%% Create test data for our animation: a dot moving along a path
% Our aim is to make a circle move around an image along a specified path.
% First, we'll create that path (xpos and ypos)
 
revolution_no = 5;         % how often around the circle
ang_resolution = 40;       % how many points (i.e. frames) per circle
da = 2*pi/ang_resolution;  % delta angle
 
t = 0:da:revolution_no*2*pi;            % time steps
 
% why not a spiral:
pathradius = linspace(0,10,length(t));  % path radius increases each dt
xpos = pathradius.*cos(t);
ypos = pathradius.*sin(t);
 
% show what we have so far:
figure(1);
subplot(1,3,1:2)
plot(t,xpos, '-k'); hold on;
plot(t,ypos, '-r');
set(gca, 'XLim', [0 max(t)]); box off;
xlabel('time steps');  ylabel('x (black) and y (red) pos')
 
subplot(1,3,3)
plot(xpos,ypos,'k'); axis equal; axis off;
title('The path our circle will move along');
 
% We now want to use these x-y coordinates to place a cirle on an image.
% Each iteration, we want the position to be updated so that it appears as
% if the circle moved around the specified path.
% In addition, we want the circle diameter to change as it goes along.
 
circlesize = linspace(0.2,2, length(t)); % circle size increases linearly

%% Test the moving circle and save it as an image sequence
% We'll now plot a circle for each time steps, according to the path and
% size specifications above. I created a separate function to create the
% circle, called 'plotfilledcircle'.
 
axlim = 100;
figure('Position', [100 100 400 400]); % match goal dimensions;
for c = 1:length(t)
    fprintf('Frame: %03d\n', c); % display counter
 
    ph = plotfilledcircle(circlesize(c), [xpos(c) ypos(c)]); % plot circle
    axis off;
    % we need to set the axes to an appropriate limit, otherwise they'll
    % resize to always show the full circle:
    axis([-axlim axlim -axlim axlim]);
    axis square;
 
    pause(0.05); % pause a bit to see animation
end

%% Same as above, but now we save it as an image sequence (TIFF stack)
%
 
axlim = 15;
figh=figure('Position', [100 100 400 400]); % match goal dimensions
for c = 1:length(t)
    fprintf('Frame: %03d\n', c); % display counter
 
    ph=plotfilledcircle(circlesize(c), [xpos(c) ypos(c)]); % plot circle
    axis off;
    % we need to set the axes to an appropriate limit, otherwise they'll
    % resize to always show the full circle:
    axis([-axlim axlim -axlim axlim]);
    axis square;
 
    % We'll save this animation as a tiff stack, so we can load it
    % back later for our grand finale
    currentframe = frame2im(getframe(figh)); % convert fig into image data
    currentframe = im2bw(currentframe,0.4); % make it binary to save space
    pause(0.1); % added to prevent skipped frames
    if c == 1
        imwrite(currentframe, 'tiffstack.tiff', 'WriteMode', 'overwrite');
    else
        imwrite(currentframe, 'tiffstack.tiff', 'WriteMode', 'append');
    end
 
    pause(0.2); % pause a bit to see animation
end

%% Putting it all together
 
% We now want a fancy animation that includes the circle object, as well
% as its position and size data in the form of 'evolving' graphs.
%
% At this point you should think about what resolution your final movie
% might have. This depends on what you want to do. If you need a full-size
% slide for an animation, you might as well just create the animation at
% that size. Chances are, it looks better if PowerPoint doesn't have to
% scale the movie.
% If it's for an HD segment of a movie, use HD sizes (eg. 720p: 1280x720px
% or 1080p: 1920x1080px). HD will result in HUGE movie files if no
% compression is used. Here we'll use 1024x768 pixels, which is the native
% resolution of many projectors and the default on my Keynote documents.
%
% We also want to think about where to place the individual graphs
% It helps to draw it out on a piece of paper.
% For the purpose of this tutorial, we want four axes:
% 1) fill plot of the circle (just like above, but with diff. colors)
% 2) plot of the images we exported above
% 3) evolving graph of the circle size
% 4) evolving graph of the circle's X and Y position
%
% I like to start by setting up the positions of all those elements:
 
fig_pos = [100 40 1024 768]; % position and size of the figure window
 
fillplot_ax_pos = [80 320 400 400];        % position and size of fill plot
image_ax_pos = [580 320 400 400];          % image plot
axlim = 15;
sizedata_ax_pos = [50 170 1024-60 70];     % circle size graph
posdata_ax_pos = [50 50 1024-60 100];      % circle position graph
 
% It's also often useful to define all the colors with variables set up
% top:
 
fig_col = [1 1 1];  % figure background color
text_col = [0 0 0]; % text color
light_grey = [.4 .4 .4];
dark_grey = [.2 .2 .2];
nice_blue = [51/255 51/255 102/255];
light_red = [.6 .4 .4];
 
 
% I like to have a little if-statement, so that only when I set a flag to 1
% will a movie file be created. Set to zero for setting stuff up. When
% you're ready, set it to one.
movieflag = 0;
moviefilename = 'tutorialmovie.avi';
 
% only if our flag is set to 1, will we open up a movie object:
if movieflag == 1
    aviobj = avifile(moviefilename, 'fps', 15, 'compression', 'none');
end
 
startframe = 100; endframe = 120; % which frames to plot (useful for debugging)
% startframe = 1; endframe = length(t); % complete loop
 
fh= figure('color', fig_col, 'name', 'Tutorial animation movie', ...
    'Position', fig_pos);
tic;
fprintf('\nWe are entering the loop...\n');
% ***************  START THE BIG LOOP AFTER CREATING FIG. ***************
for k = startframe:endframe
 
    titlestr = sprintf('Frame: %03d', k); % our title will change
    fprintf('Frame %d\n', k); % print loop counter
 
 
    % ***************  1) FILL PLOT AXES ***************
    fillplot_ax = axes;
    set(fillplot_ax, 'Units', 'pixels', 'Position', fillplot_ax_pos);
 
    p1h(1)=plot(xpos,ypos, '-.');
    set(p1h(1), 'Color', light_grey);
    hold on;
 
    p1h(2) = plotfilledcircle(circlesize(k), [xpos(k) ypos(k)], nice_blue); % plot circle
 
    p1h(3) = line([0 xpos(k)], [0 ypos(k)]);
    set(p1h(3), 'Color', light_red, 'LineWidth', 3);
    hold off;
    % we need to set the axes to an appropriate limit, otherwise they'll
    % resize to always show the full circle:
    axis([-axlim axlim -axlim axlim]);
    axis square;
    th=title(titlestr);
    xlabel('x pos'); ylabel('y pos');
    set(th, 'FontSize', 14); % make title font larger
 
 
    % ***************  2) TIFF IMAGE IMPORT PLOT AXES ***************
    image_ax = axes;
    set(image_ax, 'Units', 'pixels', 'Position', image_ax_pos);
    try
        img = imread('tiffstack.tiff', k); % load image of current index
    catch ME1
        % Get last segment of the error message identifier.
        idSegLast = regexp(ME1.identifier, '(?<=:)\w+$', 'match');
        disp(idSegLast);
        error('Failed loading tiff image');        
    end
    img = xor(1,img); % invert image to make it more exciting... XOR rules!
    imagesc(img);  colormap gray;    axis off; axis image;
 
    th=title('Inverted image from TIFF stack');
    set(th, 'FontSize', 14);
 
 
 
    % *************** 3) SIZE DATA PLOT AXES ***************
    sizedata_ax = axes;
    set(sizedata_ax, 'Units', 'pixels','Position', sizedata_ax_pos);
 
    p2h(1)=plot(t,circlesize,'--');
    set(p2h(1), 'Color', light_grey, 'LineWidth', 1);
    %  create evolving data graph:
    hold on;
    p2h(2)=plot(t(1:k),circlesize(1:k),'-');
    set(p2h(2), 'Color', nice_blue, 'LineWidth', 2);
 
    hold off;
    ylabel('dot size','fontsize',12);
 
    set(sizedata_ax, 'XLim', [0 max(t)]);
    set(gca, 'FontSize', 12);
 
 
    % *************** 4) POSITION DATA PLOT AXES ***************
 
    posdata_ax = axes;
    set(posdata_ax, 'Units', 'pixels', 'Position', posdata_ax_pos);
 
    p3h(1)=plot(t,xpos,'-.');
    set(p3h(1), 'Color', light_grey, 'LineWidth', 1);
    hold on;
    p3h(2)=plot(t,ypos,'--');
    set(p3h(2), 'Color', light_red, 'LineWidth', 1);
 
    p3h(3)=plot(t(1:k), xpos(1:k),'-');
    set(p3h(3), 'Color', dark_grey, 'LineWidth', 2);
 
    p3h(4)=plot(t(1:k), ypos(1:k),'-');
    set(p3h(4), 'Color', light_red, 'LineWidth', 2);
    set(posdata_ax, 'XLim', [0 max(t)]);
 
    xlabel('time','fontsize',12); ylabel('dot pos','fontsize',12);
 
    % Hack to move xlabel in line with the upper one (try without):
    ylabh = get(gca,'YLabel');
    set(ylabh,'Position', get(ylabh,'Position') + [.4 0 0]);
 
    set(gca, 'FontSize', 12);
 
 
 
    % ***************  FINISH THE FRAME (AVI if selected)  ***************
    pause(.2);
    if movieflag == 1
        frame = getframe(gcf);           % capture current figure
        aviobj = addframe(aviobj,frame); % use addframe to append frame
    end
    if k < endframe
        clf; % clear figure except for very last frame
    end
 
end % of the big loop
fprintf('\nDone looping...\n');
 
if movieflag == 1
    fprintf('Saving movie...\n\n');
    aviobj = close(aviobj);
end
toc

function ph = plotfilledcircle(circle_radius,circlecenter, fcol)
%
% plotfilledcircle(circle_radius,circlecenter, fcol)    
%
% Function to plot a filled circle with radius 'circle_radius'
% 'circlecenter' ... center location [0 0] is default
% 'fcol' is optional and defines the face color (black default)
% 
% Armin H 2011
 
if nargin < 2
    circlecenter = [0 0];
end
if nargin < 3
    fcol = [0 0 0];    
end
 
theta = linspace(0,2*pi,100); % 100 points between 0 and 2pi
x = circle_radius*cos(theta) + circlecenter(1);
y = circle_radius*sin(theta) + circlecenter(2);
ph = fill(x, y, 'k');
set(ph, 'FaceColor', fcol);
box off;  axis equal;
 
end