line-drawing 0.1.0.0 → 0.2.0.0

raw patch · 5 files changed

+31/−22 lines, 5 filesPVP ok

version bump matches the API change (PVP)

API changes (from Hackage documentation)

Files

• README +1/−0
• changes.txt +6/−0
• line-drawing.cabal +3/−2
• src/Line/Draw.hs +12/−14
• test/Line/DrawSpec.hs +9/−6

@@ -0,0 +1,1 @@+Various https://en.wikipedia.org/wiki/Line_drawing_algorithm

@@ -1,3 +1,9 @@+0.2.0.0+-------++- Made `bresenham` polymorphic.+- Released Sun 10 Nov 2019 15:13:29 CET.+ 0.1.0.0 ------- 

@@ -1,6 +1,6 @@ cabal-version:       >=1.10 name:                line-drawing-version:             0.1.0.0+version:             0.2.0.0 synopsis:            raster line drawing description:         Line drawing algorithms to approximate a                      line segment on discrete graphical media (raster).@@ -14,7 +14,8 @@ copyright:           © 2019 Francesco Ariis category:            Graphics build-type:          Simple-extra-source-files:  changes.txt+extra-source-files:  changes.txt,+                     README  library   exposed-modules:     Line.Draw

@@ -1,4 +1,4 @@---------------------------------------------------------------------------------+------------------------------------------------------------------------------- -- | -- Module      :  Line.Draw -- Copyright   :  (C) 2019 Francesco Ariis@@ -18,24 +18,20 @@ -- [(0,0), (1,0), (2,1), (3,1), (4,2)] -- @ -----------------------------------------------------------------------------------+------------------------------------------------------------------------------- -module Line.Draw (-                   Coords,-                   bresenham-                 )+{-# Language ScopedTypeVariables #-}++module Line.Draw ( bresenham )         where  import qualified Data.List  as L import qualified Data.Tuple as T -type Coords = (Int, Int)-type State  = (Int, Int, Int)-          -- curr x, curr y, treshold  -- | Rasterising a line using -- <https://en.wikipedia.org/wiki/Bresenham%27s_line_algorithm Bresenham's algorithm>.-bresenham :: Coords -> Coords -> [Coords]+bresenham :: Integral a => (a, a) -> (a, a) -> [(a, a)] bresenham x@(x1, y1) y@(x2, y2)             | m1Check   = bresenhamBase x y             | otherwise = let x' = T.swap x@@ -50,28 +46,30 @@ -- ANCILLARIES -- ----------------- -bresenhamBase :: Coords -> Coords -> [Coords]+bresenhamBase :: forall a . Integral a => (a, a) -> (a, a) -> [(a, a)] bresenhamBase (x1, y1) (x2, y2) =         let -- first treshold             ti = 2 * ady - adx         in L.unfoldr f (x1, y1, ti)     where           -- slope-          dx, dy, adx, ady :: Int+          dx, dy, adx, ady :: a           dx = x2 - x1           dy = y2 - y1           adx = abs dx           ady = abs dy            -- sign of increment-          ix, iy :: Int -> Int+          ix, iy :: a -> a           ix | dx > 0    = (+1)              | otherwise = (subtract 1)           iy | dy > 0    = (+1)              | otherwise = (subtract 1)            -- step function, takes (x, y, treshold)-          f :: State -> Maybe (Coords, State)+                -- type State  = (Int, Int, Int)+                -- curr x, curr y, treshold+          f :: (a, a, a) -> Maybe ((a, a), (a, a, a))           f (cx, cy, t)               | abs cx > abs x2 = Nothing               | otherwise       =

@@ -13,21 +13,24 @@    describe "bresenham" $ do     it "rasterises a simple line" $-      bresenham (0, 0) (4, 4) `shouldBe`+      bresenham (0 :: Int, 0) (4, 4) `shouldBe`         [(0,0), (1,1), (2,2), (3,3), (4,4)]+    it "rasterises a simple line starting from (1, 1)" $+      bresenham (1 :: Int, 1) (4, 4) `shouldBe`+        [(1,1), (2,2), (3,3), (4,4)]     it "rasterises a line" $-      bresenham (0, 0) (4, 2) `shouldBe`+      bresenham (0 :: Int, 0) (4, 2) `shouldBe`         [(0,0), (1,0), (2,1), (3,1), (4,2)]     it "rasterises a line, quadrant 2, m<1" $-      bresenham (0, 0) (-4, 2) `shouldBe`+      bresenham (0 :: Int, 0) (-4, 2) `shouldBe`         [(0,0), (-1,0), (-2,1), (-3,1), (-4,2)]     it "rasterises a line, quadrant 3, m<1" $-      bresenham (0, 0) (-4, -2) `shouldBe`+      bresenham (0 :: Int, 0) (-4, -2) `shouldBe`         [(0,0), (-1,0), (-2,-1), (-3,-1), (-4,-2)]     it "rasterises a line, quadrant 1, m>1" $-      bresenham (0, 0) (2, 4) `shouldBe`+      bresenham (0 :: Int, 0) (2, 4) `shouldBe`         [(0,0), (0,1), (1,2), (1,3), (2,4)]     it "rasterises a line, quadrant 4, m>1" $-      bresenham (0, 0) (2, -4) `shouldBe`+      bresenham (0 :: Int, 0) (2, -4) `shouldBe`         [(0,0), (0,-1), (1,-2), (1,-3), (2,-4)]