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move quad tree helper functions which are useful in quad-tree.sml and will be useful in quad-tree-fold.sml, to quad-tree-type.sml, so quad-tree.sml only exports public API suitable for users

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This commit is contained in:
Humza Shahid
2025-01-29 07:07:54 +00:00
parent abeff178c6
commit 7138a05cd3
4 changed files with 93 additions and 147 deletions
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1
fcore/quad-tree-fold.sml Normal file
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@@ -0,0 +1 @@

103
fcore/quad-tree-type.sml
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@@ -15,12 +15,17 @@ sig
}
| LEAF of {items: item vector, x: int, y: int, w: int, h: int}
datatype quadrant =
TOP_LEFT
| TOP_RIGHT
| BOTTOM_LEFT
| BOTTOM_RIGHT
| PARENT_QUADRANT
val isColliding: int * int * int * int * int * int * int * int -> bool
val isCollidingPlus: int * int * int * int * int * int * int * int -> bool
val visitTopLeft: int * int * int * int * int * int * int * int -> bool
val visitTopRight: int * int * int * int * int * int * int * int -> bool
val visitBottomLeft: int * int * int * int * int * int * int * int -> bool
val visitBottomRight: int * int * int * int * int * int * int * int -> bool
end
structure QuadTreeType :> QUAD_TREE_TYPE =
@@ -40,10 +45,84 @@ struct
}
| LEAF of {items: item vector, x: int, y: int, w: int, h: int}
datatype quadrant =
TOP_LEFT
| TOP_RIGHT
| BOTTOM_LEFT
| BOTTOM_RIGHT
| PARENT_QUADRANT
fun isColliding (ix, iy, ifx, ify, cx, cy, cfx, cfy) =
ix < cfx andalso ifx > cx andalso iy < cfy andalso ify > cy
fun isCollidingPlus (ix, iy, iw, ih, cx, cy, cw, ch) =
let
val ifx = ix + iw
val ify = iy + ih
val cfx = cx + cw
val cfy = cy + ch
in
isColliding (ix, iy, ifx, ify, cx, cy, cfx, cfy)
end
fun visitTopLeft (iX, iY, iW, iH, qX, qY, qW, qH) =
let
val hw = qW div 2
val hh = qH div 2
val ifx = iX + iW
val ify = iY + iH
val qmx = qX + hw
val qmy = qY + hh
val qfx = qX + qW
val qfy = qY + qH
in
isColliding (iX, iY, ifx, ify, qX, qY, qmx, qmy)
end
fun visitTopRight (iX, iY, iW, iH, qX, qY, qW, qH) =
let
val hw = qW div 2
val hh = qH div 2
val ifx = iX + iW
val ify = iY + iH
val qmx = qX + hw
val qmy = qY + hh
val qfx = qX + qW
val qfy = qY + qH
in
isColliding (iX, iY, ifx, ify, qmx, qY, qfx, qmy)
end
fun visitBottomLeft (iX, iY, iW, iH, qX, qY, qW, qH) =
let
val hw = qW div 2
val hh = qH div 2
val ifx = iX + iW
val ify = iY + iH
val qmx = qX + hw
val qmy = qY + hh
val qfx = qX + qW
val qfy = qY + qH
in
isColliding (iX, iY, ifx, ify, qX, qmy, qmx, qfy)
end
fun visitBottomRight (iX, iY, iW, iH, qX, qY, qW, qH) =
let
val hw = qW div 2
val hh = qH div 2
val ifx = iX + iW
val ify = iY + iH
val qmx = qX + hw
val qmy = qY + hh
val qfx = qX + qW
val qfy = qY + qH
in
isColliding (iX, iY, ifx, ify, qmx, qmy, qfx, qfy)
end
end

135
fcore/quad-tree.sml
View File

@@ -2,12 +2,6 @@ signature QUAD_TREE =
sig
type t
datatype collision_side =
QUERY_ON_LEFT_SIDE
| QUERY_ON_TOP_SIDE
| QUERY_ON_RIGHT_SIDE
| QUERY_ON_BOTTOM_SIDE
val insert: int * int * int * int * int * t -> t
val getCollisions: int * int * int * int * int * t -> int list
@@ -30,87 +24,6 @@ struct
fun create (width, height) =
LEAF {items = Vector.fromList [], x = 0, y = 0, w = width, h = height}
fun isColliding (ix, iy, ifx, ify, cx, cy, cfx, cfy) =
ix < cfx andalso ifx > cx andalso iy < cfy andalso ify > cy
fun isCollidingPlus (ix, iy, iw, ih, cx, cy, cw, ch) =
let
val ifx = ix + iw
val ify = iy + ih
val cfx = cx + cw
val cfy = cy + ch
in
isColliding (ix, iy, ifx, ify, cx, cy, cfx, cfy)
end
fun visitTopLeft (iX, iY, iW, iH, qX, qY, qW, qH) =
let
val hw = qW div 2
val hh = qH div 2
val ifx = iX + iW
val ify = iY + iH
val qmx = qX + hw
val qmy = qY + hh
val qfx = qX + qW
val qfy = qY + qH
in
isColliding (iX, iY, ifx, ify, qX, qY, qmx, qmy)
end
fun visitTopRight (iX, iY, iW, iH, qX, qY, qW, qH) =
let
val hw = qW div 2
val hh = qH div 2
val ifx = iX + iW
val ify = iY + iH
val qmx = qX + hw
val qmy = qY + hh
val qfx = qX + qW
val qfy = qY + qH
in
isColliding (iX, iY, ifx, ify, qmx, qY, qfx, qmy)
end
fun visitBottomLeft (iX, iY, iW, iH, qX, qY, qW, qH) =
let
val hw = qW div 2
val hh = qH div 2
val ifx = iX + iW
val ify = iY + iH
val qmx = qX + hw
val qmy = qY + hh
val qfx = qX + qW
val qfy = qY + qH
in
isColliding (iX, iY, ifx, ify, qX, qmy, qmx, qfy)
end
fun visitBottomRight (iX, iY, iW, iH, qX, qY, qW, qH) =
let
val hw = qW div 2
val hh = qH div 2
val ifx = iX + iW
val ify = iY + iH
val qmx = qX + hw
val qmy = qY + hh
val qfx = qX + qW
val qfy = qY + qH
in
isColliding (iX, iY, ifx, ify, qmx, qmy, qfx, qfy)
end
fun mkItem (id, startX, startY, width, height) : item =
{ itemID = id
, startX = startX
@@ -350,54 +263,6 @@ struct
fun getCollisions (itemX, itemY, itemWidth, itemHeight, itemID, tree) =
helpGetCollisions (itemX, itemY, itemWidth, itemHeight, itemID, [], tree)
(* no variant to represent 'no collision' case
* because caller should only try getting collision side
* after checking that there is any collision. *)
datatype collision_side =
QUERY_ON_LEFT_SIDE
| QUERY_ON_TOP_SIDE
| QUERY_ON_RIGHT_SIDE
| QUERY_ON_BOTTOM_SIDE
(* getCollisionSide function ported from this answer:
* https://stackoverflow.com/a/56607347
* *)
fun getCollisionSide (iX, iY, iW, iH, checkWith: item) =
let
val iFinishX = iX + iW
val iFinishY = iY + iH
val iHalfW = iW div 2
val iHalfH = iH div 2
val iCentreX = iX + iHalfW
val iCentreY = iY + iHalfH
val {startX = cX, startY = cY, width = cW, height = cH, ...} = checkWith
val cFinishX = cX + cW
val cFinishY = cY + cH
val cHalfW = cW div 2
val cHalfH = cH div 2
val cCentreX = cX + cHalfW
val cCentreY = cY + cHalfH
val diffX = iCentreX - cCentreX
val diffY = iCentreY - cCentreY
val minXDist = iHalfW + cHalfW
val minYDist = iHalfH + cHalfH
val depthX = if diffX > 0 then minXDist - diffX else (~minXDist) - diffX
val depthY = if diffY > 0 then minYDist - diffY else (~minYDist) - diffY
in
if abs depthX < abs depthY then
if depthX > 0 then QUERY_ON_LEFT_SIDE else QUERY_ON_RIGHT_SIDE
else if depthY > 0 then
QUERY_ON_TOP_SIDE
else
QUERY_ON_BOTTOM_SIDE
end
fun hasCollisionAtVec (iX, iY, iW, iH, itemID, pos, elements) =
if pos = Vector.length elements then
false