/* * 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 * TekHVCGcVC.c * * DESCRIPTION * Source for XcmsTekHVCClipVC() gamut * compression function. */ #ifdef HAVE_CONFIG_H #include <config.h> #endif #include "Xlibint.h" #include "Xcmsint.h" #include <math.h> #include "Cv.h" /* * INTERNALS * Internal defines that need NOT be exported to any package or * program using this package. */ #define MAXBISECTCOUNT 100 /************************************************************************ * * * PUBLIC ROUTINES * * * ************************************************************************/ /* * NAME * XcmsTekHVCClipVC - Return the closest value and chroma * * SYNOPSIS */ /* ARGSUSED */ Status XcmsTekHVCClipVC ( XcmsCCC ccc, XcmsColor *pColors_in_out, unsigned int nColors, unsigned int i, Bool *pCompressed) /* * DESCRIPTION * This routine will find the closest value and chroma * for a specific hue. The color input is converted to * HVC format and returned as CIE XYZ format. * * 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 * */ { Status retval; XcmsCCCRec myCCC; XcmsColor *pColor; XcmsColor hvc_max; XcmsRGBi rgb_max; int nCount, nMaxCount, nI, nILast; XcmsFloat Chroma, Value, bestChroma, bestValue, nT, saveDist, tmpDist; /* * Insure TekHVC installed */ if (XcmsAddColorSpace(&XcmsTekHVCColorSpace) == XcmsFailure) { return(XcmsFailure); } /* Use my own CCC */ memcpy ((char *)&myCCC, (char *)ccc, sizeof(XcmsCCCRec)); myCCC.clientWhitePt.format = XcmsUndefinedFormat;/* inherit screen white pt */ myCCC.gamutCompProc = (XcmsCompressionProc)NULL;/* no gamut compression func */ /* * 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 ! */ _XcmsDIConvertColors(ccc, pColor, &ccc->pPerScrnInfo->screenWhitePt, 1, XcmsTekHVCFormat); pColor->spec.TekHVC.H = pColor->spec.TekHVC.C = 0.0; _XcmsDIConvertColors(ccc, pColor, &ccc->pPerScrnInfo->screenWhitePt, 1, XcmsCIEXYZFormat); if (pCompressed) { *(pCompressed + i) = True; } return(XcmsSuccess); } else { /* Convert from CIEXYZ to TekHVC format */ if (_XcmsDIConvertColors(&myCCC, pColor, &myCCC.pPerScrnInfo->screenWhitePt, 1, XcmsTekHVCFormat) == XcmsFailure) { return(XcmsFailure); } 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. */ memcpy((char *)&hvc_max, (char *)pColor, sizeof(XcmsColor)); if (_XcmsTekHVCQueryMaxVCRGB (&myCCC, hvc_max.spec.TekHVC.H, &hvc_max, &rgb_max) == XcmsFailure) { return (XcmsFailure); } /* Now check and return the appropriate value */ if (pColor->spec.TekHVC.V == hvc_max.spec.TekHVC.V) { /* When the value input is equal to the maximum value */ /* merely return the chroma for that value. */ pColor->spec.TekHVC.C = hvc_max.spec.TekHVC.C; retval = _XcmsDIConvertColors(&myCCC, pColor, &myCCC.pPerScrnInfo->screenWhitePt, 1, XcmsCIEXYZFormat); } if (pColor->spec.TekHVC.V < hvc_max.spec.TekHVC.V) { /* return the intersection of the perpindicular line through */ /* the value and chroma given and the line from 0,0 and hvc_max. */ Chroma = pColor->spec.TekHVC.C; Value = pColor->spec.TekHVC.V; pColor->spec.TekHVC.C = (Value + (hvc_max.spec.TekHVC.C / hvc_max.spec.TekHVC.V * Chroma)) / ((hvc_max.spec.TekHVC.V / hvc_max.spec.TekHVC.C) + (hvc_max.spec.TekHVC.C / hvc_max.spec.TekHVC.V)); if (pColor->spec.TekHVC.C >= hvc_max.spec.TekHVC.C) { pColor->spec.TekHVC.C = hvc_max.spec.TekHVC.C; pColor->spec.TekHVC.V = hvc_max.spec.TekHVC.V; } else { pColor->spec.TekHVC.V = pColor->spec.TekHVC.C * hvc_max.spec.TekHVC.V / hvc_max.spec.TekHVC.C; } retval = _XcmsDIConvertColors(&myCCC, pColor, &myCCC.pPerScrnInfo->screenWhitePt, 1, XcmsCIEXYZFormat); if (retval != XcmsFailure && pCompressed != NULL) { *(pCompressed + i) = True; } return (retval); } /* return the closest point on the upper part of the hue leaf. */ /* must do a bisection here to compute the delta e. */ nMaxCount = MAXBISECTCOUNT; nI = nMaxCount / 2; bestValue = Value = pColor->spec.TekHVC.V; bestChroma = Chroma = pColor->spec.TekHVC.C; saveDist = (XcmsFloat) XCMS_SQRT ((double) (((Chroma - hvc_max.spec.TekHVC.C) * (Chroma - hvc_max.spec.TekHVC.C)) + ((Value - hvc_max.spec.TekHVC.V) * (Value - hvc_max.spec.TekHVC.V)))); for (nCount = 0; nCount < nMaxCount; nCount++) { nT = (XcmsFloat) nI / (XcmsFloat) nMaxCount; pColor->spec.RGBi.red = rgb_max.red * (1.0 - nT) + nT; pColor->spec.RGBi.green = rgb_max.green * (1.0 - nT) + nT; pColor->spec.RGBi.blue = rgb_max.blue * (1.0 - nT) + nT; pColor->format = XcmsRGBiFormat; /* Convert from RGBi to HVC */ if (_XcmsConvertColorsWithWhitePt(&myCCC, pColor, &myCCC.pPerScrnInfo->screenWhitePt, 1, XcmsTekHVCFormat, (Bool *) NULL) == XcmsFailure) { return (XcmsFailure); } if (!_XcmsTekHVC_CheckModify(pColor)) { return (XcmsFailure); } tmpDist = (XcmsFloat) XCMS_SQRT ((double) (((Chroma - pColor->spec.TekHVC.C) * (Chroma - pColor->spec.TekHVC.C)) + ((Value - pColor->spec.TekHVC.V) * (Value - pColor->spec.TekHVC.V)))); nILast = nI; if (tmpDist > saveDist) { nI /= 2; } else { nI = (nMaxCount + nI) / 2; saveDist = tmpDist; bestValue = pColor->spec.TekHVC.V; bestChroma = pColor->spec.TekHVC.C; } if (nI == nILast || nI == 0) { break; } } if (bestChroma >= hvc_max.spec.TekHVC.C) { pColor->spec.TekHVC.C = hvc_max.spec.TekHVC.C; pColor->spec.TekHVC.V = hvc_max.spec.TekHVC.V; } else { pColor->spec.TekHVC.C = bestChroma; pColor->spec.TekHVC.V = bestValue; } if (!_XcmsTekHVC_CheckModify(pColor)) { return (XcmsFailure); } retval = _XcmsDIConvertColors(&myCCC, pColor, &myCCC.pPerScrnInfo->screenWhitePt, 1, XcmsCIEXYZFormat); if (retval != XcmsFailure && pCompressed != NULL) { *(pCompressed + i) = True; } return(retval); } }