{- |
Module : $FreeCAD$
Description : Hets(Haskell) end-point of the interface with the OpenCascade
libraries. It reads the ouput of the C++ program "Brep_Reader"
and interprets it in order to generate the data for the basic
FreeCAD terms, which are not properly described in the file
Copyright : (c) Robert Savu and Uni Bremen 2011
License : GPLv2 or higher, see LICENSE.txt
Maintainer : Robert.Savu@dfki.de
Stability : experimental
Portability : portable
Haskell layer of the Brep-reader
-}
module FreeCAD.Brep where
import System.Process
import Text.XML.Light
import Data.Maybe
import FreeCAD.As
import FreeCAD.VecTools
import Control.Monad.Reader (ask, ReaderT (..), liftIO)
import System.FilePath
getBrep :: (String, String) -> RIO (BaseObject, Placement)
getBrep (address, "line") =
fmap proc3dLine $ get3dLine address
getBrep (address, "rectangle") =
fmap procRectangle $ getRectangle address
getBrep (_, _) = error "getBrep called with wrong arguments"
proc3dLine :: (Vector3, Vector3) -> (BaseObject, Placement)
proc3dLine (a, b) = (Line l, place)
where
l = distance3 a b
pos = a
ox = Vector3 1 0 0
direction = subtract3 b a
rotVec = v3VecProd ox direction
rotVecn = if norm3 rotVec /= 0 then
scalarprod3 (1 / norm3 rotVec) rotVec
else
Vector3 1 0 0
cosAa = cos $ if norm3 rotVec /= 0 then
acos (v3DotProd ox direction / norm3 direction) / 2
else 0
sinAa = sqrt (1 - cosAa ** 2)
quat = Vector4 (sinAa * x rotVecn) (sinAa * y rotVecn)
(sinAa * z rotVecn) cosAa
place = Placement pos quat
procRectangle :: (Vector3, Vector3, Vector3, Vector3) -> (BaseObject, Placement)
procRectangle (a, b, c, d) = (Rectangle h l, place)
where
d1 = distance3 a b -- \
d2 = distance3 a c -- > values used to compute rectangle's properties
d3 = distance3 a d -- /
mn = min d1 (min d2 d3) -- heigth/small edge value
mx = max d1 (max d2 d3) -- diagonal length
md | (d1 /= mn) && (d1 /= mx) = d1 -- length value
| (d2 /= mn) && (d2 /= mx) = d2
| (d3 /= mn) && (d3 /= mx) = d3
| otherwise = 0
h = mn
l = md
hh | mn == d1 = b -- w/o rotation is on the Oy axis
| mn == d2 = c
| mn == d3 = d
| otherwise = Vector3 0 0 0
hpoint = subtract3 hh a
ll | md == d1 = b -- w/o rotation is on the Ox axis
| md == d2 = c
| md == d3 = d
| otherwise = Vector3 0 0 0
lpoint = subtract3 ll a
{- obtain actual rotation by 2 intermediary rotations, matching points in
space ( a = 0.0.0; first: hpoint = hpoint'; then: lpoint = lpoint' )
0.0.0 --> X.Y.Z
first we rotate with regard to hpoint (and Oy axis) -}
oy = Vector3 0 1 0
rot1vec = v3VecProd oy hpoint -- rotation axis (for q1)
rot1vecn = if norm3 rot1vec /= 0 then
scalarprod3 (1 / norm3 rot1vec) rot1vec -- norm.rot.axis
else
Vector3 1 0 0
cosAa1 = cos $ if norm3 rot1vec /= 0 then
acos (v3DotProd oy hpoint / norm3 hpoint) / 2
else 0
sinAa1 = sqrt (1 - cosAa1 ** 2)
quat1 = Vector4 (sinAa1 * x rot1vecn) (sinAa1 * y rot1vecn)
(sinAa1 * z rot1vecn) cosAa1
tmatrix = quat2matrix quat1
l2point = rotate tmatrix (Vector3 (norm3 lpoint) 0 0)
-- then we rotate l2point into lpoint
rot2vec = v3VecProd l2point lpoint
rot2vecn = if norm3 rot2vec /= 0 then
scalarprod3 (1 / norm3 rot2vec) rot2vec
else Vector3 1 0 0
cosAa2 = cos $ if norm3 rot2vec /= 0 then
acos (v3DotProd l2point lpoint / norm3 lpoint) / 2
else 0
sinAa2 = sqrt (1 - cosAa2 ** 2)
quat2 = Vector4 (sinAa2 * x rot2vecn) (sinAa2 * y rot2vecn)
(sinAa2 * z rot2vecn) cosAa2
quaternion = quatProd quat1 quat2
pos = a
place = Placement pos quaternion
brepToXmlBinary :: RIO FilePath
brepToXmlBinary = return "brep_to_xml"
getBrepObject :: (String -> a) -> String -> String -> RIO a
getBrepObject parser t addr = do
tmpDir <- ask
binary <- brepToXmlBinary
fmap parser $ liftIO $ readProcess binary [joinPath [tmpDir, addr], t] ""
get3dLine :: String -> RIO (Vector3, Vector3)
get3dLine = getBrepObject parseBrepXML2 "line"
getRectangle :: String -> RIO (Vector3, Vector3, Vector3, Vector3)
getRectangle = getBrepObject parseBrepXML "rectangle"
parseBrepXML :: String -> (Vector3, Vector3, Vector3, Vector3)
parseBrepXML a = getData (fromJust (parseXMLDoc a))
parseBrepXML2 :: String -> (Vector3, Vector3)
parseBrepXML2 a = getData2 (fromJust (parseXMLDoc a))
quadFromList :: [a] -> (a, a, a, a)
quadFromList ([]) = error "quadFromList: List empty"
quadFromList (_ : []) = error "quadFromList: List too short"
quadFromList (_ : _ : []) = error "quadFromList: List too short"
quadFromList (_ : _ : _ : []) = error "quadFromList: List too short"
quadFromList (b : c : d : e) = (b, c, d, head e)
doubleFromList :: [a] -> (a, a)
doubleFromList [] = error "doubleFromList: List too short"
doubleFromList (_ : []) = error "quadFromList: List too short"
doubleFromList (b : c) = (b, head c)
getData :: Element -> (Vector3, Vector3, Vector3, Vector3)
getData e = if qName (elName e) == "rectangle" then
quadFromList (Prelude.map parseVertex (elChildren e))
else error "unsupported object type in the .brp file"
getData2 :: Element -> (Vector3, Vector3)
getData2 e = if qName (elName e) == "line" then
doubleFromList (Prelude.map parseVertex (elChildren e))
else error "unsuported ubject type in the .brp file"
parseVertex :: Element -> Vector3
parseVertex e = Vector3 (getD "x") (getD "y") (getD "z") where
getD el = maybe (error "erroneous input given by c++ module")
read (findAttr (unqual el) e)
type Env = FilePath
type RIO a = ReaderT Env IO a