add method to DanmakuTimer
add RingBuffer and BitmapRingBuffer
增加根据同屏弹幕数量动态控制字体anti alias
refactor RingBuffer and BitmapRingBuffer
调整绘制线程sleep时间
根据弹幕类型调整绘制顺序1
根据弹幕类型调整绘制顺序2
added DrawingCache class
增加一条碰撞检测规则
修复同屏滚动弹幕过多会超出屏幕的问题
update reamde
add drawing cache testing code
add drawing cache testing code2
update README.md
refactor IDrawTask
added seeking feature
refactor DanmakuSurfaceView interface method
根据核心数确定是否启用线程绘制
update readme.md
Merge pull request #6 from ctiao/develop

merge develop branch