Question

I’m developing a 2D videogame in Android, using JAVA and OpenGL-ES.

I’m having an issue with I think it’s the Garbage Collector. Every few seconds, the game freezes, no matter what I’m doing.

I have been reading some documentation and so on about it, and I removed all the loop iterators I had, now I use for(i=0,…), among others solutions. The case is, it didn’t do anything with the perfomance…

I have been looking my code and I found something I think that could be making problems, and it’s the way I change between sprites in an animation.

For instance, I have a hero which can move pressing some keys. When it walks, his sprite changes between frames. To do this, I move the texture buffer to aim the part of the image I want. And every time it does, I use this function:

protected void SetTextureBuffer(float xo, float xf, float yo, float yf) {

    float textureVertexs[] = {
            xo, yf,     // top left
            xf, yf,     // bottom left
            xf, yo,     // top right
            xo, yo      // bottom right
    };

    // a float has 4 bytes so we allocate for each coordinate 4 bytes
    ByteBuffer byteBuffer = ByteBuffer.allocateDirect(textureVertexs.length * 4);
    byteBuffer.order(ByteOrder.nativeOrder());

    // allocates the memory from the byte buffer
    textureBuffer = byteBuffer.asFloatBuffer();

    // fill the vertexBuffer with the vertices
    textureBuffer.put(textureVertexs);

    // set the cursor position to the beginning of the buffer
    textureBuffer.position(0);
}

It allocates memory to create the buffer every time is called, which could be a lot of times every second, since there are more entities with animations…

Do you think this could be a problem? Or Am I looking this wrongly? If this is a problem… how could I solve this in another more efficient way?

Answer 1

Try removing these lines:

ByteBuffer byteBuffer = ByteBuffer.allocateDirect(textureVertexs.length * 4);
byteBuffer.order(ByteOrder.nativeOrder());
textureBuffer = byteBuffer.asFloatBuffer();

Allocate textureBuffer once in your class constructor/initializer. No need to recreate the buffer again since you don’t need to keep previous data. So you just overwrite the old data in the same buffer.