col_legend2
Name
col_legend2
Authors
Konstantinis G. Kakoulis and Yihsing Song, under the supervision of Dr. Susanna Wei,
Department of Mathematics and Computer Science, Saint Joseph's University,
Philadelphia, Pennsylvania.
ACKNOWLEDGEMENT
This module is a modification of the color legend module by Lawrence Berkeley Laboratory.
The modification includes:
1. An added input port of type FIELD 1D; The minimum value, maximum value and the
visibility of the color legend are defined by the first, second, and third
element of the field, respectively.
2. Two additional parameters:
a. LEGEND WIDTH, defines the width of the color legend.
b. LEGEND HEIGHT, defines the height of the color legend.
3. The geometry produced by the module is NOT TRANSFORMABLE.
4. The first and the last labels of the color legend are not displayed on the screen.
Summary
Name col_legend2
Type
mapper
Inputs
colormap
Inputs Field 1D
Output
geometry
Parameters
Name Type Default Min Max
----- ---- ------- --- ---
Boundary On/Off boolean on
Boundary Gray Level integer 255 0 255
Legend Width real 0.08 0.01 1.0
Legend Height real 1.61 0.01 3.5
Labels On/Off boolean on
Label Density integer 12 12 12
Label Height real 0.09 0.001 0.2
Label Gray Level integer 255 0 255
Label Font integer 0 0 21
Label Boundaries On/Off boolean
Reverse Colors boolean off
Legend Orientation radio vertical vertical horizontal
Description
This module takes an input colormap and generates a
"color legend," consisting of a number of geometric
objects which may be subsequently rendered using the
render geometry module.
The range of colors in the color scale is controlled
by the input field 1D All colors in the colormap are
represented in the output color scale.
In addition to the smoothly shaded "color bar", the user
may control various parameters relating to labeling
characteristics and legend orientation.
The color legend is not transformable and the visibility of the color
legend is controlled by the input field 1D.
INPUTS
AVS Colormap (required)
Field 1D (required)
PARAMETERS
X offset
Y offset
Define the position of the color legend.
Width
Height
Define the size of the color legend
Boundary On/Off
This boolean flag indicates whether the "color bar" part of the
color legend is to have, on its perimeter, a pixel-thick
line "boundary." The boundary is useful, especially if
many colors in the "color bar" are similar to the current
background color.
Boundary Gray Level
This value is used to set the gray level of the boundary.
A value of 0 corresponds to a black boundary, while a value
of 255 corresponds to a white boundary.
Labels On/Off
This boolean value is used to enable/disable the annotation
which accompanies the color legend which indicate the values
associated with the colors.
Label Density
The number of labels produced is controlled through this
parameter. The minimum is two (the top and bottom of the
color bar), and the maximum is twelve. The max of 12 was
an arbitrary decision based upon the "busyness" of color
legends with too many labels. Feel free to change this.
Label Height
This slider controls the size of the font. The number associated
with this slider is in some arcane coordinate system.
Label Gray Level
Controls the gray level of the labels text (and the labels
boundary, as well). A value of 0 will produce black text,
a value of 255 will produce white text.
Label Font
Selects from one of 22 fonts. Whether or not all of these
fonts actually exist on your system is open for debate. The
number of available fonts comes from the Stardent documentation.
Label Boundaries On/Off
Controls whether or not a "boundary line" appears in the color
bar at the location corresponding to a particular label. So,
for example, if only two labels are specified, the two boundaries
will be draw at the top/bottom of the colormap. No boundaries
will be visible (unless the gray level is different than that
for the "regular" boundary) unless the label density parameter is
set to three or higher.
Reverse Colors
This flag will reverse the colors, and any associated labels.
Legend Orientation
The user can choose between a vertical or horizontal color legend
orientation.
OUTPUTS
AVS geometry.
Example
generate colormap
|
color scale
|
render geometry
|
display pixmap
Limitations
It is possible to produce a really messy color legend by
fiddling with the parameters enough.
There is no "title" parameter. This has been specifically
omitted as it would be impossible to appease all users
as to its location with respect to the color legend.
The positioning of the labels with respect to the color
legend is fixed: on vertical legends, the characters
appear to the right, and on horizontal legends, they
appear below the legend (compare with the NCAR utility
for producing legends).