zoom.m

matlab6.5

function out = zoom(varargin)
%ZOOM   Zoom in and out on a 2-D plot.
%   ZOOM with no arguments toggles the zoom state.
%   ZOOM(FACTOR) zooms the current axis by FACTOR.
%       Note that this does not affect the zoom state.
%   ZOOM ON turns zoom on for the current figure.
%   ZOOM XON or ZOOM YON turns zoom on for the x or y axis only.
%   ZOOM OFF turns zoom off in the current figure.
%   ZOOM RESET resets the zoom out point to the current zoom.
%   ZOOM OUT returns the plot to its current zoom out point.
%   If ZOOM RESET has not been called this is the original
%   non-zoomed plot.  Otherwise it is the zoom out point
%   set by ZOOM RESET.
%
%   When zoom is on, click the left mouse button to zoom in on the
%   point under the mouse.  Click the right mouse button to zoom out.
%   Each time you click, the axes limits will be changed by a factor 
%   of 2 (in or out).  You can also click and drag to zoom into an area.
%   It is not possible to zoom out beyond the plots' current zoom out
%   point.  If ZOOM RESET has not been called the zoom out point is the
%   original non-zoomed plot.  If ZOOM RESET has been called the zoom out
%   point is the zoom point that existed when it was called.
%   Double clicking zooms out to the current zoom out point - 
%   the point at which zoom was first turned on for this figure 
%   (or to the point to which the zoom out point was set by ZOOM RESET).
%   Note that turning zoom on, then off does not reset the zoom out point.
%   This may be done explicitly with ZOOM RESET.
%   
%   ZOOM(FIG,OPTION) applies the zoom command to the figure specified
%   by FIG. OPTION can be any of the above arguments.

%   ZOOM FILL scales a plot such that it is as big as possible
%   within the axis position rectangle for any azimuth and elevation.

%   Clay M. Thompson 1-25-93
%   Revised 11 Jan 94 by Steven L. Eddins
%   Copyright 1984-2002 The MathWorks, Inc. 
%   $Revision: 5.63 $  $Date: 2002/04/08 21:44:39 $

%   Note: zoom uses the figure buttondown and buttonmotion functions
%
%   ZOOM XON zooms x-axis only
%   ZOOM YON zooms y-axis only


%
% PARSE ARGS - set fig and zoomCommand
%
switch nargin
    % no arg in
case 0
    zoomCommand='toggle';
    fig=get(0,'currentfigure');
    if isempty(fig)
        return
    end
    % one arg in 
case 1
    % If argument is string, it is a zoom command
    % (i.e. (on, off, down, xdown, etc.). 
    if isstr(varargin{1})
        zoomCommand=varargin{1};
        % Otherwise, the argument is assumed to be a zoom factor.
    else
        scale_factor=varargin{1};
        zoomCommand='scale';
    end 
    fig=get(0,'currentfigure');
    if isempty(fig)
        return
    end
    % two arg in
case 2
    fig=varargin{1};
    if ~ishandle(fig)
        error('First argument must be a figure handle.')
    end
    zoomCommand=varargin{2};
    % too many args
otherwise
    error(nargchk(0, 2, nargin));
end % switch nargin

%------------------------------------------------------------------------------%

zoomCommand=lower(zoomCommand);

%
% zoomCommand 'off'
%
if strcmp(zoomCommand,'off')
    % turn zoom off
    doZoomOff(fig);
    scribefiglisten(fig,'off');
    state = getappdata(fig,'ZOOMFigureState');
    if ~isempty(state)
        % since we didn't set the pointer,
        % make sure it does not get reset
        ptr = get(fig,'pointer');
        % restore figure and non-uicontrol children
        % don't restore uicontrols because they were restored
        % already when zoom was turned on
        uirestore(state,'nouicontrols');
        set(fig,'pointer',ptr)
        if isappdata(fig,'ZOOMFigureState')
            rmappdata(fig,'ZOOMFigureState');
        end
        % get rid of on state appdata if it exists
        % the non-existance of this appdata
        % indicates that zoom is off.
        if isappdata(fig,'ZoomOnState')
            rmappdata(fig,'ZoomOnState');
        end
        
    end
    % done, go home.
    return
end

%---------------------------------------------------------------------------------%

%
% set some things we need for other zoomCommands
%
ax=get(fig,'currentaxes');
rbbox_mode = 0;
% initialize unconstrained state
zoomx = 1; zoomy = 1;
% catch 3d zoom
if ~isempty(ax) & any(get(ax,'view')~=[0 90]) ...
        & ~(strcmp(zoomCommand,'scale')| ...
        strcmp(zoomCommand,'fill'))
    fZoom3d = 1;
else
    fZoom3d = 0;
end

%----------------------------------------------------------------------------------%

%
% the zoomCommand is 'toggle'
%
if strcmp(zoomCommand,'toggle'),
    state = getappdata(fig,'ZOOMFigureState');
    if isempty(state)
        zoom(fig,'on');
    else
        zoom(fig,'off');
    end
    % done, go home
    return
end % if

%----------------------------------------------------------------------------------%

%
% Set/check a few more things before switching to one of remaining zoom actions
%

% Set zoomx,zoomy and zoomCommand for constrained zooms
if strcmp(zoomCommand,'xdown'),
    zoomy = 0; zoomCommand = 'down'; % Constrain y
elseif strcmp(zoomCommand,'ydown')
    zoomx = 0; zoomCommand = 'down'; % Constrain x
end

% Catch bad argin/argout match
if (nargout ~= 0) & ...
        ~isequal(zoomCommand,'getmode') & ...
        ~isequal(zoomCommand,'getlimits') & ...
        ~isequal(zoomCommand,'getconnect')
    error(['ZOOM only returns an output if the command is getmode,' ...
            ' getlimits, or getconnect']);
end

%----------------------------------------------------------------------------------%

%
% Switch for rest of zoomCommands
%

switch zoomCommand
case 'down'
    % Activate axis that is clicked in
    allAxes = findall(datachildren(fig),'flat','type','axes');
    ZOOM_found = 0;
    
    % this test may be causing failures for 3d axes
    for i=1:length(allAxes)
        ax=allAxes(i);
        ZOOM_Pt1 = get(ax,'CurrentPoint');
        xlim = get(ax,'xlim');
        ylim = get(ax,'ylim');
        if (xlim(1) <= ZOOM_Pt1(1,1) & ZOOM_Pt1(1,1) <= xlim(2) & ...
                ylim(1) <= ZOOM_Pt1(1,2) & ZOOM_Pt1(1,2) <= ylim(2))
            ZOOM_found = 1;
            set(fig,'currentaxes',ax);
            break
        end
    end
    
    if ZOOM_found==0
        return
    end
    
    % Check for selection type
    selection_type = get(fig,'SelectionType');
    zoomMode = getappdata(fig,'ZOOMFigureMode');
    
    axz = get(ax,'ZLabel');
    
    if fZoom3d
        viewData = getappdata(axz,'ZOOMAxesView');
        if isempty(viewData)
            viewProps = { 'CameraTarget'...
                    'CameraTargetMode'...
                    'CameraViewAngle'...
                    'CameraViewAngleMode'};
            setappdata(axz,'ZOOMAxesViewProps', viewProps);
            setappdata(axz,'ZOOMAxesView', get(ax,viewProps));
        end
        if isempty(zoomMode) | strcmp(zoomMode,'in');
            zoomLeftFactor = 1.5;
            zoomRightFactor = .75;         
        elseif strcmp(zoomMode,'out');
            zoomLeftFactor = .75;
            zoomRightFactor = 1.5;
        end
        switch selection_type
        case 'open'
            set(ax,getappdata(axz,'ZOOMAxesViewProps'),...
                getappdata(axz,'ZOOMAxesView'));
        case 'normal'
            newTarget = mean(get(ax,'CurrentPoint'),1);
            set(ax,'CameraTarget',newTarget);
            camzoom(ax,zoomLeftFactor);
        otherwise
            newTarget = mean(get(ax,'CurrentPoint'),1);
            set(ax,'CameraTarget',newTarget);
            camzoom(ax,zoomRightFactor);
        end
        return
    end
    
    if isempty(zoomMode) | strcmp(zoomMode,'in');
        switch selection_type
        case 'normal'
            % Zoom in
            m = 1;
            scale_factor = 2; % the default zooming factor
        case 'open'
            % Zoom all the way out
            zoom(fig,'out');
            return;
        otherwise
            % Zoom partially out
            m = -1;
            scale_factor = 2;
        end
    elseif strcmp(zoomMode,'out')
        switch selection_type
        case 'normal'
            % Zoom partially out
            m = -1;
            scale_factor = 2;
        case 'open'
            % Zoom all the way out
            zoom(fig,'out');
            return;
        otherwise
            % Zoom in
            m = 1;
            scale_factor = 2; % the default zooming factor
        end
    else % unrecognized zoomMode
        return
    end
    
    ZOOM_Pt1 = get_currentpoint(ax);
    ZOOM_Pt2 = ZOOM_Pt1;
    center = ZOOM_Pt1;
    
    if (m == 1)
        % Zoom in
        units = get(fig,'units'); set(fig,'units','pixels')
        
        rbbox([get(fig,'currentpoint') 0 0],get(fig,'currentpoint'),fig);
        
        ZOOM_Pt2 = get_currentpoint(ax);
        set(fig,'units',units)
        
        % Note the currentpoint is set by having a non-trivial up function.
        if min(abs(ZOOM_Pt1-ZOOM_Pt2)) >= ...
                min(.01*[diff(get_xlim(ax)) diff(get_ylim(ax))]),
            % determine axis from rbbox 
            a = [ZOOM_Pt1;ZOOM_Pt2]; a = [min(a);max(a)];
            
            % Undo the effect of get_currentpoint for log axes
            if strcmp(get(ax,'XScale'),'log'),
                a(1:2) = 10.^a(1:2);
            end
            if strcmp(get(ax,'YScale'),'log'),
                a(3:4) = 10.^a(3:4);
            end
            rbbox_mode = 1;
        end
    end
    limits = zoom(fig,'getlimits');
    
case 'scale',
    if all(get(ax,'view')==[0 90]), % 2D zooming with scale_factor
        
        % Activate axis that is clicked in
        ZOOM_found = 0;
        ax = gca;
        xlim = get(ax,'xlim');
        ylim = get(ax,'ylim');
        ZOOM_Pt1 = [sum(xlim)/2 sum(ylim)/2];
        ZOOM_Pt2 = ZOOM_Pt1;
        center = ZOOM_Pt1;
        
        if (xlim(1) <= ZOOM_Pt1(1,1) & ZOOM_Pt1(1,1) <= xlim(2) & ...
                ylim(1) <= ZOOM_Pt1(1,2) & ZOOM_Pt1(1,2) <= ylim(2))
            ZOOM_found = 1;
        end % if
        
        if ZOOM_found==0, return, end
        
        if (scale_factor >= 1)
            m = 1;
        else
            m = -1;
        end
        
    else % 3D
        old_CameraViewAngle = get(ax,'CameraViewAngle')*pi/360;
        ncva = atan(tan(old_CameraViewAngle)*(1/scale_factor))*360/pi;