"

 COPYRIGHT (c) 1994 by Claus Gittinger

	      All Rights Reserved

 This software is furnished under a license and may be used

 only in accordance with the terms of that license and with the

 inclusion of the above copyright notice.   This software may not

 be provided or otherwise made available to, or used by, any

 other person.  No title to or ownership of the software is

 hereby transferred.

"

SequenceableCollection subclass:#Colormap

!

!Colormap class methodsFor:'documentation'!

copyright

"

 COPYRIGHT (c) 1994 by Claus Gittinger

	      All Rights Reserved

 This software is furnished under a license and may be used

 only in accordance with the terms of that license and with the

 inclusion of the above copyright notice.   This software may not

 be provided or otherwise made available to, or used by, any

 other person.  No title to or ownership of the software is

 hereby transferred.

"

!

documentation

"

    Colormaps are used with images (and Forms) to keep the byte-to-color

    mapping.

    Internally, the values are stored as 3 separate byte-arrays

    (i.e. individual components can be 0..255).

"

! !

!Colormap class methodsFor:'instance creation'!

fromColors:aColorArray

    |n rV gV bV|

    n := aColorArray size.

    rV := ByteArray new:n.

    gV := ByteArray new:n.

    bV := ByteArray new:n.

    1 to:n do:[:i |

	|clr|

	clr := aColorArray at:i.

	rV at:i put:(clr red * 255 / 100) rounded.

	bV at:i put:(clr green * 255 / 100) rounded.

	gV at:i put:(clr blue * 255 / 100) rounded.

    ].

    ^ self new redVector:rV greenVector:gV blueVector:bV

    "

     Colormap 

	fromColors:(Array with:Color black

			  with:Color red

			  with:Color white)

    "

!

redVector:r greenVector:g blueVector:b

    ^ self new redVector:r greenVector:g blueVector:b

    "

     Colormap 

	redVector:#[0 127 255]

	greenVector:#[0 127 255]

	blueVector:#[0 127 255]

    "

! !

!Colormap methodsFor:'accessing'!

at:index 

    "return the color at index - notice, that index is a typically derived

     from an images pixel value which ranges 0..255; while the index here

     starts at 1 (to make colormap look more like a collection)."

    |r g b|

    r := redVector at:index.

    g := greenVector at:index.

    b := blueVector at:index.

    ^ Color

	red:(r * 100 / 255)

	green:(g * 100 / 255)

	blue:(b * 100 / 255)

!

at:index put:aColor

    |r g b|

    r := (aColor red * 255 / 100) rounded.

    g := (aColor green * 255 / 100) rounded.

    b := (aColor blue * 255 / 100) rounded.

    redVector at:index put:r.

    greenVector at:index put:g.

    blueVector at:index put:b.

!

blueAt:index

    "return the blue component at some index.

     The returned value is scaled from the internal 0.. 255 to

     a percentage value 0..100"

    ^ (blueVector at:index) * 100 / 255

!

blueVector

    "return blueVector"

    ^ blueVector

!

blueVector:something

    "set blueVector"

    blueVector := something.

!

colors

    "ST-80 compatibility: return a collection containing the colors I hold"

    ^ self asArray

!

greenAt:index

    "return the green component at some index.

     The returned value is scaled from the internal 0.. 255 to

     a percentage value 0..100"

    ^ (greenVector at:index) * 100 / 255

!

greenVector

    "return greenVector"

    ^ greenVector

!

greenVector:something

    "set greenVector"

    greenVector := something.

!

redAt:index

    "return the red component at some index.

     The returned value is scaled from the internal 0.. 255 to

     a percentage value 0..100"

    ^ (redVector at:index) * 100 / 255

!

redVector

    "return redVector"

    ^ redVector

!

redVector:something

    "set redVector"

    redVector := something.

!

redVector:r greenVector:g blueVector:b

    redVector := r.

    greenVector := g.

    blueVector := b.

!

size

    ^ redVector size

! !

!Colormap methodsFor:'misc'!

scaleValuesBy:scaleFactor

   "multiply all values by scaleFactor; finally round to integer.

    This can be used to brighten/darken an images colormap"

   1 to:redVector size do:[:index |

	redVector at:index put:((redVector at:index) * scaleFactor) rounded.

	greenVector at:index put:((greenVector at:index) * scaleFactor) rounded.

	blueVector at:index put:((blueVector at:index) * scaleFactor) rounded.

   ]

! !

!Colormap class methodsFor:'documentation'!

version

! !