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    <p>Well, I've been looking on your project and everything seems to be fine, but I have one idea about what's causing you the frame rate drop.</p> <p><em>You're allocating objects during runtime.</em> If you don't do that, it will make you create all objects at start, and therefore you should notice a significant drop directly (if my solution doesn't solve your problem).</p> <p>That said; <em>I'm not sure</em> whether an object pool will solve your problem, but you can try. Initialize your objects in a constructor and instead of making this call in <code>onTouchEvent():</code></p> <pre><code>new Element(getResources(), (int) event.getX(), (int) event.getY()) </code></pre> <p>You should have something like <code>mElement.add(objectPool.allocate())</code>, where the object pool finds an unused object in the pool. Also, we should have a specified amount of objects in that object pool and from there you can check if it is the allocating that is causing this error or if it is something else.</p> <blockquote> <p>With the 26th element the frame rate drops to 25fps.</p> </blockquote> <p>When (or if) you implements this, you should see the frame rate drop directly (if this doesn't solve your problem though), since the object pool will make you allocating a fixed amount (e.g. maybe 100 elements?) at start (but you're not using them visually). </p> <p>Also, I have used the memory pool pattern (object pool) in one of my sample applications for Android. In that sample; I add a line to the <code>Canvas</code> on an <code>onTouchEvent()</code> using an object pool (without allocating during runtime). In that source code you can easily change the total amounts of objects and check it out and try it yourself. Write a comment if you want to look at my sample application (and source code) and I will gladly share it since it's not public yet. My comments are in <strong>Swedish</strong>, but I think you should be able to understand, since the variables and methods are in <strong>English</strong>. :)</p> <p><strong>Side note</strong>: You wrote that you've tried (and even success) with removing the behaviour by making your <code>Bitmap</code> <code>static</code>. As it is right now, your elements have different instances of a <code>Bitmap</code>, which will make you allocate a new <code>Bitmap</code> everytime you're constructing a new object. That means that every object is pointing to a different <code>Bitmap</code> when they are using the same resource. <code>static</code> is a fully valid solution (although a magic number of 25 seems wierd). </p> <p>This <code>Bitmap</code> case can be compared to the <code>OpenGL</code> system. If you have 20 objects which all should use the same resource, there are two possible solutions: They can point to the same VRAM texture or either they can point to a different VRAM texture (like your case when you're not using <code>static</code>), but still same resource. </p> <p><strong>EDIT</strong>:</p> <p><a href="http://code.google.com/p/viktor-lanner/downloads/detail?name=Memory_Pool_pattern_PART_THREE_SOURCE.zip" rel="nofollow">Here is my sample application for Android</a> that demonstrates the Memory Pool.</p> <p>Regarding your solution with <code>BitmapFactory</code>, that probably depends on how that class works. I'm not sure, but I think that one of the <code>decode...()</code> methods generates a new <code>Bitmap</code> even if it is the same resource. It can be the case that <code>new BufferedInputStream(res.openRawResource(R.drawable.icon))</code> is reusing the <code>BufferedInputStream</code> from memory, although, that is a big guess.</p> <p>What you should do (in that case) is to decode a resource and store a reference from it in the Panel class and pass that reference into the <code>new Element(bitmapReference, ...)</code> instead. In that way, you're only allocating it once and every element is pointing to the same <code>Bitmap</code> in memory.</p>
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    1. COIf you can share your sample code, I would really like to see it. I tried it with a very simple object pool, where I created 100 elements first but showing only a number of them. With every touch event, the number of displayed elements increase and even with 100 loaded elements and 25 displayed, I got 60fps. With the 26th the drop to 25fps is still there. Anyway a colleague found a solution, added to my answer as an edit
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    2. CO@WarrenFaith: Updated my answer with a link to my project. I have also added a little information about how you can reuse the same `Bitmap` reference, so that you do not need to return a new `Bitmap` from the `BitmapFactory` class everytime you're creating a new element.
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    3. COThank you for sharing. In general I would create a bitmap cache where I store the bitmaps and share the same instance to everybody who wants to display it. Thats in general the best solution, I think. But thats a bit off topic, because the performance drop shouldn't ever happen so soon. Not with 25 elements... at least I wouldn't expect that..
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