summaryrefslogtreecommitdiff
path: root/xc/lib/X11/HVCGcV.c
blob: eeb6262a799f864ac70c23120ac3afea8d53bc92 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
/* $Xorg: HVCGcV.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
 *		TekHVCGcV.c
 *
 *	DESCRIPTION
 *		Source for XcmsTekHVCClipV() gamut compression routine.
 *
 */
/* $XFree86: xc/lib/X11/HVCGcV.c,v 1.3 2001/01/17 19:41:37 dawes Exp $ */

#include "Xlibint.h"
#include "Xcmsint.h"

/*
 *	EXTERNS
 */
extern Status _XcmsTekHVC_CheckModify();
extern XcmsColorSpace XcmsTekHVCColorSpace;
extern XcmsFunctionSet	XcmsLinearRGBFunctionSet;

/* CvCols.c */
extern Status _XcmsDIConvertColors();

/* HVCMxVC.c */
extern Status _XcmsTekHVCQueryMaxVCRGB();





/************************************************************************
 *									*
 *			 PUBLIC ROUTINES				*
 *									*
 ************************************************************************/

/*
 *	NAME
 *		XcmsTekHVCClipV - Return the closest value
 *
 *	SYNOPSIS
 */
/* ARGSUSED */
Status
XcmsTekHVCClipV (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 value 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 value within
 *		pColor_in_out intermediate results may be returned
 *		even though it may be invalid.
 *
 *	RETURNS
 *		XcmsFailure - Failure
 *              XcmsSuccess - Succeeded
 *
 */
{
    XcmsColor  *pColor;
    XcmsColor  hvc_max;
    XcmsCCCRec myCCC;
    Status retval;

    /*
     * 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 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 &&
	    FunctionSetOfCCC(ccc) != (XPointer) &XcmsLinearRGBFunctionSet) {
	/*
	 * GRAY !
	 */
	return(XcmsFailure);
    } else {
	/* Convert from CIEXYZ to TekHVC format */
	if (_XcmsDIConvertColors(&myCCC, pColor,
		&myCCC.pPerScrnInfo->screenWhitePt, 1, XcmsTekHVCFormat)
		== XcmsFailure) {
	    return(XcmsFailure);
	}

	/* check to make sure we have a valid TekHVC number */
	if (!_XcmsTekHVC_CheckModify (pColor)) {
	    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 *)&hvc_max, (char *)pColor, sizeof(XcmsColor));
	if (_XcmsTekHVCQueryMaxVCRGB (&myCCC, hvc_max.spec.TekHVC.H, &hvc_max,
		(XcmsRGBi *)NULL) == XcmsFailure) {
	    return (XcmsFailure);
	}

	/* Now check and return the appropriate value */
	if (pColor->spec.TekHVC.C == hvc_max.spec.TekHVC.C) {
	    /* When the chroma input is equal to the maximum chroma */
	    /* merely return the value for that chroma. */
	    pColor->spec.TekHVC.V = hvc_max.spec.TekHVC.V;
	    if (!_XcmsTekHVC_CheckModify (pColor)) {
		return (XcmsFailure);
	    }
	    retval = _XcmsDIConvertColors(&myCCC, pColor,
		    &myCCC.pPerScrnInfo->screenWhitePt, 1, XcmsCIEXYZFormat);
	} else if (pColor->spec.TekHVC.C > hvc_max.spec.TekHVC.C) {
	    /* When the chroma input is greater than the maximum chroma */
	    /* merely return the value and chroma for the given hue. */
	    pColor->spec.TekHVC.C = hvc_max.spec.TekHVC.C;
	    pColor->spec.TekHVC.V = hvc_max.spec.TekHVC.V;
	    return (XcmsFailure);
	} else if (pColor->spec.TekHVC.V < hvc_max.spec.TekHVC.V) {
	    /* When the value input is less than the maximum value point */
	    /* compute the intersection of the line from 0,0 to max_V, max_C */
	    /* using the chroma input. */
	    pColor->spec.TekHVC.V = pColor->spec.TekHVC.C * 
				    hvc_max.spec.TekHVC.V / hvc_max.spec.TekHVC.C;
	    if (pColor->spec.TekHVC.V >= hvc_max.spec.TekHVC.V) {
		pColor->spec.TekHVC.C = hvc_max.spec.TekHVC.C;
		pColor->spec.TekHVC.V = hvc_max.spec.TekHVC.V;
	    }
	    if (!_XcmsTekHVC_CheckModify (pColor)) {
		return (XcmsFailure);
	    }
	    retval = _XcmsDIConvertColors(&myCCC, pColor,
		    &myCCC.pPerScrnInfo->screenWhitePt, 1, XcmsCIEXYZFormat);
	} else {
	    /* When the value input is greater than the maximum value point */
	    /* use HvcMaxValue to find the maximum value for the given chroma. */
	    if (pColor->format != XcmsTekHVCFormat) {
		if (_XcmsDIConvertColors(ccc, pColor,
			&ccc->pPerScrnInfo->screenWhitePt, 1, XcmsCIEXYZFormat)
			== XcmsFailure) {
		    return(XcmsFailure);
		}
	    }
	    if (XcmsTekHVCQueryMaxV(&myCCC,
		    pColor->spec.TekHVC.H,
		    pColor->spec.TekHVC.C,
		    pColor)
		    == XcmsFailure) {
		return (XcmsFailure);
	    }
	    retval = _XcmsDIConvertColors(&myCCC, pColor,
		    &myCCC.pPerScrnInfo->screenWhitePt, 1, XcmsCIEXYZFormat);
	}
	if (retval != XcmsFailure && pCompressed != NULL) {
	    *(pCompressed + i) = True;
	}
	return(retval);
    }
}