function DisplayUndistortionHalfCylinder(calibfilename, screenid)
% Create geometric display calibration file for projection onto a cylinder or sphere.
%
% CAUTION: This function is not fully implemented and tested! It may or
% may not work for your purpose and may give totally wrong results.
%
% Usage:
%
% DisplayUndistortionHalfCylinder([calibfilename][, screenid]);
%
% Prepare display calibration file for projection of a flat screen image to
% a half-cylindrical projection surface.
%
% The script displays a calibration grid on screen 'screenid' (or the
% auto-selected screen if this parameter is omitted). Use the keys
% mentioned below to modify the grid until it is optimally aligned with
% your cylindrical projection surface. Save the final calibration settings
% to file 'calibfilename' (or an auto-selected default filename, if
% parameter is omitted) by pressing the 's' key. Exit the procedure via
% pressing the ESCape key.
%
% The saved calibration file can be later loaded and applied in a script
% via the command sequence that this script will diplay when it is
% finished.
%
%
% Keys and their meaning:
% ESCape = Quit script. Unsaved changes will be lost!
% s = Save current settings in calibration file.
% r = Change rotation angle.
% t = Change translation of output image.
% o = Change size of output image.
% i = Change size of input image.
% w = Width of the projection area at a radius distance R in cm for
% sphere curvature correction.
% b = Radius of the spherical projection screen for sphere curvature correction.
%
% -> Type "edit SphereProjectionShader.frag.txt" and look at the warp
% shader code for a full understanding of the roff and rpow coefficients
% for spherical remapping. Also see Psychtoolbox forum message 11660.
%
%
% Arrow keys change the parameter that is selected via 'r', 't', 'o' or 'i'
% key.
%
% History:
% 13.4.2009 mk Written.
% 19.12.2010 mk Updated with roff, rpow parameter setting for spherical
% projections as suggested by Ingmar Schneider.
% 25.8.2011 mk Adapt code for sphere projection undistortion to new
% convention of Ingmar Schneider's shader code.
global GL;
PsychDefaultSetup(1);
correctiontype = input('Cylinder projection (c) or sphere projection (s)? ', 's');
if ~ismember(correctiontype, {'c','s'})
error('Invalid correction type provided! Must be ''s'' or ''c''.');
end
KbName('UnifyKeyNames');
UpArrow = KbName('UpArrow');
DownArrow = KbName('DownArrow');
LeftArrow = KbName('LeftArrow');
RightArrow = KbName('RightArrow');
esckey = KbName('ESCAPE');
rkey = KbName('r');
tkey = KbName('t');
okey = KbName('o');
ikey = KbName('i');
skey = KbName('s');
Wflatkey = KbName('w');
Rkey = KbName('b');
if ~exist('screenid', 'var') || isempty(screenid)
screenid=max(Screen('Screens'));
end
if ~exist('calibfilename', 'var')
calibfilename = [];
end
if isempty(calibfilename)
% Nope: Assign default name - Store in dedicated subfolder of users PTB
% config dir, with a well defined name that also encodes the screenid
% and resolution for which to calibrate:
[w, h] = Screen('WindowSize', screenid);
if correctiontype == 'c'
defname = 'HalfCylinderCalibdata';
else
defname = 'SphereCalibdata';
end
calibfilename = [ PsychtoolboxConfigDir('GeometryCalibration') defname sprintf('_%i_%i_%i', screenid, w, h) '.mat'];
fprintf('\nNo name for calibration file provided. Using default name and location...\n');
end
% Print name of calibfile and check for existence of file:
fprintf('Name of calibration result file: %s\n\n', calibfilename);
if exist(calibfilename, 'file')
answer = input('This file already exists. Overwrite it [y/n]? ','s');
if ~strcmp(lower(answer), 'y') %#ok<STCI>
fprintf('\n\nCalibration aborted. Please choose a different name for calibration result file.\n\n');
return;
end
end
% Create initial default cylinder undistortion calibration struct:
if correctiontype == 'c'
calib.warptype = 'HalfCylinderProjection';
else
calib.warptype = 'SphereProjection';
end
calib.rotationAngle = [];
calib.inSize = [];
calib.inOffset = [];
calib.outOffset = [];
calib.outSize = [];
calib.Wflat = [];
calib.R = [];
firsttime = 1;
try
ListenChar(2);
% Open onscreen window, with this calibration applied:
% Prepare pipeline for configuration. This marks the start of a list of
% requirements/tasks to be met/executed in the pipeline:
PsychImaging('PrepareConfiguration');
PsychImaging('AddTask', 'AllViews', 'GeometryCorrection', calib);
win =PsychImaging('OpenWindow', screenid, 0);
Screen('TextSize', win, 16);
% Alpha blending for nice anti-aliased calibration dot grid:
Screen('Blendfunction', win, GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
% Assign reasonable defaults for all calibration parameters:
[winWidth, winHeight] = Screen('WindowSize', win);
calib.rotationAngle = 0;
calib.inSize = [winWidth, winHeight];
calib.inOffset = [0, 0];
calib.outOffset = [0, 0];
calib.outSize = [winWidth, winHeight];
% These screen width, and sphere radius settings are reasonable
% defaults, used by Ingmar Schneider for a tested spherical display
% setup:
calib.Wflat = 44.5;
calib.R = 32.0392;
% Query generated warpstruct:
warpstruct = CreateDisplayWarp('Query');
% Build dotgrid for visualization of current structure:
[y,x] = meshgrid(0:10:winHeight, 0:10:winWidth);
xy = [x(:)' ; y(:)'];
xylines = zeros(2,0);
li = 0;
for i = 1:length(y)
li = li + 10;
xylines = [ xylines, [1, li]', [winWidth-1, li]' ]; %#ok<AGROW>
end
for i = 1:length(x)
li = x(i);
xylines = [ xylines, [li, 0]', [li, winHeight]' ]; %#ok<AGROW>
end
mode = 1;
% Visualization and recalibration loop:
while 1
% Draw calibration grid:
Screen('DrawLines', win, xylines, 1, [0 255 0], [],1);
Screen('DrawDots', win, xy, 4, [255 255 0], [], 1);
% Show updated calibration:
Screen('Flip',win);
% Keypress?
[down, secs, keyCode] = KbCheck;
if down || firsttime
if keyCode(skey)
% Save current calibration:
warptype = calib.warptype; %#ok<NASGU>
rotationAngle = calib.rotationAngle; %#ok<NASGU>
inSize = calib.inSize; %#ok<NASGU>
inOffset = calib.inOffset; %#ok<NASGU>
outOffset = calib.outOffset; %#ok<NASGU>
outSize = calib.outSize; %#ok<NASGU>
Wflat = calib.Wflat; %#ok<NASGU>
R = calib.R; %#ok<NASGU>
% Save all relevant calibration variables to file 'calibfilename'. This
% method should work on both, Matlab 6.x, 7.x, ... and GNU/Octave - create
% files that are readable by all runtime environments:
save(calibfilename, 'warptype', 'rotationAngle', 'inSize', 'inOffset', 'outOffset', 'outSize', 'Wflat', 'R', '-mat', '-V6');
Beeper;
continue;
end
if keyCode(esckey)
break;
end
if keyCode(rkey)
mode = 1;
end
if keyCode(tkey)
mode = 2;
end
if keyCode(okey)
mode = 3;
end
if keyCode(ikey)
mode = 4;
end
if keyCode(Wflatkey)
mode = 5;
end
if keyCode(Rkey)
mode = 6;
end
dx = 0;
if keyCode(LeftArrow)
dx = -1;
end
if keyCode(RightArrow)
dx = +1;
end
dy = 0;
if keyCode(UpArrow)
dy = -1;
end
if keyCode(DownArrow)
dy = +1;
end
switch(mode)
case 1,
calib.rotationAngle = calib.rotationAngle + dx / 10;
case 2,
calib.outOffset = calib.outOffset + [dx, dy];
case 3,
calib.outSize = calib.outSize + [dx, dy];
case 4,
calib.inSize = calib.inSize + [dx, dy];
case 5,
old = calib.Wflat;
Screen('HookFunction', win, 'Disable', 'StereoLeftCompositingBlit');
calib.Wflat = GetEchoNumber(win, sprintf('Enter width of the projection area in cm at the radius distance R in cm for sphere proj. [%f]: ', calib.Wflat), 30, 30, 255, []);
Screen('HookFunction', win, 'Enable', 'StereoLeftCompositingBlit');
if isempty(calib.Wflat)
calib.Wflat = old;
end
mode = -1;
case 6,
old = calib.R;
Screen('HookFunction', win, 'Disable', 'StereoLeftCompositingBlit');
calib.R = GetEchoNumber(win, sprintf('Enter radius of the used spherical screen in cm for sphere proj. [%f]: ', calib.R), 30, 30, 255, []);
Screen('HookFunction', win, 'Enable', 'StereoLeftCompositingBlit');
if isempty(calib.R)
calib.R = old;
end
mode = -1;
otherwise
continue
end
% Build the unwarp mesh display list within the OpenGL context of
% Psychtoolbox:
Screen('BeginOpenGL', win, 1);
% Build a display list that corresponds to the current calibration:
glNewList(warpstruct.gld, GL.COMPILE);
% "Draw" the warp-mesh once, so it gets recorded in the display
% list:
% No color gain correction:
glColor4f(1,1,1,1);
glTranslatef(calib.outOffset(1), calib.outOffset(2), 0);
% Apply some rotation correction for misaligned displays:
glTranslatef(calib.outSize(1)/2, calib.outSize(2)/2, 0);
glRotatef(calib.rotationAngle, 0.0, 0.0, 1.0);
glTranslatef(-calib.outSize(1)/2, -calib.outSize(2)/2, 0);
% Draw a single default quad:
glBegin(GL.QUADS)
glTexCoord2f(0,calib.outSize(2));
glVertex2f(0,0);
glTexCoord2f(calib.outSize(1),calib.outSize(2));
glVertex2f(calib.outSize(1),0);
glTexCoord2f(calib.outSize(1),0);
glVertex2f(calib.outSize(1),calib.outSize(2));
glTexCoord2f(0,0);
glVertex2f(0,calib.outSize(2));
glEnd;
% List ready - and already updated in the imaging pipeline:
glEndList;
Screen('EndOpenGL', win);
% Update shader settings:
glUseProgram(warpstruct.glsl);
glUniform2f(glGetUniformLocation(warpstruct.glsl, 'inSize'), calib.inSize(1), calib.inSize(2));
glUniform2f(glGetUniformLocation(warpstruct.glsl, 'inOffset'), calib.inOffset(1), calib.inOffset(2));
glUniform2f(glGetUniformLocation(warpstruct.glsl, 'outSize'), calib.outSize(1), calib.outSize(2));
if strcmpi(calib.warptype, 'SphereProjection')
% Additional parameters for sphere projection:
glUniform1f(glGetUniformLocation(warpstruct.glsl, 'Wflat'), calib.Wflat);
glUniform1f(glGetUniformLocation(warpstruct.glsl, 'R'), calib.R);
end
glUseProgram(0);
% Play tricks to get rid of visual artifacts:
Screen('HookFunction', win, 'Disable', 'StereoLeftCompositingBlit');
Screen('FillRect', win, 0);
Screen('Flip', win);
Screen('Flip', win);
Screen('HookFunction', win, 'Enable', 'StereoLeftCompositingBlit');
firsttime = 0;
else
WaitSecs(0.01);
end
% Next iteration.
end
% Done.
sca;
ListenChar(0);
fprintf('Calibration finished :-)\n\n');
fprintf('You can apply the calibration in your experiment script by replacing your \n')
fprintf('win = Screen(''OpenWindow'', ...); command by the following sequence of \n');
fprintf('commands:\n\n');
fprintf('PsychImaging(''PrepareConfiguration'');\n');
fprintf('PsychImaging(''AddTask'', ''LeftView'', ''GeometryCorrection'', ''%s'');\n', calibfilename);
fprintf('win = PsychImaging(''OpenWindow'', ...);\n\n');
fprintf('This would apply the calibration to the left-eye display of a stereo setup.\n');
fprintf('Additional options would be ''RightView'' for the right-eye display of a stereo setup,\n');
fprintf('or ''AllViews'' for both views of a stereo setup or the single display of a mono\n');
fprintf('setup.\n\n');
return;
catch
sca;
ListenChar(0);
psychrethrow(psychlasterror);
end