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Diffstat (limited to 'libX11/src/xcms/HVC.c')
| -rw-r--r-- | libX11/src/xcms/HVC.c | 628 |
1 files changed, 628 insertions, 0 deletions
diff --git a/libX11/src/xcms/HVC.c b/libX11/src/xcms/HVC.c new file mode 100644 index 000000000..c242bac77 --- /dev/null +++ b/libX11/src/xcms/HVC.c @@ -0,0 +1,628 @@ +/* $XdotOrg: lib/X11/src/xcms/HVC.c,v 1.4 2005-07-03 07:00:55 daniels Exp $ */ +/* $Xorg: HVC.c,v 1.3 2000/08/17 19:44:36 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. 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 + * TekHVC.c + * + * DESCRIPTION + * This file contains routines that support the TekHVC + * color space to include conversions to and from the CIE + * XYZ space. + * + * DOCUMENTATION + * "TekColor Color Management System, System Implementor's Manual" + */ +/* $XFree86: xc/lib/X11/HVC.c,v 1.3 2001/01/17 19:41:37 dawes Exp $ */ + +#ifdef HAVE_CONFIG_H +#include <config.h> +#endif +#include "Xlibint.h" +#include "Xcmsint.h" +#include <X11/Xos.h> +#include <math.h> +#include "Cv.h" + +#include <stdio.h> + +/* + * DEFINES + */ +#define u_BR 0.7127 /* u' Best Red */ +#define v_BR 0.4931 /* v' Best Red */ +#define EPS 0.001 +#define CHROMA_SCALE_FACTOR 7.50725 +#ifndef PI +# ifdef M_PI +# define PI M_PI +# else +# define PI 3.14159265358979323846264338327950 +# endif +#endif +#ifndef degrees +# define degrees(r) ((XcmsFloat)(r) * 180.0 / PI) +#endif /* degrees */ +#ifndef radians +# define radians(d) ((XcmsFloat)(d) * PI / 180.0) +#endif /* radians */ + +/************************************************************************* + * Note: The DBL_EPSILON for ANSI is 1e-5 so my checks need to take + * this into account. If your DBL_EPSILON is different then + * adjust this define. + * + * Also note that EPS is the error factor in the calculations + * This may need to be the same as XMY_DBL_EPSILON in + * some implementations. + **************************************************************************/ +#ifdef DBL_EPSILON +# define XMY_DBL_EPSILON DBL_EPSILON +#else +# define XMY_DBL_EPSILON 0.00001 +#endif + +/* + * FORWARD DECLARATIONS + */ +static int TekHVC_ParseString(register char *spec, XcmsColor *pColor); +static Status XcmsTekHVC_ValidSpec(XcmsColor *pColor); + +/* + * LOCAL VARIABLES + */ + + /* + * NULL terminated list of functions applied to get from TekHVC to CIEXYZ + */ +static XcmsConversionProc Fl_TekHVC_to_CIEXYZ[] = { + XcmsTekHVCToCIEuvY, + XcmsCIEuvYToCIEXYZ, + NULL +}; + + /* + * NULL terminated list of functions applied to get from CIEXYZ to TekHVC + */ +static XcmsConversionProc Fl_CIEXYZ_to_TekHVC[] = { + XcmsCIEXYZToCIEuvY, + XcmsCIEuvYToTekHVC, + NULL +}; + +/* + * GLOBALS + */ + + /* + * TekHVC Color Space + */ +XcmsColorSpace XcmsTekHVCColorSpace = + { + _XcmsTekHVC_prefix, /* prefix */ + XcmsTekHVCFormat, /* id */ + TekHVC_ParseString, /* parseString */ + Fl_TekHVC_to_CIEXYZ, /* to_CIEXYZ */ + Fl_CIEXYZ_to_TekHVC, /* from_CIEXYZ */ + 1 + }; + + + + +/************************************************************************ + * * + * PRIVATE ROUTINES * + * * + ************************************************************************/ + +/* + * NAME + * TekHVC_ParseString + * + * SYNOPSIS + */ +static int +TekHVC_ParseString( + register char *spec, + XcmsColor *pColor) +/* + * DESCRIPTION + * This routines takes a string and attempts to convert + * it into a XcmsColor structure with XcmsTekHVCFormat. + * The assumed TekHVC string syntax is: + * TekHVC:<H>/<V>/<C> + * Where H, V, and C are in string input format for floats + * consisting of: + * a. an optional sign + * b. a string of numbers possibly containing a decimal point, + * c. an optional exponent field containing an 'E' or 'e' + * followed by a possibly signed integer string. + * + * RETURNS + * XcmsFailure if invalid; + * XcmsSuccess if valid. + */ +{ + int n; + char *pchar; + + if ((pchar = strchr(spec, ':')) == NULL) { + return(XcmsFailure); + } + n = (int)(pchar - spec); + + /* + * Check for proper prefix. + */ + if (strncmp(spec, _XcmsTekHVC_prefix, n) != 0) { + return(XcmsFailure); + } + + /* + * Attempt to parse the value portion. + */ + if (sscanf(spec + n + 1, "%lf/%lf/%lf", + &pColor->spec.TekHVC.H, + &pColor->spec.TekHVC.V, + &pColor->spec.TekHVC.C) != 3) { + char *s; /* Maybe failed due to locale */ + int f; + if ((s = strdup(spec))) { + for (f = 0; s[f]; ++f) + if (s[f] == '.') + s[f] = ','; + else if (s[f] == ',') + s[f] = '.'; + if (sscanf(s + n + 1, "%lf/%lf/%lf", + &pColor->spec.TekHVC.H, + &pColor->spec.TekHVC.V, + &pColor->spec.TekHVC.C) != 3) { + free(s); + return(XcmsFailure); + } + free(s); + } else + return(XcmsFailure); + } + pColor->format = XcmsTekHVCFormat; + pColor->pixel = 0; + return(XcmsTekHVC_ValidSpec(pColor)); +} + + +/* + * NAME + * ThetaOffset -- compute thetaOffset + * + * SYNOPSIS + */ +static int +ThetaOffset( + XcmsColor *pWhitePt, + XcmsFloat *pThetaOffset) +/* + * DESCRIPTION + * This routine computes the theta offset of a given + * white point, i.e. XcmsColor. It is used in both this + * conversion and the printer conversions. + * + * RETURNS + * 0 if failed. + * 1 if succeeded with no modifications. + * + * ASSUMPTIONS + * Assumes: + * pWhitePt != NULL + * pWhitePt->format == XcmsCIEuvYFormat + * + */ +{ + double div, slopeuv; + + if (pWhitePt == NULL || pWhitePt->format != XcmsCIEuvYFormat) { + return(0); + } + + if ((div = u_BR - pWhitePt->spec.CIEuvY.u_prime) == 0.0) { + return(0); + } + slopeuv = (v_BR - pWhitePt->spec.CIEuvY.v_prime) / div; + *pThetaOffset = degrees(XCMS_ATAN(slopeuv)); + return(1); +} + + + +/************************************************************************ + * * + * PUBLIC ROUTINES * + * * + ************************************************************************/ + +/* + * NAME + * XcmsTekHVC_ValidSpec() + * + * SYNOPSIS + */ +static int +XcmsTekHVC_ValidSpec( + XcmsColor *pColor) +/* + * DESCRIPTION + * Checks if values in the color specification are valid. + * Also brings hue into the range 0.0 <= Hue < 360.0 + * + * RETURNS + * 0 if not valid. + * 1 if valid. + * + */ +{ + if (pColor->format != XcmsTekHVCFormat) { + return(XcmsFailure); + } + if (pColor->spec.TekHVC.V < (0.0 - XMY_DBL_EPSILON) + || pColor->spec.TekHVC.V > (100.0 + XMY_DBL_EPSILON) + || (pColor->spec.TekHVC.C < 0.0 - XMY_DBL_EPSILON)) { + return(XcmsFailure); + } + + if (pColor->spec.TekHVC.V < 0.0) { + pColor->spec.TekHVC.V = 0.0 + XMY_DBL_EPSILON; + } else if (pColor->spec.TekHVC.V > 100.0) { + pColor->spec.TekHVC.V = 100.0 - XMY_DBL_EPSILON; + } + + if (pColor->spec.TekHVC.C < 0.0) { + pColor->spec.TekHVC.C = 0.0 - XMY_DBL_EPSILON; + } + + while (pColor->spec.TekHVC.H < 0.0) { + pColor->spec.TekHVC.H += 360.0; + } + while (pColor->spec.TekHVC.H >= 360.0) { + pColor->spec.TekHVC.H -= 360.0; + } + return(XcmsSuccess); +} + +/* + * NAME + * XcmsTekHVCToCIEuvY - convert TekHVC to CIEuvY + * + * SYNOPSIS + */ +Status +XcmsTekHVCToCIEuvY( + XcmsCCC ccc, + XcmsColor *pHVC_WhitePt, + XcmsColor *pColors_in_out, + unsigned int nColors) +/* + * DESCRIPTION + * Transforms an array of TekHVC color specifications, given + * their associated white point, to CIECIEuvY.color + * specifications. + * + * RETURNS + * XcmsFailure if failed, XcmsSuccess otherwise. + * + */ +{ + XcmsFloat thetaOffset; + XcmsColor *pColor = pColors_in_out; + XcmsColor whitePt; + XcmsCIEuvY uvY_return; + XcmsFloat tempHue, u, v; + XcmsFloat tmpVal; + register int i; + + /* + * Check arguments + */ + if (pHVC_WhitePt == NULL || pColors_in_out == NULL) { + return(XcmsFailure); + } + + /* + * Make sure white point is in CIEuvY form + */ + if (pHVC_WhitePt->format != XcmsCIEuvYFormat) { + /* Make copy of the white point because we're going to modify it */ + memcpy((char *)&whitePt, (char *)pHVC_WhitePt, sizeof(XcmsColor)); + if (!_XcmsDIConvertColors(ccc, &whitePt, (XcmsColor *)NULL, 1, + XcmsCIEuvYFormat)) { + return(XcmsFailure); + } + pHVC_WhitePt = &whitePt; + } + /* Make sure it is a white point, i.e., Y == 1.0 */ + if (pHVC_WhitePt->spec.CIEuvY.Y != 1.0) { + return(XcmsFailure); + } + + /* Get the thetaOffset */ + if (!ThetaOffset(pHVC_WhitePt, &thetaOffset)) { + return(XcmsFailure); + } + + /* + * Now convert each XcmsColor structure to CIEXYZ form + */ + for (i = 0; i < nColors; i++, pColor++) { + + /* Make sure original format is TekHVC and is valid */ + if (!XcmsTekHVC_ValidSpec(pColor)) { + return(XcmsFailure); + } + + if (pColor->spec.TekHVC.V == 0.0 || pColor->spec.TekHVC.V == 100.0) { + if (pColor->spec.TekHVC.V == 100.0) { + uvY_return.Y = 1.0; + } else { /* pColor->spec.TekHVC.V == 0.0 */ + uvY_return.Y = 0.0; + } + uvY_return.u_prime = pHVC_WhitePt->spec.CIEuvY.u_prime; + uvY_return.v_prime = pHVC_WhitePt->spec.CIEuvY.v_prime; + } else { + + /* Find the hue based on the white point offset */ + tempHue = pColor->spec.TekHVC.H + thetaOffset; + + while (tempHue < 0.0) { + tempHue += 360.0; + } + while (tempHue >= 360.0) { + tempHue -= 360.0; + } + + tempHue = radians(tempHue); + + /* Calculate u'v' for the obtained hue */ + u = (XcmsFloat) ((XCMS_COS(tempHue) * pColor->spec.TekHVC.C) / + (pColor->spec.TekHVC.V * (double)CHROMA_SCALE_FACTOR)); + v = (XcmsFloat) ((XCMS_SIN(tempHue) * pColor->spec.TekHVC.C) / + (pColor->spec.TekHVC.V * (double)CHROMA_SCALE_FACTOR)); + + /* Based on the white point get the offset from best red */ + uvY_return.u_prime = u + pHVC_WhitePt->spec.CIEuvY.u_prime; + uvY_return.v_prime = v + pHVC_WhitePt->spec.CIEuvY.v_prime; + + /* Calculate the Y value based on the L* = V. */ + if (pColor->spec.TekHVC.V < 7.99953624) { + uvY_return.Y = pColor->spec.TekHVC.V / 903.29; + } else { + tmpVal = (pColor->spec.TekHVC.V + 16.0) / 116.0; + uvY_return.Y = tmpVal * tmpVal * tmpVal; /* tmpVal ** 3 */ + } + } + + /* Copy result to pColor */ + memcpy((char *)&pColor->spec, (char *)&uvY_return, sizeof(XcmsCIEuvY)); + + /* Identify that the format is now CIEuvY */ + pColor->format = XcmsCIEuvYFormat; + } + return(XcmsSuccess); +} + + +/* + * NAME + * XcmsCIEuvYToTekHVC - convert CIEuvY to TekHVC + * + * SYNOPSIS + */ +Status +XcmsCIEuvYToTekHVC( + XcmsCCC ccc, + XcmsColor *pHVC_WhitePt, + XcmsColor *pColors_in_out, + unsigned int nColors) +/* + * DESCRIPTION + * Transforms an array of CIECIEuvY.color specifications, given + * their assiciated white point, to TekHVC specifications. + * + * RETURNS + * XcmsFailure if failed, XcmsSuccess otherwise. + * + */ +{ + XcmsFloat theta, L2, u, v, nThetaLow, nThetaHigh; + XcmsFloat thetaOffset; + XcmsColor *pColor = pColors_in_out; + XcmsColor whitePt; + XcmsTekHVC HVC_return; + register int i; + + /* + * Check arguments + */ + if (pHVC_WhitePt == NULL || pColors_in_out == NULL) { + return(XcmsFailure); + } + + /* + * Make sure white point is in CIEuvY form + */ + if (pHVC_WhitePt->format != XcmsCIEuvYFormat) { + /* Make copy of the white point because we're going to modify it */ + memcpy((char *)&whitePt, (char *)pHVC_WhitePt, sizeof(XcmsColor)); + if (!_XcmsDIConvertColors(ccc, &whitePt, (XcmsColor *)NULL, 1, + XcmsCIEuvYFormat)) { + return(XcmsFailure); + } + pHVC_WhitePt = &whitePt; + } + /* Make sure it is a white point, i.e., Y == 1.0 */ + if (pHVC_WhitePt->spec.CIEuvY.Y != 1.0) { + return(XcmsFailure); + } + if (!ThetaOffset(pHVC_WhitePt, &thetaOffset)) { + return(XcmsFailure); + } + + /* + * Now convert each XcmsColor structure to CIEXYZ form + */ + for (i = 0; i < nColors; i++, pColor++) { + if (!_XcmsCIEuvY_ValidSpec(pColor)) { + return(XcmsFailure); + } + + /* Use the white point offset to determine HVC */ + u = pColor->spec.CIEuvY.u_prime - pHVC_WhitePt->spec.CIEuvY.u_prime; + v = pColor->spec.CIEuvY.v_prime - pHVC_WhitePt->spec.CIEuvY.v_prime; + + /* Calculate the offset */ + if (u == 0.0) { + theta = 0.0; + } else { + theta = v / u; + theta = (XcmsFloat) XCMS_ATAN((double)theta); + theta = degrees(theta); + } + + nThetaLow = 0.0; + nThetaHigh = 360.0; + if (u > 0.0 && v > 0.0) { + nThetaLow = 0.0; + nThetaHigh = 90.0; + } else if (u < 0.0 && v > 0.0) { + nThetaLow = 90.0; + nThetaHigh = 180.0; + } else if (u < 0.0 && v < 0.0) { + nThetaLow = 180.0; + nThetaHigh = 270.0; + } else if (u > 0.0 && v < 0.0) { + nThetaLow = 270.0; + nThetaHigh = 360.0; + } + while (theta < nThetaLow) { + theta += 90.0; + } + while (theta >= nThetaHigh) { + theta -= 90.0; + } + + /* calculate the L value from the given Y */ + L2 = (pColor->spec.CIEuvY.Y < 0.008856) + ? + (pColor->spec.CIEuvY.Y * 903.29) + : + ((XcmsFloat)(XCMS_CUBEROOT(pColor->spec.CIEuvY.Y) * 116.0) - 16.0); + HVC_return.C = L2 * CHROMA_SCALE_FACTOR * XCMS_SQRT((double) ((u * u) + (v * v))); + if (HVC_return.C < 0.0) { + theta = 0.0; + } + HVC_return.V = L2; + HVC_return.H = theta - thetaOffset; + + /* + * If this is within the error margin let some other routine later + * in the chain worry about the slop in the calculations. + */ + while (HVC_return.H < -EPS) { + HVC_return.H += 360.0; + } + while (HVC_return.H >= 360.0 + EPS) { + HVC_return.H -= 360.0; + } + + /* Copy result to pColor */ + memcpy((char *)&pColor->spec, (char *)&HVC_return, sizeof(XcmsTekHVC)); + + /* Identify that the format is now CIEuvY */ + pColor->format = XcmsTekHVCFormat; + } + return(XcmsSuccess); +} + + +/* + * NAME + * _XcmsTekHVC_CheckModify + * + * SYNOPSIS + */ +int +_XcmsTekHVC_CheckModify( + XcmsColor *pColor) +/* + * DESCRIPTION + * Checks if values in the color specification are valid. + * If they are not it modifies the values. + * Also brings hue into the range 0.0 <= Hue < 360.0 + * + * RETURNS + * 0 if not valid. + * 1 if valid. + * + */ +{ + int n; + + /* For now only use the TekHVC numbers as inputs */ + if (pColor->format != XcmsTekHVCFormat) { + return(0); + } + + if (pColor->spec.TekHVC.V < 0.0) { + pColor->spec.TekHVC.V = 0.0 + XMY_DBL_EPSILON; + } else if (pColor->spec.TekHVC.V > 100.0) { + pColor->spec.TekHVC.V = 100.0 - XMY_DBL_EPSILON; + } + + if (pColor->spec.TekHVC.C < 0.0) { + pColor->spec.TekHVC.C = 0.0 - XMY_DBL_EPSILON; + } + + if (pColor->spec.TekHVC.H < 0.0) { + n = -pColor->spec.TekHVC.H / 360.0; + pColor->spec.TekHVC.H += (n + 1) * 360.0; + if (pColor->spec.TekHVC.H >= 360.0) + pColor->spec.TekHVC.H -= 360.0; + } else if (pColor->spec.TekHVC.H >= 360.0) { + n = pColor->spec.TekHVC.H / 360.0; + pColor->spec.TekHVC.H -= n * 360.0; + } + return(1); +} |