HowTo:BackgroundImg

From S2PLOT

It is simple to run an existing S2PLOT program over the top of a background image. This behaviour is completely controlled by runtime environment variables, so no modification to program code is required.

You will need a background image in TGA format. You can use the ImageMagick "convert" utility to write a TGA file from almost any bitmap format file.

Prior to running your S2PLOT program, simply set the following environment variables:

} The coordinates are given in the range [0,1], and define the sub-window of the S2PLOT window which is used for the S2PLOT 3-d graphics. The background image covers the entire window, even if it must be stretched to do so.

variable	meaning	sample value
S2PLOT_BGIMG	filename of background TGA image	"universe.tga"
S2PLOT_X1	X coord of bottom left corner for S2PLOT graphics	0.2
S2PLOT_Y1	Y coord of bottom left corner for S2PLOT graphics	0.1
S2PLOT_X2	X coord of top right corner for S2PLOT graphics	0.7
S2PLOT_Y2	Y coord of top right corner for S2PLOT graphics	0.9