"

 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:#Depth24Image

	 instanceVariableNames:''

	 classVariableNames:''

	 poolDictionaries:''

	 category:'Graphics-Images'

!

!Depth24Image 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 true-color (24 bit / pixel) images.

    It mainly consists of methods already implemented in Image,

    reimplemented here for more performance.

"

! !

!Depth24Image class methodsFor:'queries'!

imageDepth

    ^ 24

! !

!Depth24Image methodsFor:'accessing'!

atX: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"

    |index "{ Class: SmallInteger }"

     rVal gVal bVal|

    index := 1 + (((width * y) + x) * 3).

    rVal := bytes at:(index).

    gVal := bytes at:(index + 1).

    bVal := bytes at:(index + 2).

    photometric ~~ #rgb ifTrue:[

	self error:'format not supported'.

	^ nil

    ].

    ^ Color red:rVal * 100 / 255

	  green:gVal * 100 / 255

	   blue:bVal * 100 / 255

!

atX:x y:y put:aColor

    "set the pixel at x/y to aColor.

     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 }"

     val   "{ Class: SmallInteger }" |

    index := 1 + (((width * y) + x) * 3).

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

    bytes at:(index) put:val.

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

    bytes at:(index + 1) put:val.

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

    bytes at:(index + 2) put:val.

!

atX:x y:y putValue:aPixelValue

    "set a pixel at x/y to aPixelValue, which is 24 bits RGB.

     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 }"

     val   "{ Class: SmallInteger }" |

    index := 1 + (((width * y) + x) * 3).

    val := aPixelValue.

    bytes at:(index + 2) put:(val bitAnd:16rFF).

    val := val bitShift:-8.

    bytes at:(index + 1) put:(val bitAnd:16rFF).

    val := val bitShift:-8.

    bytes at:(index) put:val.

!

valueAtX: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"

    |index "{ Class: SmallInteger }"

     rVal  "{ Class: SmallInteger }"

     gVal  "{ Class: SmallInteger }"

     bVal  "{ Class: SmallInteger }"|

    index := 1 + (((width * y) + x) * 3).

    rVal := bytes at:(index).

    gVal := bytes at:(index + 1).

    bVal := bytes at:(index + 2).

    ^ (((rVal bitShift:8) bitOr:gVal) bitShift:8) bitOr:bVal

! !

!Depth24Image methodsFor:'converting rgb images'!

rgbImageAs2PlaneFormOn:aDevice

    "return a 2-bit device form for aDevice from the rgb picture,

     using a threshold algorithm. 

     (i.e. grey value < 0.25 -> black // 0.25..0.5 -> darkgrey //

      0.5 .. 0.75 -> lightgrey // > 0.75 -> white)."

    |twoPlaneBits f

     map rMap gMap bMap 

     failed

     r        "{ Class: SmallInteger }"

     g        "{ Class: SmallInteger }"

     b        "{ Class: SmallInteger }"

     v        "{ Class: SmallInteger }"

     w        "{ Class: SmallInteger }"

     h        "{ Class: SmallInteger }"

     srcIndex "{ Class: SmallInteger }"

     dstIndex "{ Class: SmallInteger }"

     bits     "{ Class: SmallInteger }"

     bitCount "{ Class: SmallInteger }" |

    w := width.

    h := height.

    twoPlaneBits := ByteArray uninitializedNew:(((w * 2 + 7) // 8) * h).

    failed := true.

%{

    register unsigned char *srcPtr, *dstPtr;

    register _v, _bits, _bitCount;

    register j;

    register i;

    if ((__Class(_INST(bytes)) == ByteArray)

     && (__Class(twoPlaneBits) == ByteArray)) {

	failed = false;

	srcPtr = _ByteArrayInstPtr(_INST(bytes))->ba_element;

	dstPtr = _ByteArrayInstPtr(twoPlaneBits)->ba_element;

	for (i=_intVal(h); i>0; i--) {

	    _bitCount = 0;

	    _bits = 0;

	    for (j=_intVal(w); j>0; j--) {

		_v = (*srcPtr++ * 3);   /* 0.3*r + 0.6*g + b */

		_v += (*srcPtr++ * 6);

		_v += *srcPtr++;

		_v /= 10;

		_bits <<= 2; 

		_bits |= (_v >> 6); /* take top 2 bits */

		_bitCount++;

		if (_bitCount == 4) {

		    *dstPtr++ = _bits;

		    _bits = 0;

		    _bitCount = 0;

		}

	    }

	    if (_bitCount != 0) {

		while (_bitCount++ != 4) _bits <<= 2;

		*dstPtr++ = _bits;

	    }

	}

    }

%}.

    failed ifTrue:[

"/ the above is equivalent to:

"/

"/        srcIndex := 1.

"/        dstIndex := 1.

"/        1 to:h do:[:row |

"/            bitCount := 0.

"/            bits := 0.

"/            1 to:w do:[:col |

"/                r := bytes at:srcIndex.

"/                srcIndex := srcIndex + 1.

"/                g := bytes at:srcIndex.

"/                srcIndex := srcIndex + 1.

"/                b := bytes at:srcIndex.

"/                srcIndex := srcIndex + 1.

"/                v := ((3 * r) + (6 * g) + (1 * b)) // 10.

"/                v := v bitShift:-6. "take 2 hi bits"

"/                bits := (bits bitShift:2) bitOr:v.

"/                bitCount := bitCount + 1.

"/                (bitCount == 4) ifTrue:[

"/                    twoPlaneBits at:dstIndex put:bits.

"/                    dstIndex := dstIndex + 1.

"/                    bits := 0.

"/                    bitCount := 0

"/                ]

"/            ].

"/            (bitCount ~~ 0) ifTrue:[

"/                [bitCount == 4] whileFalse:[

"/                    bitCount := bitCount + 1.

"/                    bits := bits bitShift:2.

"/                ].

"/                twoPlaneBits at:dstIndex put:bits.

"/                dstIndex := dstIndex + 1

"/            ]

"/        ]

	self primitiveFailed.

	^ nil

    ].

    f := Form width:width height:height depth:2 on:aDevice.

    f isNil ifTrue:[^ nil].

    f initGC.

    (aDevice blackpixel == 0) ifFalse:[

	"have to invert bits"

	f function:#copyInverted

    ].

    aDevice drawBits:twoPlaneBits depth:2 width:width height:height

		   x:0 y:0

		into:(f id) x:0 y:0 width:width height:height with:(f gcId).

    ^ f

!

rgbImageAs8BitGreyFormOn:aDevice

    "return an 8-bit greyForm from the rgb picture"

    |greyBits f v

     srcIndex "{ Class: SmallInteger }"

     dstIndex "{ Class: SmallInteger }"

     failed|

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

    failed := false.

%{

    register unsigned char *srcPtr, *dstPtr;

    register _v;

    register j;

    register i;

    if ((__Class(_INST(bytes)) == ByteArray)

     && (__Class(greyBits) == ByteArray)) {

	failed = false;

	srcPtr = _ByteArrayInstPtr(_INST(bytes))->ba_element;

	dstPtr = _ByteArrayInstPtr(greyBits)->ba_element;

	for (i=_intVal(_INST(height)); i>0; i--) {

	    for (j=_intVal(_INST(width)); j>0; j--) {

		_v = (*srcPtr * 3);     /* 0.3*r + 0.6*g + b */

		_v += (*srcPtr++ * 6);

		_v += *srcPtr++;

		_v /= 10;

		*dstPtr++ = _v >> 4 ;

	    }

	}

    }

%}

.

    failed ifTrue:[

"/ the above is equivalent to:

"/

"/        srcIndex := 1.

"/        dstIndex := 1.

"/

"/        1 to:height do:[:h |

"/            1 to:width do:[:w |

"/                |v

"/                 r        "{ Class: SmallInteger }"

"/                 g        "{ Class: SmallInteger }"

"/                 b        "{ Class: SmallInteger }"|

"/

"/                r := bytes at:srcIndex.

"/                srcIndex := srcIndex + 1.

"/                g := bytes at:srcIndex.

"/                srcIndex := srcIndex + 1.

"/                b := bytes at:srcIndex.

"/                srcIndex := srcIndex + 1.

"/

"/                v := ((3 * r) + (6 * g) + (1 * b)) // 10.

"/                v := v bitShift:-4.

"/                greyBits at:dstIndex put:v.

"/                dstIndex := dstIndex + 1

"/            ]

"/        ]

	self primitiveFailed.

	^ nil

    ].

    f := Form width:width height:height depth:8 on:aDevice.

    f isNil ifTrue:[^ nil].

    f initGC.

    aDevice drawBits:greyBits depth:8 width:width height:height

		       x:0 y:0

		    into:(f id) x:0 y:0 

		   width:width height:height with:(f gcId).

    ^ f

!

rgbImageAsDitheredPseudoFormOn:aDevice

    "return a dithered pseudocolor form from the rgb-picture.

     This method depends on fixColors being allocated (see Color>>getColors*)"

    ^ self rgbImageAsDitheredPseudoFormOn:aDevice

				   colors:Color fixColors

				     nRed:Color numFixRed

				     nGreen:Color numFixGreen

				     nBlue:Color numFixBlue

!

rgbImageAsDitheredPseudoFormOn:aDevice colors:fixColors nRed:nRed nGreen:nGreen nBlue:nBlue

    "return a dithered pseudocolor form from the rgb-picture"

    |pseudoBits f

     h        "{ Class: SmallInteger }"

     w        "{ Class: SmallInteger }"

"/     eR    "{Class: SmallInteger }"

"/     eG    "{Class: SmallInteger }"

"/     eB    "{Class: SmallInteger }"

"/     wantR "{Class: SmallInteger }"

"/     wantG "{Class: SmallInteger }"

"/     wantB "{Class: SmallInteger }"

     fixR  "{Class: SmallInteger }"

     fixG  "{Class: SmallInteger }"

     fixB  "{Class: SmallInteger }"

     srcIndex "{ Class: SmallInteger }"

     dstIndex "{ Class: SmallInteger }"

     deviceDepth has8BitImage 

     fixIds failed|

    aDevice ~~ Display ifTrue:[^ nil].

    fixR := nRed.

    fixR == 0 ifTrue:[ ^ nil].

    fixG := nGreen.

    fixG == 0 ifTrue:[ ^ nil].

    fixB := nBlue.

    fixB == 0 ifTrue:[ ^ nil].

    "/ simple check

    (fixR * fixG * fixB) ~~ fixColors size ifTrue:[

	self error:'invalid color array passed'.

	^ nil

    ].

    fixIds := (fixColors asArray collect:[:clr | clr colorId]) asByteArray.

    deviceDepth := aDevice depth.

    deviceDepth == 8 ifTrue:[

	has8BitImage := true.

    ] ifFalse:[

	has8BitImage := false.

	aDevice supportedImageFormats do:[:fmt |

	    (fmt at:#bitsPerPixel) == 8 ifTrue:[

		has8BitImage := true.

	    ]

	]

    ].

    has8BitImage ifFalse:[^ nil].

    'D24IMAGE: dithering ...' infoPrintNL.

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

    h := height.

    w := width.

%{

    int __x, __y;

    int __eR, __eG, __eB;

    int __wantR, __wantG, __wantB;

    unsigned char *srcP, *dstP;

    unsigned char *redP, *greenP, *blueP;

    int pix;

    unsigned char *idP;

    int __fR, __fG, __fB;

    int iR, iG, iB;

    int idx;

    if (__isByteArray(_INST(bytes))

     && __isByteArray(pseudoBits)

     && __isByteArray(fixIds)

     && __bothSmallInteger(fixR, fixG)

     && __isSmallInteger(fixB)) {

	failed = false;

	srcP = _ByteArrayInstPtr(_INST(bytes))->ba_element;

	dstP = _ByteArrayInstPtr(pseudoBits)->ba_element;

	idP = _ByteArrayInstPtr(fixIds)->ba_element;

	__fR = _intVal(fixR)-1;

	__fG = _intVal(fixG)-1;

	__fB = _intVal(fixB)-1;

	for (__y=_intVal(h); __y>0; __y--) {

	    __eR = __eG = __eB = 0;

	    for (__x=_intVal(w); __x>0; __x--) {

		int t;

		int __want;

		/*

		 * wR, wG and wB is the wanted r/g/b value;

		 * compute the index into the dId table ..

		 * values: 0..255; scale to 0..fR-1, 0..fG-1, 0..fB-1

		 *

		 * bad kludge: knows how to index into FixColor table

		 */

		__wantR = srcP[0] + __eR;

		__wantG = srcP[1] + __eG;

		__wantB = srcP[2] + __eB;

		srcP += 3;

		if (__wantR > 255) __want = 255;

		else if (__wantR < 0) __want = 0;

		else __want = __wantR;

		iR = __want * __fR / 128;

		iR = (iR / 2) + (iR & 1);

		idx = iR * (__fG+1);

		if (__wantG > 255) __want = 255;

		else if (__wantG < 0) __want = 0;

		else __want = __wantG;

		iG = __want * __fG / 128;

		iG = (iG / 2) + (iG & 1);

		idx = (idx + iG) * (__fB+1);

		if (__wantB > 255) __want = 255;

		else if (__wantB < 0) __want = 0;

		else __want = __wantB;

		iB = __want * __fB / 128;

		iB = (iB / 2) + (iB & 1);

		idx = idx + iB;

		/*

		 * store the corresponding dither colorId

		 */

		*dstP++ = idP[idx];

		/*

		 * the new error:

		 */

		__eR = __wantR - (iR * 256 / __fR); 

		__eG = __wantG - (iG * 256 / __fG); 

		__eB = __wantB - (iB * 256 / __fB); 

	    }

	}

    }

%}.

    failed ifTrue:[

	self primitiveFailed.

	^ nil

"/ for non-C programmers:

"/   the above code is (roughly) equivalent to:

"/    srcIndex := 1.

"/    dstIndex := 1.

"/    1 to:h do:[:y |

"/        eR := eG := eB := 0.

"/        1 to:w do:[:x |

"/            |pixel "{ Class: SmallInteger }"

"/             clr 

"/             idx   "{ Class: SmallInteger }"

"/             iR    "{ Class: SmallInteger }"

"/             iG    "{ Class: SmallInteger }"

"/             iB    "{ Class: SmallInteger }"

"/             wR    "{ Class: SmallInteger }"

"/             wG    "{ Class: SmallInteger }"

"/             wB    "{ Class: SmallInteger }" |

"/

"/            wantR := ((bytes at:srcIndex) + eR). srcIndex := srcIndex + 1.

"/            wantG := ((bytes at:srcIndex) + eG). srcIndex := srcIndex + 1.

"/            wantB := ((bytes at:srcIndex) + eB). srcIndex := srcIndex + 1.

"/            wR := wantR.

"/            wR > 255 ifTrue:[wR := 255] ifFalse:[wR < 0 ifTrue:[wR := 0]].

"/            wG := wantG.

"/            wG > 255 ifTrue:[wG := 255] ifFalse:[wG < 0 ifTrue:[wG := 0]].

"/            wB := wantB.

"/            wB > 255 ifTrue:[wB := 255] ifFalse:[wB < 0 ifTrue:[wB := 0]].

"/

"/            iR := wR * (fixR-1) // 128.

"/            iR := (iR // 2) + (iR bitAnd:1).

"/            iG := wG * (fixG-1) // 128.

"/            iG := (iG // 2) + (iG bitAnd:1).

"/            iB := wB * (fixB-1) // 128.

"/            iB := (iB // 2) + (iB bitAnd:1).

"/            idx := (iR * fixR + iG) * fixB + iB + 1.

"/