Colour bars/Display
You are encouraged to solve this task according to the task description, using any language you may know.
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.
Icon and Unicon
The procedure below is generalized to take a description of a test card and display it.
<lang Icon>link graphics,printf
procedure main() # generalized colour bars
DrawTestCard(Simple_TestCard()) WDone()
end
procedure DrawTestCard(TC)
size := sprintf("size=%d,%d",TC.width,TC.height)
&window := TC.window := open(TC.id,"g","bg=black",size) |
stop("Unable to open window")
every R := TC.bands[r := 1 to *TC.bands -1] do
every C := R.bars[c := 1 to *R.bars - 1] do {
Fg(R.bars[c].colour) FillRectangle( C.left, R.top, R.bars[c+1].left-C.left, TC.bands[r+1].top-R.top ) }
return TC
end
record testcard(window,id,width,height,bands) record band(top,bars) record bar(left,colour)
procedure Simple_TestCard() #: return structure simple testcard
return testcard(,"Simple Test Card",width := 800,height := 600,
[ band( 1, [ bar( 1, "black"), bar(114, "red"), bar(228, "green"), bar(342, "blue"),
bar(456, "magenta"),
bar(570, "cyan"),
bar(684, "yellow"),
bar(width) ] ),
band(height) ]) end</lang>
The following example is a wee tiny bit more interesting.
<lang Icon>procedure SMPTE_TestCard() #: return structure with 480i(ish) testcard
return testcard(,"SMPTE TV Test Card",width := 672,height := 504,
[ band( 1, [ bar( 1, "#c0c0c0"), bar( 95, "#c0c000"),
bar(191, "#00c0c0"),
bar(288, "#00c000"), bar(383, "#c000c0"), bar(480, "#c00000"), bar(575, "#0000c0"), bar(width) ] ), band(335, [ bar( 1, "#0000c0"), bar( 95, "#131313"), bar(191, "#c000c0"), bar(288, "#131313"), bar(383, "#00c0c0"), bar(480, "#131313"), bar(575, "#c0c0c0"), bar(width) ] ), band(378, [ bar( 1, "#00214c"), bar(120, "#ffffff"), bar(240, "#32006a"), bar(360, "#131313"), bar(480, "#090909"), bar(512, "#131313"), bar(544, "#1d1d1d"), bar(576, "#131313"), bar(width) ] ), band(height) ]) end</lang>
graphics.icn provides graphics printf.icn provides sprintf
J
<lang j> load 'viewmat'
size=. 2{.".wd'qm' NB. J6
size=. getscreenwh_jgtk_ NB. J7
'rgb'viewmat (|.size){. (>.&.(%&160)|.size)$ 20# 256#.255*#:i.8</lang>
Liberty BASIC
<lang lb>nomainwin colors$="black red green blue pink cyan yellow white" WindowWidth=DisplayWidth:WindowHeight=DisplayHeight UpperLeftX=1:UpperLeftY=1 barWidth=DisplayWidth/8 graphicbox #main.g, 0,0,DisplayWidth,DisplayHeight open "" for window_popup as #main
- main "trapclose [quit]"
- main.g "down; setfocus; when characterInput [quit]"
- main.g "when leftButtonUp [quit]"
- main.g "size ";barWidth
for x = barWidth/2 to DisplayWidth step barWidth
i=i+1 if i>8 then i=1 col$=word$(colors$,i) #main.g "color ";col$;"; line ";x;" 0 ";x;" ";DisplayHeight
next wait [quit] close #main:end
</lang>
Locomotive Basic
Show the default MODE 0 palette (includes two blinking colors at the end):
<lang locobasic>10 MODE 0:BORDER 23 20 FOR x=0 TO 15 30 ORIGIN x*40,0 40 GRAPHICS PEN x 50 FOR z=0 TO 39 STEP 4:MOVE z,0:DRAW z,400:NEXT 60 NEXT 70 CALL &bb06 ' wait for key press</lang>
OCaml
<lang ocaml>open Graphics
let round x =
int_of_float (floor (x +. 0.5))
let () =
open_graph ""; let cols = size_x () in let rows = size_y () in let colors = [| black; red; green; blue; magenta; cyan; yellow; white |] in let n = Array.length colors in let bar_width = (float cols) /. (float n) in Array.iteri (fun i color -> let x1 = bar_width *. (float i) in let x2 = bar_width *. (float (succ i)) in set_color color; fill_rect (round x1) 0 (round x2) rows; ) colors; ignore (read_key ());
- </lang>
execute with:
$ ocaml graphics.cma display_colour_bars.ml
Perl
<lang Perl>#!/usr/bin/perl -w use strict ; use GD ;
my %colors = ( white => [ 255 , 255 , 255 ] , red => [255 , 0 , 0 ] ,
green => [ 0 , 255 , 0 ] , blue => [ 0 , 0 , 255 ] ,
magenta => [ 255 , 0 , 255 ] , yellow => [ 255 , 255 , 0 ] ,
cyan => [ 0 , 255 , 255 ] , black => [ 0 , 0 , 0 ] ) ;
my $barwidth = 160 / 8 ; my $image = new GD::Image( 160 , 100 ) ; my $start = 0 ; foreach my $rgb ( values %colors ) {
my $paintcolor = $image->colorAllocate( @$rgb ) ; $image->filledRectangle( $start * $barwidth , 0 , $start * $barwidth +
$barwidth - 1 , 99 , $paintcolor ) ;
$start++ ;
} open ( DISPLAY , ">" , "testprogram.png" ) || die ; binmode DISPLAY ; print DISPLAY $image->png ; close DISPLAY ;#to be watched with <image viewer> testprogram.png </lang>
PicoLisp
<lang PicoLisp>(call 'clear)
(let Width (in '(tput cols) (read))
(do (in '(tput lines) (read))
(for B (range 0 7)
(call 'tput 'setab B)
(space (/ Width 8)) )
(prinl) ) )
(call 'tput 'sgr0) # reset</lang>
PureBasic
Press Enter or Escape to exit the program. <lang PureBasic>Dim color(7) color(0) = RGB($00, $00, $00) ;black color(1) = RGB($FF, $00, $00) ;red color(2) = RGB($00, $FF, $00) ;green color(3) = RGB($00, $00, $FF) ;blue color(4) = RGB($FF, $00, $FF) ;magenta color(5) = RGB($00, $FF, $FF) ;cyan color(6) = RGB($FF, $FF, $00) ;yellow color(7) = RGB($FF, $FF, $FF) ;white
If Not InitKeyboard(): End: EndIf ;can't init keyboard If Not InitSprite(): End: EndIf ;can't init sprite/screen library If Not ExamineDesktops(): End: EndIf ;can't retrieve information about desktop
height = DesktopHeight(0) width = DesktopWidth(0) depth = DesktopDepth(0) If OpenScreen(width, height, depth, "Press ENTER to exit")
StartDrawing(ScreenOutput())
For c = 0 To 7
Box((width * c) / 8, 0, width / 8, height, color(c))
Next
StopDrawing()
FlipBuffers()
Repeat Delay(10) ExamineKeyboard() Until KeyboardPushed(#PB_Key_Escape) Or KeyboardPushed(#PB_Key_Return) CloseScreen()
EndIf</lang>
Alternate method using console
<lang PureBasic>DataSection
;Black, Red, Green, Blue, Magenta, Cyan, Yellow, White Data.i 0, 12, 10, 9, 13, 11, 14, 15
EndDataSection
Dim colors(7) For c = 0 To 7
Read.i colors(c)
Next
If OpenConsole()
;The console display is 80 columns wide by 25 rows
For r = 0 To 24
For c = 0 To 7
ConsoleColor(colors(c), colors(c))
Print(Space(80 / 8))
Next
Next
EnableGraphicalConsole(1)
ConsoleLocate(0, 0)
ConsoleTitle("Press ENTER to exit"): Input()
CloseConsole()
EndIf</lang>
Scala
<lang scala>import java.awt.Color import scala.swing._
class ColorBars extends Component {
override def paintComponent(g:Graphics2D)={
val colors=List(Color.BLACK, Color.RED, Color.GREEN, Color.BLUE, Color.MAGENTA, Color.CYAN, Color.YELLOW, Color.WHITE)
val colCount=colors.size
val deltaX=size.width.toDouble/colCount
for(x <- 0 until colCount){
val startX=(deltaX*x).toInt
val endX=(deltaX*(x+1)).toInt
g.setColor(colors(x))
g.fillRect(startX, 0, endX-startX, size.height)
}
}
}</lang> Open window:
<lang scala>new MainFrame(){
title="Color bars" visible=true preferredSize=new Dimension(640, 320) contents=new ColorBars()
}</lang>
Tcl
<lang tcl>package require Tcl 8.5 package require Tk 8.5
wm attributes . -fullscreen 1 pack [canvas .c -highlightthick 0] -fill both -expand 1 set colors {black red green blue magenta cyan yellow white}
for {set x 0} {$x < [winfo screenwidth .c]} {incr x 8} {
.c create rectangle $x 0 [expr {$x+7}] [winfo screenheight .c] \
-fill [lindex $colors 0] -outline {}
set colors [list {*}[lrange $colors 1 end] [lindex $colors 0]]
}</lang>
UNIX Shell
<lang sh>#!/bin/sh clear WIDTH=`tput cols` HEIGHT=`tput lines` NUMBARS=8 BARWIDTH=`expr $WIDTH / $NUMBARS`
l="1" # Set the line counter to 1 while [ "$l" -lt $HEIGHT ]; do
b="0" # Bar counter
while [ "$b" -lt $NUMBARS ]; do
tput setab $b
s="0"
while [ "$s" -lt $BARWIDTH ]; do
echo -n " "
s=`expr $s + 1`
done
b=`expr $b + 1`
done
echo # newline
l=`expr $l + 1`
done
tput sgr0 # reset</lang>
ZX Spectrum Basic
<lang zxbasic>10 REM The ZX Spectrum display is 32 columns wide, so we have 8 columns of 4 spaces 20 FOR r=0 TO 20: REM There are 21 rows 30 FOR c=0 TO 7: REM We use the native colour sequence here 40 PAPER c: REM set the background colour for the spaces to be printed 50 PRINT " ";: REM four spaces, the semicolon prevents newline 60 NEXT c 70 REM at this point the cursor has wrapped, so we don't need a newline 80 NEXT r</lang>