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Diffstat (limited to 'libX11/src/xcms/xyY.c')
| -rw-r--r-- | libX11/src/xcms/xyY.c | 397 |
1 files changed, 397 insertions, 0 deletions
diff --git a/libX11/src/xcms/xyY.c b/libX11/src/xcms/xyY.c new file mode 100644 index 000000000..2e56a0862 --- /dev/null +++ b/libX11/src/xcms/xyY.c @@ -0,0 +1,397 @@ +/* $Xorg: xyY.c,v 1.3 2000/08/17 19:45:23 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 + * CIExyY.c + * + * DESCRIPTION + * This file contains routines that support the CIE xyY + * 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/xyY.c,v 1.3 2001/01/17 19:41:57 dawes Exp $ */ + +#ifdef HAVE_CONFIG_H +#include <config.h> +#endif +#include <stdio.h> +#include <X11/Xos.h> +#include "Xlibint.h" +#include "Xcmsint.h" +#include "Cv.h" + +/* + * DEFINES + */ +#define EPS 0.00001 /* some extremely small number */ +#ifdef DBL_EPSILON +# define XMY_DBL_EPSILON DBL_EPSILON +#else +# define XMY_DBL_EPSILON 0.00001 +#endif + +/* + * FORWARD DECLARATIONS + */ + +static int CIExyY_ParseString(register char *spec, XcmsColor *pColor); +static Status XcmsCIExyY_ValidSpec(XcmsColor *pColor); + + +/* + * LOCAL VARIABLES + */ + + /* + * NULL terminated list of functions applied to get from CIExyY to CIEXYZ + */ +static XcmsConversionProc Fl_CIExyY_to_CIEXYZ[] = { + XcmsCIExyYToCIEXYZ, + NULL +}; + + /* + * NULL terminated list of functions applied to get from CIEXYZ to CIExyY + */ +static XcmsConversionProc Fl_CIEXYZ_to_CIExyY[] = { + XcmsCIEXYZToCIExyY, + NULL +}; + + +/* + * GLOBALS + */ + + /* + * CIE xyY Color Space + */ +XcmsColorSpace XcmsCIExyYColorSpace = + { + _XcmsCIExyY_prefix, /* prefix */ + XcmsCIExyYFormat, /* id */ + CIExyY_ParseString, /* parseString */ + Fl_CIExyY_to_CIEXYZ, /* to_CIEXYZ */ + Fl_CIEXYZ_to_CIExyY, /* from_CIEXYZ */ + 1 + }; + + + +/************************************************************************ + * * + * PRIVATE ROUTINES * + * * + ************************************************************************/ + +/* + * NAME + * CIExyY_ParseString + * + * SYNOPSIS + */ +static int +CIExyY_ParseString( + register char *spec, + XcmsColor *pColor) +/* + * DESCRIPTION + * This routines takes a string and attempts to convert + * it into a XcmsColor structure with XcmsCIExyYFormat. + * The assumed CIExyY string syntax is: + * CIExyY:<x>/<y>/<Y> + * Where x, y, and Y 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 + * 0 if failed, non-zero otherwise. + */ +{ + int n; + char *pchar; + + if ((pchar = strchr(spec, ':')) == NULL) { + return(XcmsFailure); + } + n = (int)(pchar - spec); + + /* + * Check for proper prefix. + */ + if (strncmp(spec, _XcmsCIExyY_prefix, n) != 0) { + return(XcmsFailure); + } + + /* + * Attempt to parse the value portion. + */ + if (sscanf(spec + n + 1, "%lf/%lf/%lf", + &pColor->spec.CIExyY.x, + &pColor->spec.CIExyY.y, + &pColor->spec.CIExyY.Y) != 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.CIExyY.x, + &pColor->spec.CIExyY.y, + &pColor->spec.CIExyY.Y) != 3) { + free(s); + return(XcmsFailure); + } + free(s); + } else + return(XcmsFailure); + } + pColor->format = XcmsCIExyYFormat; + pColor->pixel = 0; + return(XcmsCIExyY_ValidSpec(pColor)); +} + + + +/************************************************************************ + * * + * PUBLIC ROUTINES * + * * + ************************************************************************/ + +/* + * NAME + * CIExyY_ValidSpec() + * + * SYNOPSIS + */ +static Status +XcmsCIExyY_ValidSpec( + XcmsColor *pColor) +/* + * DESCRIPTION + * Checks a valid CIExyY color specification. + * + * RETURNS + * XcmsFailure if invalid. + * XcmsSuccess if valid. + * + */ +{ + if (pColor->format != XcmsCIExyYFormat + || + (pColor->spec.CIExyY.x < 0.0 - XMY_DBL_EPSILON) + || + (pColor->spec.CIExyY.x > 1.0 + XMY_DBL_EPSILON) + || + (pColor->spec.CIExyY.y < 0.0 - XMY_DBL_EPSILON) + || + (pColor->spec.CIExyY.y > 1.0 + XMY_DBL_EPSILON) + || + (pColor->spec.CIExyY.Y < 0.0 - XMY_DBL_EPSILON) + || + (pColor->spec.CIExyY.Y > 1.0 + XMY_DBL_EPSILON)) { + return(XcmsFailure); + } + return(XcmsSuccess); +} + + +/* + * NAME + * XcmsCIExyYToCIEXYZ - convert CIExyY to CIEXYZ + * + * SYNOPSIS + */ +Status +XcmsCIExyYToCIEXYZ( + XcmsCCC ccc, + XcmsColor *pxyY_WhitePt, + XcmsColor *pColors_in_out, + unsigned int nColors) +/* + * DESCRIPTION + * Converts color specifications in an array of XcmsColor + * structures from CIExyY format to CIEXYZ format. + * + * RETURNS + * XcmsFailure if failed, + * XcmsSuccess if succeeded. + */ +{ + XcmsColor *pColor = pColors_in_out; + XcmsColor whitePt; + XcmsCIEXYZ XYZ_return; + XcmsFloat div; /* temporary storage in case divisor is zero */ + XcmsFloat u, v, x, y, z; /* temporary storage */ + register int i; + + /* + * Check arguments + */ + if (pxyY_WhitePt == NULL || pColors_in_out == NULL) { + return(XcmsFailure); + } + + + /* + * Now convert each XcmsColor structure to CIEXYZ form + */ + for (i = 0; i < nColors; i++, pColor++) { + /* Make sure original format is CIExyY and valid */ + if (!XcmsCIExyY_ValidSpec(pColor)) { + return(XcmsFailure); + } + + if ((div = (-2 * pColor->spec.CIExyY.x) + (12 * pColor->spec.CIExyY.y) + 3) == 0.0) { + /* Note that the divisor is zero */ + /* This return is abitrary. */ + XYZ_return.X = 0; + XYZ_return.Y = 0; + XYZ_return.Z = 0; + } else { + /* + * Make sure white point is in CIEXYZ form + */ + if (pxyY_WhitePt->format != XcmsCIEXYZFormat) { + /* Make copy of the white point because we're going to modify it */ + memcpy((char *)&whitePt, (char *)pxyY_WhitePt, sizeof(XcmsColor)); + if (!_XcmsDIConvertColors(ccc, &whitePt, (XcmsColor *)NULL, 1, + XcmsCIEXYZFormat)) { + return(XcmsFailure); + } + pxyY_WhitePt = &whitePt; + } + + /* Make sure it is a white point, i.e., Y == 1.0 */ + if (pxyY_WhitePt->spec.CIEXYZ.Y != 1.0) { + return(XcmsFailure); + } + + /* Convert from xyY to uvY to XYZ */ + u = (4 * pColor->spec.CIExyY.x) / div; + v = (9 * pColor->spec.CIExyY.y) / div; + div = (6.0 * u) - (16.0 * v) + 12.0; + if (div == 0.0) { + /* Note that the divisor is zero */ + /* This return is abitrary. */ + if ((div = (6.0 * whitePt.spec.CIEuvY.u_prime) - + (16.0 * whitePt.spec.CIEuvY.v_prime) + 12.0) == 0.0) { + div = EPS; + } + x = 9.0 * whitePt.spec.CIEuvY.u_prime / div; + y = 4.0 * whitePt.spec.CIEuvY.u_prime / div; + } else { + /* convert u, v to small xyz */ + x = 9.0 * u / div; + y = 4.0 * v / div; + } + z = 1.0 - x - y; + if (y == 0.0) y = EPS; /* Have to worry about divide by 0 */ + XYZ_return.Y = pColor->spec.CIExyY.Y; + XYZ_return.X = x * XYZ_return.Y / y; + XYZ_return.Z = z * XYZ_return.Y / y; + } + + /* Copy result to pColor */ + memcpy ((char *)&pColor->spec, (char *)&XYZ_return, sizeof(XcmsCIEXYZ)); + + /* Identify that the format is now CIEXYZ */ + pColor->format = XcmsCIEXYZFormat; + } + return(XcmsSuccess); +} + + +/* + * NAME + * XcmsCIEXYZToCIExyY - convert CIEXYZ to CIExyY + * + * SYNOPSIS + */ +/* ARGSUSED */ +Status +XcmsCIEXYZToCIExyY( + XcmsCCC ccc, + XcmsColor *pxyY_WhitePt, + XcmsColor *pColors_in_out, + unsigned int nColors) +/* + * DESCRIPTION + * Converts color specifications in an array of XcmsColor + * structures from CIEXYZ format to CIExyY format. + * + * RETURNS + * XcmsFailure if failed, + * XcmsSuccess if succeeded. + * + */ +{ + XcmsColor *pColor = pColors_in_out; + XcmsCIExyY xyY_return; + XcmsFloat div; /* temporary storage in case divisor is zero */ + register int i; + + /* + * Check arguments + * pxyY_WhitePt ignored + */ + if (pColors_in_out == NULL) { + return(XcmsFailure); + } + + /* + * Now convert each XcmsColor structure to CIEXYZ form + */ + for (i = 0; i < nColors; i++, pColor++) { + + if (!_XcmsCIEXYZ_ValidSpec(pColor)) { + return(XcmsFailure); + } + /* Now convert for XYZ to xyY */ + if ((div = pColor->spec.CIEXYZ.X + pColor->spec.CIEXYZ.Y + pColor->spec.CIEXYZ.Z) == 0.0) { + div = EPS; + } + xyY_return.x = pColor->spec.CIEXYZ.X / div; + xyY_return.y = pColor->spec.CIEXYZ.Y / div; + xyY_return.Y = pColor->spec.CIEXYZ.Y; + + /* Copy result to pColor */ + memcpy ((char *)&pColor->spec, (char *)&xyY_return, sizeof(XcmsCIExyY)); + + /* Identify that the format is now CIEXYZ */ + pColor->format = XcmsCIExyYFormat; + } + return(XcmsSuccess); +} |