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GLSurfaceView.javaAPI DocAndroid 5.1 API76893Thu Mar 12 22:22:40 GMT 2015android.opengl

GLSurfaceView

public class GLSurfaceView extends android.view.SurfaceView implements SurfaceHolder.Callback
An implementation of SurfaceView that uses the dedicated surface for displaying OpenGL rendering.

A GLSurfaceView provides the following features:

  • Manages a surface, which is a special piece of memory that can be composited into the Android view system.
  • Manages an EGL display, which enables OpenGL to render into a surface.
  • Accepts a user-provided Renderer object that does the actual rendering.
  • Renders on a dedicated thread to decouple rendering performance from the UI thread.
  • Supports both on-demand and continuous rendering.
  • Optionally wraps, traces, and/or error-checks the renderer's OpenGL calls.

Developer Guides

For more information about how to use OpenGL, read the OpenGL developer guide.

Using GLSurfaceView

Typically you use GLSurfaceView by subclassing it and overriding one or more of the View system input event methods. If your application does not need to override event methods then GLSurfaceView can be used as-is. For the most part GLSurfaceView behavior is customized by calling "set" methods rather than by subclassing. For example, unlike a regular View, drawing is delegated to a separate Renderer object which is registered with the GLSurfaceView using the {@link #setRenderer(Renderer)} call.

Initializing GLSurfaceView

All you have to do to initialize a GLSurfaceView is call {@link #setRenderer(Renderer)}. However, if desired, you can modify the default behavior of GLSurfaceView by calling one or more of these methods before calling setRenderer:
  • {@link #setDebugFlags(int)}
  • {@link #setEGLConfigChooser(boolean)}
  • {@link #setEGLConfigChooser(EGLConfigChooser)}
  • {@link #setEGLConfigChooser(int, int, int, int, int, int)}
  • {@link #setGLWrapper(GLWrapper)}

Specifying the android.view.Surface

By default GLSurfaceView will create a PixelFormat.RGB_888 format surface. If a translucent surface is required, call getHolder().setFormat(PixelFormat.TRANSLUCENT). The exact format of a TRANSLUCENT surface is device dependent, but it will be a 32-bit-per-pixel surface with 8 bits per component.

Choosing an EGL Configuration

A given Android device may support multiple EGLConfig rendering configurations. The available configurations may differ in how may channels of data are present, as well as how many bits are allocated to each channel. Therefore, the first thing GLSurfaceView has to do when starting to render is choose what EGLConfig to use.

By default GLSurfaceView chooses a EGLConfig that has an RGB_888 pixel format, with at least a 16-bit depth buffer and no stencil.

If you would prefer a different EGLConfig you can override the default behavior by calling one of the setEGLConfigChooser methods.

Debug Behavior

You can optionally modify the behavior of GLSurfaceView by calling one or more of the debugging methods {@link #setDebugFlags(int)}, and {@link #setGLWrapper}. These methods may be called before and/or after setRenderer, but typically they are called before setRenderer so that they take effect immediately.

Setting a Renderer

Finally, you must call {@link #setRenderer} to register a {@link Renderer}. The renderer is responsible for doing the actual OpenGL rendering.

Rendering Mode

Once the renderer is set, you can control whether the renderer draws continuously or on-demand by calling {@link #setRenderMode}. The default is continuous rendering.

Activity Life-cycle

A GLSurfaceView must be notified when the activity is paused and resumed. GLSurfaceView clients are required to call {@link #onPause()} when the activity pauses and {@link #onResume()} when the activity resumes. These calls allow GLSurfaceView to pause and resume the rendering thread, and also allow GLSurfaceView to release and recreate the OpenGL display.

Handling events

To handle an event you will typically subclass GLSurfaceView and override the appropriate method, just as you would with any other View. However, when handling the event, you may need to communicate with the Renderer object that's running in the rendering thread. You can do this using any standard Java cross-thread communication mechanism. In addition, one relatively easy way to communicate with your renderer is to call {@link #queueEvent(Runnable)}. For example: 

class MyGLSurfaceView extends GLSurfaceView {

private MyRenderer mMyRenderer;

public void start() {
mMyRenderer = ...;
setRenderer(mMyRenderer);
}

public boolean onKeyDown(int keyCode, KeyEvent event) {
if (keyCode == KeyEvent.KEYCODE_DPAD_CENTER) {
queueEvent(new Runnable() {
// This method will be called on the rendering
// thread:
public void run() {
mMyRenderer.handleDpadCenter();
}});
return true;
}
return super.onKeyDown(keyCode, event);
}
}

Fields Summary
private static final String
TAG
private static final boolean
LOG_ATTACH_DETACH
private static final boolean
LOG_THREADS
private static final boolean
LOG_PAUSE_RESUME
private static final boolean
LOG_SURFACE
private static final boolean
LOG_RENDERER
private static final boolean
LOG_RENDERER_DRAW_FRAME
private static final boolean
LOG_EGL
public static final int
RENDERMODE_WHEN_DIRTY
The renderer only renders when the surface is created, or when {@link #requestRender} is called.
public static final int
RENDERMODE_CONTINUOUSLY
The renderer is called continuously to re-render the scene.
public static final int
DEBUG_CHECK_GL_ERROR
Check glError() after every GL call and throw an exception if glError indicates that an error has occurred. This can be used to help track down which OpenGL ES call is causing an error.
public static final int
DEBUG_LOG_GL_CALLS
Log GL calls to the system log at "verbose" level with tag "GLSurfaceView".
private static final GLThreadManager
sGLThreadManager
private final WeakReference
mThisWeakRef
private GLThread
mGLThread
private Renderer
mRenderer
private boolean
mDetached
private EGLConfigChooser
mEGLConfigChooser
private EGLContextFactory
mEGLContextFactory
private EGLWindowSurfaceFactory
mEGLWindowSurfaceFactory
private GLWrapper
mGLWrapper
private int
mDebugFlags
private int
mEGLContextClientVersion
private boolean
mPreserveEGLContextOnPause
Constructors Summary
public GLSurfaceView(android.content.Context context)
Standard View constructor. In order to render something, you must call {@link #setRenderer} to register a renderer.


                          
       
        super(context);
        init();
public GLSurfaceView(android.content.Context context, android.util.AttributeSet attrs)
Standard View constructor. In order to render something, you must call {@link #setRenderer} to register a renderer.

        super(context, attrs);
        init();
Methods Summary
private voidcheckRenderThreadState()

    


       
        if (mGLThread != null) {
            throw new IllegalStateException(
                    "setRenderer has already been called for this instance.");
        }
protected voidfinalize()

        try {
            if (mGLThread != null) {
                // GLThread may still be running if this view was never
                // attached to a window.
                mGLThread.requestExitAndWait();
            }
        } finally {
            super.finalize();
        }
public intgetDebugFlags()
Get the current value of the debug flags.

return
the current value of the debug flags.

        return mDebugFlags;
public booleangetPreserveEGLContextOnPause()

return
true if the EGL context will be preserved when paused

        return mPreserveEGLContextOnPause;
public intgetRenderMode()
Get the current rendering mode. May be called from any thread. Must not be called before a renderer has been set.

return
the current rendering mode.
see
#RENDERMODE_CONTINUOUSLY
see
#RENDERMODE_WHEN_DIRTY

        return mGLThread.getRenderMode();
private voidinit()

        // Install a SurfaceHolder.Callback so we get notified when the
        // underlying surface is created and destroyed
        SurfaceHolder holder = getHolder();
        holder.addCallback(this);
        // setFormat is done by SurfaceView in SDK 2.3 and newer. Uncomment
        // this statement if back-porting to 2.2 or older:
        // holder.setFormat(PixelFormat.RGB_565);
        //
        // setType is not needed for SDK 2.0 or newer. Uncomment this
        // statement if back-porting this code to older SDKs.
        // holder.setType(SurfaceHolder.SURFACE_TYPE_GPU);
protected voidonAttachedToWindow()
This method is used as part of the View class and is not normally called or subclassed by clients of GLSurfaceView.

        super.onAttachedToWindow();
        if (LOG_ATTACH_DETACH) {
            Log.d(TAG, "onAttachedToWindow reattach =" + mDetached);
        }
        if (mDetached && (mRenderer != null)) {
            int renderMode = RENDERMODE_CONTINUOUSLY;
            if (mGLThread != null) {
                renderMode = mGLThread.getRenderMode();
            }
            mGLThread = new GLThread(mThisWeakRef);
            if (renderMode != RENDERMODE_CONTINUOUSLY) {
                mGLThread.setRenderMode(renderMode);
            }
            mGLThread.start();
        }
        mDetached = false;
protected voidonDetachedFromWindow()

        if (LOG_ATTACH_DETACH) {
            Log.d(TAG, "onDetachedFromWindow");
        }
        if (mGLThread != null) {
            mGLThread.requestExitAndWait();
        }
        mDetached = true;
        super.onDetachedFromWindow();
public voidonPause()
Inform the view that the activity is paused. The owner of this view must call this method when the activity is paused. Calling this method will pause the rendering thread. Must not be called before a renderer has been set.

        mGLThread.onPause();
public voidonResume()
Inform the view that the activity is resumed. The owner of this view must call this method when the activity is resumed. Calling this method will recreate the OpenGL display and resume the rendering thread. Must not be called before a renderer has been set.

        mGLThread.onResume();
public voidqueueEvent(java.lang.Runnable r)
Queue a runnable to be run on the GL rendering thread. This can be used to communicate with the Renderer on the rendering thread. Must not be called before a renderer has been set.

param
r the runnable to be run on the GL rendering thread.

        mGLThread.queueEvent(r);
public voidrequestRender()
Request that the renderer render a frame. This method is typically used when the render mode has been set to {@link #RENDERMODE_WHEN_DIRTY}, so that frames are only rendered on demand. May be called from any thread. Must not be called before a renderer has been set.

        mGLThread.requestRender();
public voidsetDebugFlags(int debugFlags)
Set the debug flags to a new value. The value is constructed by OR-together zero or more of the DEBUG_CHECK_* constants. The debug flags take effect whenever a surface is created. The default value is zero.

param
debugFlags the new debug flags
see
#DEBUG_CHECK_GL_ERROR
see
#DEBUG_LOG_GL_CALLS

        mDebugFlags = debugFlags;
public voidsetEGLConfigChooser(android.opengl.GLSurfaceView$EGLConfigChooser configChooser)
Install a custom EGLConfigChooser.

If this method is called, it must be called before {@link #setRenderer(Renderer)} is called.

If no setEGLConfigChooser method is called, then by default the view will choose an EGLConfig that is compatible with the current android.view.Surface, with a depth buffer depth of at least 16 bits.

param
configChooser

        checkRenderThreadState();
        mEGLConfigChooser = configChooser;
public voidsetEGLConfigChooser(boolean needDepth)
Install a config chooser which will choose a config as close to 16-bit RGB as possible, with or without an optional depth buffer as close to 16-bits as possible.

If this method is called, it must be called before {@link #setRenderer(Renderer)} is called.

If no setEGLConfigChooser method is called, then by default the view will choose an RGB_888 surface with a depth buffer depth of at least 16 bits.

param
needDepth

        setEGLConfigChooser(new SimpleEGLConfigChooser(needDepth));
public voidsetEGLConfigChooser(int redSize, int greenSize, int blueSize, int alphaSize, int depthSize, int stencilSize)
Install a config chooser which will choose a config with at least the specified depthSize and stencilSize, and exactly the specified redSize, greenSize, blueSize and alphaSize.

If this method is called, it must be called before {@link #setRenderer(Renderer)} is called.

If no setEGLConfigChooser method is called, then by default the view will choose an RGB_888 surface with a depth buffer depth of at least 16 bits.

        setEGLConfigChooser(new ComponentSizeChooser(redSize, greenSize,
                blueSize, alphaSize, depthSize, stencilSize));
public voidsetEGLContextClientVersion(int version)
Inform the default EGLContextFactory and default EGLConfigChooser which EGLContext client version to pick.

Use this method to create an OpenGL ES 2.0-compatible context. Example: 

public MyView(Context context) {
super(context);
setEGLContextClientVersion(2); // Pick an OpenGL ES 2.0 context.
setRenderer(new MyRenderer());
}

Note: Activities which require OpenGL ES 2.0 should indicate this by setting @lt;uses-feature android:glEsVersion="0x00020000" /> in the activity's AndroidManifest.xml file.

If this method is called, it must be called before {@link #setRenderer(Renderer)} is called.

This method only affects the behavior of the default EGLContexFactory and the default EGLConfigChooser. If {@link #setEGLContextFactory(EGLContextFactory)} has been called, then the supplied EGLContextFactory is responsible for creating an OpenGL ES 2.0-compatible context. If {@link #setEGLConfigChooser(EGLConfigChooser)} has been called, then the supplied EGLConfigChooser is responsible for choosing an OpenGL ES 2.0-compatible config.

param
version The EGLContext client version to choose. Use 2 for OpenGL ES 2.0

        checkRenderThreadState();
        mEGLContextClientVersion = version;
public voidsetEGLContextFactory(android.opengl.GLSurfaceView$EGLContextFactory factory)
Install a custom EGLContextFactory.

If this method is called, it must be called before {@link #setRenderer(Renderer)} is called.

If this method is not called, then by default a context will be created with no shared context and with a null attribute list.

        checkRenderThreadState();
        mEGLContextFactory = factory;
public voidsetEGLWindowSurfaceFactory(android.opengl.GLSurfaceView$EGLWindowSurfaceFactory factory)
Install a custom EGLWindowSurfaceFactory.

If this method is called, it must be called before {@link #setRenderer(Renderer)} is called.

If this method is not called, then by default a window surface will be created with a null attribute list.

        checkRenderThreadState();
        mEGLWindowSurfaceFactory = factory;
public voidsetGLWrapper(android.opengl.GLSurfaceView$GLWrapper glWrapper)
Set the glWrapper. If the glWrapper is not null, its {@link GLWrapper#wrap(GL)} method is called whenever a surface is created. A GLWrapper can be used to wrap the GL object that's passed to the renderer. Wrapping a GL object enables examining and modifying the behavior of the GL calls made by the renderer.

Wrapping is typically used for debugging purposes.

The default value is null.

param
glWrapper the new GLWrapper

        mGLWrapper = glWrapper;
public voidsetPreserveEGLContextOnPause(boolean preserveOnPause)
Control whether the EGL context is preserved when the GLSurfaceView is paused and resumed.

If set to true, then the EGL context may be preserved when the GLSurfaceView is paused. Whether the EGL context is actually preserved or not depends upon whether the Android device that the program is running on can support an arbitrary number of EGL contexts or not. Devices that can only support a limited number of EGL contexts must release the EGL context in order to allow multiple applications to share the GPU.

If set to false, the EGL context will be released when the GLSurfaceView is paused, and recreated when the GLSurfaceView is resumed.

The default is false.

param
preserveOnPause preserve the EGL context when paused

        mPreserveEGLContextOnPause = preserveOnPause;
public voidsetRenderMode(int renderMode)
Set the rendering mode. When renderMode is RENDERMODE_CONTINUOUSLY, the renderer is called repeatedly to re-render the scene. When renderMode is RENDERMODE_WHEN_DIRTY, the renderer only rendered when the surface is created, or when {@link #requestRender} is called. Defaults to RENDERMODE_CONTINUOUSLY.

Using RENDERMODE_WHEN_DIRTY can improve battery life and overall system performance by allowing the GPU and CPU to idle when the view does not need to be updated.

This method can only be called after {@link #setRenderer(Renderer)}

param
renderMode one of the RENDERMODE_X constants
see
#RENDERMODE_CONTINUOUSLY
see
#RENDERMODE_WHEN_DIRTY

        mGLThread.setRenderMode(renderMode);
public voidsetRenderer(android.opengl.GLSurfaceView$Renderer renderer)
Set the renderer associated with this view. Also starts the thread that will call the renderer, which in turn causes the rendering to start.

This method should be called once and only once in the life-cycle of a GLSurfaceView.

The following GLSurfaceView methods can only be called before setRenderer is called:

  • {@link #setEGLConfigChooser(boolean)}
  • {@link #setEGLConfigChooser(EGLConfigChooser)}
  • {@link #setEGLConfigChooser(int, int, int, int, int, int)}

The following GLSurfaceView methods can only be called after setRenderer is called:

  • {@link #getRenderMode()}
  • {@link #onPause()}
  • {@link #onResume()}
  • {@link #queueEvent(Runnable)}
  • {@link #requestRender()}
  • {@link #setRenderMode(int)}

param
renderer the renderer to use to perform OpenGL drawing.

        checkRenderThreadState();
        if (mEGLConfigChooser == null) {
            mEGLConfigChooser = new SimpleEGLConfigChooser(true);
        }
        if (mEGLContextFactory == null) {
            mEGLContextFactory = new DefaultContextFactory();
        }
        if (mEGLWindowSurfaceFactory == null) {
            mEGLWindowSurfaceFactory = new DefaultWindowSurfaceFactory();
        }
        mRenderer = renderer;
        mGLThread = new GLThread(mThisWeakRef);
        mGLThread.start();
public voidsurfaceChanged(android.view.SurfaceHolder holder, int format, int w, int h)
This method is part of the SurfaceHolder.Callback interface, and is not normally called or subclassed by clients of GLSurfaceView.

        mGLThread.onWindowResize(w, h);
public voidsurfaceCreated(android.view.SurfaceHolder holder)
This method is part of the SurfaceHolder.Callback interface, and is not normally called or subclassed by clients of GLSurfaceView.

        mGLThread.surfaceCreated();
public voidsurfaceDestroyed(android.view.SurfaceHolder holder)
This method is part of the SurfaceHolder.Callback interface, and is not normally called or subclassed by clients of GLSurfaceView.

        // Surface will be destroyed when we return
        mGLThread.surfaceDestroyed();