1 files changed, 433 insertions, 0 deletions
diff --git a/libX11/src/xcms/Lab.c b/libX11/src/xcms/Lab.c
new file mode 100644
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+++ b/libX11/src/xcms/Lab.c
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+/* $Xorg: Lab.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
+ *	    CIELab.c
+ *
+ *	DESCRIPTION
+ *		This file contains routines that support the CIE L*a*b*
+ *		color space to include conversions to and from the CIE
+ *		XYZ space.  These conversions are from Principles of
+ *		Color Technology Second Edition, Fred W. Billmeyer, Jr.
+ *		and Max Saltzman, John Wiley & Sons, Inc., 1981.
+ *
+ *		Note that the range for L* is 0 to 1.
+ */
+/* $XFree86: xc/lib/X11/Lab.c,v 1.3 2001/01/17 19:41:38 dawes Exp $ */
+
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+#include <X11/Xos.h>
+#include <stdio.h> /* sscanf */
+#include "Xlibint.h"
+#include "Xcmsint.h"
+#include "Cv.h"
+
+/*
+ *	DEFINES
+ *		Internal definitions that need NOT be exported to any package
+ *		or program using this package.
+ */
+#ifdef DBL_EPSILON
+#  define XMY_DBL_EPSILON DBL_EPSILON
+#else
+#  define XMY_DBL_EPSILON 0.00001
+#endif
+#define DIV16BY116	0.137931
+
+/*
+ *	FORWARD DECLARATIONS
+ */
+
+static int CIELab_ParseString(register char *spec, XcmsColor *pColor);
+static Status XcmsCIELab_ValidSpec(XcmsColor *pColor);
+
+
+/*
+ *	LOCAL VARIABLES
+ */
+
+
+    /*
+     * NULL terminated list of functions applied to get from CIELab to CIEXYZ
+     */
+static XcmsConversionProc Fl_CIELab_to_CIEXYZ[] = {
+    XcmsCIELabToCIEXYZ,
+    NULL
+};
+
+    /*
+     * NULL terminated list of functions applied to get from CIEXYZ to CIELab
+     */
+static XcmsConversionProc Fl_CIEXYZ_to_CIELab[] = {
+    XcmsCIEXYZToCIELab,
+    NULL
+};
+
+
+/*
+ *	GLOBALS
+ */
+    /*
+     * CIE Lab Color Space
+     */
+XcmsColorSpace	XcmsCIELabColorSpace =
+    {
+	_XcmsCIELab_prefix,	/* prefix */
+	XcmsCIELabFormat,		/* id */
+	CIELab_ParseString,	/* parseString */
+	Fl_CIELab_to_CIEXYZ,	/* to_CIEXYZ */
+	Fl_CIEXYZ_to_CIELab,	/* from_CIEXYZ */
+	1
+    };
+
+
+/************************************************************************
+ *									*
+ *			 PRIVATE ROUTINES				*
+ *									*
+ ************************************************************************/
+
+/*
+ *	NAME
+ *		CIELab_ParseString
+ *
+ *	SYNOPSIS
+ */
+static int
+CIELab_ParseString(
+    register char *spec,
+    XcmsColor *pColor)
+/*
+ *	DESCRIPTION
+ *		This routines takes a string and attempts to convert
+ *		it into a XcmsColor structure with XcmsCIELabFormat.
+ *		The assumed CIELab string syntax is:
+ *		    CIELab:<L>/<a>/<b>
+ *		Where L, a, and b 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, _XcmsCIELab_prefix, n) != 0) {
+	return(XcmsFailure);
+    }
+
+    /*
+     * Attempt to parse the value portion.
+     */
+    if (sscanf(spec + n + 1, "%lf/%lf/%lf",
+	    &pColor->spec.CIELab.L_star,
+	    &pColor->spec.CIELab.a_star,
+	    &pColor->spec.CIELab.b_star) != 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.CIELab.L_star,
+		       &pColor->spec.CIELab.a_star,
+		       &pColor->spec.CIELab.b_star) != 3) {
+                free(s);
+                return(XcmsFailure);
+            }
+            free(s);
+        } else
+	    return(XcmsFailure);
+    }
+    pColor->format = XcmsCIELabFormat;
+    pColor->pixel = 0;
+
+    return(XcmsCIELab_ValidSpec(pColor));
+}
+
+
+
+/************************************************************************
+ *									*
+ *			 PUBLIC ROUTINES				*
+ *									*
+ ************************************************************************/
+
+/*
+ *	NAME
+ *		XcmsCIELab_ValidSpec
+ *
+ *	SYNOPSIS
+ */
+static Status
+XcmsCIELab_ValidSpec(
+    XcmsColor *pColor)
+/*
+ *	DESCRIPTION
+ *		Checks if color specification valid for CIE L*a*b*.
+ *
+ *	RETURNS
+ *		XcmsFailure if invalid,
+ *		XcmsSuccess if valid.
+ *
+ */
+{
+    if (pColor->format != XcmsCIELabFormat
+	    ||
+	    (pColor->spec.CIELab.L_star < 0.0 - XMY_DBL_EPSILON)
+	    ||
+	    (pColor->spec.CIELab.L_star > 100.0 + XMY_DBL_EPSILON)) {
+	return(XcmsFailure);
+    }
+    return(XcmsSuccess);
+}
+
+
+/*
+ *	NAME
+ *		XcmsCIELabToCIEXYZ - convert CIELab to CIEXYZ
+ *
+ *	SYNOPSIS
+ */
+Status
+XcmsCIELabToCIEXYZ(
+    XcmsCCC ccc,
+    XcmsColor *pLab_WhitePt,
+    XcmsColor *pColors_in_out,
+    unsigned int nColors)
+/*
+ *	DESCRIPTION
+ *		Converts color specifications in an array of XcmsColor
+ *		structures from CIELab format to CIEXYZ format.
+ *
+ *		WARNING: This routine assumes that Yn = 1.0;
+ *
+ *	RETURNS
+ *		XcmsFailure if failed,
+ *		XcmsSuccess if succeeded.
+ *
+ */
+{
+    XcmsCIEXYZ XYZ_return;
+    XcmsFloat tmpFloat, tmpL;
+    XcmsColor whitePt;
+    int i;
+    XcmsColor *pColor = pColors_in_out;
+
+    /*
+     * Check arguments
+     */
+    if (pLab_WhitePt == NULL || pColors_in_out == NULL) {
+	return(XcmsFailure);
+    }
+
+    /*
+     * Make sure white point is in CIEXYZ form, if not, convert it.
+     */
+    if (pLab_WhitePt->format != XcmsCIEXYZFormat) {
+	/* Make a copy of the white point because we're going to modify it */
+	memcpy((char *)&whitePt, (char *)pLab_WhitePt, sizeof(XcmsColor));
+	if (!_XcmsDIConvertColors(ccc, &whitePt,
+		(XcmsColor *)NULL, 1, XcmsCIEXYZFormat)) {
+	    return(XcmsFailure);
+	}
+	pLab_WhitePt = &whitePt;
+    }
+
+    /*
+     * Make sure it is a white point, i.e., Y == 1.0
+     */
+    if (pLab_WhitePt->spec.CIEXYZ.Y != 1.0) {
+	return (0);
+    }
+
+    /*
+     * Now convert each XcmsColor structure to CIEXYZ form
+     */
+    for (i = 0; i < nColors; i++, pColor++) {
+
+	/* Make sure original format is CIELab */
+	if (!XcmsCIELab_ValidSpec(pColor)) {
+	    return(XcmsFailure);
+	}
+
+	/* Calculate Y: assume that Yn = 1.0 */
+	tmpL = (pColor->spec.CIELab.L_star + 16.0) / 116.0;
+	XYZ_return.Y = tmpL * tmpL * tmpL;
+
+	if (XYZ_return.Y < 0.008856) {
+	    /* Calculate Y: assume that Yn = 1.0 */
+	    tmpL = pColor->spec.CIELab.L_star / 9.03292;
+
+	    /* Calculate X */
+	    XYZ_return.X = pLab_WhitePt->spec.CIEXYZ.X *
+		    ((pColor->spec.CIELab.a_star / 3893.5) + tmpL);
+	    /* Calculate Y */
+	    XYZ_return.Y = tmpL;
+	    /* Calculate Z */
+	    XYZ_return.Z = pLab_WhitePt->spec.CIEXYZ.Z *
+		    (tmpL - (pColor->spec.CIELab.b_star / 1557.4));
+	} else {
+	    /* Calculate X */
+	    tmpFloat = tmpL + (pColor->spec.CIELab.a_star / 5.0);
+	    XYZ_return.X = pLab_WhitePt->spec.CIEXYZ.X * tmpFloat * tmpFloat * tmpFloat;
+
+	    /* Calculate Z */
+	    tmpFloat = tmpL - (pColor->spec.CIELab.b_star / 2.0);
+	    XYZ_return.Z = pLab_WhitePt->spec.CIEXYZ.Z * tmpFloat * tmpFloat * tmpFloat;
+	}
+
+	memcpy((char *)&pColor->spec.CIEXYZ, (char *)&XYZ_return,
+	       sizeof(XcmsCIEXYZ));
+	pColor->format = XcmsCIEXYZFormat;
+    }
+
+    return (1);
+}
+
+
+/*
+ *	NAME
+ *		XcmsCIEXYZToCIELab - convert CIEXYZ to CIELab
+ *
+ *	SYNOPSIS
+ */
+Status
+XcmsCIEXYZToCIELab(
+    XcmsCCC ccc,
+    XcmsColor *pLab_WhitePt,
+    XcmsColor *pColors_in_out,
+    unsigned int nColors)
+/*
+ *	DESCRIPTION
+ *		Converts color specifications in an array of XcmsColor
+ *		structures from CIEXYZ format to CIELab format.
+ *
+ *		WARNING: This routine assumes that Yn = 1.0;
+ *
+ *	RETURNS
+ *		XcmsFailure if failed,
+ *		XcmsSuccess if succeeded.
+ *
+ */
+{
+    XcmsCIELab Lab_return;
+    XcmsFloat fX_Xn, fY_Yn, fZ_Zn;
+    XcmsColor whitePt;
+    int i;
+    XcmsColor *pColor = pColors_in_out;
+
+    /*
+     * Check arguments
+     */
+    if (pLab_WhitePt == NULL || pColors_in_out == NULL) {
+	return(XcmsFailure);
+    }
+
+    /*
+     * Make sure white point is in CIEXYZ form, if not, convert it.
+     */
+    if (pLab_WhitePt->format != XcmsCIEXYZFormat) {
+	/* Make a copy of the white point because we're going to modify it */
+	memcpy((char *)&whitePt, (char *)pLab_WhitePt, sizeof(XcmsColor));
+	if (!_XcmsDIConvertColors(ccc, &whitePt, (XcmsColor *)NULL,
+		1, XcmsCIEXYZFormat)) {
+	    return(XcmsFailure);
+	}
+	pLab_WhitePt = &whitePt;
+    }
+
+    /*
+     * Make sure it is a white point, i.e., Y == 1.0
+     */
+    if (pLab_WhitePt->spec.CIEXYZ.Y != 1.0) {
+	return(XcmsFailure);
+    }
+
+    /*
+     * Now convert each XcmsColor structure to CIEXYZ form
+     */
+    for (i = 0; i < nColors; i++, pColor++) {
+
+	/* Make sure original format is CIELab */
+	if (!_XcmsCIEXYZ_ValidSpec(pColor)) {
+	    return(XcmsFailure);
+	}
+
+	/* Calculate L*:  assume Yn = 1.0 */
+	if (pColor->spec.CIEXYZ.Y < 0.008856) {
+	    fY_Yn = (0.07787 * pColor->spec.CIEXYZ.Y) + DIV16BY116;
+	    /* note fY_Yn used to compute Lab_return.a below */
+	    Lab_return.L_star = 116.0 * (fY_Yn - DIV16BY116);
+	} else {
+	    fY_Yn = (XcmsFloat)XCMS_CUBEROOT(pColor->spec.CIEXYZ.Y);
+	    /* note fY_Yn used to compute Lab_return.a_star below */
+	    Lab_return.L_star = (116.0 * fY_Yn) - 16.0;
+	}
+
+	/* Calculate f(X/Xn) */
+	if ((fX_Xn = pColor->spec.CIEXYZ.X / pLab_WhitePt->spec.CIEXYZ.X) < 0.008856) {
+	    fX_Xn = (0.07787 * fX_Xn) + DIV16BY116;
+	} else {
+	    fX_Xn = (XcmsFloat) XCMS_CUBEROOT(fX_Xn);
+	}
+
+	/* Calculate f(Z/Zn) */
+	if ((fZ_Zn = pColor->spec.CIEXYZ.Z / pLab_WhitePt->spec.CIEXYZ.Z) < 0.008856) {
+	    fZ_Zn = (0.07787 * fZ_Zn) + DIV16BY116;
+	} else {
+	    fZ_Zn = (XcmsFloat) XCMS_CUBEROOT(fZ_Zn);
+	}
+
+	Lab_return.a_star = 5.0 * (fX_Xn - fY_Yn);
+	Lab_return.b_star = 2.0 * (fY_Yn - fZ_Zn);
+
+	memcpy((char *)&pColor->spec.CIELab, (char *)&Lab_return,
+	       sizeof(XcmsCIELab));
+	pColor->format = XcmsCIELabFormat;
+    }
+
+    return(XcmsSuccess);
+}