Added a method for getting the grid dimensions. Fixed the

GridCell containment to be exclusive on the upper bounds so
that an object on the line isn't in two cells at once. (oops)

Author: pspeed42

src/main/java/com/simsilica/mathd/Grid.java

@@ -50,6 +50,7 @@
 public class Grid {
 
     private final Vec3i gridSpacing;
+    private final int dimensions;
 
     private final int shift;
     private final long mask;
@@ -97,6 +98,7 @@ public Grid( Vec3i gridSpacing ) {
         if( gridSpacing.z != 0 ) {
             axes++;
         }
+        this.dimensions = axes;
         int bits = 64 / axes;
         shift = bits;
 
@@ -122,6 +124,10 @@ public Grid( Vec3i gridSpacing ) {
     public final Vec3i getSpacing() {
         return gridSpacing;
     }
+ 
+    public final int getDimensions() {
+        return dimensions;
+    }
 
     private int worldToCell( int i, int size ) {
         if( size == 0 ) {

src/main/java/com/simsilica/mathd/GridCell.java

@@ -72,24 +72,28 @@ public final Vec3i getWorldOrigin() {
     public final boolean contains( Vec3d world ) {
         return contains(world.x, world.y, world.z);
     }
-    
+ 
+    /**
+     *  Returns true if this GridCell contains the specified world location
+     *  where containment is in the range of min inclusive, max exclusive.
+     */   
     public final boolean contains( double x, double y, double z ) {
         Vec3i spacing = grid.getSpacing();
         double xLocal = x - worldOrigin.x;
         double yLocal = y - worldOrigin.y;
         double zLocal = z - worldOrigin.z;
         if( spacing.x != 0 ) {
-            if( xLocal < 0 || xLocal > spacing.x ) {
+            if( xLocal < 0 || xLocal >= spacing.x ) {
                 return false;
             }
         }
         if( spacing.y != 0 ) {
-            if( yLocal < 0 || yLocal > spacing.y ) {
+            if( yLocal < 0 || yLocal >= spacing.y ) {
                 return false;
             }
         }
         if( spacing.z != 0 ) {
-            if( zLocal < 0 || zLocal > spacing.z ) {
+            if( zLocal < 0 || zLocal >= spacing.z ) {
                 return false;
             }
         }