fix bug computing initial internal event

spec/scenarios/sim_neg_time_spec.cr → spec/scenarios/sim_initial_elapsed_time_spec.cr

@@ -1,14 +1,13 @@
 require "../spec_helper"
 
-private module NegativeInitialTimeScenario
+private module InitialElapsedTimeScenario
   class TestInitialElapsed < Quartz::AtomicModel
     getter output_calls : Int32 = 0
     getter internal_calls : Int32 = 0
     getter generated : Bool = false
-    getter elapsed_values : Array(Duration) = Array(Duration).new
 
-    # Set the initial elapsed time to 4 so that initial time may be negative
-    @elapsed = Duration.new(4)
+    # Set the initial elapsed time to 1
+    @elapsed = Duration.new(1)
 
     def external_transition(bag)
     end
@@ -24,13 +23,12 @@ private module NegativeInitialTimeScenario
     def internal_transition
       @generated = true
       @internal_calls += 1
-      @elapsed_values << @elapsed
     end
   end
 
   describe TestInitialElapsed do
     describe "simulation" do
-      it "time might be negative at initialization" do
+      it "first event depends on initial elapsed time" do
         atom = TestInitialElapsed.new(:testneg)
         sim = Quartz::Simulation.new(atom, duration: Quartz::Duration::INFINITY)
 
@@ -39,15 +37,15 @@ private module NegativeInitialTimeScenario
         atom.output_calls.should eq(0)
         atom.internal_calls.should eq(0)
         atom.generated.should be_false
-        atom.elapsed_values.empty?.should be_true
 
+        sim.virtual_time.to_i.should eq(0)
         sim.step
+        sim.virtual_time.to_i.should eq(1)
 
         atom.output_calls.should eq(1)
         atom.internal_calls.should eq(1)
         atom.generated.should be_true
         atom.time_advance.should eq(Quartz::Duration::INFINITY)
-        atom.elapsed_values.first.should eq(Duration.new(0))
       end
     end
   end

src/quartz/multi_component/simulator.cr

@@ -69,7 +69,10 @@ module Quartz
         @components.each_value do |component|
           component.__initialize_state__(self)
           elapsed = component.elapsed
-          planned_duration = fixed_planned_duration(component.time_advance.as(Duration), component)
+          planned_duration = fixed_planned_duration(
+            component.time_advance.as(Duration) - elapsed,
+            component
+          )
 
           Log.debug {
             String.build { |str|

src/quartz/simulator.cr

@@ -37,7 +37,10 @@ module Quartz
 
       atomic.__initialize_state__(self)
       elapsed = atomic.elapsed
-      planned_duration = fixed_planned_duration(atomic.time_advance.as(Duration), atomic.class.precision_level)
+      planned_duration = fixed_planned_duration(
+        atomic.time_advance.as(Duration) - elapsed,
+        atomic.class.precision_level
+      )
 
       if @run_validations && atomic.invalid?(:initialization)
         Log.error {