Fix GenericMath.mod being wrong when div == 0

src/main/template/float/com/flowpowered/math/GenericMath.template

@@ -632,37 +632,18 @@ public class GenericMath {
     }
 
     /**
-     * Returns the modulo of x by div with corrections for negative numbers.
+     * Returns the modulo of 'a' by 'div' with corrections for negative numbers.
      *
-     * @param x The number as an int
+     * @param a The number as an int
      * @param div The div as an int
      * @return The corrected modulo
      */
-    public static int mod(int x, int div) {
-        return x < 0 ? (x % div) + div : x % div;
+    public static int mod(int a, int div) {
+        final int remainder = a % div;
+        return remainder < 0 ? remainder + div : remainder;
     }
 
-    /**
-     * Returns the modulo of x by div with corrections for negative numbers.
-     *
-     * @param x The number as an float
-     * @param div The div as an float
-     * @return The corrected modulo
-     */
-    public static float mod(float x, float div) {
-        return x < 0 ? (x % div) + div : x % div;
-    }
-
-    /**
-     * Returns the modulo of x by div with corrections for negative numbers.
-     *
-     * @param x The number as an double
-     * @param div The div as an double
-     * @return The corrected modulo
-     */
-    public static double mod(double x, double div) {
-        return x < 0 ? (x % div) + div : x % div;
-    }
+#REPLICATED9#
 
     /**
      * Gets a thread local Random object that is seeded using SecureRandom. Only one Random is created per thread.
@@ -779,6 +760,20 @@ public class GenericMath {
     }
 =====END_REPLICATED_CONTENT #8=====
 
+====START_REPLICATED_CONTENT #9====
+    /**
+     * Returns the modulo of 'a' by 'div' with corrections for negative numbers.
+     *
+     * @param a The dividend
+     * @param div The divider
+     * @return The corrected modulo
+     */
+    public static #e# mod(#e# a, #e# div) {
+        final #e# remainder = a % div;
+        return remainder < 0 ? remainder + div : remainder;
+    }
+=====END_REPLICATED_CONTENT #9=====
+
 ====START_REPLICATED_CONTENT #4====
     /**
      * Attempts to normalize a vector. If this fails, the method catches the exception and return a zero vector of the same dimension instead.

src/test/java/com/flowpowered/math/test/GenericMathTest.java

@@ -29,6 +29,7 @@
 
 import static com.flowpowered.math.GenericMath.floor;
 import static com.flowpowered.math.GenericMath.mean;
+import static com.flowpowered.math.GenericMath.mod;
 import static com.flowpowered.math.GenericMath.roundUpPow2;
 
 public final class GenericMathTest {
@@ -63,4 +64,43 @@ public void testFloor() {
         assertEquals(0, floor(0.9));
         assertEquals(0, floor(0.9f));
     }
+
+    @Test
+    public void testModInt() {
+        assertEquals(0, mod(-32, 16));
+        assertEquals(15, mod(-17, 16));
+        assertEquals(0, mod(-16, 16));
+        assertEquals(2, mod(-14, 16));
+        assertEquals(0, mod(0, 16));
+        assertEquals(6, mod(6, 16));
+        assertEquals(0, mod(16, 16));
+        assertEquals(8, mod(24, 16));
+        assertEquals(0, mod(32, 16));
+    }
+
+    @Test
+    public void testModFloat() {
+        assertEquals(0f, mod(-32f, 16f), 0f);
+        assertEquals(15f, mod(-17f, 16f), 0f);
+        assertEquals(0f, mod(-16f, 16f), 0f);
+        assertEquals(2f, mod(-14f, 16f), 0f);
+        assertEquals(0f, mod(0f, 16f), 0f);
+        assertEquals(6f, mod(6f, 16f), 0f);
+        assertEquals(0f, mod(16f, 16f), 0f);
+        assertEquals(8f, mod(24f, 16f), 0f);
+        assertEquals(0f, mod(32f, 16f), 0f);
+    }
+
+    @Test
+    public void testModDouble() {
+        assertEquals(0d, mod(-32d, 16d), 0d);
+        assertEquals(15d, mod(-17d, 16d), 0d);
+        assertEquals(0d, mod(-16d, 16d), 0d);
+        assertEquals(2d, mod(-14d, 16d), 0d);
+        assertEquals(0d, mod(0d, 16d), 0d);
+        assertEquals(6d, mod(6d, 16d), 0d);
+        assertEquals(0d, mod(16d, 16d), 0d);
+        assertEquals(8d, mod(24d, 16d), 0d);
+        assertEquals(0d, mod(32d, 16d), 0d);
+    }
 }

target/generated-sources/template/com/flowpowered/math/GenericMath.java

@@ -750,36 +750,39 @@ public static String decToHex(int dec, int minDigits) {
     }
 
     /**
-     * Returns the modulo of x by div with corrections for negative numbers.
+     * Returns the modulo of 'a' by 'div' with corrections for negative numbers.
      *
-     * @param x The number as an int
+     * @param a The number as an int
      * @param div The div as an int
      * @return The corrected modulo
      */
-    public static int mod(int x, int div) {
-        return x < 0 ? (x % div) + div : x % div;
+    public static int mod(int a, int div) {
+        final int remainder = a % div;
+        return remainder < 0 ? remainder + div : remainder;
     }
 
     /**
-     * Returns the modulo of x by div with corrections for negative numbers.
+     * Returns the modulo of 'a' by 'div' with corrections for negative numbers.
      *
-     * @param x The number as an float
-     * @param div The div as an float
+     * @param a The dividend
+     * @param div The divider
      * @return The corrected modulo
      */
-    public static float mod(float x, float div) {
-        return x < 0 ? (x % div) + div : x % div;
+    public static float mod(float a, float div) {
+        final float remainder = a % div;
+        return remainder < 0 ? remainder + div : remainder;
     }
 
     /**
-     * Returns the modulo of x by div with corrections for negative numbers.
+     * Returns the modulo of 'a' by 'div' with corrections for negative numbers.
      *
-     * @param x The number as an double
-     * @param div The div as an double
+     * @param a The dividend
+     * @param div The divider
      * @return The corrected modulo
      */
-    public static double mod(double x, double div) {
-        return x < 0 ? (x % div) + div : x % div;
+    public static double mod(double a, double div) {
+        final double remainder = a % div;
+        return remainder < 0 ? remainder + div : remainder;
     }
 
     /**

target/generated-sources/template/com/flowpowered/math/imaginary/Complexd.java

@@ -531,7 +531,7 @@ public static Complexd fromReal(double x) {
     }
 
     /**
-     * Creates a new quaternion from the double imaginary components.
+     * Creates a new complex from the double imaginary components.
      *
      * <p>The {@link #ZERO} constant is re-used when {@code y} is 0.</p>
      *

target/generated-sources/template/com/flowpowered/math/imaginary/Complexf.java

@@ -531,7 +531,7 @@ public static Complexf fromReal(float x) {
     }
 
     /**
-     * Creates a new quaternion from the float imaginary components.
+     * Creates a new complex from the float imaginary components.
      *
      * <p>The {@link #ZERO} constant is re-used when {@code y} is 0.</p>
      *