Android OpenGL E.S.2.0:非常不一致的帧率
我创建了一个简单的Android应用程序,如下所示: 活动:Android OpenGL E.S.2.0:非常不一致的帧率,android,opengl-es,Android,Opengl Es,我创建了一个简单的Android应用程序,如下所示: 活动: public class MainActivity extends Activity { private GLSurfaceView mGLView; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); mGLView = new MyGL
public class MainActivity extends Activity {
private GLSurfaceView mGLView;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
mGLView = new MyGLSurfaceView(this);
setContentView(mGLView);
}
}
class MyGLSurfaceView extends GLSurfaceView {
public MyGLSurfaceView(Context context){
super(context);
// Create an OpenGL ES 2.0 context
setEGLContextClientVersion(2);
// Set the Renderer for drawing on the GLSurfaceView
setRenderer(new MyGL20Renderer());
}
}
public class MyGL20Renderer implements GLSurfaceView.Renderer {
private long mCurrentTime;
public void onSurfaceCreated(GL10 unused, EGLConfig config) {
// Set the background frame color
GLES20.glClearColor(0.5f, 0.5f, 0.5f, 1.0f);
}
@Override
public void onDrawFrame(GL10 unused) {
final long newTime = getSystemTime();
final long dt = newTime - mCurrentTime;
mCurrentTime = newTime;
Log.e("test", "dt: "+dt);
// Redraw background color
GLES20.glClear(GLES20.GL_COLOR_BUFFER_BIT);
}
@Override
public void onSurfaceChanged(GL10 unused, int width, int height) {
GLES20.glViewport(0, 0, width, height);
}
private long getSystemTime() {
return System.nanoTime()/1000L;
}
}
OpenGL曲面:
public class MainActivity extends Activity {
private GLSurfaceView mGLView;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
mGLView = new MyGLSurfaceView(this);
setContentView(mGLView);
}
}
class MyGLSurfaceView extends GLSurfaceView {
public MyGLSurfaceView(Context context){
super(context);
// Create an OpenGL ES 2.0 context
setEGLContextClientVersion(2);
// Set the Renderer for drawing on the GLSurfaceView
setRenderer(new MyGL20Renderer());
}
}
public class MyGL20Renderer implements GLSurfaceView.Renderer {
private long mCurrentTime;
public void onSurfaceCreated(GL10 unused, EGLConfig config) {
// Set the background frame color
GLES20.glClearColor(0.5f, 0.5f, 0.5f, 1.0f);
}
@Override
public void onDrawFrame(GL10 unused) {
final long newTime = getSystemTime();
final long dt = newTime - mCurrentTime;
mCurrentTime = newTime;
Log.e("test", "dt: "+dt);
// Redraw background color
GLES20.glClear(GLES20.GL_COLOR_BUFFER_BIT);
}
@Override
public void onSurfaceChanged(GL10 unused, int width, int height) {
GLES20.glViewport(0, 0, width, height);
}
private long getSystemTime() {
return System.nanoTime()/1000L;
}
}
渲染器:
public class MainActivity extends Activity {
private GLSurfaceView mGLView;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
mGLView = new MyGLSurfaceView(this);
setContentView(mGLView);
}
}
class MyGLSurfaceView extends GLSurfaceView {
public MyGLSurfaceView(Context context){
super(context);
// Create an OpenGL ES 2.0 context
setEGLContextClientVersion(2);
// Set the Renderer for drawing on the GLSurfaceView
setRenderer(new MyGL20Renderer());
}
}
public class MyGL20Renderer implements GLSurfaceView.Renderer {
private long mCurrentTime;
public void onSurfaceCreated(GL10 unused, EGLConfig config) {
// Set the background frame color
GLES20.glClearColor(0.5f, 0.5f, 0.5f, 1.0f);
}
@Override
public void onDrawFrame(GL10 unused) {
final long newTime = getSystemTime();
final long dt = newTime - mCurrentTime;
mCurrentTime = newTime;
Log.e("test", "dt: "+dt);
// Redraw background color
GLES20.glClear(GLES20.GL_COLOR_BUFFER_BIT);
}
@Override
public void onSurfaceChanged(GL10 unused, int width, int height) {
GLES20.glViewport(0, 0, width, height);
}
private long getSystemTime() {
return System.nanoTime()/1000L;
}
}
如你所见,对于每一帧,我取奈米时间除以1000得到微秒的时间
现在,当我查看在onDrawFrame()
中生成的输出时,我得到了各种不同的值:
(此处为原始尺寸:)
x标度仅是帧。每帧一个值。y-刻度是在onDrawFrame()
中计算的增量时间dt。这是上一帧绘制所用的时间(以微秒为单位)
现在我完全明白了,由于以下原因,值不能保持在16666:
- 增量时间不能完全确定。此外,将nanotime除以1000并将其转换为
会导致一些计算错误long
- 系统必须等待
eglSwapBuffers()
- 函数
完成后,这只意味着OpenGL命令已发送到管道。但这并不意味着命令已经被处理onDrawFrame()
- 宏达一号
- CyanogenMod 10.2(安卓4.3)
如果其他人能够重现这一点,我将非常高兴。您将发现不一致的帧速率是由于Log语句造成的。如果您存储数据点,然后同时记录它们,您将看到帧率更加一致。使用类似以下的方法来记录数据。我每1000帧做一次,得到的dt大约为16500-18500
mDt[mStoredDtCount] = dt;
mStoredDtCount++;
if (mStoredDtCount == DT_MAX_COUNT) {
while (mStoredDtCount > 0) {
mStoredDtCount--;
Log.e("test2", "dt: "+mDt[mStoredDtCount]);
}
}
嗯,我不确定这是不是真的。我已经用你的方法完成了,现在得到了这个图(大约捕获了一分钟):我唯一的另一个想法是看看你的设备是否在帧之间进行垃圾收集。我已经从日志输出中删除了过滤器,并将其设置为“verbose”。在整个运行期间,没有一条关于GC的消息。如果您想将源代码压缩并上传到某个地方,我将在我的设备上尝试您的代码。嗨,levis501,谢谢您的回答。我在这里上传了一个zip:它包含.apk和源代码。