Add support for background blurs

Bug: 141640413
Fixes: 146384234
Test: adb shell setprop debug.sf.disableBlurs 1
Test: adb shell setprop debug.sf.gaussianBlur 0
Test: adb shell setprop ro.surface_flinger.supports_background_blur 1
Test: ./SurfaceFlinger_test --gtest_filter=Layer*Tests/Layer*Test.SetBackgroundBlur*
Test: ./librenderengine_test --gtest_filter=*BlurBackground*"
Test: atest SurfaceFlinger_test:SurfaceInterceptorTest#InterceptBackgroundBlurRadiusUpdateWorks
Change-Id: I5194c910fe7062f33e70943867012539e6c6626a
diff --git a/libs/renderengine/gl/GLFramebuffer.h b/libs/renderengine/gl/GLFramebuffer.h
index b7650bb..668685a 100644
--- a/libs/renderengine/gl/GLFramebuffer.h
+++ b/libs/renderengine/gl/GLFramebuffer.h
@@ -20,6 +20,7 @@
 
 #include <EGL/egl.h>
 #include <EGL/eglext.h>
+#include <GLES2/gl2.h>
 #include <renderengine/Framebuffer.h>
 
 struct ANativeWindowBuffer;
@@ -33,22 +34,30 @@
 class GLFramebuffer : public renderengine::Framebuffer {
 public:
     explicit GLFramebuffer(GLESRenderEngine& engine);
+    explicit GLFramebuffer(GLESRenderEngine& engine, bool multiTarget);
     ~GLFramebuffer() override;
 
     bool setNativeWindowBuffer(ANativeWindowBuffer* nativeBuffer, bool isProtected,
                                const bool useFramebufferCache) override;
+    void allocateBuffers(uint32_t width, uint32_t height);
     EGLImageKHR getEGLImage() const { return mEGLImage; }
     uint32_t getTextureName() const { return mTextureName; }
+    uint32_t getSecondaryTextureName() const { return mSecondaryTextureName; }
     uint32_t getFramebufferName() const { return mFramebufferName; }
     int32_t getBufferHeight() const { return mBufferHeight; }
     int32_t getBufferWidth() const { return mBufferWidth; }
+    GLenum getStatus() const { return mStatus; }
+    void bind() const;
+    void unbind() const;
 
 private:
     GLESRenderEngine& mEngine;
     EGLDisplay mEGLDisplay;
     EGLImageKHR mEGLImage;
     bool usingFramebufferCache = false;
+    GLenum mStatus = GL_FRAMEBUFFER_UNSUPPORTED;
     uint32_t mTextureName, mFramebufferName;
+    uint32_t mSecondaryTextureName = -1;
 
     int32_t mBufferHeight = 0;
     int32_t mBufferWidth = 0;