Plot Basics

The NeXtMidas PLOT command plots the following types of files:

• Midas Blue Files - Types 1000, 1999, 2000, 3000, 5000, 5010
• Graphical Images - gif, tif, jpg, png, etc.
• National Geospatial-Intelligence Agency (NGA) Images
• Shape files (*.shp)
• KML files (*.kml)
• GeoJSON files (*.geojson)

The single NeXtMidas command PLOT does the same thing as all these X-Midas commands combined: xplot, xrtplot, xraster, xrtraster and xgeoplot! PLOT identifies the file type of the first file and applies the appropriate plot type. The type can be overridden with the type= modifier.

The following sections detail a few caveats associated with the NeXtMidas PLOT command.

• Layer Stacking Order
• Using Features
• Backing Store
• Macro Interface
• Mouse Interaction in a Plot

Stacking Order

• Default:
  • Layers (or files) are stacked the way they are entered on the command line (first is on the bottom)
  • As new layers are added, they appear on top all the previous layers
• Backing Store layer: If Backing Store is used for a layer, that layer(s) is drawn first
• INSERT Layer Qualifier:
  • When adding a new layer, the INSERT Layer qualifier can be used to insert the new layer before an existing layer.
  • message FUNC=send ID=idplot NAME=OPENFILE DATA=lakes.shp{LAYER={INSERT="CITIES"}}
  • message FUNC=send ID=idplot NAME=OPENFILE DATA=lakes.shp{LAYER={INSERT=2}}
• The KeyVector.move(key,before) API can also be used on the MPlot layers object to move an existing layer
• MP.layers.move("LAKES","CITIES");
• MP.layers.move("LAKES",2);

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Using Features

Features are usually associated directly with the plot, though there can be Features that are directly associated with a Layer (LayerDrawable). One of the plot features can be an "Elastic Feature" and directly selectable and stretchable.

For full information, see the FEATURE explain file.

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Backing Store

Backing store is a mechanism where static layers are drawn without recomputation.

• When-to-use:
  Use Backing-store when there are static layers with non-static layers on top. Enabling Backing-store uses more memory and you do not see the static (Backing-stored layer) draw. However, the static layer does not have to be redrawn every time.
• How-to-Use:
  Backing-store is disabled by default, except for LayerPoly (Midas Type 1999) and LayerShape (*.shp) files. Individual layers may have backing-store enabled but it is not be used unless it is turned on at the plot level via the /ALL switch or OPTION= modifier.
• Default Layer Enabling:
  As mentioned above, individual layers may have backing-store enabled but it is not used unless it is turned on at the plot level. Most layers are candidates for backing-store except for:
  • All Real-Time Layers - Pipe input or forced at the command line.
  • LayerGeo - Draws Geodetic (TDOA/FDOA) lines from state vector data.
  • LayerT5 - Enabled because names and symbols, which often act like features, are frequently drawn.

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Macro Interface

PLOT (and many NeXtMidas primitives) handle events and send messages to the macro in response to these events. For instance, when the LMB is clicked in a PLOT a MARK message is sent to the macro. See the PLOT explain file for a complete list of messages.

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