Implement EGL_surfaceless_context for Android/ChromeOS and optimize eglMakeCurrent

src/libANGLE/renderer/gl/egl/DisplayEGL.cpp

@@ -105,6 +105,9 @@ void DisplayEGL::generateExtensions(egl::DisplayExtensions *outExtensions) const
 
     // Contexts are virtualized so textures can be shared globally
     outExtensions->displayTextureShareGroup = true;
+
+    // Surfaceless contexts are emulated even if there is no native support.
+    outExtensions->surfacelessContext = true;
 }
 
 void DisplayEGL::generateCaps(egl::Caps *outCaps) const

src/libANGLE/renderer/gl/egl/PbufferSurfaceEGL.cpp

@@ -15,9 +15,8 @@ PbufferSurfaceEGL::PbufferSurfaceEGL(const egl::SurfaceState &state,
                                      const FunctionsEGL *egl,
                                      EGLConfig config,
                                      const std::vector<EGLint> &attribList,
-                                     EGLContext context,
                                      RendererGL *renderer)
-    : SurfaceEGL(state, egl, config, attribList, context, renderer)
+    : SurfaceEGL(state, egl, config, attribList, renderer)
 {
 }
 

src/libANGLE/renderer/gl/egl/PbufferSurfaceEGL.h

@@ -24,7 +24,6 @@ class PbufferSurfaceEGL : public SurfaceEGL
                       const FunctionsEGL *egl,
                       EGLConfig config,
                       const std::vector<EGLint> &attribList,
-                      EGLContext context,
                       RendererGL *renderer);
     ~PbufferSurfaceEGL() override;
 

src/libANGLE/renderer/gl/egl/SurfaceEGL.cpp

@@ -17,14 +17,12 @@ SurfaceEGL::SurfaceEGL(const egl::SurfaceState &state,
                        const FunctionsEGL *egl,
                        EGLConfig config,
                        const std::vector<EGLint> &attribList,
-                       EGLContext context,
                        RendererGL *renderer)
     : SurfaceGL(state, renderer),
       mEGL(egl),
       mConfig(config),
       mAttribList(attribList),
-      mSurface(EGL_NO_SURFACE),
-      mContext(context)
+      mSurface(EGL_NO_SURFACE)
 {
 }
 
@@ -39,11 +37,7 @@ SurfaceEGL::~SurfaceEGL()
 
 egl::Error SurfaceEGL::makeCurrent()
 {
-    EGLBoolean success = mEGL->makeCurrent(mSurface, mContext);
-    if (success == EGL_FALSE)
-    {
-        return egl::Error(mEGL->getError(), "eglMakeCurrent failed");
-    }
+    // Handling of makeCurrent is done in DisplayEGL
     return egl::NoError();
 }
 
@@ -133,4 +127,9 @@ EGLint SurfaceEGL::getSwapBehavior() const
     return value;
 }
 
+EGLSurface SurfaceEGL::getSurface() const
+{
+    return mSurface;
+}
+
 }  // namespace rx

src/libANGLE/renderer/gl/egl/SurfaceEGL.h

@@ -24,7 +24,6 @@ class SurfaceEGL : public SurfaceGL
                const FunctionsEGL *egl,
                EGLConfig config,
                const std::vector<EGLint> &attribList,
-               EGLContext context,
                RendererGL *renderer);
     ~SurfaceEGL() override;
 
@@ -44,14 +43,13 @@ class SurfaceEGL : public SurfaceGL
     EGLint isPostSubBufferSupported() const override;
     EGLint getSwapBehavior() const override;
 
+    EGLSurface getSurface() const;
+
   protected:
     const FunctionsEGL *mEGL;
     EGLConfig mConfig;
     std::vector<EGLint> mAttribList;
     EGLSurface mSurface;
-
-  private:
-    EGLContext mContext;
 };
 
 }  // namespace rx

src/libANGLE/renderer/gl/egl/WindowSurfaceEGL.cpp

@@ -16,9 +16,8 @@ WindowSurfaceEGL::WindowSurfaceEGL(const egl::SurfaceState &state,
                                    EGLConfig config,
                                    EGLNativeWindowType window,
                                    const std::vector<EGLint> &attribList,
-                                   EGLContext context,
                                    RendererGL *renderer)
-    : SurfaceEGL(state, egl, config, attribList, context, renderer), mWindow(window)
+    : SurfaceEGL(state, egl, config, attribList, renderer), mWindow(window)
 {
 }
 

src/libANGLE/renderer/gl/egl/WindowSurfaceEGL.h

@@ -22,7 +22,6 @@ class WindowSurfaceEGL : public SurfaceEGL
                      EGLConfig config,
                      EGLNativeWindowType window,
                      const std::vector<EGLint> &attribList,
-                     EGLContext context,
                      RendererGL *renderer);
     ~WindowSurfaceEGL() override;
 

src/libANGLE/renderer/gl/egl/android/DisplayAndroid.cpp

@@ -33,7 +33,7 @@ namespace rx
 {
 
 DisplayAndroid::DisplayAndroid(const egl::DisplayState &state)
-    : DisplayEGL(state), mDummyPbuffer(EGL_NO_SURFACE)
+    : DisplayEGL(state), mDummyPbuffer(EGL_NO_SURFACE), mCurrentSurface(EGL_NO_SURFACE)
 {
 }
 
@@ -114,6 +114,7 @@ egl::Error DisplayAndroid::initialize(egl::Display *display)
         return egl::EglNotInitialized()
                << "eglMakeCurrent failed with " << egl::Error(mEGL->getError());
     }
+    mCurrentSurface = mDummyPbuffer;
 
     mFunctionsGL = mEGL->makeFunctionsGL();
     mFunctionsGL->initialize();
@@ -130,6 +131,7 @@ void DisplayAndroid::terminate()
     {
         ERR() << "eglMakeCurrent error " << egl::Error(mEGL->getError());
     }
+    mCurrentSurface = EGL_NO_SURFACE;
 
     if (mDummyPbuffer != EGL_NO_SURFACE)
     {
@@ -173,8 +175,7 @@ SurfaceImpl *DisplayAndroid::createWindowSurface(const egl::SurfaceState &state,
     success = mEGL->chooseConfig(configAttribList, &config, 1, &numConfig);
     ASSERT(success && numConfig == 1);
 
-    return new WindowSurfaceEGL(state, mEGL, config, window, attribs.toIntVector(), mContext,
-                                getRenderer());
+    return new WindowSurfaceEGL(state, mEGL, config, window, attribs.toIntVector(), getRenderer());
 }
 
 SurfaceImpl *DisplayAndroid::createPbufferSurface(const egl::SurfaceState &state,
@@ -188,8 +189,7 @@ SurfaceImpl *DisplayAndroid::createPbufferSurface(const egl::SurfaceState &state
     success = mEGL->chooseConfig(configAttribList, &config, 1, &numConfig);
     ASSERT(success && numConfig == 1);
 
-    return new PbufferSurfaceEGL(state, mEGL, config, attribs.toIntVector(), mContext,
-                                 getRenderer());
+    return new PbufferSurfaceEGL(state, mEGL, config, attribs.toIntVector(), getRenderer());
 }
 
 SurfaceImpl *DisplayAndroid::createPbufferFromClientBuffer(const egl::SurfaceState &state,
@@ -394,5 +394,32 @@ egl::Error DisplayAndroid::waitNative(const gl::Context *context, EGLint engine)
     UNIMPLEMENTED();
     return egl::NoError();
 }
+egl::Error DisplayAndroid::makeCurrent(egl::Surface *drawSurface,
+                                       egl::Surface *readSurface,
+                                       gl::Context *context)
+{
+    if (drawSurface)
+    {
+        SurfaceEGL *drawSurfaceEGL = GetImplAs<SurfaceEGL>(drawSurface);
+        EGLSurface surface         = drawSurfaceEGL->getSurface();
+        if (surface != mCurrentSurface)
+        {
+            if (mEGL->makeCurrent(surface, mContext) == EGL_FALSE)
+            {
+                return egl::Error(mEGL->getError(), "eglMakeCurrent failed");
+            }
+            mCurrentSurface = surface;
+        }
+    }
+
+    return DisplayGL::makeCurrent(drawSurface, readSurface, context);
+}
+
+egl::Error DisplayAndroid::makeCurrentSurfaceless(gl::Context *context)
+{
+    // Nothing to do because EGL always uses the same context and the previous surface can be left
+    // current.
+    return egl::NoError();
+}
 
 }  // namespace rx

src/libANGLE/renderer/gl/egl/android/DisplayAndroid.h

@@ -56,7 +56,13 @@ class DisplayAndroid : public DisplayEGL
     egl::Error waitClient(const gl::Context *context) const override;
     egl::Error waitNative(const gl::Context *context, EGLint engine) const override;
 
+    egl::Error makeCurrent(egl::Surface *drawSurface,
+                           egl::Surface *readSurface,
+                           gl::Context *context) override;
+
   private:
+    egl::Error makeCurrentSurfaceless(gl::Context *context) override;
+
     template <typename T>
     void getConfigAttrib(EGLConfig config, EGLint attribute, T *value) const;
 
@@ -70,6 +76,7 @@ class DisplayAndroid : public DisplayEGL
     std::vector<EGLint> mConfigAttribList;
     std::map<EGLint, EGLint> mConfigIds;
     EGLSurface mDummyPbuffer;
+    EGLSurface mCurrentSurface;
 };
 
 }  // namespace rx

src/libANGLE/renderer/gl/egl/ozone/DisplayOzone.cpp

@@ -955,4 +955,10 @@ void DisplayOzone::setSwapInterval(EGLSurface drawable, SwapControlData *data)
     ASSERT(data != nullptr);
 }
 
+egl::Error DisplayOzone::makeCurrentSurfaceless(gl::Context *context)
+{
+    // Nothing to do, handled in the GL layers
+    return egl::NoError();
+}
+
 }  // namespace rx

src/libANGLE/renderer/gl/egl/ozone/DisplayOzone.h

@@ -145,6 +145,8 @@ class DisplayOzone final : public DisplayEGL
     void setSwapInterval(EGLSurface drawable, SwapControlData *data);
 
   private:
+    egl::Error makeCurrentSurfaceless(gl::Context *context) override;
+
     GLuint makeShader(GLuint type, const char *src);
     void drawBuffer(Buffer *buffer);
     void drawWithBlit(Buffer *buffer);