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fgdata/Aircraft/Generic/WalkView/walkview.nas
2010-10-03 19:25:46 +02:00

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###############################################################################
##
## Walk view module for FlightGear.
##
## Inspired by the work of Stewart Andreason.
##
## Copyright (C) 2010 Anders Gidenstam (anders(at)gidenstam.org)
## This file is licensed under the GPL license v2 or later.
##
###############################################################################
# Global API. Automatically selects the right walker for the current view.
# NOTE: Coordinates are always 3 component lists: [x, y, z] in meters.
# The coordinate system is the same as the main 3d model one.
# X - back, Y - right and Z - up.
# Set the forward speed of the active walker.
# speed - walker speed in m/sec
# Returns 1 of there is an active walker and 0 otherwise.
var forward = func (speed) {
var cv = view.current.getPath();
if (contains(walkers, cv)) {
walkers[cv].forward(speed);
return 1;
} else {
return 0;
}
}
# Set the side step speed of the active walker.
# speed - walker speed in m/sec
# Returns 1 of there is an active walker and 0 otherwise.
var side_step = func (speed) {
var cv = view.current.getPath();
if (contains(walkers, cv)) {
walkers[cv].side_step(speed);
return 1;
} else {
return 0;
}
}
# Get the currently active walker.
# Returns the active walker object or nil otherwise.
var active_walker = func {
var cv = view.current.getPath();
if (contains(walkers, cv)) {
return walkers[cv];
} else {
return nil;
}
}
###############################################################################
# The walker class.
# ==============================================================================
# Class for a moving view.
#
# CONSTRUCTOR:
# walker.new(<view name>, <constraints>, <managers>);
#
# view name ... The name of the view : string
# constraints ... The movement constraints : constraint hash
# Determines where the view can go.
# managers ... Optional list of custom managers. A manager is a
# a hash that contains an update function of the type
# func(walker instance). The update function
# of each manager will be called as the last part of
# each walker update. Intended for controlling a
# a 3d model or similar.
#
# METHODS:
# active() : bool
# returns true if this walk view is active.
#
# forward(speed)
# Sets the forward speed of this walk view.
# speed ... speed in m/sec : double
#
# side_step(speed)
# Sets the side step speed of this walk view.
# speed ... speed in m/sec : double
#
# set_pos(pos)
# get_pos() : position
#
# set_eye_height(h)
# get_eye_height() : int (meter)
#
# set_constraints(constraints)
# get_constraints() : constraint hash
#
# EXAMPLE:
# var constraint =
# walkview.slopingYAlignedPlane.new([19.1, -0.3, -8.85],
# [19.5, 0.3, -8.85]);
# var walker = walkview.walker.new("Passenger View", constraint);
#
# NOTES:
# Currently there can only be one view manager per view so the
# walk view should not have any other view manager.
#
var walker = {
new : func (view_name, constraints = nil, managers = nil) {
var obj = { parents : [walker] };
obj.view = view.views[view.indexof(view_name)];
obj.constraints = constraints;
obj.managers = managers;
obj.position = [
obj.view.getNode("config/z-offset-m").getValue(),
obj.view.getNode("config/x-offset-m").getValue(),
obj.view.getNode("config/y-offset-m").getValue()
];
obj.heading =
obj.view.getNode("config/heading-offset-deg").getValue();
obj.speed_fwd = 0.0;
obj.speed_side = 0.0;
obj.isactive = 0;
obj.eye_height = 1.60;
obj.goal_height = obj.position[2] + obj.eye_height;
# Register this walker.
view.manager.register(view_name, obj);
walkers[obj.view.getPath()] = obj;
debug.dump(obj);
return obj;
},
active : func {
return me.isactive;
},
forward : func (speed) {
me.speed_fwd = speed;
},
side_step : func (speed) {
me.speed_side = speed;
},
set_pos : func (pos) {
me.position[0] = pos[0];
me.position[1] = pos[1];
me.position[2] = pos[2];
},
get_pos : func {
return [me.position[0], me.position[1], me.position[2]];
},
set_eye_height : func (h) {
me.eye_height = h;
},
get_eye_height : func {
return me.eye_height;
},
set_constraints : func (constraints) {
me.constraints = constraints;
},
get_constraints : func {
return me.constraints;
},
# View handler implementation.
init : func {
},
start : func {
me.isactive = 1;
me.last_time = getprop("/sim/time/elapsed-sec") - 0.0001;
me.update();
me.position[2] = me.goal_height;
},
stop : func {
me.isactive = 0;
},
# The update function is called by the view manager when the view is active.
update : func {
var t = getprop("/sim/time/elapsed-sec");
var dt = t - me.last_time;
if (dt == 0.0) return;
var cur = props.globals.getNode("/sim/current-view");
me.heading = cur.getNode("heading-offset-deg").getValue();
me.position[0] -=
me.speed_fwd * dt * math.cos(me.heading * TO_RAD) +
me.speed_side * dt * math.sin(me.heading * TO_RAD);
me.position[1] -=
me.speed_fwd * dt * math.sin(me.heading * TO_RAD) -
me.speed_side * dt * math.cos(me.heading * TO_RAD);
var cur_height = me.position[2];
if (me.constraints != nil) {
me.position = me.constraints.constrain(me.position);
me.goal_height = me.position[2] + me.eye_height;
}
# Change the view height smoothly
if (math.abs(me.goal_height - cur_height) > 2.0 * dt) {
me.position[2] =
cur_height +
2.0 * dt *
((me.goal_height > cur_height) ? 1 : -1);
} else {
me.position[2] = me.goal_height;
}
cur.getNode("z-offset-m").setValue(me.position[0]);
cur.getNode("x-offset-m").setValue(me.position[1]);
cur.getNode("y-offset-m").setValue(me.position[2]);
if (me.managers != nil) {
foreach(var m; me.managers) {
m.update(me);
}
}
me.last_time = t;
return 0.0;
},
};
###############################################################################
# Constraint classes. Determines where the view can walk.
# The union of two constraints.
# c1, c2 - the constraints : constraint
# NOTE: Assumes that the constraints are convex.
var unionConstraint = {
new : func (c1, c2) {
var obj = { parents : [unionConstraint] };
obj.c1 = c1;
obj.c2 = c2;
return obj;
},
constrain : func (pos) {
var p1 = me.c1.constrain(pos);
var p2 = me.c2.constrain(pos);
if (p1[0] == pos[0] and p1[1] == pos[1]) {
return p1;
} elsif (p2[0] == pos[0] and p2[1] == pos[1]) {
return p2;
} else {
if (closerXY(pos, p1, p2) <= 0) {
return p1;
} else {
return p2;
}
}
}
};
# Build a unionConstraint hierarchy from a list of constraints.
# cs - list of constraints : [constraint]
var makeUnionConstraint = func (cs) {
if (size(cs) < 2) return cs[0];
var ret = cs[0];
for (var i = 1; i < size(cs); i += 1) {
ret = unionConstraint.new(ret, cs[i]);
}
return ret;
}
# Mostly aligned plane sloping along the X axis.
# minp - the X,Y minimum point : position (meter)
# maxp - the X,Y maximum point : position (meter)
var slopingYAlignedPlane = {
new : func (minp, maxp) {
var obj = { parents : [slopingYAlignedPlane] };
obj.minp = minp;
obj.maxp = maxp;
obj.kxz = (maxp[2] - minp[2])/(maxp[0] - minp[0]);
return obj;
},
constrain : func (pos) {
var p = [pos[0], pos[1], pos[2]];
if (pos[0] < me.minp[0]) p[0] = me.minp[0];
if (pos[0] > me.maxp[0]) p[0] = me.maxp[0];
if (pos[1] < me.minp[1]) p[1] = me.minp[1];
if (pos[1] > me.maxp[1]) p[1] = me.maxp[1];
p[2] = me.minp[2] + me.kxz * (pos[0] - me.minp[0]);
return p;
},
};
# Action constraint
# Triggers an action when entering or exiting the constraint.
# constraint - the area in question : constraint
# on_enter() - function that is called when the walker enters the area.
# on_exit(x, y) - function that is called when the walker leaves the area.
# x and y are <0, 0 or >0 depending on in which direction(s)
# the walker left the constraint.
var actionConstraint = {
new : func (constraint, on_enter = nil, on_exit = nil) {
var obj = { parents : [actionConstraint] };
obj.constraint = constraint;
obj.on_enter = on_enter;
obj.on_exit = on_exit;
obj.inside = 0;
return obj;
},
constrain : func (pos) {
var p = me.constraint.constrain(pos);
if (p[0] == pos[0] and p[1] == pos[1]) {
if (!me.inside) {
me.inside = 1;
if (me.on_enter != nil) {
me.on_enter();
}
}
} else {
if (me.inside) {
me.inside -= 1;
if (!me.inside and me.on_exit != nil) {
me.on_exit(pos[0] - p[0], pos[1] - p[1]);
}
}
}
return p;
}
};
###############################################################################
# Manager classes.
# JSBSim pointmass manager.
# Moves a pointmass representing the crew member together with the view.
# CONSTRUCTOR:
# JSBSimPointmass.new(<pointmass index>);
#
# pointmass index ... The index of the pointmass : int
# offsets ... [x, y ,z] position in meter of the origin of the
# JSBSim structural frame in the 3d model frame.
#
# NOTE: Only supports aligned frames (yet).
#
var JSBSimPointmass = {
new : func (index, offsets = nil) {
var base = props.globals.getNode("fdm/jsbsim/inertia");
var prefix = "pointmass-location-";
var postfix = "-inches[" ~ index ~"]";
var obj = { parents : [JSBSimPointmass] };
obj.pos_ft =
[
base.getNode(prefix ~ "X" ~ postfix),
base.getNode(prefix ~ "Y" ~ postfix),
base.getNode(prefix ~ "Z" ~ postfix)
];
obj.offset = (offsets == nil) ? [0.0, 0.0, 0.0] : offsets;
return obj;
},
update : func (walker) {
var pos = walker.get_pos();
pos[2] += walker.get_eye_height()/2;
forindex (var i; pos) {
me.pos_ft[i].setValue((pos[i] - me.offset[i])*M2FT*12);
}
}
};
###############################################################################
# Module implementation below
var TO_RAD = math.pi/180;
var TO_DEG = 180/math.pi;
var walkers = {};
var closerXY = func (pos, p1, p2) {
var l1 = [p1[0] - pos[0], p1[1] - pos[1]];
var l2 = [p2[0] - pos[0], p2[1] - pos[1]];
return (l1[0]*l1[0] + l1[1]*l1[1]) - (l2[0]*l2[0] + l2[1]*l2[1]);
}