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
|
<head>
<title>color(3) - Plan 9 from User Space</title>
<meta content="text/html; charset=utf-8" http-equiv=Content-Type>
</head>
<body bgcolor=#ffffff>
<table border=0 cellpadding=0 cellspacing=0 width=100%>
<tr height=10><td>
<tr><td width=20><td>
<tr><td width=20><td><b>COLOR(3)</b><td align=right><b>COLOR(3)</b>
<tr><td width=20><td colspan=2>
<br>
<p><font size=+1><b>NAME </b></font><br>
<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
cmap2rgb, cmap2rgba, rgb2cmap – colors and color maps<br>
</table>
<p><font size=+1><b>SYNOPSIS </b></font><br>
<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
<tt><font size=+1>#include <u.h><br>
#include <libc.h><br>
#include <draw.h>
<table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
</font></tt>
<tt><font size=+1>int rgb2cmap(int red, int green, int blue)
<table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
</font></tt>
<tt><font size=+1>int cmap2rgb(int col)
<table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
</font></tt>
<tt><font size=+1>int cmap2rgba(int col)<br>
</font></tt>
</table>
<p><font size=+1><b>DESCRIPTION </b></font><br>
<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
These routines convert between ‘true color’ red/green/blue triples
and the Plan 9 color map. See <a href="../man7/color.html"><i>color</i>(7)</a> for a description of RGBV,
the standard color map.
<table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
<i>Rgb2cmap</i> takes a trio of color values, scaled from 0 (no intensity)
to 255 (full intensity), and returns the index of the color in
RGBV closest to that represented by those values.
<table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
<i>Cmap2rgb</i> decomposes the color of RGBV index <i>col</i> and returns a
24-bit integer with the low 8 bits representing the blue value,
the next 8 representing green, and the next 8 representing red.
<i>Cmap2rgba</i> decomposes the color of RGBV index <i>col</i> and returns a
32-bit integer with the low 8 bits representing an alpha
value, defined to be 255, and the next 8 representing blue, then
green, then red, as for <i>cmap2rgba</i> shifted up 8 bits. This 32-bit
representation is the format used by <a href="../man3/draw.html"><i>draw</i>(3)</a> and <a href="../man3/memdraw.html"><i>memdraw</i>(3)</a> library
routines that take colors as arguments.<br>
</table>
<p><font size=+1><b>SOURCE </b></font><br>
<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
<tt><font size=+1>/usr/local/plan9/src/libdraw<br>
</font></tt>
</table>
<p><font size=+1><b>SEE ALSO </b></font><br>
<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
<a href="../man3/graphics.html"><i>graphics</i>(3)</a>, <a href="../man3/allocimage.html"><i>allocimage</i>(3)</a>, <a href="../man3/draw.html"><i>draw</i>(3)</a>, <a href="../man7/image.html"><i>image</i>(7)</a>, <a href="../man7/color.html"><i>color</i>(7)</a><br>
</table>
<td width=20>
<tr height=20><td>
</table>
<!-- TRAILER -->
<table border=0 cellpadding=0 cellspacing=0 width=100%>
<tr height=15><td width=10><td><td width=10>
<tr><td><td>
<center>
<a href="../../"><img src="../../dist/spaceglenda100.png" alt="Space Glenda" border=1></a>
</center>
</table>
<!-- TRAILER -->
</body></html>
|