Optimized prime search utility methods and added timer to FalloffPerlinNoiseTest

Author: john01dav

Tests/src/src/john01dav/jnoise/tests/FalloffPerlinNoiseTest.java

@@ -10,8 +10,11 @@
 public class FalloffPerlinNoiseTest{
 
     public static void main(String[] args) throws IOException{
+        long start = System.currentTimeMillis();
         HeightMap heightMap = new HeightMap(2048, new PerlinNoiseTemplate(0L, 9, 2, new FalloffPerlinNoiseController()));
         heightMap.generate();
+        System.out.println("Generation Time: " + (System.currentTimeMillis() - start));
+
         heightMap.saveImage("./falloffislandperlinnoise.png");
     }
 

src/src/john01dav/jnoise/util/MathUtil.java

@@ -5,7 +5,9 @@ public final class MathUtil{
     private MathUtil(){}
 
     public static boolean isPrime(int n){
-        for(int i=2;i<n;i++){
+        int sqrtOfN = (int) Math.ceil(Math.sqrt(n));
+
+        for(int i=2;i<sqrtOfN;i++){
             if(n % i == 0){
                 return false;
             }
@@ -15,7 +17,9 @@ public static boolean isPrime(int n){
     }
 
     public static int getNextPrime(int n){
-        while(!isPrime(n)) n++;
+        if(n % 2 == 0) n++;
+
+        while(!isPrime(n)) n+=2;
         return n;
     }