95 lines
3.2 KiB
Lua
Executable File
95 lines
3.2 KiB
Lua
Executable File
function automobiles_lib.physics(self)
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local friction = self._ground_friction or 0.99
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local vel=self.object:get_velocity()
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local new_velocity = vector.new()
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--buoyancy
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local surface = nil
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local surfnodename = nil
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local spos = automobiles_lib.get_stand_pos(self)
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if not spos then return end
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spos.y = spos.y+0.01
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-- get surface height
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local snodepos = automobiles_lib.get_node_pos(spos)
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local surfnode = automobiles_lib.nodeatpos(spos)
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while surfnode and (surfnode.drawtype == 'liquid' or surfnode.drawtype == 'flowingliquid') do
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surfnodename = surfnode.name
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surface = snodepos.y +0.5
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if surface > spos.y+self.height then break end
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snodepos.y = snodepos.y+1
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surfnode = automobiles_lib.nodeatpos(snodepos)
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end
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self.isinliquid = surfnodename
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if surface then -- standing in liquid
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self.isinliquid = true
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end
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local last_accel = vector.new()
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if self._last_accel then
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last_accel = vector.new(self._last_accel)
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end
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if self.isinliquid then
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self.water_drag = 0.2
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self.isinliquid = true
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local height = self.height
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local submergence = math.min(surface-spos.y,height)/height
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-- local balance = self.buoyancy*self.height
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local buoyacc = automobiles_lib.gravity*(-1)*(self.buoyancy-submergence)
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--local buoyacc = self._baloon_buoyancy*(self.buoyancy-submergence)
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local accell = {
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x=-vel.x*self.water_drag,
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y=buoyacc-(vel.y*math.abs(vel.y)*0.4),
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z=-vel.z*self.water_drag
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}
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if self.buoyancy >= 1 then self._engine_running = false end
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if last_accel then
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accell = vector.add(accell,last_accel)
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end
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new_velocity = vector.multiply(accell,self.dtime)
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else
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self.isinliquid = false
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new_velocity = vector.multiply(last_accel,self.dtime)
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end
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if self.isonground and not self.isinliquid then
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--dumb friction
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new_velocity = {x=new_velocity.x*friction,
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y=new_velocity.y,
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z=new_velocity.z*friction}
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-- bounciness
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if self.springiness and self.springiness > 0 and self.buoyancy >= 1 then
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local vnew = vector.new(new_velocity)
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if not self.collided then -- ugly workaround for inconsistent collisions
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for _,k in ipairs({'y','z','x'}) do
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if new_velocity[k]==0 and math.abs(self.lastvelocity[k])> 0.1 then
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vnew[k]=-self.lastvelocity[k]*self.springiness
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end
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end
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end
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if not vector.equals(new_velocity,vnew) then
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self.collided = true
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else
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if self.collided then
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vnew = vector.new(self.lastvelocity)
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end
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self.collided = false
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end
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new_velocity = vnew
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end
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--fix bug with unexpected moving
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if not self.driver_name and math.abs(vel.x) < 0.2 and math.abs(vel.z) < 0.2 then
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self.object:set_velocity({x=0,y=automobiles_lib.gravity*(-1)*self.dtime,z=0})
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if self.wheels then self.wheels:set_animation_frame_speed(0) end
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return
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end
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end
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self.object:add_velocity(new_velocity)
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end
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