Files
sml-projects/fcore/enemy/enemy.sml

148 lines
3.9 KiB
Standard ML

structure Enemy =
struct
open GameType
(* returns a vector of enemies, with new state (like position, etc.).
* Also filters any enemies from list if defeated.
* Called once per frame. *)
fun updateEnemyList
( pos
, enemies
, projectiles
, projectileTree
, walls
, wallTree
, platforms
, platformTree
, player
, graph
, enemyList
) =
if pos < 0 then
Vector.fromList enemyList
else
let
val enemy = Vector.sub (enemies, pos)
(* call function to act on variant, either:
* 1. updating enemy and :: cons :: ing to enemyList, or
* 2. filtering enemy if projectile hit which enemy should not survive
* *)
val enemyList = EnemyBehaviour.updateEnemyState
( enemy
, projectiles
, projectileTree
, walls
, wallTree
, platforms
, platformTree
, player
, graph
, enemyList
)
in
updateEnemyList
( pos - 1
, enemies
, projectiles
, projectileTree
, walls
, wallTree
, platforms
, platformTree
, player
, graph
, enemyList
)
end
fun helpGenerateTree (pos, enemyVec: enemy vector, acc) =
if pos = Vector.length enemyVec then
acc
else
let
val {id, x, y, ...} = Vector.sub (enemyVec, pos)
val size = Constants.enemySize
val acc = QuadTree.insert (x, y, size, size, id, acc)
in
helpGenerateTree (pos + 1, enemyVec, acc)
end
fun generateTree enemyVec =
helpGenerateTree
( 0
, enemyVec
, QuadTree.create (Constants.worldWidth, Constants.worldHeight)
)
fun helpFind (findNum, vec: enemy vector, low, high) =
(* should only be called when we know enemy already exists in vec *)
let
val mid = low + ((high - low) div 2)
val enemy = Vector.sub (vec, mid)
val {id = curNum, ...} = enemy
in
if curNum = findNum then enemy
else if curNum < findNum then helpFind (findNum, vec, mid + 1, high)
else helpFind (findNum, vec, low, mid - 1)
end
fun find (findNum, vec) =
helpFind (findNum, vec, 0, Vector.length vec - 1)
fun helpGetDrawVec (enemy: enemy, width, height) =
let
val {x, y, ...} = enemy
val wratio = width / Constants.worldWidthReal
val hratio = height / Constants.worldHeightReal
in
if wratio < hratio then
let
val scale = Constants.worldHeightReal * wratio
val yOffset =
if height > scale then (height - scale) / 2.0
else if height < scale then (scale - height) / 2.0
else 0.0
val x = Real32.fromInt x * wratio
val y = Real32.fromInt y * wratio + yOffset
val realSize = Constants.enemySizeReal * wratio
in
Block.lerp (x, y, realSize, realSize, width, height, 0.5, 0.5, 1.0)
end
else
let
val scale = Constants.worldWidthReal * hratio
val xOffset =
if width > scale then (width - scale) / 2.0
else if width < scale then (scale - width) / 2.0
else 0.0
val x = Real32.fromInt x * hratio + xOffset
val y = Real32.fromInt y * hratio
val realSize = Constants.enemySizeReal * hratio
in
Block.lerp (x, y, realSize, realSize, width, height, 0.5, 0.5, 1.0)
end
end
fun getDrawVecLoop (pos, enemies, width, height, acc) =
if pos = Vector.length enemies then
Vector.concat acc
else
let
val e = Vector.sub (enemies, pos)
val hd = helpGetDrawVec (e, width, height)
val acc = hd :: acc
in
getDrawVecLoop (pos + 1, enemies, width, height, acc)
end
fun getDrawVec (enemies, width, height) =
getDrawVecLoop (0, enemies, width, height, [])
end