/usr/share/psychtoolbox-3/PsychGLImageProcessing/CreateSinglePassImageProcessingShader.m is in psychtoolbox-3-common 3.0.11.20140816.dfsg1-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
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 | function [shader, varargout] = CreateSinglePassImageProcessingShader(windowPtr, shaderType, varargin) %#ok<STOUT>
% Create a single-pass image processing shader for direct use with Screen('DrawTexture')
%
% Usage:
%
% [shader, varargout] = CreateSinglePassImageProcessingShader(windowPtr, shaderType, varargin)
%
% Creates a shader for window 'windowPtr' of type 'shaderType' with
% optional, type specific, parameters. Returns a handle 'shader' and
% optional other properties.
%
% The following types are currently supported:
%
% 'BackgroundMaskOut':
% --------------------
%
% shader = CreateSinglePassImageProcessingShader(windowPtr, 'BackgroundMaskOut', backgroundColor [, tolerance]);
% - This shader draws a texture, but removes all "backgroundColor" pixels
% during drawing, effectively masking them out. 'backgroundColor' is a 3
% component [R, G, B] vector with the RGB color values of the color to be
% considered a background to remove. All color values around an euclidean
% distance of 'tolerance' in 3D color space around the backgroundColor are
% considered background color. The default tolerance is 0.001 units, which
% for 8 bit colors means a perfect match -- zero tolerance.
%
% History:
% 17.07.2011 mk Written.
%
if nargin < 1 || isempty(windowPtr)
error('Required "windowPtr" argument missing!');
end
if nargin < 2 || isempty(shaderType)
error('Required "shaderType" argument missing!');
end
% Detect texture background by color key and mask it out by discarding such
% texels:
if strcmpi(shaderType, 'BackgroundMaskOut')
if length(varargin) < 1
error('Required "backgroundColor" argument missing!');
end
backgroundColor = varargin{1};
if isempty(backgroundColor) || (length(backgroundColor) < 3)
error('"backgroundColor" vector must have at least 3 components for RGB!');
end
if length(varargin) > 1 && ~isempty(varargin{2})
tolerance = varargin{2};
else
tolerance = 0.001;
end
% Remap tolerance and backgroundColor to selected colorRange:
cr = Screen('ColorRange', windowPtr);
if cr ~= 1
backgroundColor = backgroundColor / cr;
tolerance = tolerance / cr;
end
shader = LoadGLSLProgramFromFiles(which('ColorMaskedTextureBlitShader.frag.txt'), 1);
glUseProgram(shader);
glUniform1i(glGetUniformLocation(shader, 'Image'), 0);
glUniform1f(glGetUniformLocation(shader, 'epsilon'), tolerance);
glUniform3fv(glGetUniformLocation(shader, 'backgroundColor'), 1, backgroundColor);
glUseProgram(0);
return;
end
% Unhandled:
error('Unknown or unsupported "shaderType" provided!');
end
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