/usr/share/psychtoolbox-3/PsychDemos/OpenGL4MatlabDemos/FloatTextureDemo.m is in psychtoolbox-3-common 3.0.11.20131230.dfsg1-1build1.
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 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 | function FloatTextureDemo(singlefbo, trials)
if nargin < 1
singlefbo=1;
end;
if nargin < 2
trials = 1;
end;
% Is the script running in OpenGL Psychtoolbox?
AssertOpenGL;
% Find the screen to use for display:
screenid=max(Screen('Screens'));
% Setup Psychtoolbox for OpenGL 3D rendering support and initialize the
% mogl OpenGL for Matlab wrapper:
InitializeMatlabOpenGL(1);
% Open a double-buffered full-screen window on the main displays screen.
[win , winRect] = Screen('OpenWindow', screenid);
% Read test input image...
impath = [PsychtoolboxRoot '/PsychDemos/konijntjes1024x768.jpg']
%impath = [PsychtoolboxRoot '/PsychDemos/OpenGL4MatlabDemos/earth_512by256.jpg']
inputimage = imread(impath);
% ...convert into grayscale image...
inputimage = rgb2gray(inputimage);
% inputimage = inputimage(1:256,1:256);
% Pad it to be a square, power-of-two image:
msize = pow2(ceil(log2(max(size(inputimage)))))
tmpimage = zeros(msize, msize);
tmpimage(1:size(inputimage,1), 1:size(inputimage,2)) = inputimage(:,:);
inputimage = tmpimage;
% ...and convert it to texture:
inputtex = Screen('MakeTexture', win, inputimage);
% Retrieve an OpenGL handle to it:
texin = Screen('GetOpenGLTexture', win, inputtex);
% Setup the OpenGL rendering context of the onscreen window for use by
% OpenGL wrapper. After this command, all following OpenGL commands will
% draw into the onscreen window 'win':
Screen('BeginOpenGL', win);
% Use
if glGetIntegerv(GL.MAX_COLOR_ATTACHMENTS_EXT)<2 || singlefbo==0
singlefbo=0;
else
singlefbo=1;
end;
% Create framebuffer objects and color buffer textures:
if singlefbo==0
% Hw only supports one color attachment per FBO. Need to create two
% FBOs for pingpong:
[fbos(1), tex(1)]=moglCreateFBO(msize, msize);
[fbos(2), tex(2)]=moglCreateFBO(msize, msize);
else
% We use one FBO with two color attachments:
[fbos(1), tex ]=moglCreateFBO(msize, msize, 2);
% Set fbos(2) = 0 to signal not to use fbo(2).
fbos(2)=0;
end;
% Load our bias and rescale shader:
glslnormalizer = LoadGLSLProgramFromFiles('ScaleAndBiasShader');
prebias = glGetUniformLocation(glslnormalizer, 'prescaleoffset');
postbias = glGetUniformLocation(glslnormalizer, 'postscaleoffset');
scalefactor = glGetUniformLocation(glslnormalizer, 'scalefactor');
% Activate it for following blit op:
glUseProgram(glslnormalizer);
% Set no bias to be applied:
glUniform1f(prebias, 0.0);
glUniform1f(postbias, 0.0);
% Multiply all luminance values by 255, so they are in usual range 0-255
% instead of 0-1:
glUniform1f(scalefactor, 255.0);
% Bind FBO 1, colorbuffer 1:
moglChooseFBO(fbos(1), 1);
% Blit input image into it, scaling it from 0-1 to 0-255:
moglBlitTexture(texin);
% Disable shader:
glUseProgram(0);
% Read it back (only the RED channel, it is a grayscale image, so
% red, green and blue contain the same content. We read it back to make
% sure we can compare Matlabs results to the GPU results:
inputimage = glReadPixels(0, 0, msize, msize, GL_RED, GL_FLOAT);
% Unbind FBO, reset to normal framebuffer:
moglChooseFBO(0);
% Perform reduce operation to compute texture properties:
[minv, maxv, meanv] = moglComputeMinMaxMeanOfTexture(moglGetTexForFBO(fbos(1), 1), fbos(1), fbos(2), 1);
glFinish;
tic;
for c=1:trials
% We use the texture of fbo(1) as input image, as we know that fbo-1
% will not be used as drawing target in first iteration. We provide
% fbo(1) and fbo(2) as ping-pong buffers for iterative reduce
% operation:
[dminv, dmaxv, dmeanv] = moglComputeMinMaxMeanOfTexture(moglGetTexForFBO(fbos(1), 1), fbos(1), fbos(2), 1);
end;
durationgpu = toc / trials;
minc=min(min(inputimage));
maxc=max(max(inputimage));
meanc=mean(mean(inputimage));
tic;
minc=min(min(inputimage));
maxc=max(max(inputimage));
meanc=mean(mean(inputimage));
durationcpu = toc;
fprintf('Minimum CPU = %f , OpenGL = %f\n', minc, minv);
fprintf('Maximum CPU = %f , OpenGL = %f\n', maxc, maxv);
fprintf('Mean CPU = %f , OpenGL = %f\n', meanc, meanv);
fprintf('Time/pass CPU = %f ms, OpenGL = %f ms\n', durationcpu * 1000, durationgpu * 1000);
% Disable our FBO's:
moglChooseFBO(0);
% Finish OpenGL rendering into PTB window and check for OpenGL errors.
Screen('EndOpenGL', win);
% Render something into visible framebuffer just to check for
% interference...
glClearColor(1,1,0,0);
glClear(GL.COLOR_BUFFER_BIT);
glColor4f(1,0,0,1);
glBegin(GL.TRIANGLES)
glVertex2d(0,0);
glVertex2d(256,0);
glVertex2d(128,256);
glEnd;
% Show rendered image at next vertical retrace:
Screen('Flip', win);
Screen('BeginOpenGL', win);
% Ok draw our image into FBO again, this time normalizing it, so that the
% range [min ; max] maps to interval [0 ; 1]:
% Draw into FBO 1:
moglChooseFBO(fbos(1), 1);
% Activate remap shader for following blit op:
glUseProgram(glslnormalizer);
minv = minv / 255;
maxv = maxv / 255;
sf = 1.0 / (maxv - minv);
% Set bias to be applied: This maps the minimum value to zero:
glUniform1f(prebias, -minv);
% No post-scale bias:
glUniform1f(postbias, 0.0);
% Scale factor to spread out everything into range 0.0 - 1.0:
glUniform1f(scalefactor, sf);
% Blit input image into it, remapping/normalizing it to range 0.0 - 1.0:
moglBlitTexture(texin);
% Disable shader:
glUseProgram(0);
% Read blitted textures back from FBOs:
% This shows the normalized 0-1 edge-map:
moglChooseFBO(fbos(1), 1);
img = glReadPixels(0, 0, msize, msize, GL_RGB, GL_FLOAT);
imshow(img);
figure
%
if singlefbo==0
% Dual FBO-case:
moglChooseFBO(fbos(2), 1);
else
% Dual color buffer on single FBO case:
moglChooseFBO(fbos(1), 2);
end;
img2 = glReadPixels(0, 0, msize, msize, GL_RGB, GL_FLOAT);
imshow(img2, [0 255]);
figure
% Unbind FBO, reset to normal framebuffer:
moglChooseFBO(0);
% Delete all FBO's:
for i=1:length(fbos)
moglDeleteFBO(fbos(i));
end;
% Shut down OpenGL rendering:
Screen('EndOpenGL', win);
% Close onscreen window and release all other ressources:
Screen('CloseAll');
imshow(inputimage, [0 255]);
% Well done!
return
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