Android OpenGL 响应能力

Question

我制作了一个简单的 android 应用程序，它使用 openGL 渲染一个正方形。可以用手指移动方 block 。它工作正常，但在四处移动方 block 时，您会感觉到相当大的输入滞后，尤其是在做圆周运动时。有什么技巧可以减少或掩盖这种滞后吗？

代码如下:

public class InputTestActivity extends Activity {

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(new InputTestView(this));
    }

    public class InputTestView extends GLSurfaceView {
        private InputTestRenderer renderer;

        private float prevX;
        private float prevY;

        public InputTestView(Context context) {
            super(context);
            renderer = new InputTestRenderer();
            setRenderer(renderer);
        }

        @Override
        public boolean onTouchEvent(MotionEvent event) {
            float x = event.getX();
            float y = event.getY();
            switch(event.getAction()) {
            case MotionEvent.ACTION_MOVE:
                renderer.moveEye(prevX - x, prevY -y);
            case MotionEvent.ACTION_DOWN:
                prevX = x;
                prevY = y;
                break;
            }
            return true;
        }   
    }

    public class InputTestRenderer implements Renderer {
        private final float[] verts = { -0.5f, -0.5f, 0.0f, 0.5f, -0.5f, 0.0f, -0.5f, 0.5f, 0.0f, 0.5f, 0.5f, 0.0f };
        private final int nrOfVerts = verts.length / 3;
        private FloatBuffer vertBuf;

        private float eyeX;
        private float eyeY;

        public void onSurfaceCreated(GL10 gl, EGLConfig config) { 
            gl.glEnableClientState(GL10.GL_VERTEX_ARRAY);

            gl.glColor4f(1, 0, 0, 1);

            ByteBuffer byteBuffer = ByteBuffer.allocateDirect(verts.length * Float.SIZE / 8);
            byteBuffer.order(ByteOrder.nativeOrder());
            vertBuf = byteBuffer.asFloatBuffer();
            vertBuf.put(verts);
            vertBuf.position(0);
        }

        public void onSurfaceChanged(GL10 gl, int width, int height) {
            gl.glViewport(0, 0, width, height);

            gl.glMatrixMode(GL10.GL_PROJECTION);
            gl.glLoadIdentity();
            gl.glOrthof(-width / 2, width / 2, height / 2, -height / 2, 1, 100);
            gl.glMatrixMode(GL10.GL_MODELVIEW);
        }

        public void onDrawFrame(GL10 gl) {
            gl.glClear(GL10.GL_COLOR_BUFFER_BIT);

            gl.glLoadIdentity();
            synchronized (this) {
                gl.glTranslatef(-eyeX, -eyeY, -10);
            }
            gl.glScalef(200, 200, 1);

            gl.glVertexPointer(3, GL10.GL_FLOAT, 0, vertBuf);
            gl.glDrawArrays(GL10.GL_TRIANGLE_STRIP, 0, nrOfVerts);
        }

        public synchronized void moveEye(float deltaX, float deltaY) {
            this.eyeX += deltaX;
            this.eyeY += deltaY;
        }
    }
}

Answer 1

怀疑您的 UI 线程和渲染线程正在争夺 CPU 时间。尝试将此行添加到 onSurfaceCreated() :

Thread.currentThread().setPriority(Thread.MIN_PRIORITY);

降低渲染器的优先级可确保运动事件得到更迅速的处理。似乎有所作为。

FWIW 我不喜欢 GLSurfaceView 的设计，更喜欢使用 Handler.postDelayed() 来安排每帧以 20 毫秒的间隔绘制每帧。