s util.bounce.yaw = @s util.bounce.yaw.initial
+
+# -X wall
+$execute unless entity @s[x=$(x_negative_x),dx=$(x_negative_dx),y=$(y),dy=$(dy),z=-1000,dz=2000] if entity @s[y_rotation=0..180] run function entity:utils/bounce/x_negative
+
+# +X wall
+$execute unless entity @s[x=$(x_positive_x),dx=$(x_positive_dx),y=$(y),dy=$(dy),z=-1000,dz=2000] if entity @s[y_rotation=-180..0] run function entity:utils/bounce/x_positive
+
+# -Z wall
+$execute unless entity @s[x=-1000,dx=2000,y=$(y),dy=$(dy),z=$(z_negative_z),dz=$(z_negative_dz)] unless entity @s[y_rotation=-90..90] run function entity:utils/bounce/z_negative
+
+# +Z wall
+$execute unless entity @s[x=-1000,dx=2000,y=$(y),dy=$(dy),z=$(z_positive_z),dz=$(z_positive_dz)] if entity @s[y_rotation=-90..90] run function entity:utils/bounce/z_positive
+
+# Store bounced angle
+execute store result entity @s Rotation[0] float 1 run scoreboard players get @s util.bounce.yaw
+
+# If `util.bounce.yaw != util.bounce.yaw.initial`, we bounced
+$execute unless score @s util.bounce.yaw = @s util.bounce.yaw.initial run $(command_after_bouncing)

datapacks/omega-flowey/data/entity/functions/utils/bounce/shared/x.mcfunction

@@ -0,0 +1 @@
+scoreboard players operation @s util.bounce.yaw *= #-1 mathf.const

datapacks/omega-flowey/data/entity/functions/utils/bounce/shared/z.mcfunction

@@ -0,0 +1,2 @@
+scoreboard players operation @s util.bounce.yaw -= #180 mathf.const
+scoreboard players operation @s util.bounce.yaw *= #-1 mathf.const

datapacks/omega-flowey/data/entity/functions/utils/bounce/x_negative.mcfunction

@@ -0,0 +1 @@
+function entity:utils/bounce/shared/x

datapacks/omega-flowey/data/entity/functions/utils/bounce/x_positive.mcfunction

@@ -0,0 +1 @@
+function entity:utils/bounce/shared/x

datapacks/omega-flowey/data/entity/functions/utils/bounce/z_negative.mcfunction

@@ -0,0 +1 @@
+function entity:utils/bounce/shared/z

datapacks/omega-flowey/data/entity/functions/utils/bounce/z_positive.mcfunction

@@ -0,0 +1 @@
+function entity:utils/bounce/shared/z

datapacks/omega-flowey/data/omega-flowey/functions/setup/objectives.mcfunction

@@ -90,3 +90,8 @@ scoreboard objectives add player.shake.yaw dummy
 scoreboard objectives add random dummy
 scoreboard objectives add random.min dummy
 scoreboard objectives add random.range dummy
+
+# the final yaw an entity has after running bounce calculations
+scoreboard objectives add util.bounce.yaw dummy
+# the initial yaw an entity starts with before running bounce calculations
+scoreboard objectives add util.bounce.yaw.initial dummy