unsigned int mDensity; ///< How many bubbles will emit at each time, they are controlled by same uniforms in the shader.
unsigned int mTotalNumOfBubble; ///< mNumBubblePerShader*mNumShader.
unsigned int mCurrentBubble; ///< Keep track of the index for the newly emitted bubble
unsigned int mDensity; ///< How many bubbles will emit at each time, they are controlled by same uniforms in the shader.
unsigned int mTotalNumOfBubble; ///< mNumBubblePerShader*mNumShader.
unsigned int mCurrentBubble; ///< Keep track of the index for the newly emitted bubble