Add getTiles() to calculate tiles between two coords

Plugin Radioactive Cloud/src/main/java/net/simon987/pluginradioactivecloud/RadiationDetector.java

@@ -1,6 +1,6 @@
 package net.simon987.pluginradioactivecloud;
 
-import java.util.HashSet;
+import java.util.ArrayList;
 
 import org.bson.Document;
 import net.simon987.server.assembly.HardwareModule;
@@ -33,30 +33,64 @@ public class RadiationDetector extends HardwareModule {
       this.x = x;
       this.y = y;
     }
-
-    @Override
-    public boolean equals(Object o) {
-      if (o == this) {
-        return true;
-      }
-
-      if (!(o instanceof Tuple)) {
-        return false;
-      }
-
-      Tuple t = (Tuple) o;
-
-      return Integer.compare(x, t.x) == 0 && Integer.compare(y, t.y) == 0;
-    }
   }
 
   /**
-   * Find tiles between two given tiles.
+   * Find tiles between two given coordinates.
+   * 
+   * @return List of tile coordinates. An empty list indicates tiles are next to
+   *         each other.
    */
-  private HashSet<Tuple> getTiles(int x0, int y0, int x1, int y1) {
+  public ArrayList<Tuple> getTiles(int x0, int y0, int x1, int y1) {
 
-    HashSet<Tuple> ret = new HashSet<>();
-    double slope = (y1 - y0) / (double) (x1 - x0);
+    ArrayList<Tuple> ret = new ArrayList<>();
+    double slope;
+    if (x1 > x0)
+      slope = (y1 - y0) / (double) (x1 - x0);
+    else {
+      slope = (y0 - y1) / (double) (x0 - x1);
+
+      // Swap values so that x0 < x1. This preps the following code where y is
+      // determined by adding a step value (1) to x0 till it reaches x1.
+      int tmp = x1;
+      x1 = x0;
+      x0 = tmp;
+
+      tmp = y1;
+      y1 = y0;
+      y0 = tmp;
+    }
+
+    // If slope is zero or undefined, return tiles directly along the
+    // appropriate cardinal direction.
+    if (x0 == x1) {
+      int smaller = y0 < y1 ? y0 : y1;
+      int larger = y0 > y1 ? y0 : y1;
+      System.out.printf("%d %d", smaller, larger);
+      for (int i = smaller + 1; i < larger; i++) {
+        ret.add(new Tuple(x0, i));
+      }
+    } else if (y0 == y1) {
+      int smaller = x0 < x1 ? x0 : x1;
+      int larger = x0 > x1 ? x0 : x1;
+      for (int i = smaller + 1; i < larger; i++) {
+        ret.add(new Tuple(i, y0));
+      }
+    } else {
+      // Find all coordinates with 0.1 step
+      int lastX = x0;
+      int lastY = y0;
+      for (int i = x0 * 10; i < x1 * 10; i += 1) {
+        if (i / 10 != lastX || (int) (slope * i / 10) != lastY) {
+          // Update last values
+          lastX = i / 10;
+          lastY = (int) (slope * i / 10);
+
+          // Add new values to array
+          ret.add(new Tuple(lastX, lastY));
+        }
+      }
+    }
 
     return ret;
   }