/usr/share/psychtoolbox-3/PsychGLImageProcessing/CreateDisplayWarp.m is in psychtoolbox-3-common 3.0.11.20131230.dfsg1-1build1.
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% [warpstruct, filterMode] = CreateDisplayWarp(window, calibfilename [, showCalibOutput=0]);
%
% Helper routine for Geometric display undistortion mapping, not to be
% called inside normal PTB scripts!
%
% This function reads a display calibration file 'calibfilename' and builds
% a "geometric warp function" based on the calibration information in
% 'calibfilename' for the onscreen window with handle 'window'. It returns
% a struct 'warpstruct' that defines the created warp function. You could
% pass this 'warpstruct' as a parameter to the Psychtoolbox command...
%
% PsychImaging('AddTask', viewchannel, 'GeometryCorrection', warpstruct);
%
% However, you normally do not call this routine directly from your script. Its
% called internally by the PsychImaging() command...
%
% PsychImaging('AddTask', viewchannel, 'GeometryCorrection', calibfilename);
%
% ...in order to setup PTB's imaging pipeline for realtime geometry
% correction, based on the calibration info in the file 'calibfilename'.
%
% Example: You created a calibration file 'mycalib.mat' to undistort the
% left view display of a stereo setup. Then you could apply this
% undistortion function via the following setup code:
%
% PsychImaging('PrepareConfiguration');
% PsychImaging('AddTask', 'LeftView', 'GeometryCorrection', 'mycalib.mat');
% window = PsychImaging('OpenWindow', screenid);
%
% This would open an onscreen window just as window=Screen('OpenWindow', screenid);
% would do. It would configure the window for automatic undistortion based
% on the data in 'mycalib.mat'.
%
% Psychtoolbox provides multiple different interactive setup routines that
% allow you to create a calibration file for your setup. Currently the
% following routines are provided:
%
% DisplayUndistortionBVL.m -- Undistortion based on 3rd order polynomial
% surface. This is the recommended calibration procedure for most cases -
% Proven in real-world use on many different display types.
%
% DisplayUndistortionBezier.m -- Undistortion based on a NURBS surface (Non
% uniform rational bezier spline surface). A simple procedure.
%
% DisplayUndistortionHalfCylinder.m -- Undistortion for projection of
% images to a half-cylindrical projection surface.
%
% DisplayUndistortionSphere.m -- Undistortion for projection of
% images to a spherical or half-spherical projection surface.
%
% DisplayUndistortionCSV.m -- Import undistortion information from
% a .csv file with a warp mesh description suitable for use with NVidia's
% Warp API. This creates a compatible display warping to use of that NVidia
% technology.
%
% History:
% 19.7.2007 Written (MK).
% 17.2.2008 Added undistortion method donated by the Banks Vision Lab (MK).
% 10.3.2008 Fixed image inversion bug in BVL calibration (MK).
% 2.5.2008 Add support for bilinear texture filter shader to handle float
% framebuffers on hw that doesn't filter float textures (MK).
% 13.4.2009 Improved support for bilinear texture filter shaders. (MK).
% Optional 'Query' command to query last warpstruct. (MK).
% Support for half-cylinder projection. (MK).
% 25.8.2011 Adapt code for sphere projection undistortion to new convention
% of Ingmar Schneider's shader code. (MK).
% 27.7.2012 Add support for DisplayUndistortionCSV() aka "NVidia Warp-API" format (MK).
%
% Global GL handle for access to OpenGL constants needed in setup:
global GL;
% Cache last generated warpstruct, so code can easily query it:
persistent oldwarpstruct;
if isempty(GL)
sca;
error('PTB internal error: GL struct not initialized?!?');
end
% Special case of simple query of last created 'warpstruct'?
if nargin == 1
if ~ischar(window)
error('Single provided argument is not a command string!');
end
if ~strcmpi(window, 'Query')
error('Single provided argument is not the command string ''Query''!');
end
% "Query" command recognized. Return last created warpstruct:
warpstruct = oldwarpstruct;
return;
end
if nargin < 2
sca;
error('PTB internal error: Must provide all parameters!');
end
if nargin < 3 || isempty(showCalibOutput)
showCalibOutput = 0;
end
% Is calibfilename a struct with calibration settings, or a filename of a
% calibration file?
if isstruct(calibfilename)
% A struct: Assign it directly.
calib = calibfilename;
else
% Supposedly the filename of a calibration file:
if ~ischar(calibfilename)
error('In setup of geometry undistortion: Parameter "calibfilename" is not a filename string!');
end
% Load calibration file:
if ~exist(calibfilename, 'file')
sca;
error('In setup of geometry undistortion: No such calibration file %s!', calibfilename);
end
calib = load(calibfilename);
end
% Preinit warpstruct:
warpstruct.glsl = [];
warpstruct.gld = [];
% Assume no need for texture filter shader:
needFilterShader = 0;
filterMode = ':Bilinear';
% Do we need a GLSL texture filter shader? We'd need one if the given
% gfx-hardware is not capable of filtering the input image buffer:
winfo = Screen('GetWindowInfo', window);
effectivebpc = 8;
if winfo.BitsPerColorComponent >= 16
% Window is a floating point window with at least 16bpc.
effectivebpc = 16;
if winfo.BitsPerColorComponent >= 32
% All buffers are 32 bpc for certain:
effectivebpc = 32;
end
if (winfo.BitsPerColorComponent == 16)
% First buffer is 16 bpc, following ones could be 32 bpc:
if bitand(winfo.ImagingMode, kPsychUse32BPCFloatAsap)
% All following buffers are 32bpc float. In the tradition of
% "better safe than sorry", we assume that the warp op will use
% one of the 32 bpc float buffers as input.
effectivebpc = 32;
end
end
end
% Highres input buffer?
if effectivebpc > 8
% Yes. Our input is a float texture. Check if the hardware can filter
% textures of effectivebpc bpc in hardware:
if effectivebpc > winfo.GLSupportsFilteringUpToBpc
% Hardware not capable of handling such deep textures. We need to
% create and attach our own bilinear texture filter shader:
needFilterShader = 1;
filterMode = '';
end
end
% Actual setup code for display warp struct.
% ==========================================
% Type of setup depends on type of calibration:
switch(calib.warptype)
case {'HalfCylinderProjection', 'SphereProjection'}
% Build combo of displaylist and GLSL shader for projection of flat
% screen image onto a half-cylinder or sphere:
% Query effective onscreen window size:
[winWidth, winHeight] = Screen('WindowSize', window);
% Build the unwarp mesh display list within the OpenGL context of
% Psychtoolbox:
Screen('BeginOpenGL', window, 1);
% Build a display list that corresponds to the current calibration:
gld = glGenLists(1);
glNewList(gld, GL.COMPILE);
% "Draw" the warp-mesh once, so it gets recorded in the display list:
if isempty(calib.rotationAngle)
calib.rotationAngle = 0;
end
if isempty(calib.inSize)
calib.inSize = [winWidth, winHeight];
end
if isempty(calib.inOffset)
calib.inOffset = [0, 0];
end
if isempty(calib.outOffset)
calib.outOffset = [0, 0];
end
if isempty(calib.outSize)
calib.outSize = [winWidth, winHeight];
end
if isempty(calib.Wflat)
calib.Wflat = 44;
end
if isempty(calib.R)
calib.R = 32;
end
% 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', window);
% Assign display list to output warpstruct:
warpstruct.gld = gld;
if strcmpi(calib.warptype, 'SphereProjection')
% Use spherical projection shader:
warpstruct.glsl = LoadGLSLProgramFromFiles('SphereProjectionShader');
else
% Use cylindrical projection shader:
warpstruct.glsl = LoadGLSLProgramFromFiles('CylinderProjectionShader');
end
glUseProgram(warpstruct.glsl);
glUniform1i(glGetUniformLocation(warpstruct.glsl, 'doFilter'), needFilterShader);
glUniform1i(glGetUniformLocation(warpstruct.glsl, 'Image'), 0);
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);
% Ready.
case {'BezierDisplayList'}
% Build warp display list for Bezier surface based
% calibration/remapping:
Screen('BeginOpenGL', window, 1);
gld = glGenLists(1);
% Build a display list that corresponds to the current calibration:
glNewList(gld, GL.COMPILE);
glColor4f(1,1,1,1);
subdivision = calib.subdivision;
% Setup a 2D parametric grid with 'subdivision' subdivisions:
glMapGrid2d(subdivision, 0, 1, subdivision, 0, 1);
% Enable Bezier evaluators:
glEnable(GL.MAP2_VERTEX_3);
glEnable(GL.MAP2_TEXTURE_COORD_2);
% Setup initial mapping table for texture coordinates (source image control
% points):
frompts = calib.frompts;
% Establish mapping for texture coordinates:
glMap2d(GL.MAP2_TEXTURE_COORD_2, 0, 1, 2, size(frompts,2), 0, 1, 2*size(frompts,2), size(frompts,3), frompts);
% Establish mapping for vertex coordinates:
topts = calib.topts;
% Setup mapping based on current control point matrix for destination
% points:
glMap2d(GL.MAP2_VERTEX_3, 0, 1, 3, size(topts,2), 0, 1, 3*size(topts,2), size(topts,3), topts);
% Compute the mesh based on current mappings:
glEvalMesh2(GL.FILL, 0, subdivision, 0, subdivision);
% Disable mesh evaluators:
glDisable(GL.MAP2_VERTEX_3);
glDisable(GL.MAP2_TEXTURE_COORD_2);
% List ready - and already updated in the imaging pipeline:
glEndList;
% Assign display list to output warpstruct:
warpstruct.gld = gld;
% Ready.
Screen('EndOpenGL', window);
case {'BVLDisplayList'}
% Build warp display list for calibration/remapping method
% donated by the Banks Vision Lab:
% Query effective onscreen window size:
[winWidth, winHeight] = Screen('WindowSize', window);
% Additional optional parameters provided?
xLoomSize = [];
yLoomSize = [];
if nargin >= 5
% At least two additional parameters. Really?
if ~isempty(varargin{1})
xLoomSize = varargin{1};
end
if ~isempty(varargin{2})
yLoomSize = varargin{2};
end
end
% Compute vertex- and texcoord-arrays that define the mesh
% of quadrilaterals which should be rendered (with the stimulus
% texture applied) to create the undistortion warp:
[xyzcalibpos, xytexcoords] = BVLComputeWarpMesh(winWidth, winHeight, calib.scal, showCalibOutput, xLoomSize, yLoomSize);
% Build the unwarp mesh display list within the OpenGL context of
% Psychtoolbox:
Screen('BeginOpenGL', window, 1);
% Build a display list that corresponds to the current calibration:
gld = glGenLists(1);
glNewList(gld, GL.COMPILE);
% "Draw" the warp-mesh once, so it gets recorded in the display list:
glColor4f(1,1,1,1);
glEnableClientState(GL.VERTEX_ARRAY);
glVertexPointer(2, GL.DOUBLE, 0, xyzcalibpos);
glEnableClientState(GL.TEXTURE_COORD_ARRAY);
glTexCoordPointer(2, GL.DOUBLE, 0, xytexcoords);
glDrawArrays(GL.QUADS, 0, length(xyzcalibpos)/2);
glDisableClientState(GL.TEXTURE_COORD_ARRAY);
glDisableClientState(GL.VERTEX_ARRAY);
% List ready - and already updated in the imaging pipeline:
glEndList;
Screen('EndOpenGL', window);
% Assign display list to output warpstruct:
warpstruct.gld = gld;
% Ready.
case {'CSVDisplayList'}
% Build warp display list for a calibration/remapping method that
% is compatible with the method used, e.g., by NVidia's Warp API:
% Query effective onscreen window size:
[winWidth, winHeight] = Screen('WindowSize', window);
% Compute vertex- and texcoord-arrays that define the mesh
% of quadrilaterals which should be rendered (with the stimulus
% texture applied) to create the undistortion warp:
[xyzcalibpos, xytexcoords] = CSVComputeWarpMesh(winWidth, winHeight, calib.scal, showCalibOutput);
% Build the unwarp mesh display list within the OpenGL context of
% Psychtoolbox:
Screen('BeginOpenGL', window, 1);
% Build a display list that corresponds to the current calibration:
gld = glGenLists(1);
glNewList(gld, GL.COMPILE);
% "Draw" the warp-mesh once, so it gets recorded in the display list:
glColor4f(1,1,1,1);
glEnableClientState(GL.VERTEX_ARRAY);
glVertexPointer(2, GL.DOUBLE, 0, xyzcalibpos);
glEnableClientState(GL.TEXTURE_COORD_ARRAY);
glTexCoordPointer(2, GL.DOUBLE, 0, xytexcoords);
glDrawArrays(GL.QUADS, 0, length(xyzcalibpos)/2);
glDisableClientState(GL.TEXTURE_COORD_ARRAY);
glDisableClientState(GL.VERTEX_ARRAY);
% List ready - and already updated in the imaging pipeline:
glEndList;
Screen('EndOpenGL', window);
% Assign display list to output warpstruct:
warpstruct.gld = gld;
% Ready.
otherwise
sca;
error('Unknown calibration method id: %s!', calib.warptype);
end
% Need a filtershader and don't have one assigned yet?
if (needFilterShader > 0) && isempty(warpstruct.glsl)
% Yes. Load, create and assign our default bilinear texture filter
% shader:
warpstruct.glsl = LoadGLSLProgramFromFiles('BilinearTextureFilterShader');
glUseProgram(warpstruct.glsl);
glUniform1i(glGetUniformLocation(warpstruct.glsl, 'Image'), 0);
glUseProgram(0);
end
% Cache created warptstruct for later queries:
oldwarpstruct = warpstruct;
% Done. Return the warpstruct:
return;
% --- Helper routines for setup of the calibration method 'BVLDisplayList' ---
function [xyzcalibpos, xytexcoords] = BVLComputeWarpMesh(windowWidth, windowHeight, scal, showCalibOutput, xLoomSize, yLoomSize)
% [xyzcalibpos, xytexcoords] = BVLComputeWarpMesh(windowWidth, windowHeight, scal, showCalibOutput, xLoomSize, yLoomSize)
%
% Internal helper routine: Called by CreateDisplayWarp.m, which is in turn
% called by PsychImaging.m. Implements the geometric display calibration
% and undistortion procedure developed by the Banks Vision Lab at UC
% Berkeley.
%
% Use the calibration information stored in 'scal', together with the
% current 'windowWidth' and 'windowHeight' of the onscreen window to
% calibrate and compute vectors of vertex coordinates and texture
% coordinates for a mesh that performs the proper "display undistortion".
%
% History:
% 02/17/08 Derived from BFloadtimecalib.m with minimal modifications. (MK)
%
% Check resolution against the calibration file resolutions:
if (windowWidth ~= scal.rect(3)) || (windowHeight ~= scal.rect(4))
fprintf('\n\nCALIBRATION WARNING!\n');
fprintf('Onscreen window resolution (%d, %d) does not match ', ...
windowWidth, windowHeight);
fprintf('the resolution used in the calibration file (%d, %d)!\n', ...
scal.rect(3), scal.rect(4));
fprintf('Using the window resolution to draw the stimuli.\n');
fprintf('\n\n');
end
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% Calibration
% Generate the calibration vertices here so we only do this once.
% We calculate the uncalibrated vertex coordinates, in screenspace
% (pixel coordinates), then pass them into our fitting routine to
% interpolate the calibrated coordinates.
% PreCompute vertex values
if isempty(xLoomSize)
xLoomSize = 73; %length(XVALUES) %Can reduce loom resolution to speed up calib
end
if isempty(yLoomSize)
yLoomSize = 53; %length(YVALUES)
end
xStep = windowWidth / (xLoomSize-1);
yStep = windowHeight / (yLoomSize-1);
numVerts = xLoomSize * yLoomSize;
% vertexCoords = Nx2 array, N rows of [x y] pairs.
vertexCoords = zeros(numVerts, 2);
vertexCoordsFit = zeros(numVerts, 2);
% Calculate the 'uncalibrated' vertex coordinates
for y=1:yLoomSize
for x=1:xLoomSize
index = ((y-1) * xLoomSize) + x;
xCoord = (x-1) * xStep;
yCoord = (y-1) * yStep;
vertexCoords(index, :) = [xCoord yCoord];
%fprintf('(%f, %f)\n', vertexCoords(index, 1), vertexCoords(index, 2));
end
end
% Some debug plots, if requested:
if showCalibOutput
figure(9)
hold off
plot(scal.XCALIBDOTS, scal.YCALIBDOTS, 'b.')
hold on
plot(scal.SELECTXCALIBDOTS, scal.SELECTYCALIBDOTS, 'r.')
size(scal.XCALIBDOTS)
size(scal.YCALIBDOTS)
size(scal.SELECTXCALIBDOTS)
size(vertexCoords(:,1))
size(vertexCoords(:,2))
end
% Fit mesh vertices to locations of calibrated points - Use Matlabs
% griddata fitting and interpolation routine:
if ~IsOctave
% Matlab: Use 'v4' method - the interpolation method used by Matlab V4
% for interpolation:
vertexCoordsFit(:,1)= griddata(scal.XCALIBDOTS, scal.YCALIBDOTS, scal.SELECTXCALIBDOTS, vertexCoords(:,1), vertexCoords(:,2), 'v4'); %#ok<*GRIDD>
vertexCoordsFit(:,2)= griddata(scal.XCALIBDOTS, scal.YCALIBDOTS, scal.SELECTYCALIBDOTS, vertexCoords(:,1), vertexCoords(:,2), 'v4');
else
% Octave: griddata() is also supported by GNU/Octave, but the 'v4' method is
% only supported by Matlab, not by Octave. 'Cubic' isn't supported
% either, so the best we can do is to use the default 'linear' method.
% This is problematic as it creates different results when running on
% Octave vs. Matlab:
% Ok - Actually it doesn't work at all on Octave, because the relevant
% implementation of Octave's griddata() seems to be quite buggy :-(
% TODO FIXME: Is this still true? Octave 3.4 supports 'cubic' and maybe
% 'linear' has been fixed already?
vertexCoordsFit(:,1)= griddata(scal.XCALIBDOTS, scal.YCALIBDOTS, scal.SELECTXCALIBDOTS, vertexCoords(:,1), vertexCoords(:,2));
vertexCoordsFit(:,2)= griddata(scal.XCALIBDOTS, scal.YCALIBDOTS, scal.SELECTYCALIBDOTS, vertexCoords(:,1), vertexCoords(:,2));
end
% Some debug plots, if requested:
if showCalibOutput
figure(10)
hold off
plot(vertexCoords(:,1), vertexCoords(:,2), 'b.')
hold on
plot(vertexCoordsFit(:,1), vertexCoordsFit(:,2), 'r.')
figure(11)
hold off
plot(scal.SELECTXCALIBDOTS, scal.SELECTYCALIBDOTS, 'o')
hold on
plot(vertexCoordsFit(:,1), vertexCoordsFit(:,2), 'r.')
end
% Fit the coordinates to the calibrated space (values are in pixels)
% [vertexCoordsFit(:,1) vertexCoordsFit(:,2)] = BFbvlFitCoords(vertexCoords(:,1), ...
% vertexCoords(:,2), xFitCoef_R, yFitCoef_R);
% Compute final vertex- and texcoords. Need to swap y-positions upside-down
% as our internal vertex/texcoord assignment is upside down wrt. original
% Banks lab calibration:
vertexCoords(:,2) = windowHeight - vertexCoords(:,2);
[xyzcalibpos, xytexcoords] = BVLGeneratetextcoord(yLoomSize, xLoomSize, vertexCoords, vertexCoordsFit, showCalibOutput);
% Done. Return results:
return;
function [xyzcalibpos, xytexcoords]=BVLGeneratetextcoord(yLoomSize, xLoomSize, vertexCoords, vertexCoordsFit, showCalibOutput)
% Internal helper routine: Called by BVLComputeWarpMesh.m.
% Implements the geometric display calibration and undistortion procedure
% developed by the Banks Vision Lab at UC Berkeley.
%
% History:
% 02/17/08 Derived from BFGeneratetextcoord.m with minimal modifications. (MK)
%
numVerts = (xLoomSize-1) * (yLoomSize-1) * 4;
xyzcalibpos = zeros(1, numVerts*2);
xytexcoords = zeros(1, numVerts*2);
xtemp = zeros(1, numVerts);
ytemp = zeros(1, numVerts);
xverts= zeros(1, numVerts);
yverts= zeros(1, numVerts);
vectaddress=0;
if showCalibOutput
figure(100);
axis ij;
hold on;
plot(vertexCoords(:,1), vertexCoords(:,2), 'r.');
plot(vertexCoordsFit(:,1), vertexCoordsFit(:,2), 'b.');
end
for y=1:(yLoomSize-1)
for x=1:(xLoomSize-1)
index = ((y-1) * xLoomSize) + x;
vectaddress=vectaddress+1;
xtemp(vectaddress) = vertexCoords(index, 1); %LowerLeftXTex
ytemp(vectaddress) = vertexCoords(index, 2); %LowerLeftYTex
xverts(vectaddress) = vertexCoordsFit(index, 1); % Lower left fit coord x
yverts(vectaddress) = vertexCoordsFit(index, 2); % lower left fit coord y
vectaddress=vectaddress+1;
xtemp(vectaddress) = vertexCoords(index+1, 1); %LowerrightXTex
ytemp(vectaddress) = vertexCoords(index+1, 2); %LowerrightYTex
xverts(vectaddress) = vertexCoordsFit(index+1, 1); %lower right fit coord x
yverts(vectaddress) = vertexCoordsFit(index+1, 2); %lower right fit coord y
vectaddress=vectaddress+1;
xtemp(vectaddress) = vertexCoords(index+xLoomSize+1, 1); %UpperRightXTex
ytemp(vectaddress) = vertexCoords(index+xLoomSize+1, 2); %UpperRightYTex
xverts(vectaddress) = vertexCoordsFit(index+xLoomSize+1, 1); %Upper right fit coord x
yverts(vectaddress) = vertexCoordsFit(index+xLoomSize+1, 2); %upper right fit coord y
vectaddress=vectaddress+1;
xtemp(vectaddress) = vertexCoords(index+xLoomSize, 1); %UpperLeft X Tex
ytemp(vectaddress) = vertexCoords(index+xLoomSize, 2); %Upperleft Y tex
xverts(vectaddress) = vertexCoordsFit(index+xLoomSize, 1); %upper left fit coord x
yverts(vectaddress) = vertexCoordsFit(index+xLoomSize, 2); %upper left fit coord y
end
end
xyzcalibpos(1:2:end) = xverts;
xyzcalibpos(2:2:end) = yverts;
xytexcoords(1:2:end) = xtemp;
xytexcoords(2:2:end) = ytemp;
return;
% --- End of Helper routines for setup of the calibration method 'BVLDisplayList' ---
% --- Helper routines for setup of the calibration method 'CSVDisplayList' ---
function [xyzcalibpos, xytexcoords] = CSVComputeWarpMesh(windowWidth, windowHeight, scal, showCalibOutput)
% [xyzcalibpos, xytexcoords] = CSVComputeWarpMesh(windowWidth, windowHeight, scal, showCalibOutput)
%
% Use the calibration information stored in 'scal', together with the
% current 'windowWidth' and 'windowHeight' of the onscreen window to
% generate vectors of vertex coordinates and texture coordinates for a mesh
% that performs the proper "display undistortion".
%
% History:
% 07/26/12 Derived from BVLComputeWarpMesh.m with major simplifications. (MK)
%
% Generate the calibration vertices here so we only do this once.
xLoomSize = size(scal.vcoords, 2);
yLoomSize = size(scal.vcoords, 1);
numVerts = xLoomSize * yLoomSize;
% vertexCoords = Nx2 array, N rows of [x y] pairs. Row-Major format encoding.
textureCoords = zeros(numVerts, 2);
vertexCoords = zeros(numVerts, 2);
% Parse the matrices passed in scal and rearrange them to the format of the
% vertexCoords and textureCoords vectors: Scanning is row-major order.
% We also scale all positions with window width and height, as the scal
% matrices contain normalized coordinates in 0.0 - 1.0 range for display
% width/height of a "unit display". vcoords can exceed that range or be
% negative - they are assigned to positions outside the framebuffer.
for y=1:yLoomSize
for x=1:xLoomSize
index = ((y-1) * xLoomSize) + x;
vertexCoords(index, :) = [scal.vcoords(y, x, 1) * windowWidth, scal.vcoords(y, x, 2) * windowHeight];
textureCoords(index, :) = [scal.tcoords(y, x, 1) * windowWidth, scal.tcoords(y, x, 2) * windowHeight];
end
end
% Compute final vertex- and texcoords. Need to swap y-positions upside-down
% as our internal vertex/texcoord assignment is upside down wrt. original
% calibration:
textureCoords(:,2) = windowHeight - textureCoords(:,2);
% Some debug plots, if requested:
if showCalibOutput
figure;
hold on;
axis ij;
plot(textureCoords(:,1), textureCoords(:,2), 'b.');
plot(vertexCoords(:,1), vertexCoords(:,2), 'r.');
hold off;
end
% textureCoords are regularly spaced texture 2D coordinates.
% vertexCoords are irregularly placed vertex 2D coordinates.
[xyzcalibpos, xytexcoords] = BVLGeneratetextcoord(yLoomSize, xLoomSize, textureCoords, vertexCoords, showCalibOutput);
% Done. Return results:
return;
% --- End of helper routines for setup of the calibration method 'CSVDisplayList' ---
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