怎么画得更快？ SurfaceView、SurfaceHolder 脏矩形答案

【问题标题】：How to draw faster? SurfaceView, SurfaceHolder dirty rect怎么画得更快？ SurfaceView、SurfaceHolder 脏矩形
【发布时间】：2012-12-04 10:01:48
【问题描述】：

我对 SurfaceView 有疑问。

函数DrawWave是由一个定时器间隔5ms调用，但实际上两次调用之间需要超过30ms，（我试过删除drawColor，drawPath）。

我尝试了“模式1”和“模式2”，通过使用Dirty rect，希望它可以运行得更快。 Interval一样，都是30ms以上，（这个宽度是800px，eScrX-sScrX

问题 1：使用 SurfaceView/SurfaceHolder 是不是我做错了什么？

问题2：如何提高绘图速度？我希望它能在 10 毫秒内完成绘制。

我的代码：

public class VS_VChannel extends SurfaceView
{//Wave Show Class
    //-------------------------------------------------------------------------------
    private Paint paint = new Paint();  
    private SurfaceHolder sHolder = null;
    private Canvas cvs = null;
    private Path P = new Path();
    //Data source of the wave point Y
    protected VSChannel Channel = null;
    private float drawY;
    //-------------------------------------------------------------------------------
    public VS_VChannel(Context context) 
    {
        super(context);
    }
    //------------------------------------------------------------------------------
    public VS_VChannel(Context context, AttributeSet attrs) 
    {
        super(context, attrs);
        //Bind the wave data source whith AttributeSet name:vs_wave
        String vsName = attrs.getAttributeValue(null, "vs_wave");
        Channel = (VSChannel)VS.GetItem(vsName);//Find the wave data source from collection with name
        //
        paint.setAntiAlias(true);         
        paint.setDither(true);  
        paint.setColor(Channel.getColor());
        paint.setStyle(Paint.Style.STROKE);     
        paint.setStrokeWidth(2);                
        //
        sHolder = this.getHolder(); 
        this.setZOrderOnTop(true);  
        sHolder.setFormat(PixelFormat.TRANSPARENT);
    }
    //------------------------------------------------------------------------------
    /** DrawWave is Call by a timer Interval 5ms, 
     *  BUT actually it need more than 30ms between twice call,(tried delete drawColor, drawPath)
     *  I try as "Mode 1" and "Mode 2", by using Dirty rect, hope it can run faster
     *  The Interval is the same, both more than 30ms,
     *  (The width of this is 800px, and eScrX-sScrX<20px)
     */
    protected void DrawWave(int sScrX, int eScrX)
    {   
        Rect rect = new Rect(sScrX, 0, eScrX+8, getHeight());   //Mode 1    
        //Rect rect = new Rect(0, 0, getWidth(), getHeight());  //Mode 2
        //
        cvs = sHolder.lockCanvas(rect);     
        cvs.drawColor(Color.TRANSPARENT, PorterDuff.Mode.CLEAR);
        cvs.drawPath(P, paint);
        sHolder.unlockCanvasAndPost(cvs);   
    }
    //-------------------------------------------------------------------------------
    protected void GetWaveY()
    {
        drawY = Channel.GetWaveY(getHeight());
    }
    //-------------------------------------------------------------------------------
    protected void MoveTo(float x)
    {
        P.moveTo(x, drawY);
    }
    //-------------------------------------------------------------------------------
    protected void LineTo(float x)
    {
        P.lineTo(x, drawY);
    }
    //-------------------------------------------------------------------------------
    protected void DrawReturn()
    {
        P.reset();//Clear
        P.moveTo(0, drawY);
    }
    //-------------------------------------------------------------------------------
}
//-------------------------------------------------------------------------------

【问题讨论】：

标签： surfaceview rect surfaceholder

【解决方案1】：

如果您在显示线程之上运行，您只能以该线程允许的速度进行处理和绘制。我可能会建议在另一个线程中绘制位图，然后使用表面支架解锁、绘制位图并发布。

【讨论】：