Files
sml-projects/functional-core/app-update.sml
2024-08-06 07:38:46 +01:00

407 lines
13 KiB
Standard ML

structure AppUpdate =
struct
open AppType
(* This function adjusts the x position to be centre-aligned to the grid
* if windowWidth is greater than height
* (where screen size does not have 1:1 aspect ratio). *)
fun calcRelativeX (x, windowWidth, windowHeight, halfWidth) =
if windowWidth > windowHeight then
let
val difference = windowWidth - windowHeight
val offset = Real32.fromInt (difference div 2)
in
x * (halfWidth - offset)
end
else
x * halfWidth
(* Similar to calcRelativeX, except it centre-aligns the y-point
* when windowHeight is greater than windowWidth. *)
fun calcRelativeY (y, windowWidth, windowHeight, halfHeight) =
if windowHeight > windowWidth then
let
val difference = windowHeight - windowWidth
val offset = Real32.fromInt (difference div 2)
in
y * (halfHeight - offset)
end
else
y * halfHeight
local
fun helpGetTrianglesVector
(lst, acc, windowWidth, windowHeight, halfWidth, halfHeight) =
case lst of
{x1, y1, x2, y2, x3, y3} :: tl =>
let
val x1 = calcRelativeX (x1, windowWidth, windowHeight, halfWidth)
val x2 = calcRelativeX (x2, windowWidth, windowHeight, halfWidth)
val x3 = calcRelativeX (x3, windowWidth, windowHeight, halfWidth)
val y1 = calcRelativeY (y1, windowWidth, windowHeight, halfHeight)
val y2 = calcRelativeY (y2, windowWidth, windowHeight, halfHeight)
val y3 = calcRelativeY (y3, windowWidth, windowHeight, halfHeight)
val vec =
#[ x1 / halfWidth
, y1 / halfHeight
, x2 / halfWidth
, y2 / halfHeight
, x3 / halfWidth
, y3 / halfHeight
]
val acc = vec :: acc
in
helpGetTrianglesVector
(tl, acc, windowWidth, windowHeight, halfWidth, halfHeight)
end
| [] => acc
in
fun getTrianglesVector (app: app_type) =
let
val windowWidth = #windowWidth app
val windowHeight = #windowHeight app
val halfWidth = Real32.fromInt (windowWidth div 2)
val halfHeight = Real32.fromInt (windowHeight div 2)
val lst = helpGetTrianglesVector
(#triangles app, [], windowWidth, windowHeight, halfWidth, halfHeight)
in
Vector.concat lst
end
end
fun ltrbToVertex (left, top, right, bottom, r, g, b) =
#[ left, bottom, r, g, b
, right, bottom, r, g, b
, left, top, r, g, b
, left, top, r, g, b
, right, bottom, r, g, b
, right, top, r, g, b
]
local
(*
* 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 getVerticalClickPos
( yClickPoints
, idx
, horizontalPos
, mouseX
, mouseY
, r
, g
, b
, windowWidth
, windowHeight
) =
if idx = Vector.length yClickPoints then
(#[], 0.0, 0.0)
else
let
val curVerticalPos = Vector.sub (yClickPoints, idx)
in
if mouseY < curVerticalPos - range orelse mouseY > curVerticalPos + range then
getVerticalClickPos
( yClickPoints
, idx + 1
, horizontalPos
, mouseX
, mouseY
, r
, g
, b
, windowWidth
, windowHeight
)
else
let
(* calculate normalised device coordinates *)
val halfWidth = Real32.fromInt (windowWidth div 2)
val halfHeight = Real32.fromInt (windowHeight div 2)
val hpos = horizontalPos - halfWidth
val vpos = ~(curVerticalPos - 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
(* normalised device coordinates of drawVec should be relative
* to actual windowWidth and windowHeight,
* even if not a square, to display cursor position... *)
val drawVec = ltrbToVertex (left, top, right, bottom, r, g, b)
in
(*
* ...however, normalised device coordinate of hpos and vpos
* should be relative to the vertical centre
* (if height is greater than width)
* or horizontal centre
* (if width is greater than height).
*
* So, for example, a 900x1000 resolution
* will have clickable points from 50...950,
* in increments of 50.
* Because we always want to show canvas as a square
* with an aspect ratio of 1:1.
* For displaying the click position on the screen, drawVec
* which uses actual windowWidth and windowHeight, is fine.
* However, we want to attach the meaning "start" to 50
* and "end" to 950,
* so the hpos and vpos stored in the app's triangle list
* subtracts the offset 50 if needed,
* allowing us to treat the coordinates as a 900x900 square.
*
* We may not actually want to render a square to the screen
* if the screen's aspect ratio is not 1:1,
* but it's the responsibility of the rendering code
* which turns triangles into OpenGL vectors
* to do that.
* *)
if windowWidth = windowHeight then
let
val hpos = hpos / halfWidth
val vpos = vpos / halfHeight
in
(drawVec, hpos, vpos)
end
else if windowWidth > windowHeight then
let
val difference = windowWidth - windowHeight
val offset = Real32.fromInt (difference div 2)
val hpos = hpos / (halfWidth - offset)
val vpos = vpos / halfHeight
in
(drawVec, hpos, vpos)
end
else
(* windowHeight > windowWidth *)
let
val difference = windowHeight - windowWidth
val offset = Real32.fromInt (difference div 2)
val hpos = hpos / halfWidth
val vpos = vpos / (halfHeight - offset)
in
(drawVec, hpos, vpos)
end
end
end
fun getHorizontalClickPos
( xClickPoints
, yClickPoints
, idx
, mouseX
, mouseY
, r
, g
, b
, windowWidth
, windowHeight
) =
if idx = Vector.length xClickPoints then
(#[], 0.0, 0.0)
else
let
val curPos = Vector.sub (xClickPoints, idx)
in
if mouseX < curPos - range orelse mouseX > curPos + range then
getHorizontalClickPos
( xClickPoints
, yClickPoints
, idx + 1
, mouseX
, mouseY
, r
, g
, b
, windowWidth
, windowHeight
)
else
getVerticalClickPos
( yClickPoints
, 0
, curPos
, mouseX
, mouseY
, r
, g
, b
, windowWidth
, windowHeight
)
end
in
(*
* This function returns a vector containing the position data of the
* clicked square.
* If a square wasn't found at the clicked position,
* an empty vector is returned.
*)
fun getClickPos (mouseX, mouseY, r, g, b, model: app_type) =
getHorizontalClickPos
( #xClickPoints model
, #yClickPoints model
, 0
, mouseX
, mouseY
, r
, g
, b
, #windowWidth model
, #windowHeight model
)
end
fun getFirstTriangleStageVector (x1, y1, drawVec, model) =
let
val windowWidth = #windowWidth model
val windowHeight = #windowHeight model
val halfWidth = Real32.fromInt (windowWidth div 2)
val halfHeight = Real32.fromInt (windowHeight div 2)
val x1px = calcRelativeX (x1, windowWidth, windowHeight, halfWidth)
val left = (x1px - 5.0) / halfWidth
val right = (x1px + 5.0) / halfWidth
val y1px = calcRelativeY (y1, windowWidth, windowHeight, halfHeight)
val top = (y1px + 5.0) / halfHeight
val bottom = (y1px - 5.0) / halfHeight
val firstVec = ltrbToVertex (left, top, right, bottom, 0.0, 0.0, 1.0)
in
Vector.concat [firstVec, drawVec]
end
fun getSecondTriangleStageVector (x1, y1, x2, y2, drawVec, model) =
let
val windowWidth = #windowWidth model
val windowHeight = #windowHeight model
val halfWidth = Real32.fromInt (windowWidth div 2)
val halfHeight = Real32.fromInt (windowHeight div 2)
val x1px = calcRelativeX (x1, windowWidth, windowHeight, halfWidth)
val left = (x1px - 5.0) / halfWidth
val right = (x1px + 5.0) / halfWidth
val y1px = calcRelativeY (y1, windowWidth, windowHeight, halfHeight)
val top = (y1px + 5.0) / halfHeight
val bottom = (y1px - 5.0) / halfHeight
val firstVec = ltrbToVertex (left, top, right, bottom, 0.0, 0.0, 1.0)
val x2px = calcRelativeX (x2, windowWidth, windowHeight, halfWidth)
val left = (x2px - 5.0) / halfWidth
val right = (x2px + 5.0) / halfWidth
val y2px = calcRelativeY (y2, windowWidth, windowHeight, halfHeight)
val top = (y2px + 5.0) / halfHeight
val bottom = (y2px - 5.0) / halfHeight
val secVec = ltrbToVertex (left, top, right, bottom, 0.0, 0.0, 1.0)
in
Vector.concat [firstVec, secVec, drawVec]
end
fun getTriangleStageVector (model: app_type, drawVec) =
case #triangleStage model of
NO_TRIANGLE => drawVec
| FIRST {x1, y1} => getFirstTriangleStageVector (x1, y1, drawVec, model)
| SECOND {x1, y1, x2, y2} =>
getSecondTriangleStageVector (x1, y1, x2, y2, drawVec, model)
local
open DrawMessage
open InputMessage
fun mouseMoveOrRelease (model: app_type, mouseX, mouseY) =
let
val {xClickPoints, yClickPoints, ...} = model
val (drawVec, _, _) = getClickPos (mouseX, mouseY, 1.0, 0.0, 0.0, model)
val drawVec = getTriangleStageVector (model, drawVec)
val drawMsg = DRAW_BUTTON drawVec
in
(model, drawMsg, mouseX, mouseY)
end
fun mouseLeftClick (model: app_type, mouseX, mouseY) =
let
val {xClickPoints, yClickPoints, ...} = model
val (buttonVec, hpos, vpos) = getClickPos
(mouseX, mouseY, 0.0, 0.0, 1.0, model)
in
if Vector.length buttonVec > 0 then
case #triangleStage model of
NO_TRIANGLE =>
let
val drawVec = getTriangleStageVector (model, buttonVec)
val drawMsg = DRAW_BUTTON drawVec
val newTriangleStage = FIRST {x1 = hpos, y1 = vpos}
val model = AppType.withTriangleStage (model, newTriangleStage)
in
(model, drawMsg, mouseX, mouseY)
end
| FIRST {x1, y1} =>
let
val drawVec =
getFirstTriangleStageVector (x1, y1, buttonVec, model)
val drawMsg = DRAW_BUTTON drawVec
val newTriangleStage = SECOND
{x1 = x1, y1 = y1, x2 = hpos, y2 = vpos}
val model = AppType.withTriangleStage (model, newTriangleStage)
in
(model, drawMsg, mouseX, mouseY)
end
| SECOND {x1, y1, x2, y2} =>
let
val model = AppType.addTriangleAndResetStage
(model, x1, y1, x2, y2, hpos, vpos)
val drawVec = getTrianglesVector model
val drawMsg = DRAW_TRIANGLES_AND_RESET_BUTTONS drawVec
in
(model, drawMsg, mouseX, mouseY)
end
else
(model, NO_DRAW, mouseX, mouseY)
end
fun resizeWindow (model, mouseX, mouseY, width, height) =
let
val model = AppType.withWindowResize (model, width, height)
val triangles = getTrianglesVector model
val graphLines = #graphLines model
val drawMsg =
RESIZE_TRIANGLES_BUTTONS_AND_GRAPH
{triangles = triangles,
graphLines = graphLines}
in
(model, drawMsg, mouseX, mouseY)
end
in
fun update (model: app_type, mouseX, mouseY, inputMsg) =
case inputMsg of
MOUSE_MOVE {x = mouseX, y = mouseY} =>
mouseMoveOrRelease (model, mouseX, mouseY)
| MOUSE_LEFT_RELEASE => mouseMoveOrRelease (model, mouseX, mouseY)
| MOUSE_LEFT_CLICK => mouseLeftClick (model, mouseX, mouseY)
| RESIZE_WINDOW {width, height} =>
resizeWindow (model, mouseX, mouseY, width, height)
end
end