Plumb through EGL_NV_post_sub_buffer and GLX_MESA_copy_sub_buffer.

These two extensions allow a partial swap: just pushing part of the backbuffer to the front buffer. This will allow the WK compositor to push a partial update to the screen instead of a full frame update (https://bugs.webkit.org/show_bug.cgi?id=70533).

We should be able to do something similar for TOUCHUI ImageTransportSurfaces (hence the hooks into GLSurface and the glPostSubBufferCHROMIUM command).

Review URL: http://codereview.chromium.org/8512005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@109625 0039d316-1c4b-4281-b951-d872f2087c98

7 files changed, 67 insertions, 3 deletions

diff --git a/ui/gfx/gl/generate_bindings.py b/ui/gfx/gl/generate_bindings.py
index 2e1a1e0..4207533 100644
--- a/ui/gfx/gl/generate_bindings.py
+++ b/ui/gfx/gl/generate_bindings.py
@@ -363,6 +363,9 @@ EGL_FUNCTIONS = [
     'EGLDisplay dpy, EGLSurface surface, EGLNativePixmapType target'],
 ['__eglMustCastToProperFunctionPointerType', ['eglGetProcAddress'],
     'const char* procname'],
+['EGLBoolean', ['eglPostSubBufferNV'],
+    'EGLDisplay dpy, EGLSurface surface, '
+    'EGLint x, EGLint y, EGLint width, EGLint height'],
 ['EGLBoolean', ['eglQuerySurfacePointerANGLE'],
     'EGLDisplay dpy, EGLSurface surface, EGLint attribute, void** value'],
 ]
@@ -396,6 +399,9 @@ WGL_FUNCTIONS = [
 GLX_FUNCTIONS = [
 ['XVisualInfo*', ['glXChooseVisual'],
     'Display* dpy, int screen, int* attribList'],
+['void', ['glXCopySubBufferMESA'],
+    'Display* dpy, GLXDrawable drawable, '
+    'int x, int y, int width, int height'],
 ['GLXContext', ['glXCreateContext'],
     'Display* dpy, XVisualInfo* vis, GLXContext shareList, int direct'],
 ['void', ['glXBindTexImageEXT'],
diff --git a/ui/gfx/gl/gl_surface.cc b/ui/gfx/gl/gl_surface.cc
index 34d4464..78cada4 100644
--- a/ui/gfx/gl/gl_surface.cc
+++ b/ui/gfx/gl/gl_surface.cc
@@ -94,6 +94,14 @@ unsigned int GLSurface::GetBackingFrameBufferObject() {
   return 0;
 }
 
+bool GLSurface::SupportsPostSubBuffer() {
+  return false;
+}
+
+bool GLSurface::PostSubBuffer(int x, int y, int width, int height) {
+  return false;
+}
+
 bool GLSurface::OnMakeCurrent(GLContext* context) {
   return true;
 }
diff --git a/ui/gfx/gl/gl_surface.h b/ui/gfx/gl/gl_surface.h
index 5843a9c..150182e 100644
--- a/ui/gfx/gl/gl_surface.h
+++ b/ui/gfx/gl/gl_surface.h
@@ -50,6 +50,10 @@ class GL_EXPORT GLSurface : public base::RefCounted<GLSurface> {
   // FBO. Otherwise returns 0.
   virtual unsigned int GetBackingFrameBufferObject();
 
+  // Copy part of the backbuffer to the frontbuffer.
+  virtual bool SupportsPostSubBuffer();
+  virtual bool PostSubBuffer(int x, int y, int width, int height);
+
   static bool InitializeOneOff();
 
   // Called after a context is made current with this surface. Returns false
diff --git a/ui/gfx/gl/gl_surface_egl.cc b/ui/gfx/gl/gl_surface_egl.cc
index 6f6d630..8301bc4 100644
--- a/ui/gfx/gl/gl_surface_egl.cc
+++ b/ui/gfx/gl/gl_surface_egl.cc
@@ -173,7 +173,8 @@ EGLNativeDisplayType GLSurfaceEGL::GetNativeDisplay() {
 NativeViewGLSurfaceEGL::NativeViewGLSurfaceEGL(bool software,
                                                gfx::PluginWindowHandle window)
     : window_(window),
-      surface_(NULL)
+      surface_(NULL),
+      supports_post_sub_buffer_(false)
 {
   software_ = software;
 }
@@ -190,11 +191,18 @@ bool NativeViewGLSurfaceEGL::Initialize() {
     return false;
   }
 
+  static const EGLint egl_window_attributes_sub_buffer[] = {
+    EGL_POST_SUB_BUFFER_SUPPORTED_NV, EGL_TRUE,
+    EGL_NONE
+  };
+
   // Create a surface for the native window.
   surface_ = eglCreateWindowSurface(GetDisplay(),
                                     GetConfig(),
                                     window_,
-                                    NULL);
+                                    gfx::g_EGL_NV_post_sub_buffer ?
+                                        egl_window_attributes_sub_buffer :
+                                        NULL);
 
   if (!surface_) {
     LOG(ERROR) << "eglCreateWindowSurface failed with error "
@@ -203,6 +211,13 @@ bool NativeViewGLSurfaceEGL::Initialize() {
     return false;
   }
 
+  EGLint surfaceVal;
+  EGLBoolean retVal = eglQuerySurface(GetDisplay(),
+                                      surface_,
+                                      EGL_POST_SUB_BUFFER_SUPPORTED_NV,
+                                      &surfaceVal);
+  supports_post_sub_buffer_ = (surfaceVal && retVal) == EGL_TRUE;
+
   return true;
 }
 
@@ -247,6 +262,21 @@ EGLSurface NativeViewGLSurfaceEGL::GetHandle() {
   return surface_;
 }
 
+bool NativeViewGLSurfaceEGL::SupportsPostSubBuffer() {
+  return supports_post_sub_buffer_;
+}
+
+bool NativeViewGLSurfaceEGL::PostSubBuffer(
+    int x, int y, int width, int height) {
+  DCHECK(supports_post_sub_buffer_);
+  if (!eglPostSubBufferNV(GetDisplay(), surface_, x, y, width, height)) {
+    VLOG(1) << "eglPostSubBufferNV failed with error "
+            << GetLastEGLErrorString();
+    return false;
+  }
+  return true;
+}
+
 PbufferGLSurfaceEGL::PbufferGLSurfaceEGL(bool software, const gfx::Size& size)
     : size_(size),
       surface_(NULL) {
diff --git a/ui/gfx/gl/gl_surface_egl.h b/ui/gfx/gl/gl_surface_egl.h
index de68fc8..352c052 100644
--- a/ui/gfx/gl/gl_surface_egl.h
+++ b/ui/gfx/gl/gl_surface_egl.h
@@ -43,7 +43,7 @@ class GL_EXPORT GLSurfaceEGL : public GLSurface {
   static EGLDisplay GetSoftwareDisplay();
   static EGLNativeDisplayType GetNativeDisplay();
 
-protected:
+ protected:
   bool software_;
 
  private:
@@ -63,10 +63,13 @@ class NativeViewGLSurfaceEGL : public GLSurfaceEGL {
   virtual bool SwapBuffers();
   virtual gfx::Size GetSize();
   virtual EGLSurface GetHandle();
+  virtual bool SupportsPostSubBuffer();
+  virtual bool PostSubBuffer(int x, int y, int width, int height);
 
  private:
   gfx::PluginWindowHandle window_;
   EGLSurface surface_;
+  bool supports_post_sub_buffer_;
 
   DISALLOW_COPY_AND_ASSIGN(NativeViewGLSurfaceEGL);
 };
diff --git a/ui/gfx/gl/gl_surface_glx.cc b/ui/gfx/gl/gl_surface_glx.cc
index 2f2380f..373bc85 100644
--- a/ui/gfx/gl/gl_surface_glx.cc
+++ b/ui/gfx/gl/gl_surface_glx.cc
@@ -203,6 +203,17 @@ void* NativeViewGLSurfaceGLX::GetConfig() {
   return config_;
 }
 
+bool NativeViewGLSurfaceGLX::SupportsPostSubBuffer() {
+  return g_GLX_MESA_copy_sub_buffer;
+}
+
+bool NativeViewGLSurfaceGLX::PostSubBuffer(
+    int x, int y, int width, int height) {
+  DCHECK(SupportsPostSubBuffer());
+  glXCopySubBufferMESA(g_display, window_, x, y, width, height);
+  return true;
+}
+
 PbufferGLSurfaceGLX::PbufferGLSurfaceGLX(const gfx::Size& size)
   : size_(size),
     config_(NULL),
diff --git a/ui/gfx/gl/gl_surface_glx.h b/ui/gfx/gl/gl_surface_glx.h
index 7784a79..f880b66 100644
--- a/ui/gfx/gl/gl_surface_glx.h
+++ b/ui/gfx/gl/gl_surface_glx.h
@@ -53,6 +53,8 @@ class GL_EXPORT NativeViewGLSurfaceGLX : public GLSurfaceGLX {
   virtual gfx::Size GetSize();
   virtual void* GetHandle();
   virtual void* GetConfig();
+  virtual bool SupportsPostSubBuffer();
+  virtual bool PostSubBuffer(int x, int y, int width, int height);
 
  protected:
   NativeViewGLSurfaceGLX();