Allow frame callback to be enabled/disabled

Since per-frame readback is slow and clients don't need it on all the
time, this change allows the callback to be registered after
initialization, and allows it to be disabled later.

Change-Id: Ic73d4515d302a0981ee0c80b9e6f9ba5c84b82ae

3 files changed, 48 insertions, 22 deletions

diff --git a/emulator/opengl/host/libs/libOpenglRender/FrameBuffer.cpp b/emulator/opengl/host/libs/libOpenglRender/FrameBuffer.cpp
index fde82a1..2f7cd61 100644
--- a/emulator/opengl/host/libs/libOpenglRender/FrameBuffer.cpp
+++ b/emulator/opengl/host/libs/libOpenglRender/FrameBuffer.cpp
@@ -101,7 +101,7 @@ void FrameBuffer::finalize(){
     }
 }
 
-bool FrameBuffer::initialize(int width, int height, OnPostFn onPost, void* onPostContext)
+bool FrameBuffer::initialize(int width, int height)
 {
     if (s_theFrameBuffer != NULL) {
         return true;
@@ -110,7 +110,7 @@ bool FrameBuffer::initialize(int width, int height, OnPostFn onPost, void* onPos
     //
     // allocate space for the FrameBuffer object
     //
-    FrameBuffer *fb = new FrameBuffer(width, height, onPost, onPostContext);
+    FrameBuffer *fb = new FrameBuffer(width, height);
     if (!fb) {
         ERR("Failed to create fb\n");
         return false;
@@ -335,17 +335,6 @@ bool FrameBuffer::initialize(int width, int height, OnPostFn onPost, void* onPos
     fb->initGLState();
 
     //
-    // Allocate space for the onPost framebuffer image
-    //
-    if (onPost) {
-        fb->m_fbImage = (unsigned char*)malloc(4 * width * height);
-        if (!fb->m_fbImage) {
-            delete fb;
-            return false;
-        }
-    }
-
-    //
     // Cache the GL strings so we don't have to think about threading or
     // current-context when asked for them.
     //
@@ -363,8 +352,7 @@ bool FrameBuffer::initialize(int width, int height, OnPostFn onPost, void* onPos
     return true;
 }
 
-FrameBuffer::FrameBuffer(int p_width, int p_height,
-        OnPostFn onPost, void* onPostContext) :
+FrameBuffer::FrameBuffer(int p_width, int p_height) :
     m_width(p_width),
     m_height(p_height),
     m_eglDisplay(EGL_NO_DISPLAY),
@@ -381,8 +369,8 @@ FrameBuffer::FrameBuffer(int p_width, int p_height,
     m_eglContextInitialized(false),
     m_statsNumFrames(0),
     m_statsStartTime(0LL),
-    m_onPost(onPost),
-    m_onPostContext(onPostContext),
+    m_onPost(NULL),
+    m_onPostContext(NULL),
     m_fbImage(NULL),
     m_glVendor(NULL),
     m_glRenderer(NULL),
@@ -396,6 +384,22 @@ FrameBuffer::~FrameBuffer()
     free(m_fbImage);
 }
 
+void FrameBuffer::setPostCallback(OnPostFn onPost, void* onPostContext)
+{
+    android::Mutex::Autolock mutex(m_lock);
+    m_onPost = onPost;
+    m_onPostContext = onPostContext;
+    if (m_onPost && !m_fbImage) {
+        m_fbImage = (unsigned char*)malloc(4 * m_width * m_height);
+        if (!m_fbImage) {
+            ERR("out of memory, cancelling OnPost callback");
+            m_onPost = NULL;
+            m_onPostContext = NULL;
+            return;
+        }
+    }
+}
+
 bool FrameBuffer::setupSubWindow(FBNativeWindowType p_window,
                                   int p_x, int p_y,
                                   int p_width, int p_height, float zRot)
diff --git a/emulator/opengl/host/libs/libOpenglRender/FrameBuffer.h b/emulator/opengl/host/libs/libOpenglRender/FrameBuffer.h
index 89a708b..de0b71c 100644
--- a/emulator/opengl/host/libs/libOpenglRender/FrameBuffer.h
+++ b/emulator/opengl/host/libs/libOpenglRender/FrameBuffer.h
@@ -46,7 +46,7 @@ struct FrameBufferCaps
 class FrameBuffer
 {
 public:
-    static bool initialize(int width, int height, OnPostFn onPost, void* onPostContext);
+    static bool initialize(int width, int height);
     static bool setupSubWindow(FBNativeWindowType p_window,
                                 int x, int y,
                                 int width, int height, float zRot);
@@ -59,6 +59,8 @@ public:
     int getWidth() const { return m_width; }
     int getHeight() const { return m_height; }
 
+    void setPostCallback(OnPostFn onPost, void* onPostContext);
+
     void getGLStrings(const char** vendor, const char** renderer, const char** version) const {
         *vendor = m_glVendor;
         *renderer = m_glRenderer;
@@ -96,7 +98,7 @@ public:
     }
 
 private:
-    FrameBuffer(int p_width, int p_height, OnPostFn onPost, void* onPostContext);
+    FrameBuffer(int p_width, int p_height);
     ~FrameBuffer();
     HandleType genHandle();
     bool bindSubwin_locked();
diff --git a/emulator/opengl/host/libs/libOpenglRender/render_api.cpp b/emulator/opengl/host/libs/libOpenglRender/render_api.cpp
index 7d7a981..72cd9ba 100644
--- a/emulator/opengl/host/libs/libOpenglRender/render_api.cpp
+++ b/emulator/opengl/host/libs/libOpenglRender/render_api.cpp
@@ -76,8 +76,7 @@ int initLibrary(void)
     return true;
 }
 
-int initOpenGLRenderer(int width, int height, int portNum,
-        OnPostFn onPost, void* onPostContext)
+int initOpenGLRenderer(int width, int height, int portNum)
 {
 
     //
@@ -94,7 +93,7 @@ int initOpenGLRenderer(int width, int height, int portNum,
     // initialize the renderer and listen to connections
     // on a thread in the current process.
     //
-    bool inited = FrameBuffer::initialize(width, height, onPost, onPostContext);
+    bool inited = FrameBuffer::initialize(width, height);
     if (!inited) {
         return false;
     }
@@ -191,6 +190,27 @@ int initOpenGLRenderer(int width, int height, int portNum,
     return true;
 }
 
+void setPostCallback(OnPostFn onPost, void* onPostContext)
+{
+#ifdef RENDER_API_USE_THREAD  // should be defined for mac
+    FrameBuffer* fb = FrameBuffer::getFB();
+    if (fb) {
+        fb->setPostCallback(onPost, onPostContext);
+    }
+#else
+    if (onPost) {
+        // onPost callback not supported with separate renderer process.
+        //
+        // If we ever revive separate process support, we could make the choice
+        // between thread and process at runtime instead of compile time, and
+        // choose the thread path if an onPost callback is requested. Or, the
+        // callback could be supported with a separate process using shmem or
+        // other IPC mechanism.
+        return false;
+    }
+#endif
+}
+
 void getHardwareStrings(const char** vendor, const char** renderer, const char** version)
 {
     FrameBuffer* fb = FrameBuffer::getFB();