SurfaceTexture: add GL context attach & detach

This change adds Java API support for detaching a SurfaceTexture from one GLES
context and then attaching it to a different one.

Change-Id: I8eed4b0d0e339c11598cb0408d9f4f2d99b3aa06

Author: Jamie Gennis

core/jni/android/graphics/SurfaceTexture.cpp

@@ -218,6 +218,18 @@ static jint SurfaceTexture_updateTexImage(JNIEnv* env, jobject thiz)
     return surfaceTexture->updateTexImage();
 }
 
+static jint SurfaceTexture_detachFromGLContext(JNIEnv* env, jobject thiz)
+{
+    sp<SurfaceTexture> surfaceTexture(SurfaceTexture_getSurfaceTexture(env, thiz));
+    return surfaceTexture->detachFromContext();
+}
+
+static jint SurfaceTexture_attachToGLContext(JNIEnv* env, jobject thiz, jint tex)
+{
+    sp<SurfaceTexture> surfaceTexture(SurfaceTexture_getSurfaceTexture(env, thiz));
+    return surfaceTexture->attachToContext((GLuint)tex);
+}
+
 static void SurfaceTexture_getTransformMatrix(JNIEnv* env, jobject thiz,
         jfloatArray jmtx)
 {
@@ -242,14 +254,16 @@ static void SurfaceTexture_release(JNIEnv* env, jobject thiz)
 // ----------------------------------------------------------------------------
 
 static JNINativeMethod gSurfaceTextureMethods[] = {
-    {"nativeClassInit",          "()V",   (void*)SurfaceTexture_classInit },
-    {"nativeInit",               "(ILjava/lang/Object;Z)V", (void*)SurfaceTexture_init },
-    {"nativeFinalize",           "()V",   (void*)SurfaceTexture_finalize },
+    {"nativeClassInit",            "()V",   (void*)SurfaceTexture_classInit },
+    {"nativeInit",                 "(ILjava/lang/Object;Z)V", (void*)SurfaceTexture_init },
+    {"nativeFinalize",             "()V",   (void*)SurfaceTexture_finalize },
     {"nativeSetDefaultBufferSize", "(II)V", (void*)SurfaceTexture_setDefaultBufferSize },
-    {"nativeUpdateTexImage",     "()I",   (void*)SurfaceTexture_updateTexImage },
-    {"nativeGetTransformMatrix", "([F)V", (void*)SurfaceTexture_getTransformMatrix },
-    {"nativeGetTimestamp",       "()J",   (void*)SurfaceTexture_getTimestamp },
-    {"nativeRelease",            "()V",   (void*)SurfaceTexture_release },
+    {"nativeUpdateTexImage",       "()I",   (void*)SurfaceTexture_updateTexImage },
+    {"nativeDetachFromGLContext",  "()I",   (void*)SurfaceTexture_detachFromGLContext },
+    {"nativeAttachToGLContext",    "(I)I",   (void*)SurfaceTexture_attachToGLContext },
+    {"nativeGetTransformMatrix",   "([F)V", (void*)SurfaceTexture_getTransformMatrix },
+    {"nativeGetTimestamp",         "()J",   (void*)SurfaceTexture_getTimestamp },
+    {"nativeRelease",              "()V",   (void*)SurfaceTexture_release },
 };
 
 int register_android_graphics_SurfaceTexture(JNIEnv* env)

graphics/java/android/graphics/SurfaceTexture.java

@@ -161,7 +161,31 @@ public void setDefaultBufferSize(int width, int height) {
     public void updateTexImage() {
         int err = nativeUpdateTexImage(); 
         if (err != 0) {
-            throw new RuntimeException("Error during updateTexImage (see logs)");
+            throw new RuntimeException("Error during updateTexImage (see logcat for details)");
+        }
+    }
+
+    /**
+     * Detach the SurfaceTexture from the OpenGL ES context with which it is currently associated.
+     * This can be used to change from one OpenGL ES context to another.
+     *
+     * @hide
+     */
+    public void detachFromGLContext() {
+        int err = nativeDetachFromGLContext();
+        if (err != 0) {
+            throw new RuntimeException("Error during detachFromGLContext (see logcat for details)");
+        }
+    }
+
+    /**
+     *
+     * @hide
+     */
+    public void attachToGLContext(int texName) {
+        int err = nativeAttachToGLContext(texName);
+        if (err != 0) {
+            throw new RuntimeException("Error during detachFromGLContext (see logcat for details)");
         }
     }
 
@@ -269,6 +293,8 @@ private static void postEventFromNative(Object selfRef) {
     private native long nativeGetTimestamp();
     private native void nativeSetDefaultBufferSize(int width, int height);
     private native int nativeUpdateTexImage();
+    private native int nativeDetachFromGLContext();
+    private native int nativeAttachToGLContext(int texName);
     private native int nativeGetQueuedCount();
     private native void nativeRelease();