Class: Pongo::PhysicsEngine

Inherits:
Object
  • Object
show all
Defined in:
lib/pongo/apengine.rb

Overview

The main engine class.

Instance Attribute Summary collapse

Instance Method Summary collapse

Instance Attribute Details

#constraint_collision_cycles ⇒ Object

Returns the value of attribute constraint_collision_cycles.



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# File 'lib/pongo/apengine.rb', line 5

def constraint_collision_cycles
  @constraint_collision_cycles
end

#constraint_cycles ⇒ Object

Returns the value of attribute constraint_cycles.



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# File 'lib/pongo/apengine.rb', line 5

def constraint_cycles
  @constraint_cycles
end

#container ⇒ Object

Returns the value of attribute container.



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# File 'lib/pongo/apengine.rb', line 5

def container
  @container
end

#damping ⇒ Object

Returns the value of attribute damping.



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# File 'lib/pongo/apengine.rb', line 5

def damping
  @damping
end

#forces ⇒ Object

Returns the value of attribute forces.



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# File 'lib/pongo/apengine.rb', line 5

def forces
  @forces
end

#groups ⇒ Object

Returns the value of attribute groups.



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# File 'lib/pongo/apengine.rb', line 5

def groups
  @groups
end

#logger ⇒ Object

Returns the value of attribute logger.



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# File 'lib/pongo/apengine.rb', line 5

def logger
  @logger
end

#renderer ⇒ Object

Returns the value of attribute renderer.



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# File 'lib/pongo/apengine.rb', line 5

def renderer
  @renderer
end

#tile_step ⇒ Object

Returns the value of attribute tile_step.



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# File 'lib/pongo/apengine.rb', line 5

def tile_step
  @tile_step
end

Instance Method Details

#<<(item) ⇒ Object 



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# File 'lib/pongo/apengine.rb', line 122

def <<(item)
  if item.is_a?(Group)
    add_group(item)
  else
    if @groups.empty?
      @groups << Group.new(true) 
      @groups.first.is_parented = true
      @groups.first.init
    end
    @groups.last << item
  end
end

#add_force(force) ⇒ Object

Adds a force to all particles in the system. The forces added to the APEngine class are persistent - once a force is added it is continually applied each APEngine.step() cycle.



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# File 'lib/pongo/apengine.rb', line 39

def add_force(force)
  @forces << force
end

#add_group(group) ⇒ Object

Adds a Group to the engine.



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# File 'lib/pongo/apengine.rb', line 73

def add_group(group)
  @groups << group
  group.is_parented = true
  group.init
end

#build_group(collide_internal = false) ⇒ Object 



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# File 'lib/pongo/apengine.rb', line 66

def build_group(collide_internal=false)
  group = Group.new(collide_internal)
  @groups << group
  group
end

#check_collisions ⇒ Object 



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# File 'lib/pongo/apengine.rb', line 118

def check_collisions
  @groups.each {|g| g.check_collisions}
end

#create_group(collide_internal = true, &block) ⇒ Object 



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# File 'lib/pongo/apengine.rb', line 135

def create_group(collide_internal=true, &block)
  @groups << Group.new(collide_internal)
  block.call(@groups.last) if block
  @groups.last
end

#draw ⇒ Object Also known as: paint

Calling this method will in turn call each Group’s paint() method. Generally you would call this method after stepping the engine in the main program cycle.



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# File 'lib/pongo/apengine.rb', line 105

def draw
  @groups.each {|g| g.draw}
end

#gravity=(val) ⇒ Object 



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# File 'lib/pongo/apengine.rb', line 43

def gravity=(val)
  case val
  when Numeric
    add_force(VectorForce.new(false, 0, val))
  when Array
    add_force(VectorForce.new(false, *val))
  when VectorForce
    add_force(val)
  else
    raise ArgumentError
  end
end

#integrate ⇒ Object 



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# File 'lib/pongo/apengine.rb', line 110

def integrate
  @groups.each {|g| g.integrate(@time_step)}
end

#log(message, level = :info) ⇒ Object 



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# File 'lib/pongo/apengine.rb', line 151

def log(message, level=:info)
  message = message.message + "\n" + message.backtrace.join("\n") if message.is_a?(Exception)
  @logger.send(level, message) if @logger
end

#next_frame(options = {}) ⇒ Object 



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# File 'lib/pongo/apengine.rb', line 141

def next_frame(options={})
  options[:before].call if options[:before]
  step
  draw
  options[:after].call if options[:after]
rescue
  log($!)
  raise $!
end

#remove_all_forces ⇒ Object

Removes all forces from the engine.



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# File 'lib/pongo/apengine.rb', line 62

def remove_all_forces
  @forces.clear
end

#remove_force(force) ⇒ Object

Removes a force from the engine.



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# File 'lib/pongo/apengine.rb', line 57

def remove_force(force)
  @forces.remove(force)
end

#remove_group(group) ⇒ Object

Removes a Group from the engine.



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# File 'lib/pongo/apengine.rb', line 80

def remove_group(group)
  if @groups.delete(group)
    group.is_parented = false
    group.cleanup
  end
end

#satisfy_constraints ⇒ Object 



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# File 'lib/pongo/apengine.rb', line 114

def satisfy_constraints
  @groups.each {|g| g.satisfy_constraints}
end

#setup(options = {}) ⇒ Object Also known as: init

Initializes the engine. You must call this method prior to adding any particles or constraints.



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# File 'lib/pongo/apengine.rb', line 16

def setup(options={}) #dt=0.25)
  options = {
    :dt => 0.25, :damping => 1, :constraint_cycles => 0, 
    :constraint_collision_cycles => 1
  }.update(options.is_a?(Numeric) ? {:dt => options} : options)

  @time_step = options[:dt] * options[:dt]
  @groups = []
  @forces = []
  self.damping = options[:damping]
  self.constraint_cycles = options[:constraint_cycles]
  self.constraint_collision_cycles = options[:constraint_collision_cycles] 

  self.container = options[:container] if options[:container]
  self.renderer = options[:renderer] if options[:renderer]
  self.logger = options[:logger] if options[:logger]
  self.gravity = options[:gravity] if options[:gravity]
end

#step ⇒ Object

The main step function of the engine. This method should be called continously to advance the simulation. The faster this method is called, the faster the simulation will run. Usually you would call this in your main program loop.



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# File 'lib/pongo/apengine.rb', line 91

def step
  integrate
  constraint_cycles.times do
    satisfy_constraints
  end
  constraint_collision_cycles.times do
    satisfy_constraints
    check_collisions
  end
end