NAME: spd_ui_draw_object PURPOSE: This object generates an object graphics tree using the IDLgr* objects that are built into IDL. It generates this tree by querying the loaded data object and the window storage object to get the settings generated by the panel. This object also performs other utility operations related to drawing. These include animations of vertical bars and markers, updating the legend by performing a lookup in a hashed version of the plotted data, and reporting information about the current display.(Cursor segment selected, range of displayed data, etc...) There are a few major functions in this object. #1 'update': will update the draw area to correspond to new settings #2 'setCursor' : actually makes the draw object do all the animation updates #3 'draw' : use it to force the object to redraw the draw area.\ #4 'getInfo(panelIndex)' : get a struct with information about a panel in the currently drawn display This includes information like the actual range and scaling for each axis, the number of tics, etc... NOTES: 1. In almost all cases ranges will be stored and passed around as 2-element arrays. If they are on log scaled axis, the ranges will be in log space, this tends to make some calculations simpler(and others more complex) By log space, I mean, if scaling eq 1 then range = alog10(normalRange), if scaling eq 2 then range = alog(normalRange) 2. The codes used for different scaling values are consistent. 0 indicates linear scaling, 1 indicates base 10 logarithm, 2 indicates natural logarithm 3. Positions in this code are generally specified in one of three different coordinate systems. a. They are normalized to the draw area. So [.5,.5] is the center of the draw area. b. They are normalized to the panel. So [.5,.5] is the center of a panel. c. They are specified in pixels. Often when pixels are used, the value used may actually be 2x or 4x the actual number of screen pixels to prevent aliasing. Somewhat ambiguously, c. is sometimes called points(because it is a scaled number of pixels). This is not the same as the measurement in note 5. Rectangles(like panels) will normally be specified using two variables, which are each 2 element doubles. xpos = [xstart,xstop], ypos = [ystart,stop] These are absolute locations. The alternative representation [xstart,xsize],[ystart,ysize], is rarely, if ever, used as a parameter, although sizes are used for various computations throughout the code. 4. distances that aren't specified in the above coordinates are often specified in pts. This is a desktop publishing standard, that ideally is consistent across output devices. 1 pt should be 127/360 mm. The goal is to make all output consistent across output devices. $LastChangedBy: jimm $ $LastChangedDate: 2014-02-11 10:54:32 -0800 (Tue, 11 Feb 2014) $ $LastChangedRevision: 14326 $ $URL: svn+ssh://thmsvn@ambrosia.ssl.berkeley.edu/repos/spdsoft/trunk/spedas/gui/display/spd_ui_draw_object__define.pro $