"

 COPYRIGHT (c) 1993 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.

"

Image subclass:#Depth8Image

	instanceVariableNames:''

	classVariableNames:''

	poolDictionaries:''

	category:'Graphics-Images'

!

!Depth8Image class methodsFor:'documentation'!

copyright

"

 COPYRIGHT (c) 1993 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

"

    this class represents 256-color (8 bit / pixel) images (palette, greyscale ...).

    It mainly consists of methods already implemented in Image,

    reimplemented here for more performance.

    [author:]

        Claus Gittinger

    [see also:]

        Depth1Image Depth2Image Depth4Image Depth16Image Depth24Image

        ImageReader

"

! !

!Depth8Image class methodsFor:'queries'!

imageDepth

    "return the depth of images represented by instances of

     this class - here we return 8"

    ^ 8

    "Modified: 20.4.1996 / 23:40:22 / cg"

! !

!Depth8Image methodsFor:'accessing - pixels'!

colorAtX:x y:y

    "retrieve a pixel at x/y; return a color.

     Pixels start at x=0 , y=0 for upper left pixel, end at

     x = width-1, y=height-1 for lower right pixel"

    |value "{ Class: SmallInteger }"

     index "{ Class: SmallInteger }"|

    index := (width * y) + 1 + x.

    value := bytes at:index.

    photometric == #whiteIs0 ifTrue:[

        ^ Color gray:100 - (100 / 255 * value)

    ].

    photometric == #blackIs0 ifTrue:[

        ^ Color gray:(100 / 255 * value)

    ].

    photometric ~~ #palette ifTrue:[

        ^ self colorFromValue:value

    ].

    index := value + 1.

    ^ colorMap at:index

    "Modified: 8.6.1996 / 10:52:48 / cg"

    "Created: 24.4.1997 / 17:33:58 / cg"

!

pixelAtX:x y:y

    "retrieve a pixel at x/y; return a pixelValue.

     Pixels start at x=0 , y=0 for upper left pixel, end at

     x = width-1, y=height-1 for lower right pixel"

    |index "{ Class: SmallInteger }"|

%{  /* NOCONTEXT */

    OBJ b = _INST(bytes);

    OBJ w = _INST(width);

    if (__isByteArray(b) 

     && __bothSmallInteger(x, y) 

     && __isSmallInteger(w) ) {

        int _idx, _pix;

        _idx = (__intVal(w) * __intVal(y)) + __intVal(x);

        if ((unsigned)_idx < __byteArraySize(b)) {

            _pix = _ByteArrayInstPtr(b)->ba_element[_idx];

            RETURN( __MKSMALLINT(_pix) );

        }

    }

%}.

    "/ should not be reached ...

    index := (width * y) + 1 + x.

    ^ bytes at:index.

!

pixelAtX:x y:y put:aPixelValue

    "set the pixel at x/y to aPixelValue.

     Pixels start at x=0 , y=0 for upper left pixel, end at

     x = width-1, y=height-1 for lower right pixel"

    |index "{ Class: SmallInteger }"|

%{  /* NOCONTEXT */

    OBJ b = _INST(bytes);

    OBJ w = _INST(width);

    if (__isByteArray(b) 

     && __bothSmallInteger(x, y) 

     && __bothSmallInteger(w, aPixelValue) ) {

        int _idx;

        _idx = (__intVal(w) * __intVal(y)) + __intVal(x);

        if ((unsigned)_idx < __byteArraySize(b)) {

            _ByteArrayInstPtr(b)->ba_element[_idx] = __intVal(aPixelValue);

            RETURN( self );

        }

    }

%}.

    "/ should not be reached ...

    index := (width * y) + 1 + x.

    bytes at:index put:aPixelValue.

!

rowAt:rowIndex into:aPixelBuffer startingAt:startIndex

    "fill aPixelBuffer with pixel values from a single row.

     Notice: row indexing starts at 0."

    |srcIdx|

    srcIdx := (rowIndex * width) + 1.

    aPixelBuffer replaceFrom:startIndex to:startIndex+width-1 with:bytes startingAt:srcIdx

    "Modified: 24.4.1997 / 15:47:22 / cg"

!

rowAt:rowIndex putAll:pixelArray

    "replace a single rows bits from bits in the argument;

     Notice: row indexing starts at 0."

    |dstIdx|

    dstIdx := (rowIndex*width) + 1.

    bytes replaceFrom:dstIdx to:dstIdx+width-1 with:pixelArray startingAt:1.

    ^ pixelArray

    "Modified: 24.4.1997 / 14:34:23 / cg"

!

rowAt:rowIndex putAll:pixelArray startingAt:startIndex

    "store a single rows bits from bits in the pixelArray argument;

     Return the pixelArray.

     Notice: row indexing starts at 0."

    |dstIdx|

    dstIdx := (rowIndex * width) + 1.

    bytes replaceFrom:dstIdx to:dstIdx+width-1 with:pixelArray startingAt:startIndex.

    ^ pixelArray

    "Created: 24.4.1997 / 15:49:42 / cg"

! !

!Depth8Image methodsFor:'converting'!

fromImage:anImage

    "setup the receiver from another image.

     The code here is tuned for depth 1, 2 and 4 source images;

     other conversions are done in the superclasses fallBack method."

    |srcBytesPerRow srcBuffer dstBuffer srcBytes srcIdx dstIdx 

     srcDepth map|

    srcDepth := anImage depth.

    (#(1 2 4) includes:srcDepth) ifFalse:[

        ^ super fromImage:anImage

    ].

    width := anImage width.

    height := anImage height.

    bytes := ByteArray uninitializedNew:(width * height).

    bitsPerSample := self bitsPerSample.

    samplesPerPixel := self samplesPerPixel.

    self colormapFromImage:anImage.

    colorMap isNil ifTrue:[

        "/ if source has no colorMap, more work is needed ...

        map := #(

                #[0 16rFF]

                #[0 16r55 16rAA 16rFF]

                nil

                #[16r00 16r11 16r22 16r33 16r44 16r55 16r66 16r77

                  16r88 16r99 16rAA 16rBB 16rCC 16rDD 16rEE 16rFF]

               ) at:srcDepth.

    ].

    self mask:anImage mask.

    "/ only expand & translate pixels

    srcBytes := anImage bits.

    srcBytesPerRow := anImage bytesPerRow.

    srcBuffer := ByteArray new:srcBytesPerRow.

    dstBuffer := ByteArray new:width.

    srcIdx := 1.

    dstIdx := 1.

    1 to:height do:[:hi |

        srcBuffer replaceFrom:1 to:srcBytesPerRow with:srcBytes startingAt:srcIdx.

        srcBuffer expandPixels:srcDepth width:width height:1 into:dstBuffer

                       mapping:map. 

        bytes replaceFrom:dstIdx to:dstIdx+width-1 with:dstBuffer startingAt:1.

        dstIdx := dstIdx + width.

        srcIdx := srcIdx + srcBytesPerRow.

    ]

    "

     |i1 i2 i4 i8 i16 i24|

     i1 := Image fromFile:'bitmaps/SBrowser.xbm'.

     i2 := Depth2Image fromImage:i1.

     i4 := Depth4Image fromImage:i1.

     i8 := Depth8Image fromImage:i1.

     i8 inspect.

     i8 := Depth8Image fromImage:i2.

     i8 inspect.

     i8 := Depth8Image fromImage:i4.

     i8 inspect.

    "

    "Modified: 24.4.1997 / 14:01:14 / cg"

! !

!Depth8Image methodsFor:'converting palette images'!

asGray8FormOn:aDevice

    "return an 8-bit greyForm from the 8-bit receiver image.

     Redefined, since only a translation has to be done here."

    |greyBits map

     mapSize "{ Class: SmallInteger }"|

    greyBits := ByteArray uninitializedNew:(width * height).

    map := ByteArray uninitializedNew:256.

    1 to:256 do:[:i |

        map at:i put:((self colorFromValue:(i-1)) brightness * 255) rounded

    ].

"/    mapSize := colorMap size.

"/

"/    1 to:mapSize do:[:i |

"/        map at:i put:((colorMap at:i) brightness * 255) rounded

"/    ].

    bytes expandPixels:8         "xlate only"

                width:width 

               height:height

                 into:greyBits

              mapping:map.

    ^ self makeDeviceGrayPixmapOn:aDevice depth:8 fromArray:greyBits

    "Modified: 10.6.1996 / 20:10:14 / cg"

    "Created: 14.6.1996 / 15:23:09 / cg"

!

asGrayFormOn:aDevice

    "get a gray device form.

     Redefined, since we can do it with simple translate, 

     if the depth matches my depth."

    (aDevice visualType == #StaticGray) ifTrue:[

        (aDevice depth == 8) ifTrue:[

            ^ self asGray8FormOn:aDevice

        ].

    ].

    ^ super asGrayFormOn:aDevice

    "Created: 10.6.1996 / 18:51:19 / cg"

    "Modified: 10.6.1996 / 18:54:36 / cg"

!

paletteImageAsPseudoFormOn:aDevice

    "return a pseudoForm from the palette picture. The main work is

     in color reduction, when not all colors can be aquired."

    |pseudoBits f gcRound has8BitImage deviceDepth

     imgMap newImage pixelRow dColors

     usedColors usageCounts maxIndex map

     fit scale lastOK error 

     div 

     bitsPerRGB "{Class: SmallInteger }"

     shift      "{Class: SmallInteger }"

     m          "{Class: SmallInteger }" 

     cube nR nG nB ditherColors|

    (cube := aDevice fixColors) notNil ifTrue:[

        nR := aDevice numFixRed.

        nG := aDevice numFixGreen.

        nB := aDevice numFixBlue.

        DitherAlgorithm == #floydSteinberg ifTrue:[

            f := self

                   asFloydSteinbergDitheredDepth8FormOn:aDevice 

                   colors:cube 

                   nRed:nR

                   nGreen:nG

                   nBlue:nB.

        ] ifFalse:[

            f := self

                   asNearestPaintDepth8FormOn:aDevice 

                   colors:cube 

                   nRed:nR

                   nGreen:nG

                   nBlue:nB.

        ].

        f notNil ifTrue:[^ f].

    ].

    "find used colors"

    usedColors := bytes usedValues.    "gets us an array filled with used values"

                                       "(could use bytes asBag)"

    maxIndex := usedColors max + 1.

    usedColors size > 20 ifTrue:[

        ('Depth8Image [info]: allocating ' , usedColors size printString , ' colors ...') infoPrintCR.

    ].

    "sort by usage"

    usageCounts := bytes usageCounts.

    usageCounts := usedColors asArray collect:[:clr | usageCounts at:(clr + 1)].

    usageCounts sort:[:a :b | a > b] with:usedColors.

    "allocate the colors (in order of usage count)"

    imgMap := Array new:maxIndex.

    "

     first, try to get the exact colors ...

    "

    bitsPerRGB := aDevice bitsPerRGB.

    shift := (8 - bitsPerRGB) negated.

    m := (1 bitShift:bitsPerRGB) - 1.

    div := m asFloat.

    fit := true.

    scale := 100.0 / div.       "to scale 0..255 into 0.0 .. 100.0"

    lastOK := 0.

    gcRound := 0.

    usedColors do:[:aColorIndex |

        |devColor color

         r        "{Class: SmallInteger }"

         g        "{Class: SmallInteger }"

         b        "{Class: SmallInteger }"

         mapIndex "{Class: SmallInteger }"|

        fit ifTrue:[

            mapIndex := aColorIndex + 1.

            color := colorMap at:mapIndex.

            (color colorId notNil 

            and:[color graphicsDevice == aDevice]) ifTrue:[

                "wow - an immediate hit"

                devColor := color

            ] ifFalse:[

                devColor := color exactOn:aDevice.

                devColor isNil ifTrue:[

                    "

                     could not allocate color - on the first round, do a GC to flush 

                     unused colors - this may help if some colors where locked by 

                     already free images.

                    "

                    gcRound == 0 ifTrue:[

                        ObjectMemory scavenge; finalize.

                        devColor := color exactOn:aDevice.

                        gcRound := 1

                    ].

                    devColor isNil ifTrue:[

                        gcRound == 1 ifTrue:[

                            CollectGarbageWhenRunningOutOfColors ifTrue:[

                                'Depth8Image [info]: force GC for possible color reclamation.' infoPrintCR.

                                ObjectMemory incrementalGC; finalize.

                                devColor := color exactOn:aDevice.

                            ].    

                            gcRound := 2

                        ]

                    ]

                ].

            ].

            (devColor notNil and:[devColor colorId notNil]) ifTrue:[

                imgMap at:mapIndex put:devColor.

                lastOK := lastOK + 1.

            ] ifFalse:[

                fit := false

            ]

        ]

    ].

    fit ifFalse:[

        ('Depth8Image [info]: got %1 exact colors (out of %2)' bindWith:lastOK with:usedColors size) infoPrintCR.

        DitherAlgorithm == #floydSteinberg ifTrue:[

            dColors := colorMap asArray collect:[:clr | clr isNil ifTrue:[clr]

                                                          ifFalse:[clr nearestOn:aDevice]].

            dColors := dColors select:[:clr | clr notNil].

            dColors := dColors collect:[:clr | clr exactOn:aDevice].

            dColors := dColors select:[:clr | clr notNil].

            dColors := dColors asSet.

            ditherColors := aDevice availableDitherColors.

            ditherColors notNil ifTrue:[

                dColors addAll:ditherColors.

            ].

            dColors := dColors asArray.

            ^ self asFloydSteinbergDitheredPseudoFormUsing:dColors on:aDevice

        ].

        "

         again, this time allow wrong colors (loop while increasing allowed error)

        "

        error := 1.

        [fit] whileFalse:[

            fit := true.

            usedColors from:(lastOK+1) to:(usedColors size) do:[:aColorIndex |

                |devColor color

                 r        "{Class: SmallInteger }"

                 g        "{Class: SmallInteger }"

                 b        "{Class: SmallInteger }"

                 mapIndex "{Class: SmallInteger }"

                 rMask    "{Class: SmallInteger }"

                 gMask    "{Class: SmallInteger }"

                 bMask    "{Class: SmallInteger }"|

                fit ifTrue:[

                    gMask := bMask := rMask := m.

                    mapIndex := aColorIndex + 1.

                    color := colorMap at:mapIndex.

                    r := (color red * 255 / 100.0) rounded.

                    g := (color green * 255 / 100.0) rounded.

                    b := (color blue * 255 / 100.0) rounded.

                    color := Color red:((r bitShift:shift) bitAnd:rMask) * scale

                                 green:((g bitShift:shift) bitAnd:gMask) * scale

                                  blue:((b bitShift:shift) bitAnd:bMask) * scale.

                    (color colorId notNil 

                    and:[color graphicsDevice == aDevice]) ifTrue:[

                        "wow - an immediate hit"

                        devColor := color.

                    ] ifFalse:[

                        devColor := color nearestOn:aDevice.

                        (devColor notNil and:[(devColor deltaFrom:color) > error]) ifTrue:[

                            devColor := nil

                        ].