"

 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.

"

"{ Package: 'stx:libview' }"

"{ NameSpace: Smalltalk }"

Image subclass:#Depth1Image

	instanceVariableNames:''

	classVariableNames:''

	poolDictionaries:''

	category:'Graphics-Images'

!

!Depth1Image 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 bilevel (1 bit / pixel) images.

    It mainly consists of methods which are already implemented in Image,

    but reimplemented here for more performance. If you plan to do heavy

    image processing on bilevel images, you may want to add more

    specialized methods here.

    #blackIs0 / #whiteIs0 and #palette formats are supported here.

    [author:]

	Claus Gittinger

    [see also:]

	Depth2Image Depth4Image Depth8Image Depth16Image Depth24Image

	ImageReader

"

! !

!Depth1Image class methodsFor:'queries'!

imageDepth

    "return the depth of images represented by instances of

     this class - here we return 1"

    ^ 1

    "Modified: 20.4.1996 / 23:40:06 / cg"

! !

!Depth1Image methodsFor:'accessing-pixels'!

pixelAtX:x y:y

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

     The interpretation of the returned value depends on the photometric

     and the colormap. See also Image>>atX:y:)

     Pixels start at 0@0 for upper left pixel, end at

     (width-1)@(height-1) for lower right pixel"

    |index       "{Class: SmallInteger}"

     byte        "{Class: SmallInteger}"

     mask        "{Class: SmallInteger}"|

%{  /* NOCONTEXT */

    OBJ b = __INST(bytes);

    OBJ w = __INST(width);

    if (__bothSmallInteger(x, y) 

     && __isSmallInteger(w)

     && __isByteArrayLike(b)

     && (__INST(pixelFunction)==nil) ) {

        int _w = __intVal(w);

        int _y = __intVal(y);

        int _x = __intVal(x);

        unsigned _byte;

        int _idx;

        _idx = ((_w + 7) >> 3) * _y + (_x >> 3);

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

            _byte = __ByteArrayInstPtr(b)->ba_element[_idx];

            RETURN( (_byte & (0x80 >> (_x & 7))) ? __MKSMALLINT(1) : __MKSMALLINT(0) );

        }

    }

%}.

    pixelFunction notNil ifTrue:[^ pixelFunction value:x value:y].

    "/ the code below is only evaluated if the bytes-collection is

    "/ not a ByteArray, or the arguments are not integers

    index := (self bytesPerRow * y) + 1 + (x // 8).

    "left pixel is in high bit"

    byte := bytes at:index.

    mask := 1 bitShift:(7 - (x \\ 8)).

    (byte bitAnd:mask) == 0 ifTrue:[^ 0].

    ^ 1

!

pixelAtX:x y:y put:aPixelValue

    "set a pixels value 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}"

     byte        "{Class: SmallInteger}"

     mask        "{Class: SmallInteger}"|

%{  /* NOCONTEXT */

    OBJ b = __INST(bytes);

    OBJ w = __INST(width);

    if (__isByteArray(b) && __bothSmallInteger(x, y) && __isSmallInteger(w) ) {

	int _w = __intVal(w);

	int _y = __intVal(y);

	int _x = __intVal(x);

	int _idx;

	_idx = ((_w + 7) >> 3) * _y + (_x >> 3);

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

	    if (aPixelValue == __MKSMALLINT(0)) {

		__ByteArrayInstPtr(b)->ba_element[_idx] &= ~(0x80 >> (_x & 7));

	    } else {

		__ByteArrayInstPtr(b)->ba_element[_idx] |= (0x80 >> (_x & 7));

	    }

	    RETURN( self );

	}

    }

%}.

    "fall back code for nonByteArray or nonInteger arguments"

    index := (self bytesPerRow * y) + 1 + (x // 8).

    "left pixel is in high bit"

    byte := bytes at:index.

    mask := #(16r80 16r40 16r20 16r10 16r08 16r04 16r02 16r01) at:((x \\ 8) + 1).

    aPixelValue == 0 ifTrue:[

	byte := byte bitAnd:(mask bitInvert)

    ] ifFalse:[

	byte := byte bitOr:mask

    ].

    bytes at:index put:byte

! !

!Depth1Image methodsFor:'converting'!

asFormOn:aDevice

    "convert a monochrome image to a device form"

    ^ self anyImageAsFormOn:aDevice

!

clearMaskedPixels

    colorMap isNil ifTrue:[

        "this works only for b/w images"

        super clearMaskedPixels.

    ].

!

greyImageAsFormOn:aDevice

    "convert a greyscale image to a device form"

    ^ self anyImageAsFormOn:aDevice

!

greyImageAsMonoFormOn:aDevice

    "convert to a monochrome form - thats easy"

    ^ self anyImageAsFormOn:aDevice

!

paletteImageAsMonoFormOn:aDevice

    "convert a palette image to a b&w monochrome device form"

    |f c0 c1|

    f := Form width:width height:height fromArray:self bits onDevice:aDevice.

    c0 := self colorFromValue:0.

    c1 := self colorFromValue:1.

    c0 brightness > 0.5 ifTrue:[

	c0 := Color white

    ] ifFalse:[

	c0 := Color black.

    ].

    c1 brightness > 0.5 ifTrue:[

	c1 := Color white

    ] ifFalse:[

	c1 := Color black.

    ].

    f colorMap:(Array with:c0 with:c1).

    ^ f

    "Modified: 24.4.1997 / 17:51:54 / cg"

!

paletteImageAsTrueColorFormOn:aDevice

    "since all devices must support monochrome images, and

     a 2-entry colormap is implemented by ST/X's drawForm methods,

     we can do this on all color devices as a palette image."

    ^ self anyImageAsFormOn:aDevice

    "

     |i|

     i := Depth1Image

		width:4

		height:4

		fromArray:#[ 2r00000000

			     2r11110000

			     2r01010000

			     2r10100000 ].

     i photometric:#rgb.

     i samplesPerPixel:3.

     i bitsPerSample:#(1 0 0).

     i := i magnifiedBy:30.

     i inspect.

    "

    "Modified: 14.6.1996 / 15:21:37 / cg"

! !

!Depth1Image methodsFor:'enumerating'!

colorsAtY:y from:xLow to:xHigh do:aBlock

    "perform aBlock for each pixel from x1 to x2 in row y.

     The block is passed the color at each pixel.

     This method allows slighly faster processing of an

     image than using atX:y:, since some processing can be

     avoided when going from pixel to pixel. However, for

     real image processing, specialized methods should be written."

    |srcIndex "{ Class: SmallInteger }"

     byte     "{ Class: SmallInteger }"

     mask     "{ Class: SmallInteger }"

     x1       "{ Class: SmallInteger }"

     x2       "{ Class: SmallInteger }"

     color0 color1

     bytes|

    bytes := self bits.

    x1 := xLow.

    x2 := xHigh.

    srcIndex := (self bytesPerRow * y) + 1.

    "left pixel is in high bit"

    color0 := self colorFromValue:0.

    color1 := self colorFromValue:1.

    srcIndex := srcIndex + (x1 // 8).

    mask := #[2r10000000

	      2r01000000

	      2r00100000

	      2r00010000

	      2r00001000

	      2r00000100

	      2r00000010

	      2r00000001] at:((x1 \\ 8) + 1).

    byte := bytes at:srcIndex.

    x1 to:x2 do:[:x |

	(byte bitAnd:mask) == 0 ifTrue:[

	    aBlock value:x value:color0

	] ifFalse:[

	    aBlock value:x value:color1

	].

	mask := mask bitShift:-1.

	mask == 0 ifTrue:[

	    mask := 2r10000000.

	    srcIndex := srcIndex + 1.

	    x < x2 ifTrue:[

		byte := bytes at:srcIndex.

	    ]

	]

    ]

    "Created: 7.6.1996 / 19:12:26 / cg"

    "Modified: 10.6.1996 / 10:33:06 / cg"

!

valuesAtY:y from:xLow to:xHigh do:aBlock

    "perform aBlock for each pixelValue from x1 to x2 in row y.

     The block is passed the color at each pixel.

     This method allows slighly faster processing of an

     image than using atX:y:, since some processing can be

     avoided when going from pixel to pixel. However, for

     real image processing, specialized methods should be written."

    |srcIndex "{ Class: SmallInteger }"

     byte     "{ Class: SmallInteger }"

     mask     "{ Class: SmallInteger }"

     x1       "{ Class: SmallInteger }"

     x2       "{ Class: SmallInteger }"

     bytes|

    bytes := self bits.

    "this method needs more tuning, if used heavily

     (fetch 8 bits at once, unroll the loop over these 8 pixels)"

    x1 := xLow.

    x2 := xHigh.

    srcIndex := (self bytesPerRow * y) + 1.

    "left pixel is in high bit"

    srcIndex := srcIndex + (x1 // 8).

    mask := #[2r10000000

	      2r01000000

	      2r00100000

	      2r00010000

	      2r00001000

	      2r00000100

	      2r00000010

	      2r00000001] at:((x1 \\ 8) + 1).

    byte := bytes at:srcIndex.

    x1 to:x2 do:[:x |

	(byte bitAnd:mask) == 0 ifTrue:[

	    aBlock value:x value:0

	] ifFalse:[

	    aBlock value:x value:1

	].

	mask := mask bitShift:-1.

	mask == 0 ifTrue:[

	    mask := 2r10000000.

	    srcIndex := srcIndex + 1.

	    x < x2 ifTrue:[

		byte := bytes at:srcIndex.

	    ]

	]

    ]

    "Created: 7.6.1996 / 19:09:38 / cg"

    "Modified: 8.6.1996 / 13:36:37 / cg"

! !

!Depth1Image methodsFor:'magnification'!

hardMagnifiedBy:scalePoint

    "return a new image magnified by scalePoint, aPoint.

     This is the general magnification method, handling non-integral values.

     It is slower than the integral magnification method."

    |mX

     mY

     newWidth  "{ Class: SmallInteger }"

     newHeight "{ Class: SmallInteger }"

     newImage newBits bitsPerPixel newBytesPerRow

     newMask

     bytes|

    bytes := self bits.

    bytes isNil ifTrue:[

	self error:'cannot magnify image without bits'.

	^ self

    ].

    mX := scalePoint x.

    mY := scalePoint y.

    newWidth := (width * mX) truncated.

    newHeight := (height * mY) truncated.

    bitsPerPixel := self depth.

    newBytesPerRow := ((newWidth * bitsPerPixel) + 7) // 8.

    newBits := ByteArray new:(newBytesPerRow * newHeight).

    mask notNil ifTrue:[

	newMask := (mask magnifiedBy:scalePoint)

    ].

    newImage := self species new.

    newImage

	width:newWidth

	height:newHeight

	photometric:photometric

	samplesPerPixel:samplesPerPixel

	bitsPerSample:bitsPerSample

	colorMap:colorMap copy

	bits:newBits

	mask:newMask.

    "walk over destination image fetching pixels from source image"

    mX := mX asFloat.

    mY := mY asFloat.

%{

{

    OBJ b1 = bytes;

    int _w1 = __intVal(__INST(width));

    int _y1, _y2;

    OBJ b2 = newBits;

    int _w2 = __intVal(newWidth);

    int _h2 = __intVal(newHeight);

    int _x2, _x1;

    int _idx2;

    unsigned _byte;

    double _mY = __floatVal(mY);

    double _mX = __floatVal(mX);

    for (_y2 = 0; _y2 < _h2; _y2++) {

	_y1 = (int)( (double)_y2 / _mY);

	for (_x2 = 0; _x2 < _w2; _x2++) {

	    _x1 = (int)( (double)_x2 / _mX);

	    _byte = __ByteArrayInstPtr(b1)->ba_element[(_w1 + 7) / 8 * _y1 + (_x1 / 8)];

	    if ((_byte & (0x80 >> (_x1 % 8)))) {

		_idx2 = (_w2 + 7) / 8 * _y2 + (_x2 / 8);

		__ByteArrayInstPtr(b2)->ba_element[_idx2] |= (0x80 >> (_x2 % 8));

	    }

	}

    }

}

%}.

"/    w := newWidth - 1.

"/    h := newHeight - 1.

"/

"/    0 to:h do:[:row |

"/        dstRow := row.

"/        srcRow := (row // mY).

"/        0 to:w do:[:col |

"/

"/            dstCol := col.

"/            srcCol := col // mX.

"/            value := self valueAtX:(col // mX) y:srcRow.

"/            newImage atX:col y:row putValue:value.

"/        ]

"/    ].

    ^ newImage

    "((Image fromFile:'bitmaps/claus.gif') magnifiedBy:0.5@0.5)"

    "Created: 18.6.1996 / 16:04:26 / cg"

!

magnifyRowFrom:srcBytes offset:srcStart

	  into:dstBytes offset:dstStart factor:mX

    "magnify a single pixel row - can only magnify by integer factors.

     This method has been specially tuned for magnification by 2 and 4."

%{

    unsigned char *srcP, *dstP;

    int _mag;

    REGISTER int i;

    REGISTER unsigned char _byte;

    int _pixels, bpr;

    REGISTER int outcnt, bits, bit, mask, incnt;

    int shift;

    unsigned char byte1, byte2, byte3, byte4;

    OBJ w = __INST(width);

    /* helper for monochrome magnification by 2 */

    static unsigned char mag1[16] = {0x00, 0x03, 0x0c, 0x0f, 0x30, 0x33, 0x3c, 0x3f,

				     0xc0, 0xc3, 0xcc, 0xcf, 0xf0, 0xf3, 0xfc, 0xff};