Android APIs
public class

GLSurfaceView

extends SurfaceView
implements SurfaceHolder.Callback
java.lang.Object
   ↳ android.view.View
     ↳ android.view.SurfaceView
       ↳ android.opengl.GLSurfaceView

Class Overview

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 setRenderer(Renderer) call.

Initializing GLSurfaceView

All you have to do to initialize a GLSurfaceView is call setRenderer(Renderer). However, if desired, you can modify the default behavior of GLSurfaceView by calling one or more of these methods before calling setRenderer:

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 setDebugFlags(int), and setGLWrapper(GLSurfaceView.GLWrapper). 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 setRenderer(GLSurfaceView.Renderer) to register a GLSurfaceView.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 setRenderMode(int). 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 onPause() when the activity pauses and 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 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);
     }
 }

Summary

Nested Classes
interface GLSurfaceView.EGLConfigChooser An interface for choosing an EGLConfig configuration from a list of potential configurations. 
interface GLSurfaceView.EGLContextFactory An interface for customizing the eglCreateContext and eglDestroyContext calls. 
interface GLSurfaceView.EGLWindowSurfaceFactory An interface for customizing the eglCreateWindowSurface and eglDestroySurface calls. 
interface GLSurfaceView.GLWrapper An interface used to wrap a GL interface. 
interface GLSurfaceView.Renderer A generic renderer interface. 
[Expand]
Inherited XML Attributes
From class android.view.View
Constants
int DEBUG_CHECK_GL_ERROR Check glError() after every GL call and throw an exception if glError indicates that an error has occurred.
int DEBUG_LOG_GL_CALLS Log GL calls to the system log at "verbose" level with tag "GLSurfaceView".
int RENDERMODE_CONTINUOUSLY The renderer is called continuously to re-render the scene.
int RENDERMODE_WHEN_DIRTY The renderer only renders when the surface is created, or when requestRender() is called.
[Expand]
Inherited Constants
From class android.view.View
[Expand]
Inherited Fields
From class android.view.View
Public Constructors
GLSurfaceView(Context context)
Standard View constructor.
GLSurfaceView(Context context, AttributeSet attrs)
Standard View constructor.
Public Methods
int getDebugFlags()
Get the current value of the debug flags.
boolean getPreserveEGLContextOnPause()
int getRenderMode()
Get the current rendering mode.
void onPause()
Inform the view that the activity is paused.
void onResume()
Inform the view that the activity is resumed.
void queueEvent(Runnable r)
Queue a runnable to be run on the GL rendering thread.
void requestRender()
Request that the renderer render a frame.
void setDebugFlags(int debugFlags)
Set the debug flags to a new value.
void setEGLConfigChooser(GLSurfaceView.EGLConfigChooser configChooser)
Install a custom EGLConfigChooser.
void setEGLConfigChooser(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.
void setEGLConfigChooser(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.
void setEGLContextClientVersion(int version)
Inform the default EGLContextFactory and default EGLConfigChooser which EGLContext client version to pick.
void setEGLContextFactory(GLSurfaceView.EGLContextFactory factory)
Install a custom EGLContextFactory.
void setEGLWindowSurfaceFactory(GLSurfaceView.EGLWindowSurfaceFactory factory)
Install a custom EGLWindowSurfaceFactory.
void setGLWrapper(GLSurfaceView.GLWrapper glWrapper)
Set the glWrapper.
void setPreserveEGLContextOnPause(boolean preserveOnPause)
Control whether the EGL context is preserved when the GLSurfaceView is paused and resumed.
void setRenderMode(int renderMode)
Set the rendering mode.
void setRenderer(GLSurfaceView.Renderer renderer)
Set the renderer associated with this view.
void surfaceChanged(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.
void surfaceCreated(SurfaceHolder holder)
This method is part of the SurfaceHolder.Callback interface, and is not normally called or subclassed by clients of GLSurfaceView.
void surfaceDestroyed(SurfaceHolder holder)
This method is part of the SurfaceHolder.Callback interface, and is not normally called or subclassed by clients of GLSurfaceView.
Protected Methods
void finalize()
Invoked when the garbage collector has detected that this instance is no longer reachable.
void onAttachedToWindow()
This method is used as part of the View class and is not normally called or subclassed by clients of GLSurfaceView.
void onDetachedFromWindow()
This is called when the view is detached from a window.
[Expand]
Inherited Methods
From class android.view.SurfaceView
From class android.view.View
From class java.lang.Object
From interface android.graphics.drawable.Drawable.Callback
From interface android.view.KeyEvent.Callback
From interface android.view.SurfaceHolder.Callback
From interface android.view.accessibility.AccessibilityEventSource

Constants

public static final int DEBUG_CHECK_GL_ERROR

Added in API level 3

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.

See Also
Constant Value: 1 (0x00000001)

public static final int DEBUG_LOG_GL_CALLS

Added in API level 3

Log GL calls to the system log at "verbose" level with tag "GLSurfaceView".

See Also
Constant Value: 2 (0x00000002)

public static final int RENDERMODE_CONTINUOUSLY

Added in API level 3

The renderer is called continuously to re-render the scene.

See Also
Constant Value: 1 (0x00000001)

public static final int RENDERMODE_WHEN_DIRTY

Added in API level 3

The renderer only renders when the surface is created, or when requestRender() is called.

See Also
Constant Value: 0 (0x00000000)

Public Constructors

public GLSurfaceView (Context context)

Added in API level 3

Standard View constructor. In order to render something, you must call setRenderer(GLSurfaceView.Renderer) to register a renderer.

public GLSurfaceView (Context context, AttributeSet attrs)

Added in API level 3

Standard View constructor. In order to render something, you must call setRenderer(GLSurfaceView.Renderer) to register a renderer.

Public Methods

public int getDebugFlags ()

Added in API level 3

Get the current value of the debug flags.

Returns
  • the current value of the debug flags.

public boolean getPreserveEGLContextOnPause ()

Added in API level 11

Returns
  • true if the EGL context will be preserved when paused

public int getRenderMode ()

Added in API level 3

Get the current rendering mode. May be called from any thread. Must not be called before a renderer has been set.

Returns
  • the current rendering mode.
See Also

public void onPause ()

Added in API level 3

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.

public void onResume ()

Added in API level 3

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.

public void queueEvent (Runnable r)

Added in API level 3

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.

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

public void requestRender ()

Added in API level 3

Request that the renderer render a frame. This method is typically used when the render mode has been set to 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.

public void setDebugFlags (int debugFlags)

Added in API level 3

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.

Parameters
debugFlags the new debug flags
See Also

public void setEGLConfigChooser (GLSurfaceView.EGLConfigChooser configChooser)

Added in API level 3

Install a custom EGLConfigChooser.

If this method is called, it must be called before 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.

public void setEGLConfigChooser (boolean needDepth)

Added in API level 3

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 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.

public void setEGLConfigChooser (int redSize, int greenSize, int blueSize, int alphaSize, int depthSize, int stencilSize)

Added in API level 3

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 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.

public void setEGLContextClientVersion (int version)

Added in API level 8

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 setRenderer(Renderer) is called.

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

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

public void setEGLContextFactory (GLSurfaceView.EGLContextFactory factory)

Added in API level 5

Install a custom EGLContextFactory.

If this method is called, it must be called before 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.

public void setEGLWindowSurfaceFactory (GLSurfaceView.EGLWindowSurfaceFactory factory)

Added in API level 5

Install a custom EGLWindowSurfaceFactory.

If this method is called, it must be called before setRenderer(Renderer) is called.

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

public void setGLWrapper (GLSurfaceView.GLWrapper glWrapper)

Added in API level 3

Set the glWrapper. If the glWrapper is not null, its 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.

Parameters
glWrapper the new GLWrapper

public void setPreserveEGLContextOnPause (boolean preserveOnPause)

Added in API level 11

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.

Parameters
preserveOnPause preserve the EGL context when paused

public void setRenderMode (int renderMode)

Added in API level 3

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 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 setRenderer(Renderer)

Parameters
renderMode one of the RENDERMODE_X constants
See Also

public void setRenderer (GLSurfaceView.Renderer renderer)

Added in API level 3

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:

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

Parameters
renderer the renderer to use to perform OpenGL drawing.

public void surfaceChanged (SurfaceHolder holder, int format, int w, int h)

Added in API level 3

This method is part of the SurfaceHolder.Callback interface, and is not normally called or subclassed by clients of GLSurfaceView.

Parameters
holder The SurfaceHolder whose surface has changed.
format The new PixelFormat of the surface.
w The new width of the surface.
h The new height of the surface.

public void surfaceCreated (SurfaceHolder holder)

Added in API level 3

This method is part of the SurfaceHolder.Callback interface, and is not normally called or subclassed by clients of GLSurfaceView.

Parameters
holder The SurfaceHolder whose surface is being created.

public void surfaceDestroyed (SurfaceHolder holder)

Added in API level 3

This method is part of the SurfaceHolder.Callback interface, and is not normally called or subclassed by clients of GLSurfaceView.

Parameters
holder The SurfaceHolder whose surface is being destroyed.

Protected Methods

protected void finalize ()

Added in API level 3

Invoked when the garbage collector has detected that this instance is no longer reachable. The default implementation does nothing, but this method can be overridden to free resources.

Note that objects that override finalize are significantly more expensive than objects that don't. Finalizers may be run a long time after the object is no longer reachable, depending on memory pressure, so it's a bad idea to rely on them for cleanup. Note also that finalizers are run on a single VM-wide finalizer thread, so doing blocking work in a finalizer is a bad idea. A finalizer is usually only necessary for a class that has a native peer and needs to call a native method to destroy that peer. Even then, it's better to provide an explicit close method (and implement Closeable), and insist that callers manually dispose of instances. This works well for something like files, but less well for something like a BigInteger where typical calling code would have to deal with lots of temporaries. Unfortunately, code that creates lots of temporaries is the worst kind of code from the point of view of the single finalizer thread.

If you must use finalizers, consider at least providing your own ReferenceQueue and having your own thread process that queue.

Unlike constructors, finalizers are not automatically chained. You are responsible for calling super.finalize() yourself.

Uncaught exceptions thrown by finalizers are ignored and do not terminate the finalizer thread. See Effective Java Item 7, "Avoid finalizers" for more.

Throws
Throwable

protected void onAttachedToWindow ()

Added in API level 3

This method is used as part of the View class and is not normally called or subclassed by clients of GLSurfaceView.

protected void onDetachedFromWindow ()

Added in API level 3

This is called when the view is detached from a window. At this point it no longer has a surface for drawing.