initial

Author: K0Te

README.md

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+Raytrace in Haskell. Just for fun.

Setup.hs

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+import Distribution.Simple
+main = defaultMain

raytrace.cabal

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+name:                raytrace
+version:             0.1.0.0
+-- synopsis:
+-- description:
+homepage:            https://github.com/githubuser/raytrace#readme
+license:             BSD3
+license-file:        LICENSE
+author:              Author name here
+maintainer:          [email protected]
+copyright:           2017 Author name here
+category:            Web
+build-type:          Simple
+cabal-version:       >=1.10
+extra-source-files:  README.md
+
+executable raytrace
+  hs-source-dirs:      src
+  main-is:             Main.hs
+  ghc-options:         -threaded -rtsopts -with-rtsopts=-N -O2
+  default-language:    Haskell2010
+  build-depends:       base >= 4.7 && < 5
+                       , JuicyPixels >= 3.2 && < 4

src/Main.hs

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+module Main where
+
+import Data.Tuple (swap)
+import GHC.Word (Word8)
+import Codec.Picture
+import Codec.Picture.Types
+
+-- Where is camera pointed ?
+maxX = 480
+maxY = 240
+
+main :: IO ()
+main = do
+  let objects = [ --Line (Point 0 0 0) (Vector 1 2 1)
+                --, Line (Point 0 100 0) (Vector 1 (-1) 1)
+                Plane]
+  let myPlot = dumbRender maxX maxY objects
+  let rim = generateImage (\x y -> let (r, g, b) = myPlot !! (x+(maxY-y-1)*maxX) in PixelRGB8 r g b) maxX maxY
+  -- \let rim = generateFoldImage  (\acc -> \x -> \y -> (acc+1, PixelRGB8 (acc `mod` 255) ( 255) (255))) 0 640 480
+  writePng "test.png" rim
+  putStrLn "hello world"
+
+enumCoord :: [a] -> [((Int, Int), a)]
+enumCoord [] = []
+enumCoord xs = let coords = map toCoord (fst <$> zip [0..] xs)
+               in zip coords xs
+               where toCoord num = swap $ num `divMod` maxX
+
+type MyPixel = (Word8, Word8, Word8)
+class Object a where
+  draw :: a -> [MyPixel] -> [MyPixel]
+
+
+data Point = Point Int Int Int deriving Show
+data Vector = Vector Int Int Int deriving Show
+data Line = Line Point Vector deriving Show
+
+instance Object Line where
+  draw line plot =
+    snd . markWhite <$> enumCoord plot
+    where
+      markWhite :: ((Int, Int), MyPixel) -> ((Int, Int), MyPixel)
+      markWhite (screenPoint, pixel) = (screenPoint, newPixel)
+        where newPixel = if visibleLine screenPoint line then whitePixel else pixel
+              whitePixel = (200, 200, 200)
+              visibleLine :: (Int, Int) -> Line -> Bool
+              visibleLine (sx, sy) (Line (Point x y z) (Vector vx vy vz)) = isTooFar lineY lineZ sy
+                where deltaK = fromIntegral (sx - x) / fromIntegral vx
+                      lineY = deltaK * fromIntegral vy + fromIntegral y
+                      lineZ = deltaK * fromIntegral vz + fromIntegral z
+                      isTooFar ly lz sy = ((abs . sqrt) $ (fromIntegral sy - ly) ** 2 + lz ** 2) < 30
+
+data Plane = Plane
+cameraPos = Point (maxX `div` 2) (maxY * 3 `div` 4) maxX
+screenPointToPlanePoint :: (Int, Int) -> Maybe Point
+screenPointToPlanePoint (sx, sy) =
+  let (Point cx cy cz) = cameraPos
+      -- plane at y=0 allows to simplify equasion
+      steps = (fromIntegral cy) / (fromIntegral $ cy - sy)
+      z = (floor $ steps * (fromIntegral cz)) - cz
+      x = (floor $ steps * (fromIntegral $ cx - sx)) - cx
+  in
+  if sy >= cy
+  then Nothing -- parallel to plane or diverging
+  else Just $ Point x 0 z
+
+
+instance Object Plane where
+  draw plane plot =
+    snd . markPlane <$> enumCoord plot
+    where
+      markPlane :: ((Int, Int), MyPixel) -> ((Int, Int), MyPixel)
+      markPlane (screenPoint, pixel) = (screenPoint, newPixel)
+        where newPixel = lineToPixel screenPoint Plane
+              whitePixel = (200, 200, 200)
+              blackPixel = (100, 100, 100)
+              isBlack (Point x _ z) = mx < squareSize && mz < squareSize || mx >= squareSize && mz >= squareSize
+                where mx = x `mod` (squareSize * 2)
+                      mz = z `mod` (squareSize * 2)
+                      squareSize = 100
+              lineToPixel :: (Int, Int) -> Plane -> MyPixel
+              lineToPixel screenPoint _ = case screenPointToPlanePoint screenPoint of Nothing -> pixel
+                                                                                      (Just plx) -> if isBlack plx then blackPixel else whitePixel
+
+type Render a = Int -> Int -> [a] -> [MyPixel]
+
+dumbRender :: Object a => Render a
+dumbRender x y = foldr draw emptyPlot
+  where emptyPlot = replicate (x*y) (0, 0, 0)

stack.yaml

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+# This file was automatically generated by 'stack init'
+#
+# Some commonly used options have been documented as comments in this file.
+# For advanced use and comprehensive documentation of the format, please see:
+# http://docs.haskellstack.org/en/stable/yaml_configuration/
+
+# Resolver to choose a 'specific' stackage snapshot or a compiler version.
+# A snapshot resolver dictates the compiler version and the set of packages
+# to be used for project dependencies. For example:
+#
+# resolver: lts-3.5
+# resolver: nightly-2015-09-21
+# resolver: ghc-7.10.2
+# resolver: ghcjs-0.1.0_ghc-7.10.2
+# resolver:
+#  name: custom-snapshot
+#  location: "./custom-snapshot.yaml"
+resolver: lts-9.2
+
+# User packages to be built.
+# Various formats can be used as shown in the example below.
+#
+# packages:
+# - some-directory
+# - https://example.com/foo/bar/baz-0.0.2.tar.gz
+# - location:
+#    git: https://github.com/commercialhaskell/stack.git
+#    commit: e7b331f14bcffb8367cd58fbfc8b40ec7642100a
+# - location: https://github.com/commercialhaskell/stack/commit/e7b331f14bcffb8367cd58fbfc8b40ec7642100a
+#   extra-dep: true
+#  subdirs:
+#  - auto-update
+#  - wai
+#
+# A package marked 'extra-dep: true' will only be built if demanded by a
+# non-dependency (i.e. a user package), and its test suites and benchmarks
+# will not be run. This is useful for tweaking upstream packages.
+packages:
+- '.'
+# Dependency packages to be pulled from upstream that are not in the resolver
+# (e.g., acme-missiles-0.3)
+extra-deps: []
+
+# Override default flag values for local packages and extra-deps
+flags: {}
+
+# Extra package databases containing global packages
+extra-package-dbs: []
+
+# Control whether we use the GHC we find on the path
+# system-ghc: true
+#
+# Require a specific version of stack, using version ranges
+# require-stack-version: -any # Default
+# require-stack-version: ">=1.4"
+#
+# Override the architecture used by stack, especially useful on Windows
+# arch: i386
+# arch: x86_64
+#
+# Extra directories used by stack for building
+# extra-include-dirs: [/path/to/dir]
+# extra-lib-dirs: [/path/to/dir]
+#
+# Allow a newer minor version of GHC than the snapshot specifies
+# compiler-check: newer-minor