523b81e317
functions when used in $FG_ROOT/Nasal/*.nas, because it
depends on props.nas being available; no restrictions in
aircraft files, where it will proof most useful
gui.nas: replace inefficient FPS display polling loop with listener
callback
89 lines
2.6 KiB
Text
89 lines
2.6 KiB
Text
##
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# Returns true if the first object is an instance of the second
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# (class) object. Example: isa(someObject, props.Node)
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#
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isa = func {
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obj = arg[0]; class = arg[1];
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if(!contains(obj, "parents")) { return 0; }
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foreach(c; obj.parents) {
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if(c == class) { return 1; }
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elsif(isa(obj, c)) { return 1; }
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}
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return 0;
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}
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##
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# Invokes a FlightGear command specified by the first argument. The
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# second argument specifies the property tree to be passed to the
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# command as its argument. It may be either a props.Node object or a
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# string, in which case it specifies a path in the global property
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# tree.
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#
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fgcommand = func {
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if(isa(arg[1], props.Node)) { arg[1] = arg[1]._g }
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_fgcommand(arg[0], arg[1]);
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}
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##
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# Returns the SGPropertyNode argument to the currently executing
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# function. Wrapper for the internal _cmdarg function that retrieves
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# the ghost handlet to the argument and wraps it in a
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# props.Node object.
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#
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cmdarg = func { props.wrapNode(_cmdarg()) }
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##
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# Utility. Does what it you think it does.
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#
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abs = func { if(arg[0] < 0) { -arg[0] } else { arg[0] } }
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##
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# Convenience wrapper for the _interpolate function. Takes a
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# single string or props.Node object in arg[0] indicating a target
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# property, and a variable-length list of time/value pairs. Example:
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#
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# interpolate("/animations/radar/angle",
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# 180, 1, 360, 1, 0, 0,
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# 180, 1, 360, 1, 0, 0,
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# 180, 1, 360, 1, 0, 0,
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# 180, 1, 360, 1, 0, 0,
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# 180, 1, 360, 1, 0, 0,
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# 180, 1, 360, 1, 0, 0,
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# 180, 1, 360, 1, 0, 0,
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# 180, 1, 360, 1, 0, 0);
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#
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# This will swing the "radar dish" smoothly through 8 revolutions over
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# 16 seconds. Note the use of zero-time interpolation between 360 and
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# 0 to wrap the interpolated value properly.
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#
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interpolate = func {
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if(isa(arg[0], props.Node)) { arg[0] = arg[0]._g; }
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elsif(typeof(arg[0]) != "scalar") { return; }
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_interpolate(arg[0], size(arg) == 1 ? [] : subvec(arg, 1));
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}
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##
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# Convenience wrapper for the _setlistener function. Takes a
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# single string or props.Node object in arg[0] indicating the
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# listened to property, and a function in arg[1].
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#
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setlistener = func {
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_setlistener(isa(arg[0], props.Node) ? arg[0]._g : arg[0], arg[1]);
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}
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##
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# Returns true if the symbol name is defined in the caller, or the
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# caller's lexical namespace. (i.e. defined("varname") tells you if
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# you can use varname in an expression without a undefined symbol
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# error.
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#
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defined = func(sym) {
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var fn = 1;
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while((var frame = caller(fn)) != nil) {
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if(contains(frame[0], sym)) { return 1; }
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fn += 1;
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}
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return 0;
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}
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