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AI 145531: am: CL 145523 am: CL 145244 Fully document GLSurfaceView and related classes.

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Original author: jackpal
  Merged from: //branches/cupcake/...
  Original author: android-build

Automated import of CL 145531
This commit is contained in:
Jack Palevich
2009-04-09 14:54:12 -07:00
committed by The Android Open Source Project
parent 580b13017e
commit b47c641fe8
1 changed files with 349 additions and 51 deletions
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400
opengl/java/android/opengl/GLSurfaceView.java
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@@ -16,7 +16,6 @@
package android.opengl;
import java.io.IOException;
import java.io.Writer;
import java.util.ArrayList;
import java.util.concurrent.Semaphore;
@@ -38,32 +37,163 @@ import android.view.SurfaceView;
/**
* An implementation of SurfaceView that uses the dedicated surface for
* displaying an OpenGL animation. This allows the animation to run in a
* separate thread, without requiring that it be driven by the update mechanism
* of the view hierarchy.
* displaying OpenGL rendering.
* <p>
* A GLSurfaceView provides the following features:
* <p>
* <ul>
* <li>Manages a surface, which is a special piece of memory that can be
* composited into the Android view system.
* <li>Manages an EGL display, which enables OpenGL to render into a surface.
* <li>Accepts a user-provided Renderer object that does the actual rendering.
* <li>Renders on a dedicated thread to decouple rendering performance from the
* UI thread.
* <li>Supports both on-demand and continuous rendering.
* <li>Optionally wraps, traces, and/or error-checks the renderer's OpenGL calls.
* </ul>
*
* <h3>Using GLSurfaceView</h3>
* <p>
* 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.
* <p>
* <h3>Initializing GLSurfaceView</h3>
* 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:
* <ul>
* <li>{@link #setDebugFlags(int)}
* <li>{@link #setEGLConfigChooser(boolean)}
* <li>{@link #setEGLConfigChooser(EGLConfigChooser)}
* <li>{@link #setEGLConfigChooser(int, int, int, int, int, int)}
* <li>{@link #setGLWrapper(GLWrapper)}
* </ul>
* <p>
* <h4>Choosing an EGL Configuration</h4>
* A given Android device may support multiple possible types of drawing surfaces.
* The available surfaces 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 type of surface to use.
* <p>
* By default GLSurfaceView chooses an available surface that's closest to a 16-bit R5G6B5 surface
* with a 16-bit depth buffer and no stencil. If you would prefer a different surface (for example,
* if you do not need a depth buffer) you can override the default behavior by calling one of the
* setEGLConfigChooser methods.
* <p>
* <h4>Debug Behavior</h4>
* 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.
* <p>
* <h4>Setting a Renderer</h4>
* Finally, you must call {@link #setRenderer} to register a {@link Renderer}.
* The renderer is
* responsible for doing the actual OpenGL rendering.
* <p>
* <h3>Rendering Mode</h3>
* 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.
* <p>
* <h3>Activity Life-cycle</h3>
* 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.
* <p>
* <h3>Handling events</h3>
* <p>
* 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:
* <pre class="prettyprint">
* 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);
* }
* }
* </pre>
*
* The application-specific rendering code is delegated to a GLView.Renderer
* instance.
*/
public class GLSurfaceView extends SurfaceView implements SurfaceHolder.Callback {
/**
* The renderer only renders
* when the surface is created, or when {@link #requestRender} is called.
*
* @see #getRenderMode()
* @see #setRenderMode(int)
*/
public final static int RENDERMODE_WHEN_DIRTY = 0;
/**
* The renderer is called
* continuously to re-render the scene.
*
* @see #getRenderMode()
* @see #setRenderMode(int)
* @see #requestRender()
*/
public final static int RENDERMODE_CONTUOUSLY = 1;
/**
* Check glError() after every GL call.
* 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 #getDebugFlags
* @see #setDebugFlags
*/
public final static int DEBUG_CHECK_GL_ERROR = 1;
/**
* Log GL calls to the system log at "verbose" level with tag "GLSurfaceView".
*
* @see #getDebugFlags
* @see #setDebugFlags
*/
public final static int DEBUG_LOG_GL_CALLS = 2;
/**
* Standard View constructor. In order to render something, you
* must call {@link #setRenderer} to register a renderer.
*/
public GLSurfaceView(Context context) {
super(context);
init();
}
/**
* Standard View constructor. In order to render something, you
* must call {@link #setRenderer} to register a renderer.
*/
public GLSurfaceView(Context context, AttributeSet attrs) {
super(context, attrs);
init();
@@ -78,8 +208,16 @@ public class GLSurfaceView extends SurfaceView implements SurfaceHolder.Callback
}
/**
* Set the glWrapper to a new value. The current glWrapper is used
* whenever a surface is created. The default value is null.
* 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.
* <p>
* Wrapping is typically used for debugging purposes.
* <p>
* The default value is null.
* @param glWrapper the new GLWrapper
*/
public void setGLWrapper(GLWrapper glWrapper) {
@@ -87,7 +225,9 @@ public class GLSurfaceView extends SurfaceView implements SurfaceHolder.Callback
}
/**
* Set the debug flags to a new value. The debug flags take effect
* 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
@@ -97,13 +237,39 @@ public class GLSurfaceView extends SurfaceView implements SurfaceHolder.Callback
mDebugFlags = debugFlags;
}
/**
* Get the current value of the debug flags.
* @return the current value of the debug flags.
*/
public int getDebugFlags() {
return mDebugFlags;
}
/**
* Set the renderer associated with this view. Can only be called once.
* @param 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.
* <p>This method should be called once and only once in the life-cycle of
* a GLSurfaceView.
* <p>The following GLSurfaceView methods can only be called <em>before</em>
* setRenderer is called:
* <ul>
* <li>{@link #setEGLConfigChooser(boolean)}
* <li>{@link #setEGLConfigChooser(EGLConfigChooser)}
* <li>{@link #setEGLConfigChooser(int, int, int, int, int, int)}
* </ul>
* <p>
* The following GLSurfaceView methods can only be called <em>after</em>
* setRenderer is called:
* <ul>
* <li>{@link #getRenderMode()}
* <li>{@link #onPause()}
* <li>{@link #onResume()}
* <li>{@link #queueEvent(Runnable)}
* <li>{@link #requestRender()}
* <li>{@link #setRenderMode(int)}
* </ul>
*
* @param renderer the renderer to use to perform OpenGL drawing.
*/
public void setRenderer(Renderer renderer) {
if (mGLThread != null) {
@@ -118,11 +284,14 @@ public class GLSurfaceView extends SurfaceView implements SurfaceHolder.Callback
}
/**
* Set the EGLConfigChooser associated with this view. If this method is
* called at all, it must be called before {@link #setRenderer(Renderer)}
* Install a custom EGLConfigChooser.
* <p>If this method is
* called, it must be called before {@link #setRenderer(Renderer)}
* is called.
* <p>
* The supplied configChooser will be used to choose a configuration.
* If no setEGLConfigChooser method is called, then by default the
* view will choose a config as close to 16-bit RGB as possible, with
* a depth buffer as close to 16 bits as possible.
* @param configChooser
*/
public void setEGLConfigChooser(EGLConfigChooser configChooser) {
@@ -134,17 +303,16 @@ public class GLSurfaceView extends SurfaceView implements SurfaceHolder.Callback
}
/**
* Set the EGLConfigChooser associated with this view. If this method is
* 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.
* <p>If this method is
* called, it must be called before {@link #setRenderer(Renderer)}
* is called.
* <p>
* This method installs 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.
* <p>
* If no setEGLConfigChooser method is called, then by default the
* If no setEGLConfigChooser method is called, then by default the
* view will choose a config as close to 16-bit RGB as possible, with
* a depth buffer as close to 16-bits as possible.
* a depth buffer as close to 16 bits as possible.
*
* @param needDepth
*/
@@ -153,13 +321,16 @@ public class GLSurfaceView extends SurfaceView implements SurfaceHolder.Callback
}
/**
* Set the EGLConfigChooser associated with this view. If this method is
* Install a config chooser which will choose a config
* with at least the specified component sizes, and as close
* to the specified component sizes as possible.
* <p>If this method is
* called, it must be called before {@link #setRenderer(Renderer)}
* is called.
* <p>
* This method installs a config chooser which will choose a config
* with at least the specified component sizes, and as close
* to the specified component sizes as possible.
* If no setEGLConfigChooser method is called, then by default the
* view will choose a config as close to 16-bit RGB as possible, with
* a depth buffer as close to 16 bits as possible.
*
*/
public void setEGLConfigChooser(int redSize, int greenSize, int blueSize,
@@ -168,12 +339,20 @@ public class GLSurfaceView extends SurfaceView implements SurfaceHolder.Callback
blueSize, alphaSize, depthSize, stencilSize));
}
/**
* Set the rendering mode. When the renderMode is
* RENDERMODE_CONTINUOUSLY, the renderer is called
* repeatedly to re-render the scene. When the rendermode
* Set the rendering mode. When renderMode is
* RENDERMODE_CONTUOUSLY, 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.
* is created, or when {@link #requestRender} is called. Defaults to RENDERMODE_CONTUOUSLY.
* <p>
* 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.
* <p>
* This method can only be called after {@link #setRenderer(Renderer)}
*
* @param renderMode one of the RENDERMODE_X constants
* @see #RENDERMODE_CONTUOUSLY
* @see #RENDERMODE_WHEN_DIRTY
*/
public void setRenderMode(int renderMode) {
mGLThread.setRenderMode(renderMode);
@@ -182,38 +361,55 @@ public class GLSurfaceView extends SurfaceView implements SurfaceHolder.Callback
/**
* Get the current rendering mode. May be called
* from any thread. Must not be called before a renderer has been set.
* @return true if the renderer will render continuously.
* @return the current rendering mode.
* @see #RENDERMODE_CONTUOUSLY
* @see #RENDERMODE_WHEN_DIRTY
*/
public int getRenderMode() {
return mGLThread.getRenderMode();
}
/**
* Request that the renderer render a frame. May be called
* from any thread. Must not be called before a renderer has been set.
* Request that the renderer render a frame.
* This method is typically used when the render mode has been set to
* false, so that frames are only rendered on demand.
* {@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.
*/
public void requestRender() {
mGLThread.requestRender();
}
/**
* This method is part of the SurfaceHolder.Callback interface, and is
* not normally called or subclassed by clients of GLSurfaceView.
*/
public void surfaceCreated(SurfaceHolder holder) {
mGLThread.surfaceCreated();
}
/**
* This method is part of the SurfaceHolder.Callback interface, and is
* not normally called or subclassed by clients of GLSurfaceView.
*/
public void surfaceDestroyed(SurfaceHolder holder) {
// Surface will be destroyed when we return
mGLThread.surfaceDestroyed();
}
/**
* This method is part of the SurfaceHolder.Callback interface, and is
* not normally called or subclassed by clients of GLSurfaceView.
*/
public void surfaceChanged(SurfaceHolder holder, int format, int w, int h) {
mGLThread.onWindowResize(w, h);
}
/**
* Inform the view that the activity is paused. The owner of this view must
* call this method when the activity is paused.
* 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 onPause() {
mGLThread.onPause();
@@ -221,20 +417,30 @@ public class GLSurfaceView extends SurfaceView implements SurfaceHolder.Callback
/**
* Inform the view that the activity is resumed. The owner of this view must
* call this method when the activity is resumed.
* 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 onResume() {
mGLThread.onResume();
}
/**
* Queue an "event" to be run on the GL rendering thread.
* 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.
*/
public void queueEvent(Runnable r) {
mGLThread.queueEvent(r);
}
/**
* This method is used as part of the View class and is not normally
* called or subclassed by clients of GLSurfaceView.
* Must not be called before a renderer has been set.
*/
@Override
protected void onDetachedFromWindow() {
super.onDetachedFromWindow();
@@ -243,40 +449,129 @@ public class GLSurfaceView extends SurfaceView implements SurfaceHolder.Callback
// ----------------------------------------------------------------------
/**
* An interface used to wrap a GL interface.
* <p>Typically
* used for implementing debugging and tracing on top of the default
* GL interface. You would typically use this by creating your own class
* that implemented all the GL methods by delegating to another GL instance.
* Then you could add your own behavior before or after calling the
* delegate. All the GLWrapper would do was instantiate and return the
* wrapper GL instance:
* <pre class="prettyprint">
* class MyGLWrapper implements GLWrapper {
* GL wrap(GL gl) {
* return new MyGLImplementation(gl);
* }
* static class MyGLImplementation implements GL,GL10,GL11,... {
* ...
* }
* }
* </pre>
* @see #setGLWrapper(GLWrapper)
*/
public interface GLWrapper {
GL wrap(GL gl);
/**
* Wraps a gl interface in another gl interface.
* @param gl a GL interface that is to be wrapped.
* @return either the input argument or another GL object that wraps the input argument.
*/
GL wrap(GL gl);
}
// ----------------------------------------------------------------------
/**
* A generic renderer interface.
* <p>
* The renderer is responsible for making OpenGL calls to render a frame.
* <p>
* GLSurfaceView clients typically create their own classes that implement
* this interface, and then call {@link GLSurfaceView#setRenderer} to
* register the renderer with the GLSurfaceView.
* <p>
* <h3>Threading</h3>
* The renderer will be called on a separate thread, so that rendering
* performance is decoupled from the UI thread. Clients typically need to
* communicate with the renderer from the UI thread, because that's where
* input events are received. Clients can communicate using any of the
* standard Java techniques for cross-thread communication, or they can
* use the {@link GLSurfaceView#queueEvent(Runnable)} convenience method.
* <p>
* <h3>EGL Context Lost</h3>
* There are situations where the EGL rendering context will be lost. This
* typically happens when device wakes up after going to sleep. When
* the EGL context is lost, all OpenGL resources (such as textures) that are
* associated with that context will be automatically deleted. In order to
* keep rendering correctly, a renderer must recreate any lost resources
* that it still needs. The {@link #onSurfaceCreated(GL10, EGLConfig)} method
* is a convenient place to do this.
*
*
* @see #setRenderer(Renderer)
*/
public interface Renderer {
/**
* Surface created.
* Called when the surface is created. Called when the application
* starts, and whenever the GPU is reinitialized. This will
* typically happen when the device awakes after going to sleep.
* Set your textures here.
* Called when the surface is created or recreated.
* <p>
* Called when the rendering thread
* starts and whenever the EGL context is lost. The context will typically
* be lost when the Android device awakes after going to sleep.
* <p>
* Since this method is called at the beginning of rendering, as well as
* every time the EGL context is lost, this method is a convenient place to put
* code to create resources that need to be created when the rendering
* starts, and that need to be recreated when the EGL context is lost.
* Textures are an example of a resource that you might want to create
* here.
* <p>
* Note that when the EGL context is lost, all OpenGL resources associated
* with that context will be automatically deleted. You do not need to call
* the corresponding "glDelete" methods such as glDeleteTextures to
* manually delete these lost resources.
* <p>
* @param gl the GL interface. Use <code>instanceof</code> to
* test if the interface supports GL11 or higher interfaces.
* @param config the EGLConfig of the created surface. Can be used
* to create matching pbuffers.
*/
void onSurfaceCreated(GL10 gl, EGLConfig config);
/**
* Surface changed size.
* Called when the surface changed size.
* <p>
* Called after the surface is created and whenever
* the OpenGL ES surface size changes. Set your viewport here.
* the OpenGL ES surface size changes.
* <p>
* Typically you will set your viewport here. If your camera
* is fixed then you could also set your projection matrix here:
* <pre class="prettyprint">
* void onSurfaceChanged(GL10 gl, int width, int height) {
* gl.glViewport(0, 0, width, height);
* // for a fixed camera, set the projection too
* float ratio = (float) width / height;
* gl.glMatrixMode(GL10.GL_PROJECTION);
* gl.glLoadIdentity();
* gl.glFrustumf(-ratio, ratio, -1, 1, 1, 10);
* }
* </pre>
* @param gl the GL interface. Use <code>instanceof</code> to
* test if the interface supports GL11 or higher interfaces.
* @param width
* @param height
*/
void onSurfaceChanged(GL10 gl, int width, int height);
/**
* Draw the current frame.
* Called to draw the current frame.
* <p>
* This method is responsible for drawing the current frame.
* <p>
* The implementation of this method typically looks like this:
* <pre class="prettyprint">
* void onDrawFrame(GL10 gl) {
* gl.glClear(GL10.GL_COLOR_BUFFER_BIT | GL10.GL_DEPTH_BUFFER_BIT);
* //... other gl calls to render the scene ...
* }
* </pre>
* @param gl the GL interface. Use <code>instanceof</code> to
* test if the interface supports GL11 or higher interfaces.
*/
@@ -284,15 +579,18 @@ public class GLSurfaceView extends SurfaceView implements SurfaceHolder.Callback
}
/**
* An interface for choosing a configuration from a list of
* An interface for choosing an EGLConfig configuration from a list of
* potential configurations.
*
* <p>
* This interface must be implemented by clients wishing to call
* {@link GLSurfaceView#setEGLConfigChooser(EGLConfigChooser)}
*/
public interface EGLConfigChooser {
/**
* Choose a configuration from the list. Implementors typically
* implement this method by calling
* {@link EGL10#eglChooseConfig} and iterating through the results.
* {@link EGL10#eglChooseConfig} and iterating through the results. Please consult the
* EGL specification available from The Khronos Group to learn how to call eglChooseConfig.
* @param egl the EGL10 for the current display.
* @param display the current display.
* @return the chosen configuration.