Files
sml-projects/temp-squares/fcore/click-points.sml
2025-07-06 03:53:26 +01:00

76 lines
2.5 KiB
Standard ML

structure ClickPoints =
struct
fun generate (start, finish, numPoints) =
let
val difference = finish - start
val increment = Real32.fromInt difference / Real32.fromInt numPoints
val start = Real32.fromInt start
in
Vector.tabulate (numPoints + 1, fn idx =>
(Real32.fromInt idx * increment) + start)
end
(*
* Range to detect from clickable position.
* For example, if we have a clickable position at (x, y) = (500, 500),
* with a range of 15, we can detect clicks targeting this position
* from top left at (485, 485) to bottom right at (515, 515).
* *)
val range = 15.0
fun getClickPos (clickPoints, mousePos, idx) =
if idx = Vector.length clickPoints then
NONE
else
let
val curPos = Vector.sub (clickPoints, idx)
in
if mousePos < curPos - range orelse mousePos > curPos + range then
getClickPos (clickPoints, mousePos, idx + 1)
else
SOME idx
end
fun getClickPositionFromMouse (app: AppType.app_type) =
case getClickPos (#xClickPoints app, #mouseX app, 0) of
SOME hIdx =>
(case getClickPos (#yClickPoints app, #mouseY app, 0) of
SOME vIdx => SOME (hIdx, vIdx)
| NONE => NONE)
| NONE => NONE
fun getDrawDot (xpos, ypos, windowWidth, windowHeight) =
let
(* calculate normalised device coordinates *)
val halfWidth = Real32.fromInt (windowWidth div 2)
val halfHeight = Real32.fromInt (windowHeight div 2)
val hpos = xpos - halfWidth
val vpos = ~(ypos - halfHeight)
(* coordinates to form small box around clicked area *)
val left = (hpos - 5.0) / halfWidth
val right = (hpos + 5.0) / halfWidth
val bottom = (vpos - 5.0) / halfHeight
val top = (vpos + 5.0) / halfHeight
in
Ndc.ltrbToVertex (left, top, right, bottom)
end
fun getDrawDotRgb (xpos, ypos, r, g, b, windowWidth, windowHeight) =
let
(* calculate normalised device coordinates *)
val halfWidth = Real32.fromInt (windowWidth div 2)
val halfHeight = Real32.fromInt (windowHeight div 2)
val hpos = xpos - halfWidth
val vpos = ~(ypos - halfHeight)
(* coordinates to form small box around clicked area *)
val left = (hpos - 5.0) / halfWidth
val right = (hpos + 5.0) / halfWidth
val bottom = (vpos - 5.0) / halfHeight
val top = (vpos + 5.0) / halfHeight
in
Ndc.ltrbToVertexRgb (left, top, right, bottom, r, g, b)
end
end