Merge pull request #5359 from Anewbe/arc_projectiles

Adds arcing projectiles

code/modules/projectiles/projectile/arc.dm

@@ -0,0 +1,134 @@
+// These projectiles are somewhat different from the other projectiles in the code.
+// First, these have an 'arcing' visual, that is accomplished by having the projectile icon rotate as its flying, and
+// moving up, then down as it approaches the target. There is also a small shadow effect that follows the projectile
+// as its flying.
+
+// Besides the visuals, arcing projectiles do not collide with anything until they reach the target, as they fly over them.
+// For best effect, use this only when it makes sense to do so, IE on the Surface. The projectiles don't care about ceilings or gravity.
+
+/obj/item/projectile/arc
+	name = "arcing shot"
+	icon_state = "fireball" // WIP
+	step_delay = 2 // Travel a bit slower, to really sell the arc visuals.
+	plane = ABOVE_PLANE // Since projectiles are 'in the air', they might visually overlap mobs while in flight, so the projectile needs to be above their plane.
+	var/target_distance = null	// How many tiles the impact site is.
+	var/fired_dir = null		// Which direction was the projectile fired towards. Needed to invert the projectile turning based on if facing left or right.
+	var/obj/effect/projectile_shadow/shadow = null // Visual indicator for the projectile's 'true' position. Needed due to being bound to two dimensions in reality.
+
+/obj/item/projectile/arc/initialize()
+	shadow = new(get_turf(src))
+	return ..()
+
+/obj/item/projectile/arc/Destroy()
+	qdel_null(shadow)
+	return ..()
+
+/obj/item/projectile/arc/Bump(atom/A, forced=0)
+	return 0
+//	if(get_turf(src) != original)
+//		return 0
+//	else
+//		return ..()
+
+// This is a test projectile in the sense that its testing the code to make sure it works,
+// as opposed to a 'can I hit this thing' projectile.
+/obj/item/projectile/arc/test/on_impact(turf/T)
+	new /obj/effect/explosion(T)
+	return ..()
+
+/obj/item/projectile/arc/launch(atom/target, target_zone, x_offset=0, y_offset=0, angle_offset=0)
+	var/expected_distance = get_dist(target, loc)
+	kill_count = expected_distance // So the projectile "hits the ground."
+	target_distance = expected_distance
+	fired_dir = get_dir(loc, target)
+	..() // Does the regular launching stuff.
+	if(fired_dir & EAST)
+		transform = turn(transform, -45)
+	else if(fired_dir & WEST)
+		transform = turn(transform, 45)
+
+
+// Visuals.
+/obj/item/projectile/arc/after_move()
+	// Handle projectile turning in flight.
+	// This won't turn if fired north/south, as it looks weird.
+	var/turn_per_step = 90 / target_distance
+	if(fired_dir & EAST)
+		transform = turn(transform, turn_per_step)
+	else if(fired_dir & WEST)
+		transform = turn(transform, -turn_per_step)
+
+	// Now for the fake height.
+	// We need to know how far along our "arc" we are.
+	var/arc_progress = get_dist(src, original)
+	var/arc_max_height = (target_distance * world.icon_size) / 2 // TODO: Real math.
+//	var/arc_center = target_distance / 2
+//	var/projectile_position = abs(arc_progress - arc_center)
+//	var/height_multiplier = projectile_position / arc_center
+//	height_multiplier = abs(height_multiplier - 1)
+//	height_multiplier = height_multiplier ** 2
+
+
+//	animate(src, pixel_z = arc_max_height * height_multiplier, time = step_delay)
+	var/projectile_position = arc_progress / target_distance
+	var/sine_position = projectile_position * 180
+	var/pixel_z_position = arc_max_height * sin(sine_position)
+	animate(src, pixel_z = pixel_z_position, time = step_delay)
+
+	// Update our shadow.
+	shadow.forceMove(loc)
+
+/obj/effect/projectile_shadow
+	name = "shadow"
+	desc = "You better avoid the thing coming down!"
+	icon = 'icons/obj/projectiles.dmi'
+	icon_state = "arc_shadow"
+	anchored = TRUE
+
+//////////////
+//	Subtypes
+//////////////
+
+// Generic, Hivebot related
+/obj/item/projectile/arc/blue_energy
+	name = "energy missile"
+	icon_state = "force_missile"
+	damage = 15
+	damage_type = BURN
+
+// Fragmentation arc shot
+/obj/item/projectile/arc/fragmentation
+	name = "fragmentation shot"
+	icon_state = "shell"
+	var/list/fragment_types = list(
+		/obj/item/projectile/bullet/pellet/fragment, /obj/item/projectile/bullet/pellet/fragment, \
+		/obj/item/projectile/bullet/pellet/fragment, /obj/item/projectile/bullet/pellet/fragment/strong
+		)
+	var/fragment_amount = 63 // Same as a grenade.
+	var/spread_range = 7
+
+/obj/item/projectile/arc/fragmentation/on_impact(turf/T)
+	fragmentate(T, fragment_amount, spread_range, fragment_types)
+
+// EMP arc shot
+/obj/item/projectile/arc/emp_blast
+	name = "emp blast"
+	icon_state = "bluespace"
+
+/obj/item/projectile/arc/emp_blast/on_impact(turf/T)
+	empulse(T, 2, 4, 7, 10) // Normal EMP grenade.
+	return ..()
+
+/obj/item/projectile/arc/emp_blast/weak/on_impact(turf/T)
+	empulse(T, 1, 2, 3, 4) // Sec EMP grenade.
+	return ..()
+
+// Radiation arc shot
+/obj/item/projectile/arc/radioactive
+	name = "radiation blast"
+	icon_state = "green_pellet"
+	icon_scale = 2
+	var/rad_power = 50
+
+/obj/item/projectile/arc/radioactive/on_impact(turf/T)
+	radiation_repository.radiate(T, rad_power)