/usr/share/psychtoolbox-3/PsychDemos/OpenGL4MatlabDemos/UtahTeapotDemo.m is in psychtoolbox-3-common 3.0.11.20131230.dfsg1-1build1.
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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 | function UtahTeapotDemo
% UtahTeapotDemo - Demonstrate use of MATLAB-OpenGL toolbox
%
% This demo demonstrates use of OpenGL commands in a Matlab script to
% perform some 3D animation in Psychtoolbox.
% It shows a randomly spinning, lit teapot, the so called "Utah Teapot".
%
% Stop the demo by pressing any key.
%
% Notable implementation details:
% The call InitializeMatlabOpenGL(1) at the top of the script initializes the
% Matlab-OpenGL toolbox and enables the 3D gfx support in Psychtoolbox to
% allow proper interfacing between the OpenGL toolbox and Psychtoolbox.
%
% After this call, all OpenGL functions are made available to Matlab with
% the same - or a very similar - calling syntax as in the C programming
% language. OpenGL constants are made available in C-Style, e.g.,
% GL_DEPTH_TEST, and in a format that is optimized for Matlab, where the
% first underscore is replaced by a dot, e.g., GL.DEPTH_TEST. The former
% style is more convenient if you want to copy & paste OpenGL code written
% in C into a Matlab M-File for use, but it only works if you put all your
% code into one single M-File or function. The second style works in
% subfunctions as well, if you place the commands "global GL" and "global
% GLU" at the top of each function... This inconvenience is unavoidable due
% to the design of Matlab.
%
% In order to execute OpenGL 3D drawing commands to draw 3D stims into a
% Psychtoolbox Onscreen- or offscreen window, one needs to call
% Screen('BeginOpenGL', windowPtr). After OpenGL drawing and before
% execution of standard Screen() commands, one needs to call
% Screen('EndOpenGL', windowPtr) to tell Psychtoolbox that 3D drawing is
% finished.
%
% Some OpenGL functions that return complex parameters to Matlab are not
% yet implemented - this is work in progress. The performance will be also
% lower than when coding in a compiled language like C++ or C -- that's the
% Matlab tax you'll have to pay ;-)
%
% Apart from that, use of OpenGL for Matlab is the same as OpenGL for the C
% programming language. If you are used to OpenGL coding in C, it should be
% a zero effort transition to code in Matlab+PTB. If you don't know OpenGL
% then get yourself one of the many good books or visit one of the many
% OpenGL tutorials on the internet.
%
% The OpenGL Red Book is a great introduction and reference for OpenGL
% programming. Release 1.0 is available online, later releases can be
% purchased in any good book store:
%
% http://www.opengl.org/documentation/red_book_1.0/
%
% For more infos, code samples, tutorials, online documentation, go to:
%
% http://www.opengl.org
%
% The OpenGL for Matlab toolbox was developed and contributed under
% GPL license by Prof. Richard F. Murray, University of York, Canada.
%
% 15-Dec-2005 -- created (RFM)
% 21-Jan-2006 -- Modified for use with OpenGL-Psychtoolbox (MK)
% 16-Feb-2006 -- Modified for use with new MOGL (MK)
% 05-Mar-2006 -- Cleaned up for public consumption (MK)
% Is the script running in OpenGL Psychtoolbox?
AssertOpenGL;
% Find the screen to use for display:
screenid=max(Screen('Screens'));
% Disable Synctests for this simple demo:
Screen('Preference','SkipSyncTests',1);
% 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);
% 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);
% Get the aspect ratio of the screen:
ar=winRect(4)/winRect(3);
% Turn on OpenGL local lighting model: The lighting model supported by
% OpenGL is a local Phong model with Gouraud shading.
glEnable(GL_LIGHTING);
% Enable the first local light source GL_LIGHT_0. Each OpenGL
% implementation is guaranteed to support at least 8 light sources.
glEnable(GL_LIGHT0);
% Enable two-sided lighting - Back sides of polygons are lit as well.
glLightModelfv(GL_LIGHT_MODEL_TWO_SIDE,GL_TRUE);
% Enable proper occlusion handling via depth tests:
glEnable(GL_DEPTH_TEST);
% Define the cubes light reflection properties by setting up reflection
% coefficients for ambient, diffuse and specular reflection:
glMaterialfv(GL_FRONT_AND_BACK,GL_AMBIENT, [ 1 1 1 1 ]);
glMaterialfv(GL_FRONT_AND_BACK,GL_DIFFUSE, [ .78 .57 .11 1 ]);
glMaterialfv(GL_FRONT_AND_BACK,GL_SPECULAR, [ 1 1 1 1 ]);
glMaterialfv(GL_FRONT_AND_BACK,GL_SHININESS,128);
% Set projection matrix: This defines a perspective projection,
% corresponding to the model of a pin-hole camera - which is a good
% approximation of the human eye and of standard real world cameras --
% well, the best aproximation one can do with 3 lines of code ;-)
glMatrixMode(GL_PROJECTION);
glLoadIdentity;
% Field of view is +/- 25 degrees from line of sight. Objects close than
% 0.1 distance units or farther away than 100 distance units get clipped
% away, aspect ratio is adapted to the monitors aspect ratio:
gluPerspective(25,1/ar,0.1,100);
% Setup modelview matrix: This defines the position, orientation and
% looking direction of the virtual camera:
glMatrixMode(GL_MODELVIEW);
glLoadIdentity;
% Cam is located at 3D position (0,0,10), points upright (0,1,0) and fixates
% at the origin (0,0,0) of the worlds coordinate system:
gluLookAt(0,0,10,0,0,0,0,1,0);
% Setup position and emission properties of the light source:
% Set background color to 'black':
glClearColor(0,0,0,0);
% Point lightsource at (1,2,3)...
glLightfv(GL_LIGHT0,GL_POSITION,[ 0 0 -100 0 ]);
% Emits white (1,1,1,1) diffuse light:
glLightfv(GL_LIGHT0,GL_DIFFUSE, [ 1 1 1 1 ]);
% Emits reddish (1,1,1,1) specular light:
glLightfv(GL_LIGHT0,GL_SPECULAR, [ 1 0 0 1 ]);
% There's also some blue, but weak (R,G,B) = (0.1, 0.1, 0.1)
% ambient light present:
glLightfv(GL_LIGHT0,GL_AMBIENT, [ .1 .1 .6 1 ]);
% Initialize amount and direction of rotation
theta=0;
rotatev=[ 0 0 1 ];
% Animation loop: Run until key press...
while (1)
% Calculate rotation angle for next frame:
theta=mod(theta+0.3,360);
rotatev=rotatev+0.1*[ sin((pi/180)*theta) sin((pi/180)*2*theta) sin((pi/180)*theta/5) ];
rotatev=rotatev/sqrt(sum(rotatev.^2));
% Setup cubes rotation around axis:
glPushMatrix;
glRotated(theta,rotatev(1),rotatev(2),rotatev(3));
% Clear out the backbuffer: This also cleans the depth-buffer for
% proper occlusion handling:
glClear;
glutSolidTeapot(1.0);
glPopMatrix;
% Finish OpenGL rendering into PTB window and check for OpenGL errors.
Screen('EndOpenGL', win);
% Show rendered image at next vertical retrace:
Screen('Flip', win);
% Switch to OpenGL rendering again for drawing of next frame:
Screen('BeginOpenGL', win);
% Check for keyboard press and exit, if so:
if KbCheck
break;
end;
end
% Shut down OpenGL rendering:
Screen('EndOpenGL', win);
% Close onscreen window and release all other ressources:
Screen('CloseAll');
% Reenable Synctests after this simple demo:
Screen('Preference','SkipSyncTests',1);
% Well done!
return
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