Liren Large Software Subsidy 10/10.iso/l/l460/2.ddi/GRAPHICS.DI$/BLT.M

Text File | 1993-03-07 | 4.2 KB | 171 lines

function output_colors = blt( object, contrastColor, colors )
%BLT Set line and text objects to Black or White.
%    BLT is an M-file that will recursively change the color
%    properties of the given object, or the current Figure window by
%    default, and its children to give proper black on white or white
%    on blackhardcopy output. The color of the line/text object depends
%    on the contrastColor RGB triplet supplied, or the Figure's color
%    attribute if none is supplied.
%
%    Returned are the colors of all line and text objects found while
%    traversing the tree of objects. This can be used to restore the
%    previous colors to all line and text objects.
%
%    See also PRINT.

%       Copyright (c) 1984-93 by The MathWorks, Inc.

%
% input is a) none  b) just colors  c) object and contrastColor  d) everything
%

%
% if only 1 input, it should be nx3 matrix of RGB values
%
if nargin == 1
    if isempty(object)
        return
    end
    colors = object;
    if size(colors,2) ~= 3
        error('Argument must be a 3-column matrix of RGB triplets.');
    end
end

%
% assume current figure if given no input or only colors
%
if nargin < 2
    object = gcf;
    contrastColor = get(gcf,'color');
end

%
% get descendents in family tree of objects
%
kids = get(object, 'Children')';

if (nargin == 2) | (nargin == 0)

    %
    % all current colors will be stored for return
    %
    colors = [];
    old_colors = [];

    if  strcmp(get(object,'type'), 'axes')
        for whichAxis = 'xyz'
            c = get(object, [ whichAxis 'color' ]);
            old_colors = [ old_colors; c];

            if (3 ~= sum(c == [1 1 1])) & (3 ~= sum(c == [0 0 0]))
                %
                % if contrastColor color converted to NTSC gray scale is close
                % to white, set line/text to black, else white
                %
                if (contrastColor * [.3 ; .59 ; .11]) > .75
                    set(object, [ whichAxis 'color' ], 'black');
                else
                    set(object, [ whichAxis 'color' ], 'white');
                end
            end
        end


    %
    % need to replace current colors of line/text objects
    %
    elseif strcmp(get(object,'type'), 'line') | strcmp(get(object,'type'), 'text')
        c = get(object, 'color');
        old_colors = [colors; c];

        %
        % is line/text object not black or white
        %
        if (3 ~= sum(c == [1 1 1])) & (3 ~= sum(c == [0 0 0]))
            %
            % if contrastColor color converted to NTSC gray scale is close
            % to white, set line/text to black, else white
            %
            if (contrastColor * [.3 ; .59 ; .11]) > .75
                set(object, 'color', 'black');
            else
                set(object, 'color', 'white');
            end
        end

    elseif strcmp(get(object,'type'), 'surface')
        %
        % see if it has the attributes of a mesh plot
        %
        c = get(object, 'Facecolor');
        if ( (1 == size(c,1)) & (3 == size(c,2)) ...
          & strcmp('flat', get(object, 'EdgeColor')) )
            %
            % give meshes a grid color that contrasts
            %
            if (contrastColor * [.3 ; .59 ; .11]) > .75
                set(object, 'EdgeColor', 'black');
            else
                set(object, 'EdgeColor', 'white');
            end

            %
            % hold onto handle of this particular mesh object
            % so we can replace flat shading
            %
            old_colors = [colors; [object NaN NaN] ];
        else
            % space holder
            old_colors = [colors; [NaN NaN NaN] ];
        end

    end

    for obj = kids
        old_colors = [ old_colors ; blt(obj, contrastColor) ];
    end

else
    %
    % need to set the object's color back to what it was, the old color
    % was passed in
    %
    old_colors = colors;

    if  strcmp(get(object,'type'), 'axes')
        for whichAxis = 'xyz'
            set(object, [ whichAxis 'color' ], old_colors(1,:) );
            old_colors(1,:) = [];
        end

    elseif strcmp(get(object,'type'), 'line') | strcmp(get(object,'type'), 'text')
        set(object, 'color', old_colors(1,:) );
        old_colors(1,:) = [];

    elseif strcmp(get(object,'type'), 'surface')
        %
        % see if it is one of the mesh objects we turned from flat to colored
        %
        if object == old_colors(1,1)
            set(object, 'Edgecolor', 'flat')
            old_colors(1,:) = [];
        end

    end

    for obj = kids
        old_colors = blt(obj, contrastColor, old_colors);
    end

end

%
% echo the colors we changed, so a future call to blt can use
% swap the colors back, only if user asked for the output or set
% ans if using all default input
%
if (nargout == 1) | (nargin == 0)
    output_colors = old_colors;
end