aboutsummaryrefslogtreecommitdiff
path: root/libX11/src/xcms/XRGB.c
blob: 0d7e24c7d848e53ca71fd774b20cf378b28a4e8f (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
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
/* $Xorg: XRGB.c,v 1.3 2000/08/17 19:45:04 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
 *		XcmsRtoX.c
 *
 *	DESCRIPTION
 *		Convert color specifications in XcmsRGB format in one array of
 *		XcmsColor structures to RGB in an array of XColor structures.
 *
 *
 */
/* $XFree86: xc/lib/X11/XRGB.c,v 3.3 2001/07/29 05:01:11 tsi Exp $ */

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include "Xlibint.h"
#include "Xcmsint.h"
#include "Cv.h"

/*
 *      LOCAL VARIABLES
 */

static unsigned short const MASK[17] = {
    0x0000,	/*  0 bitsPerRGB */
    0x8000,	/*  1 bitsPerRGB */
    0xc000,	/*  2 bitsPerRGB */
    0xe000,	/*  3 bitsPerRGB */
    0xf000,	/*  4 bitsPerRGB */
    0xf800,	/*  5 bitsPerRGB */
    0xfc00,	/*  6 bitsPerRGB */
    0xfe00,	/*  7 bitsPerRGB */
    0xff00,	/*  8 bitsPerRGB */
    0xff80,	/*  9 bitsPerRGB */
    0xffc0,	/* 10 bitsPerRGB */
    0xffe0,	/* 11 bitsPerRGB */
    0xfff0,	/* 12 bitsPerRGB */
    0xfff8,	/* 13 bitsPerRGB */
    0xfffc,	/* 14 bitsPerRGB */
    0xfffe,	/* 15 bitsPerRGB */
    0xffff	/* 16 bitsPerRGB */
};



/************************************************************************
 *									*
 *			API PRIVATE ROUTINES				*
 *									*
 ************************************************************************/

/*
 *	NAME
 *		_XcmsRGB_to_XColor - 
 *
 *	SYNOPSIS
 */
void
_XcmsRGB_to_XColor(
    XcmsColor *pColors,
    XColor *pXColors,
    unsigned int nColors)
/*
 *	DESCRIPTION
 *	    Translates a color specification in XcmsRGBFormat in a XcmsColor
 * 	    structure to an XColor structure.
 *
 *	RETURNS
 *		void.
 */
{
    for (; nColors--; pXColors++, pColors++) {
	pXColors->pixel = pColors->pixel;
	pXColors->red = pColors->spec.RGB.red;
	pXColors->green = pColors->spec.RGB.green;
	pXColors->blue  = pColors->spec.RGB.blue;
	pXColors->flags = (DoRed | DoGreen | DoBlue);
    }
}


/*
 *	NAME
 *		_XColor_to_XcmsRGB
 *
 *	SYNOPSIS
 */
void
_XColor_to_XcmsRGB(
    XcmsCCC ccc,
    XColor *pXColors,
    XcmsColor *pColors,
    unsigned int nColors)
/*
 *	DESCRIPTION
 *		Translates an RGB color specification in an XColor
 *		structure to an XcmsRGB structure.
 *
 *		IMPORTANT NOTE:  Bit replication that may have been caused
 *		with ResolveColor() routine in the X Server is undone
 *		here if requested!  For example, if red = 0xcaca and the
 *		bits_per_rgb is 8, then spec.RGB.red will be 0xca00.
 *
 *	RETURNS
 *		void
 */
{
    int bits_per_rgb = ccc->visual->bits_per_rgb;

    for (; nColors--; pXColors++, pColors++) {
	pColors->spec.RGB.red = (pXColors->red & MASK[bits_per_rgb]);
	pColors->spec.RGB.green = (pXColors->green & MASK[bits_per_rgb]);
	pColors->spec.RGB.blue = (pXColors->blue & MASK[bits_per_rgb]);
	pColors->format = XcmsRGBFormat;
	pColors->pixel = pXColors->pixel;
    }
}


/*
 *	NAME
 *		_XcmsResolveColor
 *
 *	SYNOPSIS
 */
void
_XcmsResolveColor(
    XcmsCCC ccc,
    XcmsColor *pXcmsColor)
/*
 *	DESCRIPTION
 *	    Uses the X Server ResolveColor() algorithm to
 *	    modify values to closest values supported by hardware.
 *	    Old algorithm simply masked low-order bits.  The new algorithm
 *	    has the effect of replicating significant bits into lower order
 *	    bits in order to stretch the hardware value into all 16 bits.
 *
 *	    On a display with N-bit DACs, the "hardware" color is computed as:
 *
 *	    ((unsignedlong)(ClientValue >> (16-N)) * 0xFFFF) / ((1 << N) - 1)
 *		
 *
 *	RETURNS
 *		void.
 */
{
    int shift;
    int max_color;

    shift = 16 - ccc->visual->bits_per_rgb;
    max_color = (1 << ccc->visual->bits_per_rgb) - 1;


    pXcmsColor->spec.RGB.red =
	    ((unsigned long)(pXcmsColor->spec.RGB.red >> shift) * 0xFFFF)
	    / max_color;
    pXcmsColor->spec.RGB.green =
	    ((unsigned long)(pXcmsColor->spec.RGB.green >> shift) * 0xFFFF)
	    / max_color;
    pXcmsColor->spec.RGB.blue =
	    ((unsigned long)(pXcmsColor->spec.RGB.blue  >> shift) * 0xFFFF)
	    / max_color;
}


/*
 *	NAME
 *		_XcmsUnresolveColor
 *
 *	SYNOPSIS
 */
void
_XcmsUnresolveColor(
    XcmsCCC ccc,
    XcmsColor *pColor)
/*
 *	DESCRIPTION
 *		Masks out insignificant bits.
 *
 *	RETURNS
 *		void.
 *
 *	ASSUMPTIONS
 *		format == XcmsRGBFormat
 */
{
    int bits_per_rgb = ccc->visual->bits_per_rgb;

    pColor->spec.RGB.red &= MASK[bits_per_rgb];
    pColor->spec.RGB.green &= MASK[bits_per_rgb];
    pColor->spec.RGB.blue &= MASK[bits_per_rgb];
}


/*
 *	NAME
 *		_XUnresolveColor
 *
 *	SYNOPSIS
 */
void
_XUnresolveColor(
    XcmsCCC ccc,
    XColor *pXColor)
/*
 *	DESCRIPTION
 *		Masks out insignificant bits.
 *
 *	RETURNS
 *		void.
 */
{
    int bits_per_rgb = ccc->visual->bits_per_rgb;

    pXColor->red &= MASK[bits_per_rgb];
    pXColor->green &= MASK[bits_per_rgb];
    pXColor->blue &= MASK[bits_per_rgb];
}