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
|
function err = LoadClut(windowPtr,clut,startEntry,bits)
% [err]=LoadClut(windowPtrOrScreenNumber,clut,[startEntry],[bits])
%
% Load the hardware color lookup table (CLUT) of a video screen. It uses
% Screen('LoadCLUT'), as appropriate, to leave the hardware CLUT
% containing the numbers you provide in "clut", with no transformation.
% There *are* restrictions: On Microsoft Windows you can't use CLUTs for
% animation, as the operating system requires all CLUTs to contain mono-
% tonically increasing entries. Psychtoolbox currently has no way of
% detecting the resolution of your graphics cards DAC, so unless you
% explicitly provide the DAC resolution in the optional parameter 'bits',
% it will always assume a 8-Bit DAC. This assumption is safe, but it does
% not allow you to automatically take advantage of higher resolution DACs.
% Apart from that, all pixelSizes are supported. It should works with all
% graphics cards on MacOS-X, Windows and Linux. Fully supports 8-or-more-bit
% DACs.
%
% We *strongly* suggest that all users use Screen('LoadNormalizedGammaTable')
% in new code. Its values range between 0.0 and 1.0 and are independent
% of DAC size, the system automatically maps the range 0.0 - 1.0 to the
% range really available on your graphics card, so no need for you (or for
% Psychtoolbox) to know the resolution of your graphics cards DAC. You will
% always automatically benefit from the highest possible resolution of your
% graphics card.
%
%
% FUNCTION ARGUMENTS:
%
% The err return argument is only here for backwards compatibility to
% the old Psychtoolbox. It always will be empty.
%
% "clut", the user-supplied color table, should be a clutSizex3 matrix.
% Each row in the "clut" matrix is loaded into an RGB entry in the
% hardware CLUT. The values of the matrix elements should be integers in
% the range 0 to 2^bits-1.
%
% The maximum clut size is 256 rows, but you can pass less rows if you only
% want to change a portion of the hardware CLUT.
%
% "startEntry" is optional and determines which hardware CLUT entry to
% load first. Entries are numbered from 0 up. The default is 0. The first
% element of "clut", i.e. clut(1), will be loaded into hardware entry
% "startEntry".
%
% "bits" specifies how many bits you want to write to the CLUT. Typically
% it will be 8 bits, which is the default value. If you set it to
% some other value, the range of allowable entries scales accordingly.
% Thus if you use a 10-bit CLUT, then each entry should be between 0 and
% 1023, etc.
%
% GRAPHICS CARDS WITH MORE-THAN-8-BIT DACS:
%
% Some ATI Radeon's have 10-bit DACs. The BITS++ adapter from Cambridge
% Research Systems has 14-bit DACs.
% http://www.crsltd.com/catalog/bits++/
%
% See also Screen subfunctions 'LoadCLUT', 'LoadNormalizedGammaTable',
% 'ReadNormalizedGammaTable'
% 4/20/06 mk Derived it from the OS-9 PTB's LoadClut.m dated to
% 8/24/02. Only the argument checking and parts of the
% online help text have been used due to the significantly
% different implementation in the OpenGL Psychtoolbox.
% Check the arguments
if nargin<2 || nargin>4
error('USAGE: LoadClut(windowPtr,clut,[startEntry],[bits])');
end
if nargin<4
bits=8;
end
if nargin<3 || isempty(startEntry)
startEntry=0;
end
if startEntry<0 || startEntry>255
error('startEntry %d must be in range 0 to %d',startEntry,255);
end
if max(clut(:))>2^bits-1 || min(clut(:))<0
error(sprintf('\"clut\" values must be in range 0 to %d',2^bits-1));
end
if size(clut,1)<1 || size(clut,1)>256-startEntry
error('Number of rows of clut must be in range 1 to 256-startEntry');
end
if size(clut,2)~=3
error('Number of columns of clut must be 3');
end
% Setup our empty return argument:
err=[];
% Call Screens LoadCLUT and hope the best.
Screen('LoadCLUT', windowPtr, clut, startEntry, bits);
return;
|
