Colour Flood Filling

in HSV ( or RGB).

After a delay for you to take in the starting image, part of the right-hand image is filled with a continuous cycle forward and backward through the whole spectral colour range. An indicator rotates showing which H value is currently selected.

You can also alter the S and V values.

If you instead choose RGB description for colour, you can fade white up to grey, or fade between saturated or unsaturated colours.

-

Code. Save in a LB directory and save there also from this page, above, the initial 'dancer5.bmp' image.

    nomainwin

    global pi,       col$, rd, gn, bu

    WindowWidth     = 600
    WindowHeight    = 610

    open "Fill Demo" for graphics_nsb as #w

    hw      =hwnd( #w)
    calldll #user32, "GetDC", hw as ulong, hdc as ulong

    #w   "trapclose quit"
    #w   "fill 200 200 200"

    x   =250 : y =300
    i   =0

    loadbmp "scr", "dancer5.bmp"
    #w "drawbmp scr 50 30 ; flush ; down ; size 6"

    call delay 3000

    xS =520: yS =126: direction =1:i =0

    do
        #w "color "; rd; " "; gn; " "; bu
        #w "set "; xS; " "; yS
        call hsv2rgb i, 0.49, 0.99
        'call hsv2rgb int( 360 *i /200), 0.99, 0.99         '   hue 0-359, saturation 0-0.99, value 0-0.99
                                                            '   alters col$, rd, gn, bu values
        #w "backcolor "; col$                               '   this is colour to fill WITH
        targetcolor   =254 +255 *2^8 +255 *2^16             '   bu *2^16    +gn *2^8 this is colour to fill out TO ie desired border

        calldll #gdi32, "ExtFloodFill", hdc as ulong,_
            x                  as  long,  y as  long,_
            targetcolor        as  long,_
            _FLOODFILLBORDER   as  long, result as  long    '   ie fill out 'til this colour is met..
            '   replace with _FLOODFILLSURFACE   as  long, result as  long
            '   ie fill out 'WHILE this colour is encountered.

        scan
        if i =359 then direction =0': #w "up; goto 460 126 ; backcolor "; int(256 *rnd( 1)); " "; int(256 *rnd( 1)); " "; int(256 *rnd( 1)); " down ; circlefilled 40"
        if i =  1 then direction =1': #w "up; goto 460 126 ; backcolor "; int(256 *rnd( 1)); " "; int(256 *rnd( 1)); " "; int(256 *rnd( 1)); " down ; circlefilled 40"
        if direction =0 then i =i -1 else i =i +1
        xS  =int( 460 +60 *sin( ( i +90) *3.14159265 /180))
        yS  =int( 126 +60 *cos( ( i +90) *3.14159265 /180))
        call delay 40
        #w "color white ; set "; xS; " "; yS
        '#w "backcolor "; col$
        call delay 40
    loop until 1 =2

    wait
    end

    sub quit h$
        calldll #user32, "ReleaseDC", hw as ulong, hdc as ulong, ret as void   'release the DCclose #h$
        close #w
        end
    end sub

     sub hsv2rgb h, s, v '                       hue 0-360, saturation 0-1, value 0-1
        c   =v *s       '                           chroma
        h   =h
        x   =c *( 1 -abs( ( ( h /60) mod 2) -1))
        m   =v -c   '                               matching adjustment

        select case
            case h < 60
                r = c: g = x: b = 0
            case h <120
                r = x: g = c: b = 0
            case h <180
                r = 0: g = c: b = x
            case h <240
                r = 0: g = x: b = c
            case h <300
                r = x: g = 0: b = c
            case else
                r = c: g = 0: b = x
        end select

        rd      = abs( int( 256 *( r + m)))
        gn      = abs( int( 256 *( g + m)))
        bu      = abs( int( 256 *( b + m)))
        col$    =right$( "  " +str$( rd), 3) +" " +right$( "   " +str$( gn), 3) +" " +right$( "   " +str$( bu), 3)
    end sub

    function cosRad( th)
        cosRad =cos( th *3.14159265 /180)
    end function

    sub delay sleeptime
        calldll #kernel32, "Sleep", sleeptime as long, ret as void
        scan
    end sub