Update sample to showcase bitmap explosion capability

README.md

@@ -21,6 +21,13 @@ ExplosionField explosionField = ...;
 explosionField.explode(view);
 ```
 
+explosive effects can also be applied directly to bitmaps (with provided bounds) using:
+
+```java
+ExplosionField explosionField = ...;
+explosionField.explode(bitmap, bound, startDelay, duration);
+```
+
 ## License
 
     Copyright 2015 tyrantgit

app/src/main/java/tyrantgit/sample/MainActivity.java

@@ -1,25 +1,33 @@
 package tyrantgit.sample;
 
 import android.app.Activity;
+import android.graphics.Bitmap;
+import android.graphics.BitmapFactory;
+import android.graphics.Rect;
 import android.os.Bundle;
 import android.view.Menu;
 import android.view.MenuItem;
+import android.view.MotionEvent;
 import android.view.View;
 import android.view.ViewGroup;
 
 import tyrantgit.explosionfield.ExplosionField;
+import tyrantgit.explosionfield.Utils;
 
 
-public class MainActivity extends Activity {
+public class MainActivity extends Activity implements View.OnTouchListener {
 
     private ExplosionField mExplosionField;
+    private View root;
+    private int size = Utils.dp2Px(50);
 
     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.activity_main);
         mExplosionField = ExplosionField.attach2Window(this);
-        addListener(findViewById(R.id.root));
+        root = findViewById(R.id.root);
+        addListener(root);
     }
 
     private void addListener(View root) {
@@ -35,6 +43,7 @@ private void addListener(View root) {
                 public void onClick(View v) {
                     mExplosionField.explode(v);
                     v.setOnClickListener(null);
+                    v.setClickable(false);
                 }
             });
         }
@@ -70,4 +79,66 @@ private void reset(View root) {
             root.setAlpha(1);
         }
     }
+
+    @Override
+    protected void onResume() {
+        super.onResume();
+        root.setOnTouchListener(this);
+    }
+
+    @Override
+    protected void onPause() {
+        super.onPause();
+        root.setOnTouchListener(null);
+    }
+
+    float lastX, lastY;
+    @Override
+    public boolean onTouch(View v, MotionEvent event) {
+        Bitmap tmp = BitmapFactory.decodeResource(getResources(), R.drawable.p5);
+        if (event.getAction() == MotionEvent.ACTION_DOWN) {
+            lastX = event.getX(); lastY = event.getY();
+            if (tmp == null) return true;
+            int x = (int) lastX, y = (int) lastY;
+            Rect r = new Rect(x - size, y - size, x + size, y + size);
+            mExplosionField.explode(tmp, r, 0, 0x300);
+            return true;
+        } else if(event.getAction() == MotionEvent.ACTION_MOVE) {
+            float distance = getDistance(lastX, lastY, event);
+            if (distance < size/2) {
+                // let's not explode for every move you make !!
+                // limit the explosion to a movement distance of half the explosion size
+                return false;
+            }
+            lastX = event.getX(); lastY = event.getY();
+            if (tmp == null) return true;
+            int x = (int) lastX, y = (int) lastY;
+            Rect r = new Rect(x - size, y - size, x + size, y + size);
+            mExplosionField.explode(tmp, r, 0, 0x300);
+            return true;
+        }
+        return false;
+    }
+
+    float getDistance(float startX, float startY, MotionEvent ev) {
+        float distanceSum = 0;
+        final int historySize = ev.getHistorySize();
+        for (int h = 0; h < historySize; h++) {
+            // historical point
+            float hx = ev.getHistoricalX(0, h);
+            float hy = ev.getHistoricalY(0, h);
+            // distance between startX,startY and historical point
+            float dx = (hx - startX);
+            float dy = (hy - startY);
+            distanceSum += Math.sqrt(dx * dx + dy * dy);
+            // make historical point the start point for next loop iteration
+            startX = hx;
+            startY = hy;
+        }
+        // add distance from last historical point to event's point
+        float dx = (ev.getX(0) - startX);
+        float dy = (ev.getY(0) - startY);
+        distanceSum += Math.sqrt(dx * dx + dy * dy);
+        return distanceSum;
+    }
 }

app/src/main/res/layout/activity_main.xml

@@ -72,7 +72,7 @@
         android:layout_width="match_parent"
         android:gravity="center"
         android:layout_marginTop="48dp"
-        android:text="click to destroy"
+        android:text="click to destroy\nor swipe anywhere on the empty area"
         android:layout_height="wrap_content" />