Add support for preserving EGL contexts when pausing / resuming.

Hidden for now.

Change-Id: I350576c11960a1aa232da7aebc5c6ec60ff796b5

1 files changed, 43 insertions, 7 deletions

diff --git a/opengl/java/android/opengl/GLSurfaceView.java b/opengl/java/android/opengl/GLSurfaceView.java
index 8f2f974..4099c4c 100644
--- a/opengl/java/android/opengl/GLSurfaceView.java
+++ b/opengl/java/android/opengl/GLSurfaceView.java
@@ -272,6 +272,37 @@ public class GLSurfaceView extends SurfaceView implements SurfaceHolder.Callback
     }
 
     /**
+     * @hide
+     * Control whether the EGL context is preserved when the GLSurfaceView is paused and
+     * resumed.
+     * <p>
+     * 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.
+     * <p>
+     * If set to false, the EGL context will be released when the GLSurfaceView is paused,
+     * and recreated when the GLSurfaceView is resumed.
+     * <p>
+     *
+     * The default is false.
+     *
+     * @param preserveOnPause preserve the EGL context when paused
+     */
+    public void setPreserveEGLContextOnPause(boolean preserveOnPause) {
+        mPreserveEGLContextOnPause = preserveOnPause;
+    }
+
+    /**
+     * @hide
+     * @return true if the EGL context will be preserved when paused
+     */
+    public boolean getPreserveEGLContextOnPause() {
+        return mPreserveEGLContextOnPause;
+    }
+
+    /**
      * 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
@@ -1240,7 +1271,7 @@ public class GLSurfaceView extends SurfaceView implements SurfaceHolder.Callback
                                     Log.i("GLThread", "releasing EGL surface because paused tid=" + getId());
                                 }
                                 stopEglSurfaceLocked();
-                                if (sGLThreadManager.shouldReleaseEGLContextWhenPausing()) {
+                                if (!mPreserveEGLContextOnPause || sGLThreadManager.shouldReleaseEGLContextWhenPausing()) {
                                     stopEglContextLocked();
                                     if (LOG_SURFACE) {
                                         Log.i("GLThread", "releasing EGL context because paused tid=" + getId());
@@ -1705,7 +1736,7 @@ public class GLSurfaceView extends SurfaceView implements SurfaceHolder.Callback
             // Release the EGL context when pausing even if
             // the hardware supports multiple EGL contexts.
             // Otherwise the device could run out of EGL contexts.
-            return true;
+            return mLimitedGLESContexts;
         }
 
         public synchronized boolean shouldTerminateEGLWhenPausing() {
@@ -1716,16 +1747,18 @@ public class GLSurfaceView extends SurfaceView implements SurfaceHolder.Callback
         public synchronized void checkGLDriver(GL10 gl) {
             if (! mGLESDriverCheckComplete) {
                 checkGLESVersion();
+                String renderer = gl.glGetString(GL10.GL_RENDERER);
                 if (mGLESVersion < kGLES_20) {
-                    String renderer = gl.glGetString(GL10.GL_RENDERER);
                     mMultipleGLESContextsAllowed =
                         ! renderer.startsWith(kMSM7K_RENDERER_PREFIX);
-                    if (LOG_SURFACE) {
-                        Log.w(TAG, "checkGLDriver renderer = \"" + renderer + "\" multipleContextsAllowed = "
-                            + mMultipleGLESContextsAllowed);
-                    }
                     notifyAll();
                 }
+                mLimitedGLESContexts = !mMultipleGLESContextsAllowed || renderer.startsWith(kADRENO);
+                if (LOG_SURFACE) {
+                    Log.w(TAG, "checkGLDriver renderer = \"" + renderer + "\" multipleContextsAllowed = "
+                        + mMultipleGLESContextsAllowed
+                        + " mLimitedGLESContexts = " + mLimitedGLESContexts);
+                }
                 mGLESDriverCheckComplete = true;
             }
         }
@@ -1750,9 +1783,11 @@ public class GLSurfaceView extends SurfaceView implements SurfaceHolder.Callback
         private int mGLESVersion;
         private boolean mGLESDriverCheckComplete;
         private boolean mMultipleGLESContextsAllowed;
+        private boolean mLimitedGLESContexts;
         private static final int kGLES_20 = 0x20000;
         private static final String kMSM7K_RENDERER_PREFIX =
             "Q3Dimension MSM7500 ";
+        private static final String kADRENO = "Adreno";
         private GLThread mEglOwner;
     }
 
@@ -1768,4 +1803,5 @@ public class GLSurfaceView extends SurfaceView implements SurfaceHolder.Callback
     private GLWrapper mGLWrapper;
     private int mDebugFlags;
     private int mEGLContextClientVersion;
+    private boolean mPreserveEGLContextOnPause;
 }