4.4BSD/usr/src/contrib/X11R5-lib/lib/X/TekHVCGcV.c
/* $XConsortium: TekHVCGcV.c,v 1.7 91/07/25 01:08:03 rws Exp $" */
/*
* Code and supporting documentation (c) Copyright 1990 1991 Tektronix, Inc.
* All Rights Reserved
*
* This file is a component of an X Window System-specific implementation
* of Xcms based on the TekColor Color Management System. TekColor is a
* trademark of Tektronix, Inc. The term "TekHVC" designates a particular
* color space that is the subject of U.S. Patent No. 4,985,853 (equivalent
* foreign patents pending). Permission is hereby granted to use, copy,
* modify, sell, and otherwise distribute this software and its
* documentation for any purpose and without fee, provided that:
*
* 1. This copyright, permission, and disclaimer notice is reproduced in
* all copies of this software and any modification thereof and in
* supporting documentation;
* 2. Any color-handling application which displays TekHVC color
* cooordinates identifies these as TekHVC color coordinates in any
* interface that displays these coordinates and in any associated
* documentation;
* 3. The term "TekHVC" is always used, and is only used, in association
* with the mathematical derivations of the TekHVC Color Space,
* including those provided in this file and any equivalent pathways and
* mathematical derivations, regardless of digital (e.g., floating point
* or integer) representation.
*
* Tektronix makes no representation about the suitability of this software
* for any purpose. It is provided "as is" and with all faults.
*
* TEKTRONIX DISCLAIMS ALL WARRANTIES APPLICABLE TO THIS SOFTWARE,
* INCLUDING THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
* PARTICULAR PURPOSE. IN NO EVENT SHALL TEKTRONIX BE LIABLE FOR ANY
* SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER
* RESULTING FROM LOSS OF USE, DATA, OR PROFITS, WHETHER IN AN ACTION OF
* CONTRACT, NEGLIGENCE, OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
* CONNECTION WITH THE USE OR THE PERFORMANCE OF THIS SOFTWARE.
*
* NAME
* TekHVCGcV.c
*
* DESCRIPTION
* Source for XcmsTekHVCClipV() gamut compression routine.
*
*/
#include "Xlibint.h"
#include "Xcmsint.h"
/*
* EXTERNS
*/
extern Status _XcmsTekHVC_CheckModify();
extern XcmsColorSpace XcmsTekHVCColorSpace;
extern XcmsFunctionSet XcmsLinearRGBFunctionSet;
/************************************************************************
* *
* PUBLIC ROUTINES *
* *
************************************************************************/
/*
* NAME
* XcmsTekHVCClipV - Return the closest value
*
* SYNOPSIS
*/
/* ARGSUSED */
Status
XcmsTekHVCClipV (ccc, pColors_in_out, nColors, i, pCompressed)
XcmsCCC ccc;
XcmsColor *pColors_in_out;
unsigned int nColors;
unsigned int i;
Bool *pCompressed;
/*
* DESCRIPTION
* Return the closest value for a specific hue and chroma.
* This routine takes any color as input and outputs
* a CIE XYZ color.
*
* Since this routine works with the value within
* pColor_in_out intermediate results may be returned
* even though it may be invalid.
*
* RETURNS
* XcmsFailure - Failure
* XcmsSuccess - Succeeded
*
*/
{
XcmsColor *pColor;
XcmsColor hvc_max;
XcmsCCCRec myCCC;
Status retval;
/*
* Insure TekHVC installed
*/
if (XcmsAddColorSpace(&XcmsTekHVCColorSpace) == XcmsFailure) {
return(XcmsFailure);
}
/* Use my own CCC */
bcopy ((char *)ccc, (char *)&myCCC, sizeof(XcmsCCCRec));
myCCC.clientWhitePt.format = XcmsUndefinedFormat;/* Inherit Screen WP */
myCCC.gamutCompProc = (XcmsCompressionProc)NULL;/* no gamut compression */
/*
* Color specification passed as input can be assumed to:
* 1. Be in XcmsCIEXYZFormat
* 2. Already be white point adjusted for the Screen White Point.
* This means that the white point now associated with this
* color spec is the Screen White Point (even if the
* ccc->clientWhitePt differs).
*/
pColor = pColors_in_out + i;
if (ccc->visual->class < StaticColor &&
FunctionSetOfCCC(ccc) != (XPointer) &XcmsLinearRGBFunctionSet) {
/*
* GRAY !
*/
return(XcmsFailure);
} else {
/* Convert from CIEXYZ to TekHVC format */
if (_XcmsDIConvertColors(&myCCC, pColor,
&myCCC.pPerScrnInfo->screenWhitePt, 1, XcmsTekHVCFormat)
== XcmsFailure) {
return(XcmsFailure);
}
/* check to make sure we have a valid TekHVC number */
if (!_XcmsTekHVC_CheckModify (pColor)) {
return (XcmsFailure);
}
/* Step 1: compute the maximum value and chroma for this hue. */
/* This copy may be overkill but it preserves the pixel etc. */
bcopy((char *)pColor, (char *)&hvc_max, sizeof(XcmsColor));
if (_XcmsTekHVCQueryMaxVCRGB (&myCCC, hvc_max.spec.TekHVC.H, &hvc_max,
(XcmsRGBi *)NULL) == XcmsFailure) {
return (XcmsFailure);
}
/* Now check and return the appropriate value */
if (pColor->spec.TekHVC.C == hvc_max.spec.TekHVC.C) {
/* When the chroma input is equal to the maximum chroma */
/* merely return the value for that chroma. */
pColor->spec.TekHVC.V = hvc_max.spec.TekHVC.V;
if (!_XcmsTekHVC_CheckModify (pColor)) {
return (XcmsFailure);
}
retval = _XcmsDIConvertColors(&myCCC, pColor,
&myCCC.pPerScrnInfo->screenWhitePt, 1, XcmsCIEXYZFormat);
} else if (pColor->spec.TekHVC.C > hvc_max.spec.TekHVC.C) {
/* When the chroma input is greater than the maximum chroma */
/* merely return the value and chroma for the given hue. */
pColor->spec.TekHVC.C = hvc_max.spec.TekHVC.C;
pColor->spec.TekHVC.V = hvc_max.spec.TekHVC.V;
return (XcmsFailure);
} else if (pColor->spec.TekHVC.V < hvc_max.spec.TekHVC.V) {
/* When the value input is less than the maximum value point */
/* compute the intersection of the line from 0,0 to max_V, max_C */
/* using the chroma input. */
pColor->spec.TekHVC.V = pColor->spec.TekHVC.C *
hvc_max.spec.TekHVC.V / hvc_max.spec.TekHVC.C;
if (pColor->spec.TekHVC.V >= hvc_max.spec.TekHVC.V) {
pColor->spec.TekHVC.C = hvc_max.spec.TekHVC.C;
pColor->spec.TekHVC.V = hvc_max.spec.TekHVC.V;
}
if (!_XcmsTekHVC_CheckModify (pColor)) {
return (XcmsFailure);
}
retval = _XcmsDIConvertColors(&myCCC, pColor,
&myCCC.pPerScrnInfo->screenWhitePt, 1, XcmsCIEXYZFormat);
} else {
/* When the value input is greater than the maximum value point */
/* use HvcMaxValue to find the maximum value for the given chroma. */
if (pColor->format != XcmsTekHVCFormat) {
if (_XcmsDIConvertColors(ccc, pColor,
&ccc->pPerScrnInfo->screenWhitePt, 1, XcmsCIEXYZFormat)
== XcmsFailure) {
return(XcmsFailure);
}
}
if (XcmsTekHVCQueryMaxV(&myCCC,
pColor->spec.TekHVC.H,
pColor->spec.TekHVC.C,
pColor)
== XcmsFailure) {
return (XcmsFailure);
}
retval = _XcmsDIConvertColors(&myCCC, pColor,
&myCCC.pPerScrnInfo->screenWhitePt, 1, XcmsCIEXYZFormat);
}
if (retval != XcmsFailure && pCompressed != NULL) {
*(pCompressed + i) = True;
}
return(retval);
}
}