2016 Update

Task/Colour-bars-Display/00DESCRIPTION

@@ -1 +1,14 @@
-The task is to display a series of vertical color bars across the width of the display. The color bars should either use the system palette, or the sequence of colors: Black, Red, Green, Blue, Magenta, Cyan, Yellow, White.
+;Task:
+Display a series of vertical color bars across the width of the display.
+
+The color bars should either use:
+:::*   the system palette,   or
+:::*   the sequence of colors:
+::::::*   black
+::::::*   red
+::::::*   green
+::::::*   magenta
+::::::*   cyan
+::::::*   yellow
+::::::*   white
+<br>

Task/Colour-bars-Display/Haskell/colour-bars-display-1.hs

@@ -0,0 +1,38 @@
+#!/usr/bin/env stack
+-- stack --resolver lts-7.0 --install-ghc runghc --package vty -- -threaded
+
+import Graphics.Vty
+
+colorBars :: Int -> [(Int, Attr)] -> Image
+colorBars h bars = horizCat $ map colorBar bars
+  where colorBar (w, attr) = charFill attr ' ' w h
+
+barWidths :: Int -> Int -> [Int]
+barWidths nBars totalWidth = map barWidth [0..nBars-1]
+  where fracWidth = fromIntegral totalWidth / fromIntegral nBars
+        barWidth n =
+          let n' = fromIntegral n :: Double
+          in floor ((n' + 1) * fracWidth) - floor (n' * fracWidth)
+
+barImage :: Int -> Int -> Image
+barImage w h = colorBars h $ zip (barWidths nBars w) attrs
+  where attrs = map color2attr colors
+        nBars = length colors
+        colors = [black, brightRed, brightGreen, brightMagenta, brightCyan, brightYellow, brightWhite]
+        color2attr c = Attr Default Default (SetTo c)
+
+main = do
+    cfg <- standardIOConfig
+    vty <- mkVty cfg
+    let output = outputIface vty
+    bounds <- displayBounds output
+    let showBars (w,h) = do
+          let img = barImage w h
+              pic = picForImage img
+          update vty pic
+          e <- nextEvent vty
+          case e of
+            EvResize w' h' -> showBars (w',h')
+            _ -> return ()
+    showBars bounds
+    shutdown vty

Task/Colour-bars-Display/Haskell/colour-bars-display-2.hs

@@ -0,0 +1,51 @@
+-- Before you can install the SFML Haskell library, you need to install
+-- the CSFML C library.  (For example, "brew install csfml" on OS X.)
+
+-- This program runs in fullscreen mode.
+-- Press any key or mouse button to exit.
+
+import Control.Exception
+import SFML.Graphics
+import SFML.SFResource
+import SFML.Window hiding (width, height)
+
+withResource :: SFResource a => IO a -> (a -> IO b) -> IO b
+withResource acquire = bracket acquire destroy
+
+withResources :: SFResource a => IO [a] -> ([a] -> IO b) -> IO b
+withResources acquire = bracket acquire (mapM_ destroy)
+
+colors :: [Color]
+colors = [black, red, green, magenta, cyan, yellow, white]
+
+makeBar :: (Float, Float) -> (Color, Int) -> IO RectangleShape
+makeBar (barWidth, height) (c, i) = do
+  bar <- err $ createRectangleShape
+  setPosition  bar $ Vec2f (fromIntegral i * barWidth) 0
+  setSize      bar $ Vec2f barWidth height
+  setFillColor bar c
+  return bar
+
+barSize :: VideoMode -> (Float, Float)
+barSize (VideoMode w h _ ) = ( fromIntegral w / fromIntegral (length colors)
+                             , fromIntegral h )
+
+loop :: RenderWindow -> [RectangleShape] -> IO ()
+loop wnd bars = do
+  mapM_ (\x -> drawRectangle wnd x Nothing) bars
+  display wnd
+  evt <- waitEvent wnd
+  case evt of
+    Nothing -> return ()
+    Just SFEvtClosed -> return ()
+    Just (SFEvtKeyPressed {}) -> return ()
+    Just (SFEvtMouseButtonPressed {}) -> return ()
+    _ -> loop wnd bars
+
+main :: IO ()
+main = do
+  vMode <- getDesktopMode
+  let wStyle = [SFFullscreen]
+  withResource (createRenderWindow vMode "color bars" wStyle Nothing) $
+     \wnd -> withResources (mapM (makeBar $ barSize vMode) $ zip colors [0..]) $
+     \bars -> loop wnd bars

Task/Colour-bars-Display/PowerShell/colour-bars-display.psh

@@ -0,0 +1,14 @@
+[string[]]$colors = "Black"   , "DarkBlue"   , "DarkGreen" , "DarkCyan",
+                    "DarkRed" , "DarkMagenta", "DarkYellow", "Gray",
+                    "DarkGray", "Blue"       , "Green"     , "Cyan",
+                    "Red"     , "Magenta"    , "Yellow"    , "White"
+
+for ($i = 0; $i -lt 64; $i++)
+{
+    for ($j = 0; $j -lt $colors.Count; $j++)
+    {
+        Write-Host (" " * 12) -BackgroundColor $colors[$j] -NoNewline
+    }
+
+    Write-Host
+}

Task/Colour-bars-Display/REXX/colour-bars-display.rexx

@@ -1,26 +1,26 @@
-/*REXX program displays eight colored vertical bars on the full screen. */
-parse  value  scrsize()  with sd sw .              /*screen depth,width.*/
-barWidth=sw%8                                      /*calculate bar width*/
-_.=copies('db'x,barWidth)                          /*the bar, full width*/
-_.8=left(_.,barWidth-1)                            /*last bar width.    */
-    $ = x2c('1b5b73') || x2c('1b5b313b33376d')     /* preamble, header. */
-hdr.1 = x2c('1b5b303b33306d')                      /* the color black.  */
-hdr.2 = x2c('1b5b313b33316d')                      /* the color red.    */
-hdr.3 = x2c('1b5b313b33326d')                      /* the color green.  */
-hdr.4 = x2c('1b5b313b33346d')                      /* the color blue.   */
-hdr.5 = x2c('1b5b313b33356d')                      /* the color magenta.*/
-hdr.6 = x2c('1b5b313b33366d')                      /* the color cyan.   */
-hdr.7 = x2c('1b5b313b33336d')                      /* the color yellow. */
-hdr.8 = x2c('1b5b313b33376d')                      /* the color white.  */
- tail = x2c('1b5b751b5b303b313b33363b34303b306d')  /* epilogue, trailer.*/
-                                       /* [↓]  last bar width is shrunk.*/
-       do j=1  for 8                   /*build the line, color by color.*/
-       $=$ || hdr.j || _.j             /*append the color header + bar. */
-       end   /*j*/                     /* [↑]  color order is the list. */
-                                       /* [↓]  the tail is overkill.    */
-$=$ || tail                            /*append the epilogue (trailer). */
-                                       /* [↓]  show full screen of bars.*/
-       do k=1  for sd                  /*SD = screen depth (from above).*/
-       say $                           /*have REXX display line of bars.*/
-       end   /*k*/                     /* [↑]  Note:  SD  could be zero.*/
-                                       /*stick a fork in it, we're done.*/
+/*REXX program  displays  eight colored vertical bars  on a full screen.                */
+parse  value  scrsize()  with sd sw .                 /*the screen depth and width.     */
+barWidth=sw%8                                         /*calculate the bar width.        */
+_.=copies('db'x, barWidth)                            /*the bar, full width.            */
+_.8=left(_.,barWidth-1)                               /*the last bar width,  less one.  */
+    $ = x2c('1b5b73')  ||  x2c("1b5b313b33376d")      /* the preamble,  and the header. */
+hdr.1 = x2c('1b5b303b33306d')                         /*  "  color black.               */
+hdr.2 = x2c('1b5b313b33316d')                         /*  "  color red.                 */
+hdr.3 = x2c('1b5b313b33326d')                         /*  "  color green.               */
+hdr.4 = x2c('1b5b313b33346d')                         /*  "  color blue.                */
+hdr.5 = x2c('1b5b313b33356d')                         /*  "  color magenta.             */
+hdr.6 = x2c('1b5b313b33366d')                         /*  "  color cyan.                */
+hdr.7 = x2c('1b5b313b33336d')                         /*  "  color yellow.              */
+hdr.8 = x2c('1b5b313b33376d')                         /*  "  color white.               */
+ tail = x2c('1b5b751b5b303b313b33363b34303b306d')     /*  "  epilogue,  and the trailer.*/
+                                                      /* [↓]  last bar width is shrunk. */
+       do j=1  for 8                                  /*build the line, color by color. */
+       $=$ || hdr.j || _.j                            /*append the color header + bar.  */
+       end   /*j*/                                    /* [↑]  color order is the list.  */
+                                                      /* [↓]  the tail is overkill.     */
+$=$ || tail                                           /*append the epilogue (trailer).  */
+                                                      /* [↓]  show full screen of bars. */
+       do k=1  for sd                                 /*SD = screen depth (from above). */
+       say $                                          /*have REXX display line of bars. */
+       end   /*k*/                                    /* [↑]  Note:  SD  could be zero. */
+                                                      /*stick a fork in it, we're done. */