From 5121b193b9836cefbc6be511497d92aea9ffba3e Mon Sep 17 00:00:00 2001
From: Brychan Dempsey <brychand@hotmail.com>
Date: Fri, 14 May 2021 14:29:28 +1200
Subject: [PATCH] Successfully implmented physics system

---
 .../ac/massey/programming_project_159333_s1_2021/App.java | 4 +++-
 .../FrameRateSystem.java                                  | 4 ++--
 .../LogVec2DSystem.java                                   | 2 +-
 .../programming_project_159333_s1_2021/SystemManager.java | 8 ++++----
 4 files changed, 10 insertions(+), 8 deletions(-)

diff --git a/javaecs/src/main/java/nz/ac/massey/programming_project_159333_s1_2021/App.java b/javaecs/src/main/java/nz/ac/massey/programming_project_159333_s1_2021/App.java
index 9fc537e..990eb17 100644
--- a/javaecs/src/main/java/nz/ac/massey/programming_project_159333_s1_2021/App.java
+++ b/javaecs/src/main/java/nz/ac/massey/programming_project_159333_s1_2021/App.java
@@ -61,6 +61,7 @@ public final class App {
         double dt = 0.0;
 
         double frameRate = 1.0 / 20; // 1 second divided by target number of frames
+        double idleTime = 0.0; // the amount of time spent sleeping
 
         boolean quit = false;
         long loopStart = System.currentTimeMillis();
@@ -68,13 +69,14 @@ public final class App {
             // Get the time between frames for accurate time-based calculations (i.e. physics systems etc)
             long startTime = System.nanoTime();
 
-            frameRateSystem.update(dt);
+            frameRateSystem.update(dt, idleTime);
             physicsSystem.update(dt);
             logVec2DSystem.update(dt);
             dt = (System.nanoTime() - startTime) / 1e9; // convert nanoseconds to seconds
 
             // Limit frame rate (approximately) to minimum of 16 ms
             if (dt < frameRate){
+                idleTime = frameRate-dt;
                 Thread.sleep((int)((frameRate-dt)*1000));
                 dt = (System.nanoTime() - startTime) / 1e9;
             }
diff --git a/javaecs/src/main/java/nz/ac/massey/programming_project_159333_s1_2021/FrameRateSystem.java b/javaecs/src/main/java/nz/ac/massey/programming_project_159333_s1_2021/FrameRateSystem.java
index 900f5fe..5ceac97 100644
--- a/javaecs/src/main/java/nz/ac/massey/programming_project_159333_s1_2021/FrameRateSystem.java
+++ b/javaecs/src/main/java/nz/ac/massey/programming_project_159333_s1_2021/FrameRateSystem.java
@@ -3,7 +3,7 @@ package nz.ac.massey.programming_project_159333_s1_2021;
 public class FrameRateSystem extends ECSSystem{
     void init() {}
 
-    void update(double dt){
-        System.out.print("dt: " + dt + " ");
+    void update(double dt, double idleTime){
+        System.out.print(String.format("dt: %.3g (%.3g idle) ", dt, idleTime));
     }
 }
diff --git a/javaecs/src/main/java/nz/ac/massey/programming_project_159333_s1_2021/LogVec2DSystem.java b/javaecs/src/main/java/nz/ac/massey/programming_project_159333_s1_2021/LogVec2DSystem.java
index 1c0a47a..d953a00 100644
--- a/javaecs/src/main/java/nz/ac/massey/programming_project_159333_s1_2021/LogVec2DSystem.java
+++ b/javaecs/src/main/java/nz/ac/massey/programming_project_159333_s1_2021/LogVec2DSystem.java
@@ -11,7 +11,7 @@ public class LogVec2DSystem extends ECSSystem{
     void update(double dt){
         for (Integer entity : entities) {
             Vec2D pos = (Vec2D)gameEngine.getComponentData(entity, Vec2D.class.getName());
-            System.out.println("X: " + pos.x + ", Y:" + pos.y);
+            System.out.println(String.format("X: %.6g, Y: %.6g", pos.x, pos.y));
         }
     }
 }
diff --git a/javaecs/src/main/java/nz/ac/massey/programming_project_159333_s1_2021/SystemManager.java b/javaecs/src/main/java/nz/ac/massey/programming_project_159333_s1_2021/SystemManager.java
index db2603c..187cf26 100644
--- a/javaecs/src/main/java/nz/ac/massey/programming_project_159333_s1_2021/SystemManager.java
+++ b/javaecs/src/main/java/nz/ac/massey/programming_project_159333_s1_2021/SystemManager.java
@@ -26,13 +26,13 @@ class SystemManager{
     // instance.
     // I.e., create an object that represents the system class; then store that class in the system
     // table.
-    public boolean registerSystem(String system, ECSSystem action){
-        if (systems.containsKey(system)){
+    public boolean registerSystem(String systemName, ECSSystem system){
+        if (systems.containsKey(systemName)){
             System.err.println("System already registered");
             return false;
         }
-        systems.put(system, action);
-        signatures.put(system, new BitSet());
+        systems.put(systemName, system);
+        signatures.put(systemName, new BitSet());
         return true;
     }