OVERVIEW

Because of limitations that exist in both DataViews and PicsViews, some special considerations are needed when using DV-Draw to create drawings for use in PicsViews.

DEFAULT COLOR TABLE

PicsViews uses the entry for color table found in the %DVHOME%DVCONFIG.DAT file. DV-Draw uses the same entry once and in a slightly different way. The first time DV-Draw is run, it reads the DVCONFIG.DAT file and then saves a number of the settings it found there into the registry as user preferences. These settings may be changed by using the Edit|Preferences dialog within DV-Draw.

By default, the entry for DVCOLORTABLE is commented out in DVCONFIG.DAT, causing DV-Draw and DataViews to use a default color table. For unknown reasons, the default color table that DV-Draw uses is different than that used by DV-Tools applications (such as PicsViews). DV-Tools applications use the file %DVHOME%DEFAULT.CLUT when no color table is specified. DV-Draw, however, uses a setting of '<default>' which means to use its internally compiled default colors. To ensure that DV-Draw and PicsViews are using the same color set, DV-Draw should be configured to use the same file that PicsViews will be using. There is a 'Browse' button in the dialog to make locating the file easier. Once selected, DV-Draw will retain the setting until it is changed by the user, so this should only need to be done once.

COLOR SELECTION

During the design phase, it was determined that a black background with colored objects was going to be standard at FPC. With this in mind, the printing portion of the program was designed to swap black and white before printing, in order to prevent 'black-out' which frequently happens when trying to print a predominantly black image, with fine white or colored lines. PicsViews has a setting to enable/disable the black and white swap (and also an unimplemented [future] option to use a color map).

Two different issues arise in the selection of colors for DataViews objects.

The 'Magic' Color

DataViews treats the color in index 127 in a special way. When used in subdrawings, this color is automatically translated to the drawing background color, allowing subdrawings to have 'transparent' components. This is used extensively in subdrawing templates (see the DV-Draw manual).

Graph Issues

Due to some oversights (I call them bugs) in the graph formatters, there is a problem that occurs if the both the graph and drawing background colors are the same and you have enabled the option to swap black and white. In this situation, the graph code sometimes gets confused about the background color for the text components of the graph context (axis labels, legends, etc.) and still prints them with a black background. This can make them rather difficult to read with a black foreground, too. Currently, one solution is to create all graphs using 'print-ready' colors and disable the color swapping feature. Another is to use a slightly different color for the graph background. The PicsViews color swapping routine will swap black and white (index 0 and 15) as well as near black and near white (index 16 and 31) to facilitate this option.

COLOR LOOKUPS

Two (at least) of the object dynamics supported by DataViews allow you to use a color lookup table to alter the object color(s). These color tables are NOT remapped by the PicsViews print engine. Unless you are using black and/or white in these color sets, this is not a problem because PicsViews doesn't map other colors at this time.

RULES

DataViews rules are a very power feature that would be nice to support within PicsViews. However, the rules system is capable of performing actions without PicsViews' knowledge, which would eliminate much of the special, PICS-related, functionality of PicsViews (such as mapping objects to PICS data when a view is loaded). Because of this, PicsViews does not support rules at this time. However, you may include rules in a view and use them in the DV-Draw test module if you desire, PicsViews will ignore them.

DV-Draw Testing

DV-Draw includes an option to test run your views. At this time, DV-Draw itself is not capable of accessing PICS data. This is a possibility for future enhancement, but that work doesn't fit into the schedule at this time.