#
# This demo also shows an example of some of the physical simulation 
# features of breve.  It features a ball rolling down a set of stairs 
# over and over, changing the starting conditions each time.
#

@use Mobile.
@use PhysicalControl.
@use Stationary.

Controller Gravity.

PhysicalControl : Gravity {
	+ variables: 
		theBall (object).
		theSquare (object).
	+ to init:
		# This demo is actually so fast that we're going to intentionally
		# slow it down by setting the integration step to be very very small.  
		# This will also increase the accuracy of the simulation.

		self set-integration-step to .00005.

		# create a bunch of steps.

		new Step create at (-.5, 0, 0) size (1.0, .22, 1).
		new Step create at (.2, -.2, 0) size (.2, .22, 1).
		new Step create at (.4, -.4, 0) size (.2, .22, 1.5).
		new Step create at (.6, -.6, 0) size (.2, .22, 2).
		new Step create at (.8, -.8, 0) size (.2, .22, 2.5).
		new Step create at (1.0, -1.0, 0) size (.2, .22, 5).

		new Step create at (2.0, -1.2, 0) size (2, .22, 5).

            new Step create at (3.0, -1.2, 0) size (.2, .4, 5).
		new Step create at (1.5, -1.2, 2.5) size (3, .5, .1).
            # and some balls.

		8 new Balls.
      	3 new Squares.

		self point-camera at (1.0, -.8, -.6) from (3.5, 1.1, 5.0).
	#	self enable-shadow-volumes.
		self add-menu named "Reset Ball" for-method "reset-ball".
            
	+ to reset-ball:
		theBall reset.
		theSquare reset.
}

Stationary : Step {
	+ to create at location (vector) size sizeVector (vector):
		stepShape (object).
		stepShape = (new Cube init-with size sizeVector).
		# self set-e to 0.01.
		# self set-mu to 999999999.
		self set-shape to stepShape.
		self move to location.
}

Mobile : Ball (aka Balls) {
	+ to iterate:
		# The iterate method is called each timestep...
		# if the Y component (height) of our position is less than -2.0, 
		# then the ball has passed the steps and is continuing to fall,
		# so we'll reset the ball with new starting conditions.

		if (self get-location)::y < -2.0: self reset.
	+ to init:
		self set-shape to (new Sphere init-with radius .05 + random[ .01 ] ).
		self enable-physics.
		self reset.

	+ to reset:
		# vary initial conditions slightly each time

		self set-color to random[(1, 1, 1)].
		self move to ( -.9, .5, -1 ) + random[ ( .5, .1, 4) ].
		self set-velocity to (1 + random[4.0], 1.0 + random[1.0], 1).
}
Mobile : Square (aka Squares) {
	+ to iterate:
		tx (int).
		tx = 0.
		# The iterate method is called each timestep...
		# if the Y component (height) of our position is less than -2.0, 
		# then the Cube has passed the steps and is continuing to fall,
		# so we'll reset the cube with new starting conditions.
		if (self get-location)::y < -2.0: self reset.
         #   if (abs((self get-velocity)::x) < 0.0001): self reset.
	+ to init:
	#	self set-shape to (new Cube init-with size (.05, .05, .05)).
            self set-shape to (new PolygonCone init-with sides 5 height .128 radius .238).
		self enable-physics.
		self reset.

	+ to reset:
		# vary initial conditions slightly each time

		self set-color to random[(1, 1, 1)].
		self move to ( -.9, .5, -1 ) + random[ ( .5, .1, 4) ].
		self set-velocity to (1 + random[1.0], 1.0 + random[.5], .3).
}