surfaceflinger: add RenderEngine::BindNativeBufferAsFramebuffer

It replaces BindImageAsFramebuffer and makes EGLImage an
implementation detail of RenderEngine.

Test: SurfaceFlinger_test
Change-Id: I01be2d95fb9af9cbefa1a72131afb0975f1e0296
diff --git a/services/surfaceflinger/RenderEngine/RenderEngine.cpp b/services/surfaceflinger/RenderEngine/RenderEngine.cpp
index 560f74e..dfd9856 100644
--- a/services/surfaceflinger/RenderEngine/RenderEngine.cpp
+++ b/services/surfaceflinger/RenderEngine/RenderEngine.cpp
@@ -337,21 +337,33 @@
 
 // ---------------------------------------------------------------------------
 
-RenderEngine::BindImageAsFramebuffer::BindImageAsFramebuffer(
-        RenderEngine& engine, EGLImageKHR image) : mEngine(engine)
+RenderEngine::BindNativeBufferAsFramebuffer::BindNativeBufferAsFramebuffer(
+        RenderEngine& engine, ANativeWindowBuffer* buffer) : mEngine(engine)
 {
-    mEngine.bindImageAsFramebuffer(image, &mTexName, &mFbName, &mStatus);
+    mImage = eglCreateImageKHR(mEngine.mEGLDisplay, EGL_NO_CONTEXT,
+            EGL_NATIVE_BUFFER_ANDROID, buffer, NULL);
+    if (mImage == EGL_NO_IMAGE_KHR) {
+        mStatus = GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT;
+        return;
+    }
+
+    mEngine.bindImageAsFramebuffer(mImage, &mTexName, &mFbName, &mStatus);
 
     ALOGE_IF(mStatus != GL_FRAMEBUFFER_COMPLETE_OES,
             "glCheckFramebufferStatusOES error %d", mStatus);
 }
 
-RenderEngine::BindImageAsFramebuffer::~BindImageAsFramebuffer() {
+RenderEngine::BindNativeBufferAsFramebuffer::~BindNativeBufferAsFramebuffer() {
+    if (mImage == EGL_NO_IMAGE_KHR) {
+        return;
+    }
+
     // back to main framebuffer
     mEngine.unbindFramebuffer(mTexName, mFbName);
+    eglDestroyImageKHR(mEngine.mEGLDisplay, mImage);
 }
 
-status_t RenderEngine::BindImageAsFramebuffer::getStatus() const {
+status_t RenderEngine::BindNativeBufferAsFramebuffer::getStatus() const {
     return mStatus == GL_FRAMEBUFFER_COMPLETE_OES ? NO_ERROR : BAD_VALUE;
 }
 
diff --git a/services/surfaceflinger/RenderEngine/RenderEngine.h b/services/surfaceflinger/RenderEngine/RenderEngine.h
index 074e97c..2d5bfa3 100644
--- a/services/surfaceflinger/RenderEngine/RenderEngine.h
+++ b/services/surfaceflinger/RenderEngine/RenderEngine.h
@@ -31,6 +31,8 @@
 
 #define EGL_NO_CONFIG ((EGLConfig)0)
 
+struct ANativeWindowBuffer;
+
 // ---------------------------------------------------------------------------
 namespace android {
 // ---------------------------------------------------------------------------
@@ -90,13 +92,14 @@
     void deleteTextures(size_t count, uint32_t const* names);
     void readPixels(size_t l, size_t b, size_t w, size_t h, uint32_t* pixels);
 
-    class BindImageAsFramebuffer {
+    class BindNativeBufferAsFramebuffer {
         RenderEngine& mEngine;
+        EGLImageKHR mImage;
         uint32_t mTexName, mFbName;
         uint32_t mStatus;
     public:
-        BindImageAsFramebuffer(RenderEngine& engine, EGLImageKHR image);
-        ~BindImageAsFramebuffer();
+        BindNativeBufferAsFramebuffer(RenderEngine& engine, ANativeWindowBuffer* buffer);
+        ~BindNativeBufferAsFramebuffer();
         int getStatus() const;
     };
 
diff --git a/services/surfaceflinger/SurfaceFlinger.cpp b/services/surfaceflinger/SurfaceFlinger.cpp
index c34854b..f139683 100644
--- a/services/surfaceflinger/SurfaceFlinger.cpp
+++ b/services/surfaceflinger/SurfaceFlinger.cpp
@@ -4546,26 +4546,6 @@
     });
 }
 
-// A simple RAII class that holds an EGLImage and destroys it either:
-//   a) When the destroy() method is called
-//   b) When the object goes out of scope
-class ImageHolder {
-public:
-    ImageHolder(EGLDisplay display, EGLImageKHR image) : mDisplay(display), mImage(image) {}
-    ~ImageHolder() { destroy(); }
-
-    void destroy() {
-        if (mImage != EGL_NO_IMAGE_KHR) {
-            eglDestroyImageKHR(mDisplay, mImage);
-            mImage = EGL_NO_IMAGE_KHR;
-        }
-    }
-
-private:
-    const EGLDisplay mDisplay;
-    EGLImageKHR mImage;
-};
-
 status_t SurfaceFlinger::captureScreenImplLocked(const RenderArea& renderArea,
                                                  TraverseLayersFunction traverseLayers,
                                                  ANativeWindowBuffer* buffer,
@@ -4584,22 +4564,11 @@
         return PERMISSION_DENIED;
     }
 
-    // create an EGLImage from the buffer so we can later
-    // turn it into a texture
-    EGLImageKHR image = eglCreateImageKHR(mEGLDisplay, EGL_NO_CONTEXT,
-            EGL_NATIVE_BUFFER_ANDROID, buffer, NULL);
-    if (image == EGL_NO_IMAGE_KHR) {
-        return BAD_VALUE;
-    }
-
-    // This will automatically destroy the image if we return before calling its destroy method
-    ImageHolder imageHolder(mEGLDisplay, image);
-
     // this binds the given EGLImage as a framebuffer for the
     // duration of this scope.
-    RenderEngine::BindImageAsFramebuffer imageBond(getRenderEngine(), image);
-    if (imageBond.getStatus() != NO_ERROR) {
-        ALOGE("got GL_FRAMEBUFFER_COMPLETE_OES error while taking screenshot");
+    RenderEngine::BindNativeBufferAsFramebuffer bufferBond(getRenderEngine(), buffer);
+    if (bufferBond.getStatus() != NO_ERROR) {
+        ALOGE("got ANWB binding error while taking screenshot");
         return INVALID_OPERATION;
     }
 
@@ -4621,8 +4590,6 @@
         delete [] pixels;
     }
 
-    // destroy our image
-    imageHolder.destroy();
     return NO_ERROR;
 }