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-- Implicit CAD. Copyright (C) 2011, Christopher Olah (chris@colah.ca)
-- Copyright (C) 2014 2015, Julia Longtin (julial@turinglace.com)
-- Released under the GNU GPL, see LICENSE
{-# LANGUAGE OverloadedStrings, ViewPatterns #-}
-- A Snap(HTTP) server providing an ImplicitCAD REST API.
-- Let's be explicit about what we're getting from where :)
import Control.Applicative ((<|>))
import Snap.Core (Snap, route, writeBS, method, Method(GET), modifyResponse, setContentType, getRequest, rqParam)
import Snap.Http.Server (quickHttpServe)
import Snap.Util.GZip (withCompression)
-- Our Extended OpenScad interpreter, and the extrudeR function for making 2D objects 3D.
import Graphics.Implicit (runOpenscad, extrudeR)
import Graphics.Implicit.ExtOpenScad.Definitions (OVal (ONum))
-- Functions for finding a box around an object, so we can define the area we need to raytrace inside of.
import Graphics.Implicit.ObjectUtil (getBox2, getBox3)
import Graphics.Implicit.Export.TriangleMeshFormats (jsTHREE, stl)
import Graphics.Implicit.Export.PolylineFormats (svg, hacklabLaserGCode)
import Graphics.Implicit.Definitions (xmlErrorOn, errorMessage, )
-- class DiscreteApprox
import Graphics.Implicit.Export.Definitions (discreteAprox)
import Data.Map.Strict as Map (lookup)
import Text.ParserCombinators.Parsec (errorPos, sourceLine)
import Text.ParserCombinators.Parsec.Error (errorMessages, showErrorMessages)
import System.IO.Unsafe (unsafePerformIO)
import System.IO.Silently (capture)
import qualified Data.ByteString.Char8 as BS.Char (pack, unpack)
import qualified Data.Text.Lazy as TL (unpack)
main :: IO ()
main = quickHttpServe site
site :: Snap ()
site = route
[
("render/", renderHandler)
] <|> writeBS "fall through"
renderHandler :: Snap ()
renderHandler = method GET $ withCompression $ do
modifyResponse $ setContentType "application/x-javascript"
request <- getRequest
case (rqParam "source" request, rqParam "callback" request, rqParam "format" request) of
(Just [source], Just [callback], Nothing) -> do
writeBS $ BS.Char.pack $ executeAndExport
(BS.Char.unpack source)
(BS.Char.unpack callback)
Nothing
(Just [source], Just [callback], Just [format]) -> do
writeBS $ BS.Char.pack $ executeAndExport
(BS.Char.unpack source)
(BS.Char.unpack callback)
(Just $ BS.Char.unpack format)
(_, _, _) -> writeBS "must provide source and callback as 1 GET variable each"
getRes (varlookup, obj2s, obj3s) =
let
qual = case Map.lookup "$quality" varlookup of
Just (ONum n) | n >= 1 -> n
_ -> 1
(defaultRes, qualRes) = case (obj2s, obj3s) of
(_, obj:_) -> ( min (minimum [x,y,z]/2) ((x*y*z )**(1/3) / 22)
, min (minimum [x,y,z]/2) ((x*y*z/qual)**(1/3) / 22))
where
((x1,y1,z1),(x2,y2,z2)) = getBox3 obj
(x,y,z) = (x2-x1, y2-y1, z2-z1)
(obj:_, _) -> ( min (min x y/2) ((x*y )**0.5 / 30)
, min (min x y/2) ((x*y/qual)**0.5 / 30) )
where
((x1,y1),(x2,y2)) = getBox2 obj
(x,y) = (x2-x1, y2-y1)
_ -> (1, 1)
in case Map.lookup "$res" varlookup of
Just (ONum requestedRes) ->
if defaultRes <= 30*requestedRes
then requestedRes
else -1
_ ->
if qual <= 30
then qualRes
else -1
getWidth (varlookup, _, obj:_) = maximum [x2-x1, y2-y1, z2-z1]
where ((x1,y1,z1),(x2,y2,z2)) = getBox3 obj
getWidth (varlookup, obj:_, _) = max (x2-x1) (y2-y1)
where ((x1,y1),(x2,y2)) = getBox2 obj
-- | Give an openscad object to run and the basename of
-- the target to write to... write an object!
executeAndExport :: String -> String -> Maybe String -> String
executeAndExport content callback maybeFormat =
let
showB True = "true"
showB False = "false"
callbackF :: Bool -> Bool -> -> String -> String
callbackF False is2D w msg =
callback ++ "([null," ++ show msg ++ "," ++ showB is2D ++ "," ++ show w ++ "]);"
callbackF True is2D w msg =
callback ++ "([new Shape()," ++ show msg ++ "," ++ showB is2D ++ "," ++ show w ++ "]);"
callbackS str msg = callback ++ "([" ++ show str ++ "," ++ show msg ++ ",null,null]);"
in case runOpenscad content of
Left err ->
let
line = sourceLine . errorPos $ err
showErrorMessages' = showErrorMessages
"or" "unknown parse error" "expecting" "unexpected" "end of input"
msgs :: String
msgs = showErrorMessages' $ errorMessages err
in callbackF False False 1 $ (\s-> "error (" ++ show line ++ "):" ++ s) msgs
Right openscadProgram -> unsafePerformIO $ do
(msgs,s) <- capture $ openscadProgram
let
res = getRes s
w = getWidth s
is2D = case s of
(_, _, x:xs) -> False
(_, x:xs, _) -> True
_ -> False
highResError = "Unreasonable resolution requested: "
++ "the server imps revolt! "
++ "(Install ImplicitCAD locally -- github.com/colah/ImplicitCAD/)"
objOrErr = case s of
(_, _, x:xs) ->
if res > 0
then Right (Nothing, x)
else Left highResError
(_, x:xs, _) ->
if res > 0
then Right (Just x, extrudeR 0 x res)
else Left highResError
_ -> Left $ msgs ++ "Nothing to render."
return $ case (objOrErr, maybeFormat) of
(Left errmsg, _) -> callbackF False False 1 errmsg
(Right (_,obj), Nothing) ->
TL.unpack (jsTHREE (discreteAprox res obj)) ++ callbackF True is2D w msgs
(Right (_,obj), Just "STL") ->
callbackS (TL.unpack (stl (discreteAprox res obj))) msgs
(Right (Just obj, _), Just "SVG") ->
callbackS (TL.unpack (svg (discreteAprox res obj))) msgs
(Right (Just obj, _), Just "gcode/hacklab-laser") ->
callbackS (TL.unpack (hacklabLaserGCode (discreteAprox res obj))) msgs