sml-projects/fcore/pipe-cursor.sml

structure PipeCursor = 
struct
  fun xToNdc (xOffset, xpos, scale, halfWidth) =
    ((xpos * scale + xOffset) - halfWidth) / halfWidth

  fun yToNdc (yOffset, ypos, scale, halfHeight) =
   ~(((ypos * scale + yOffset) - halfHeight) / halfHeight)

  fun lerp (xOffset: Real32.real, yOffset, z, scale, windowWidth, windowHeight, r, g, b) =
    let
      val halfWidth = windowWidth / 2.0
      val halfHeight = windowHeight / 2.0
    in
     #[
xToNdc (xOffset, 0.000000000000000, scale, halfWidth),
yToNdc (yOffset, 13.000000000000000, scale, halfHeight),
z,
r, g, b,
xToNdc (xOffset, 1.000000000000000, scale, halfWidth),
yToNdc (yOffset, 13.000000000000000, scale, halfHeight),
z,
r, g, b,
xToNdc (xOffset, 0.000000000000000, scale, halfWidth),
yToNdc (yOffset, 0.000000000000000, scale, halfHeight),
z,
r, g, b,
xToNdc (xOffset, 0.000000000000000, scale, halfWidth),
yToNdc (yOffset, 0.000000000000000, scale, halfHeight),
z,
r, g, b,
xToNdc (xOffset, 1.000000000000000, scale, halfWidth),
yToNdc (yOffset, 13.000000000000000, scale, halfHeight),
z,
r, g, b,
xToNdc (xOffset, 1.000000000000000, scale, halfWidth),
yToNdc (yOffset, 0.000000000000000, scale, halfHeight),
z,
r, g, b
      ]
    end
end