/* $Xorg: LabGcL.c,v 1.3 2000/08/17 19:44:39 cpqbld 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. 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 this copyright, permission, and disclaimer notice is reproduced in * all copies of this software and in supporting documentation. TekColor * is a trademark of Tektronix, Inc. * * 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 * CIELabGcL.c * * DESCRIPTION * Source for XcmsCIELabClipL() gamut compression routine. * */ /* $XFree86: xc/lib/X11/LabGcL.c,v 1.3 2001/01/17 19:41:38 dawes Exp $ */ #ifdef HAVE_CONFIG_H #include <config.h> #endif #include "Xlibint.h" #include "Xcmsint.h" #include "Cv.h" /************************************************************************ * * * PUBLIC ROUTINES * * * ************************************************************************/ /* * NAME * XcmsCIELabClipL - Return the closest L* * * SYNOPSIS */ /* ARGSUSED */ Status XcmsCIELabClipL (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 L* 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 L* within * pColor_in_out intermediate results may be returned * even though it may be invalid. * * RETURNS * XcmsFailure - Failure * XcmsSuccess - Succeeded * */ { XcmsCCCRec myCCC; XcmsColor *pColor; XcmsColor Lab_max; XcmsFloat hue, chroma, maxChroma; Status retval; /* Use my own CCC */ memcpy ((char *)&myCCC, (char *)ccc, 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) { /* * GRAY ! */ return(XcmsFailure); } else { /* Convert from CIEXYZ to CIE L*u*v* format */ if (_XcmsDIConvertColors(&myCCC, pColor, ScreenWhitePointOfCCC(&myCCC), 1, XcmsCIELabFormat) == XcmsFailure) { return(XcmsFailure); } hue = XCMS_CIELAB_PMETRIC_HUE(pColor->spec.CIELab.a_star, pColor->spec.CIELab.b_star); chroma = XCMS_CIELAB_PMETRIC_CHROMA(pColor->spec.CIELab.a_star, pColor->spec.CIELab.b_star); /* Step 1: compute the maximum L* and chroma for this hue. */ /* This copy may be overkill but it preserves the pixel etc. */ memcpy((char *)&Lab_max, (char *)pColor, sizeof(XcmsColor)); if (_XcmsCIELabQueryMaxLCRGB (&myCCC, hue, &Lab_max, (XcmsRGBi *)NULL) == XcmsFailure) { return (XcmsFailure); } maxChroma = XCMS_CIELAB_PMETRIC_CHROMA(Lab_max.spec.CIELab.a_star, Lab_max.spec.CIELab.b_star); /* Now check and return the appropriate L* */ if (chroma == maxChroma) { /* When the chroma input is equal to the maximum chroma */ /* merely return the L* for that chroma. */ memcpy((char *)pColor, (char *)&Lab_max, sizeof(XcmsColor)); retval = _XcmsDIConvertColors(&myCCC, pColor, ScreenWhitePointOfCCC(&myCCC), 1, XcmsCIEXYZFormat); } else if (chroma > maxChroma) { /* When the chroma input is greater than the maximum chroma */ /* merely return the L* and chroma for the given hue. */ memcpy((char *)pColor, (char *)&Lab_max, sizeof(XcmsColor)); return (XcmsFailure); } else if (pColor->spec.CIELab.L_star < Lab_max.spec.CIELab.L_star) { /* Find the minimum lightness for the given chroma. */ if (pColor->format != XcmsCIELabFormat) { if (_XcmsDIConvertColors(ccc, pColor, ScreenWhitePointOfCCC(ccc), 1, XcmsCIELabFormat) == XcmsFailure) { return(XcmsFailure); } } if (XcmsCIELabQueryMinL(&myCCC, degrees(hue), chroma, pColor) == XcmsFailure) { return (XcmsFailure); } retval = _XcmsDIConvertColors(&myCCC, pColor, ScreenWhitePointOfCCC(&myCCC), 1, XcmsCIEXYZFormat); } else { /* Find the maximum lightness for the given chroma. */ if (pColor->format != XcmsCIELabFormat) { if (_XcmsDIConvertColors(ccc, pColor, ScreenWhitePointOfCCC(ccc), 1, XcmsCIELabFormat) == XcmsFailure) { return(XcmsFailure); } } if (XcmsCIELabQueryMaxL(&myCCC, degrees(hue), chroma, pColor) == XcmsFailure) { return (XcmsFailure); } retval = _XcmsDIConvertColors(&myCCC, pColor, ScreenWhitePointOfCCC(&myCCC), 1, XcmsCIEXYZFormat); } if (retval != XcmsFailure && pCompressed != NULL) { *(pCompressed + i) = True; } return(retval); } }