Overlay interface for ozone.

ui/gfx/ozone/surface_factory_ozone.h

Index: ui/gfx/ozone/surface_factory_ozone.h
diff --git a/ui/gfx/ozone/surface_factory_ozone.h b/ui/gfx/ozone/surface_factory_ozone.h
index 889a56db9f352a3dc37ec6374abcc1e1864c923e..6579c3021d0d3568e309a705320d5c322fed973f 100644
--- a/ui/gfx/ozone/surface_factory_ozone.h
+++ b/ui/gfx/ozone/surface_factory_ozone.h
@@ -12,12 +12,15 @@
 #include "ui/gfx/geometry/rect.h"
 #include "ui/gfx/gfx_export.h"
 #include "ui/gfx/native_widget_types.h"
+#include "ui/gfx/rect.h"
 
 class SkBitmap;
 class SkCanvas;
 
 namespace gfx {
 class VSyncProvider;
+class OverlayCandidatesOzone;
+typedef intptr_t NativeBufferOzone;
 
 // The Ozone interface allows external implementations to hook into Chromium to
 // provide a system specific implementation. The Ozone interface supports two
@@ -55,6 +58,26 @@ class GFX_EXPORT SurfaceFactoryOzone {
     FAILED,
   };
 
+  // Describes overlay buffer format.
+  // TODO: this is a placeholder for now and will be populated with more
+  // formats once we know what sorts of content, video, etc. we can support.
+  enum BufferFormat {
+    UNKNOWN,
+    RGBA_8888,
+    RGB_888,
+  };
+
+  // Describes transformation to be applied to the buffer before presenting
+  // to screen.
+  enum OverlayTransform {
+    NONE,
+    FLIP_HORIZONTAL,
+    FLIP_VERTICAL,
+    ROTATE_90,
+    ROTATE_180,
+    ROTATE_270,
+  };
+
   typedef void*(*GLGetProcAddressProc)(const char* name);
   typedef base::Callback<void(base::NativeLibrary)> AddGLLibraryCallback;
   typedef base::Callback<void(GLGetProcAddressProc)>
@@ -136,6 +159,27 @@ class GFX_EXPORT SurfaceFactoryOzone {
   // Sets the cursor position to |location|.
   virtual void MoveCursorTo(const gfx::Point& location);
 
+  // Get the hal struct to check for overlay support.
+  virtual gfx::OverlayCandidatesOzone* GetOverlayCandidates();

[rjkroege, 2014/03/04 18:54:08]

there is conceptually a separate OCOz per display so this should probably take
an AcceleratedWidget.

also: how does atomic flip work with multi-mon? 

+
+  // Sets the overlay plane to switch to at the next page flip.
+  // |plane_id| specifies the location of the plane above the main framebuffer.

[rjkroege, 2014/03/04 18:54:08]

the id is merely to specify the the stacking order of the planes? This needs to
be stated I think. Perhaps it should be renamed as "plane_z_order" or something
similar?

this gets called for every plane? is the base plane implied? does there even
need to be a base plane? Some SoCs won't have such a thing. I would have think
that "base plane" is 0?

I am opposed to treating the base plane as special.

do the set planes persist? i.e.: after 2 flips if nothing is called, what planes
are on the display? perhaps this call should take a flag to "persist" or
"transient" the plane on 2nd flip (well, 2nd vblank really when scan out is
done)

[alexst (slow to review), 2014/03/04 20:04:53]

This is z_order, I'll rename.

We get the base plane (plane 0) from eglSwapBuffers via the platform
implementation, nothing prevents us from setting it here too.

I envisioned this as persistent, same as the underlying api's, if you set the
plane, it stays there until you reset it, I don't want to destroy the image on
the screen after a couple of scanouts. If CC doesn't need to redraw, we should
be able to keep scanning out from the same buffers.

+  // |plane_transform| specifies how the buffer is to be transformed during.
+  // composition.
+  // |buffer| to be presented by the overlay.
+  // |display_bounds| specify where it is supposed to be on the screen.
+  // |crop_rect| specifies the region within the buffer to be placed inside
+  // |display_bounds|.
+  virtual void ScheduleOverlayPlane(int plane_id,
+                                    OverlayTransform plane_transform,
+                                    gfx::NativeBufferOzone buffer,
+                                    const gfx::Rect& display_bounds,
+                                    gfx::RectF crop_rect);
+
+  // Cleate a single native buffer to be used for overlay planes.
+  virtual gfx::NativeBufferOzone CreateNativeBuffer(gfx::Size size,
+                                                    BufferFormat format);
+
  private:
   static SurfaceFactoryOzone* impl_; // not owned
 };