summaryrefslogtreecommitdiff
path: root/src/xcms/HVCMxVs.c
blob: bc21d941fd9b412f658ecee986275ed44323d3a9 (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
/* $Xorg: HVCMxVs.c,v 1.3 2000/08/17 19:44:37 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
 *		TekHVCMxVs.c
 *
 *	DESCRIPTION
 *		Source for the XcmsTekHVCQueryMaxVSamples() gamut boundary
 *		querying routine.
 */
/* $XFree86: xc/lib/X11/HVCMxVs.c,v 1.4 2003/04/13 19:22:16 dawes Exp $ */

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

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

/*
 *	NAME
 *		XcmsTekHVCQueryMaxVSamples - Compute a set of value/chroma
 *						pairs.
 *
 *	SYNOPSIS
 */
Status
XcmsTekHVCQueryMaxVSamples(ccc, hue, pColor_in_out, nSamples)
    XcmsCCC ccc;
    XcmsFloat hue;
    XcmsColor *pColor_in_out;
    unsigned int nSamples;

/*
 *	DESCRIPTION
 *		Return a set of values and chromas for the input Hue.
 *		This routine will take any color as input.  
 *		It returns TekHVC colors.
 *
 *		Since this routine works with the value within
 *		pColor_in_out 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
 *
 */
{
    XcmsCCCRec myCCC;
    XcmsColor *pHVC;
    XcmsRGBi rgb_saved;
    unsigned short nI;
    XcmsFloat nT;

    /*
     * Check Arguments
     */
    if (ccc == NULL || pColor_in_out == NULL || nSamples == 0) {
	return(XcmsFailure);
    }

    /*
     * Insure TekHVC installed
     */
    if (XcmsAddColorSpace(&XcmsTekHVCColorSpace) == XcmsFailure) {
	return(XcmsFailure);
    }

    /* setup the CCC to use for the conversions. */
    memcpy ((char *) &myCCC, (char *) ccc, sizeof(XcmsCCCRec));
    myCCC.clientWhitePt.format = XcmsUndefinedFormat;
    myCCC.gamutCompProc = (XcmsCompressionProc) NULL;

    /* Step 1: compute the maximum value and chroma for this hue. */


    /* save the Hue for use later. */
    while (hue < 0.0) {
	hue += 360.0;
    }
    while (hue > 360.0) {
	hue -= 360.0;
    }
    pColor_in_out->spec.TekHVC.H = hue;
    pColor_in_out->format = XcmsTekHVCFormat;

    /* Get the maximum value and chroma point for this hue */
    if (_XcmsTekHVCQueryMaxVCRGB(&myCCC, pColor_in_out->spec.TekHVC.H,
	    pColor_in_out, (XcmsRGBi *)&rgb_saved) == XcmsFailure) {
	return (XcmsFailure);
    }

    /* Step 2:  Convert each of the RGBi's to HVC's */
    pHVC = pColor_in_out;
    for (nI = 0; nI < nSamples; nI++, pHVC++) {
	nT = (XcmsFloat) nI / (XcmsFloat) nSamples;
	pHVC->spec.RGBi.red   = rgb_saved.red * (1.0 - nT) + nT;
	pHVC->spec.RGBi.green = rgb_saved.green * (1.0 - nT) + nT;
	pHVC->spec.RGBi.blue  = rgb_saved.blue * (1.0 - nT) + nT;
	pHVC->format          = XcmsRGBiFormat;
	pHVC->pixel           = pColor_in_out->pixel;
	/* convert from RGB to HVC */
	if (_XcmsConvertColorsWithWhitePt(&myCCC, pHVC,
		&myCCC.pPerScrnInfo->screenWhitePt, 1, XcmsTekHVCFormat,
		(Bool *) NULL) == XcmsFailure) {
	    return(XcmsFailure);
	}

	/* make sure to return the input hue */
	pHVC->spec.TekHVC.H = hue;
    }

    return(XcmsSuccess);
}