[Blindmath] Using color in SVGDraw01

[Richard Baldwin]

The most recent four or five versions of SVGDraw01 have supported color for
strokes and fills. I haven't said much about that because I was under the
impression that it wouldn't be of much interest to blind users. However, on
October 6, John Gardner of ViewPlus told us the following:

"Now a comment on color.  There is an undocumented feature in all ViewPlus
printer drivers that permit one to substitute a tactile pattern of your
design for a color.  I intend to write an article for Access2Science
documenting use of this feature - which you can then use with SVG drawings
created with SVG Draw."

Also, I have had another experience that has a bearing on color, which I
will relate to you later in this message.

If you would like to add color (or even specific shades of gray) to your
drawings, do the following:

1. Create your shapes as usual, probably setting the opacity for strokes and
fills to 1.0 (Setting to less than 1.0 causes the color to be partially
transparent. This can be interesting for overlapping colors, and the white
background is a color.)

2. Pull down the Advanced menu and select Set Attributes (Alt+Shift+S)

3. Mark one or more shapes of interest in the list of shapes (or check the
checkbox to select all shapes)

4a. For stroke color, tab down and check the stroke checkbox. Then type the
name of your color into the text field that will open up. (More on color
names later.)

4b. For fill color, check the fill checkbox and type the name of your color
into the text field that will open up.

5a. For stroke opacity, check the stroke-opacity checkbox and enter a value
between 0 and 1.0 in the text field  (0 is transparent and 1.0 is opaque).

5b. For fill opacity, check the fill-opacity checkbox and enter a value
between 0 and 1.0 in the text field.

6. Tab down and press the Set attributes button

7. Do it again for other shapes and other colors if desired.

8. Save the file, read John's article on Tiger color and have fun.

The webpage at http://www.december.com/html/spec/colorsvg.html lists the
names of 147 different colors that should work with SVGDraw01. Be sure to
spell the names of the colors correctly. Otherwise, the SVG processor will
probably revert to black.

Now back to that other experience I mentioned earlier. I have been
exchanging email messages with an individual with low vision who never
before had a tool that made it possible for him to draw with any degree of
accuracy. He is now drawing and having a lot of fun. He may be creating
drawings using SVGDraw01 and then editing the SVG output file to incorporate
features that I haven't purposely included in SVGDraw01, such as animation.
If so, he is not only enjoying being able to draw, he is also learning about
XML/SVG in the process.

Dick Baldwin
-- 
Richard G. Baldwin (Dick Baldwin)
Home of Baldwin's on-line Java Tutorials
http://www.DickBaldwin.com

Professor of Computer Information Technology
Austin Community College
(512) 223-4758
mailto:Baldwin at DickBaldwin.com
http://www.austincc.edu/baldwin/