/* * 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 * TekHVCMnV.c * * DESCRIPTION * Source for XcmsTekHVCQueryMinV gamut boundary querying routine. * */ #ifdef HAVE_CONFIG_H #include <config.h> #endif #include "Xlibint.h" #include "Xcmsint.h" #include "Cv.h" /* * DEFINES */ #define EPS 0.001 /************************************************************************ * * * PUBLIC ROUTINES * * * ************************************************************************/ /* * NAME * XcmsTekHVCQueryMinV - Compute minimum value for hue and chroma * * SYNOPSIS */ Status XcmsTekHVCQueryMinV ( XcmsCCC ccc, XcmsFloat hue, XcmsFloat chroma, XcmsColor *pColor_return) /* * DESCRIPTION * Return the minimum value for a specific hue, and the * corresponding chroma. The input color specification * may be in any format, however output is in XcmsTekHVCFormat. * * Since this routine works with the value within * pColor_return intermediate results may be returned * even though it may be invalid. * * ASSUMPTIONS * This routine assumes that the white point associated with * the color specification is the Screen White Point. The * Screen White Point will also be associated with the * returned color specification. * * RETURNS * XcmsFailure - Failure * XcmsSuccess - Succeeded with no modifications * */ { XcmsCCCRec myCCC; XcmsColor tmp; XcmsColor max_vc; /* * Check Arguments */ if (ccc == NULL || pColor_return == NULL) { return(XcmsFailure); } /* * 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 comp func */ tmp.spec.TekHVC.H = hue; tmp.spec.TekHVC.V = 100.0; tmp.spec.TekHVC.C = chroma; tmp.pixel = pColor_return->pixel; tmp.format = XcmsTekHVCFormat; /* Check for a valid HVC */ if (!_XcmsTekHVC_CheckModify (&tmp)) { 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 *)&max_vc, (char *)&tmp, sizeof(XcmsColor)); if (_XcmsTekHVCQueryMaxVCRGB (&myCCC, max_vc.spec.TekHVC.H, &max_vc, (XcmsRGBi *)NULL) == XcmsFailure) { return(XcmsFailure); } /* Step 2: find the intersection with the maximum hvc and chroma line. */ if (tmp.spec.TekHVC.C > max_vc.spec.TekHVC.C + EPS) { /* If the chroma is to large then return maximum hvc. */ tmp.spec.TekHVC.C = max_vc.spec.TekHVC.C; tmp.spec.TekHVC.V = max_vc.spec.TekHVC.V; } else { tmp.spec.TekHVC.V = tmp.spec.TekHVC.C * max_vc.spec.TekHVC.V / max_vc.spec.TekHVC.C; if (tmp.spec.TekHVC.V > max_vc.spec.TekHVC.V) { tmp.spec.TekHVC.V = max_vc.spec.TekHVC.V; } else if (tmp.spec.TekHVC.V < 0.0) { tmp.spec.TekHVC.V = tmp.spec.TekHVC.C = 0.0; } } if (_XcmsTekHVC_CheckModify (&tmp)) { memcpy ((char *) pColor_return, (char *) &tmp, sizeof (XcmsColor)); return(XcmsSuccess); } else { return(XcmsFailure); } }