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[sml3d] View of /trunk/sml3d/src/sml3d/base/vec4f.sml
 [sml3d] / trunk / sml3d / src / sml3d / base / vec4f.sml

# View of /trunk/sml3d/src/sml3d/base/vec4f.sml

Tue Jan 17 14:01:50 2012 UTC (7 years, 8 months ago) by jhr
File size: 1507 byte(s)
```  Working on new SML3d core library
```
```(* vec4f.sml
*
* COPYRIGHT (c) 2012 The SML3d Project (http://sml3d.cs.uchicago.edu)
*
* Operations on vectors in R^4 (float version).
*)

structure Vec4f :> VEC4 where type flt = Float.flt
= struct

structure Flt = Float

type flt = Flt.flt

val epsilon : flt = Flt.epsilon

type vec4 = flt SML3dTypes.vec4

open Vec4

val zero : vec4 = (0.0, 0.0, 0.0, 0.0)

fun toString ((x, y, z, w) : vec4) = concat[
"<", Flt.toString x, ",", Flt.toString y, ",", Flt.toString z,
Flt.toString w, ">"
]

fun neg ((x, y, z, w) : vec4) = (~x, ~y, ~z, ~w)

fun add ((x1, y1, z1, w1) : vec4, (x2, y2, z2, w2)) =
(x1+x2, y1+y2, z1+z2, w1+w2)

fun sub ((x1, y1, z1, w1) : vec4, (x2, y2, z2, w2)) =
(x1-x2, y1-y2, z1-z2, w1-w2)

fun mul ((x1, y1, z1, w1) : vec4, (x2, y2, z2, w2)) =
(x1*x2, y1*y2, z1*z2, w1*w2)

fun scale (s, (x, y, z, w) : vec4) = (s*x, s*y, s*z, s*w)

fun lerp (v1, t, v2) = add(scale(1.0-t, v1), scale(t, v2))

fun dot ((x1, y1, z1, w1) : vec4, (x2, y2, z2, w2)) =
(x1*x2 + y1*y2 + z1*z2 + w1*w2)

fun lengthSq (v : vec4) = dot(v, v)

fun length v = Flt.sqrt(lengthSq v)

fun distanceSq (u : vec4, v) = lengthSq (sub (u, v))

fun lengthAndDir (v as (x, y, z, w)) = let
val l = length v
in
if (l > epsilon)
then (l, scale(1.0 / l, v))
else (l, v)
end

fun normalize v = #2(lengthAndDir v)

end
```