Bring back support for glReadPixels screenshot path

Squashed commit of the following:

commit 012d3fe41d1d6cd38a0858b59145e9a4447641fa
Author: Hashcode <hashcode0f@gmail.com>
Date:   Sun Dec 8 19:36:50 2013 +0000

    sf: Always use opengles for screen capture

    Go back to the usage of GRALLOC_USAGE_HW_TEXTURE and GRALLOC_USAGE_HW_RENDERER
    in captureScreenImplLocked regardless of useReadPixels value

    This fixes the EGL_NO_IMAGE_KHR error returned from
    eglCreateImageKHR (blank images returned from screenshot path)

    Change-Id: I62fe90a081607b9e89c67f3dcfd34c84efc89d35

commit 4866ddf98ac98d8e22a1cd6a21894bb17f274588
Author: Ricardo Cerqueira <cyanogenmod@cerqueira.org>
Date:   Thu Oct 31 03:53:39 2013 +0000

    Revert "remove support for glReadPixels screenshot path"

    This reverts commit 3ca76f416bc8665a97636ca8a2d0128b9da9d92c.

    Conflicts:
    	include/gui/ISurfaceComposer.h
    	libs/gui/ISurfaceComposer.cpp
    	libs/gui/SurfaceComposerClient.cpp
    	services/surfaceflinger/SurfaceFlinger.cpp
    	services/surfaceflinger/SurfaceFlinger.h

    Change-Id: I8c239e533757af770e418dbb198f5a86c736961f

Change-Id: I8c239e533757af770e418dbb198f5a86c736961f

6 files changed, 79 insertions, 35 deletions

diff --git a/services/surfaceflinger/RenderEngine/GLES11RenderEngine.cpp b/services/surfaceflinger/RenderEngine/GLES11RenderEngine.cpp
index 1a9f59b..aded96f 100644
--- a/services/surfaceflinger/RenderEngine/GLES11RenderEngine.cpp
+++ b/services/surfaceflinger/RenderEngine/GLES11RenderEngine.cpp
@@ -210,28 +210,46 @@ void GLES11RenderEngine::disableBlending() {
 }
 
 void GLES11RenderEngine::bindImageAsFramebuffer(EGLImageKHR image,
-        uint32_t* texName, uint32_t* fbName, uint32_t* status) {
+        uint32_t* texName, uint32_t* fbName, uint32_t* status,
+        bool useReadPixels, int reqWidth, int reqHeight) {
     GLuint tname, name;
-    // turn our EGLImage into a texture
-    glGenTextures(1, &tname);
-    glBindTexture(GL_TEXTURE_2D, tname);
-    glEGLImageTargetTexture2DOES(GL_TEXTURE_2D, (GLeglImageOES)image);
-
-    // create a Framebuffer Object to render into
-    glGenFramebuffersOES(1, &name);
-    glBindFramebufferOES(GL_FRAMEBUFFER_OES, name);
-    glFramebufferTexture2DOES(GL_FRAMEBUFFER_OES,
-            GL_COLOR_ATTACHMENT0_OES, GL_TEXTURE_2D, tname, 0);
+    if (!useReadPixels) {
+        // turn our EGLImage into a texture
+        glGenTextures(1, &tname);
+        glBindTexture(GL_TEXTURE_2D, tname);
+        glEGLImageTargetTexture2DOES(GL_TEXTURE_2D, (GLeglImageOES)image);
+
+        // create a Framebuffer Object to render into
+        glGenFramebuffersOES(1, &name);
+        glBindFramebufferOES(GL_FRAMEBUFFER_OES, name);
+        glFramebufferTexture2DOES(GL_FRAMEBUFFER_OES,
+                GL_COLOR_ATTACHMENT0_OES, GL_TEXTURE_2D, tname, 0);
+    } else {
+        // since we're going to use glReadPixels() anyways,
+        // use an intermediate renderbuffer instead
+        glGenRenderbuffersOES(1, &tname);
+        glBindRenderbufferOES(GL_RENDERBUFFER_OES, tname);
+        glRenderbufferStorageOES(GL_RENDERBUFFER_OES, GL_RGBA8_OES, reqWidth, reqHeight);
+        // create a FBO to render into
+        glGenFramebuffersOES(1, &name);
+        glBindFramebufferOES(GL_FRAMEBUFFER_OES, name);
+        glFramebufferRenderbufferOES(GL_FRAMEBUFFER_OES, GL_COLOR_ATTACHMENT0_OES,
+                GL_RENDERBUFFER_OES, tname);
+    }
 
     *status = glCheckFramebufferStatusOES(GL_FRAMEBUFFER_OES);
     *texName = tname;
     *fbName = name;
 }
 
-void GLES11RenderEngine::unbindFramebuffer(uint32_t texName, uint32_t fbName) {
+void GLES11RenderEngine::unbindFramebuffer(uint32_t texName, uint32_t fbName,
+        bool useReadPixels) {
     glBindFramebufferOES(GL_FRAMEBUFFER_OES, 0);
     glDeleteFramebuffersOES(1, &fbName);
-    glDeleteTextures(1, &texName);
+    if (!useReadPixels)
+        glDeleteTextures(1, &texName);
+    else
+        glDeleteRenderbuffersOES(1, &texName);
 }
 
 void GLES11RenderEngine::setupFillWithColor(float r, float g, float b, float a) {
diff --git a/services/surfaceflinger/RenderEngine/GLES11RenderEngine.h b/services/surfaceflinger/RenderEngine/GLES11RenderEngine.h
index 08de646..77824ce 100644
--- a/services/surfaceflinger/RenderEngine/GLES11RenderEngine.h
+++ b/services/surfaceflinger/RenderEngine/GLES11RenderEngine.h
@@ -40,8 +40,9 @@ class GLES11RenderEngine : public RenderEngine {
     GLint mMaxTextureSize;
 
     virtual void bindImageAsFramebuffer(EGLImageKHR image,
-            uint32_t* texName, uint32_t* fbName, uint32_t* status);
-    virtual void unbindFramebuffer(uint32_t texName, uint32_t fbName);
+            uint32_t* texName, uint32_t* fbName, uint32_t* status, bool useReadPixels,
+            int reqWidth, int reqHeight);
+    virtual void unbindFramebuffer(uint32_t texName, uint32_t fbName, bool useReadPixels);
 
 public:
     GLES11RenderEngine();
diff --git a/services/surfaceflinger/RenderEngine/GLES20RenderEngine.cpp b/services/surfaceflinger/RenderEngine/GLES20RenderEngine.cpp
index 1fabaf5..a35aa78 100644
--- a/services/surfaceflinger/RenderEngine/GLES20RenderEngine.cpp
+++ b/services/surfaceflinger/RenderEngine/GLES20RenderEngine.cpp
@@ -185,27 +185,44 @@ void GLES20RenderEngine::disableBlending() {
 
 
 void GLES20RenderEngine::bindImageAsFramebuffer(EGLImageKHR image,
-        uint32_t* texName, uint32_t* fbName, uint32_t* status) {
+        uint32_t* texName, uint32_t* fbName, uint32_t* status,
+        bool useReadPixels, int reqWidth, int reqHeight) {
     GLuint tname, name;
-    // turn our EGLImage into a texture
-    glGenTextures(1, &tname);
-    glBindTexture(GL_TEXTURE_2D, tname);
-    glEGLImageTargetTexture2DOES(GL_TEXTURE_2D, (GLeglImageOES)image);
-
-    // create a Framebuffer Object to render into
-    glGenFramebuffers(1, &name);
-    glBindFramebuffer(GL_FRAMEBUFFER, name);
-    glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, tname, 0);
+    if (!useReadPixels) {
+        // turn our EGLImage into a texture
+        glGenTextures(1, &tname);
+        glBindTexture(GL_TEXTURE_2D, tname);
+        glEGLImageTargetTexture2DOES(GL_TEXTURE_2D, (GLeglImageOES)image);
+
+        // create a Framebuffer Object to render into
+        glGenFramebuffers(1, &name);
+        glBindFramebuffer(GL_FRAMEBUFFER, name);
+        glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, tname, 0);
+    } else {
+        // since we're going to use glReadPixels() anyways,
+        // use an intermediate renderbuffer instead
+        glGenRenderbuffers(1, &tname);
+        glBindRenderbuffer(GL_RENDERBUFFER, tname);
+        glRenderbufferStorage(GL_RENDERBUFFER, GL_RGBA8_OES, reqWidth, reqHeight);
+        // create a FBO to render into
+        glGenFramebuffers(1, &name);
+        glBindFramebuffer(GL_FRAMEBUFFER, name);
+        glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_RENDERBUFFER, tname);
+    }
 
     *status = glCheckFramebufferStatus(GL_FRAMEBUFFER);
     *texName = tname;
     *fbName = name;
 }
 
-void GLES20RenderEngine::unbindFramebuffer(uint32_t texName, uint32_t fbName) {
+void GLES20RenderEngine::unbindFramebuffer(uint32_t texName, uint32_t fbName,
+        bool useReadPixels) {
     glBindFramebuffer(GL_FRAMEBUFFER, 0);
     glDeleteFramebuffers(1, &fbName);
-    glDeleteTextures(1, &texName);
+    if (!useReadPixels)
+        glDeleteTextures(1, &texName);
+    else
+        glDeleteRenderbuffers(1, &texName);
 }
 
 void GLES20RenderEngine::setupFillWithColor(float r, float g, float b, float a) {
diff --git a/services/surfaceflinger/RenderEngine/GLES20RenderEngine.h b/services/surfaceflinger/RenderEngine/GLES20RenderEngine.h
index 819356a..6074a3d 100644
--- a/services/surfaceflinger/RenderEngine/GLES20RenderEngine.h
+++ b/services/surfaceflinger/RenderEngine/GLES20RenderEngine.h
@@ -55,8 +55,9 @@ class GLES20RenderEngine : public RenderEngine {
     Vector<Group> mGroupStack;
 
     virtual void bindImageAsFramebuffer(EGLImageKHR image,
-            uint32_t* texName, uint32_t* fbName, uint32_t* status);
-    virtual void unbindFramebuffer(uint32_t texName, uint32_t fbName);
+            uint32_t* texName, uint32_t* fbName, uint32_t* status,
+            bool useReadPixels, int reqWidth, int reqHeight);
+    virtual void unbindFramebuffer(uint32_t texName, uint32_t fbName, bool useReadPixels);
 
 public:
     GLES20RenderEngine();
diff --git a/services/surfaceflinger/RenderEngine/RenderEngine.cpp b/services/surfaceflinger/RenderEngine/RenderEngine.cpp
index 7cd42e4..faae6fc 100644
--- a/services/surfaceflinger/RenderEngine/RenderEngine.cpp
+++ b/services/surfaceflinger/RenderEngine/RenderEngine.cpp
@@ -262,9 +262,11 @@ void RenderEngine::dump(String8& result) {
 // ---------------------------------------------------------------------------
 
 RenderEngine::BindImageAsFramebuffer::BindImageAsFramebuffer(
-        RenderEngine& engine, EGLImageKHR image) : mEngine(engine)
+        RenderEngine& engine, EGLImageKHR image, bool useReadPixels,
+        int reqWidth, int reqHeight) : mEngine(engine), mUseReadPixels(useReadPixels)
 {
-    mEngine.bindImageAsFramebuffer(image, &mTexName, &mFbName, &mStatus);
+    mEngine.bindImageAsFramebuffer(image, &mTexName, &mFbName, &mStatus,
+            useReadPixels, reqWidth, reqHeight);
 
     ALOGE_IF(mStatus != GL_FRAMEBUFFER_COMPLETE_OES,
             "glCheckFramebufferStatusOES error %d", mStatus);
@@ -272,7 +274,7 @@ RenderEngine::BindImageAsFramebuffer::BindImageAsFramebuffer(
 
 RenderEngine::BindImageAsFramebuffer::~BindImageAsFramebuffer() {
     // back to main framebuffer
-    mEngine.unbindFramebuffer(mTexName, mFbName);
+    mEngine.unbindFramebuffer(mTexName, mFbName, mUseReadPixels);
 }
 
 status_t RenderEngine::BindImageAsFramebuffer::getStatus() const {
diff --git a/services/surfaceflinger/RenderEngine/RenderEngine.h b/services/surfaceflinger/RenderEngine/RenderEngine.h
index 31a961e..c9a043a 100644
--- a/services/surfaceflinger/RenderEngine/RenderEngine.h
+++ b/services/surfaceflinger/RenderEngine/RenderEngine.h
@@ -51,8 +51,11 @@ class RenderEngine {
     EGLContext mEGLContext;
     void setEGLHandles(EGLConfig config, EGLContext ctxt);
 
-    virtual void bindImageAsFramebuffer(EGLImageKHR image, uint32_t* texName, uint32_t* fbName, uint32_t* status) = 0;
-    virtual void unbindFramebuffer(uint32_t texName, uint32_t fbName) = 0;
+    virtual void bindImageAsFramebuffer(EGLImageKHR image, uint32_t* texName,
+            uint32_t* fbName, uint32_t* status, bool useReadPixels, int reqWidth,
+            int reqHeight) = 0;
+    virtual void unbindFramebuffer(uint32_t texName, uint32_t fbName,
+            bool useReadPixels) = 0;
 
 protected:
     RenderEngine();
@@ -83,8 +86,10 @@ public:
         RenderEngine& mEngine;
         uint32_t mTexName, mFbName;
         uint32_t mStatus;
+        bool mUseReadPixels;
     public:
-        BindImageAsFramebuffer(RenderEngine& engine, EGLImageKHR image);
+        BindImageAsFramebuffer(RenderEngine& engine, EGLImageKHR image,
+                bool useReadPixels, int reqWidth, int reqHeight);
         ~BindImageAsFramebuffer();
         int getStatus() const;
     };