Add the xrender backend to the window manager.

compositor/xrender/xrender_visitor.h

Index: compositor/xrender/xrender_visitor.h
diff --git a/compositor/xrender/xrender_visitor.h b/compositor/xrender/xrender_visitor.h
new file mode 100644
index 0000000000000000000000000000000000000000..f5636ec0b7087da0ebdbab131943c78e75657f65
--- /dev/null
+++ b/compositor/xrender/xrender_visitor.h
@@ -0,0 +1,91 @@
+// Copyright (c) 2011 The Chromium OS Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef WINDOW_MANAGER_XRENDER_XRENDER_VISITOR_H_

[Daniel Erat, 2011/04/02 14:54:36]

this should be WINDOW_MANAGER_COMPOSITOR_XRENDER_XRENDER_VISITOR_H_

[marcheu, 2011/04/04 19:55:58]

Done.

+#define WINDOW_MANAGER_XRENDER_XRENDER_VISITOR_H_
+
+#include <vector>
+
+#include "base/logging.h"
+#include "base/scoped_ptr.h"
+#include "window_manager/compositor/compositor.h"
+#include "window_manager/compositor/real_compositor.h"
+#include "window_manager/compositor/texture_data.h"
+#include "window_manager/x11/x_connection.h"
+
+namespace window_manager {
+
+class ImageContainer;
+
+// This class visits an actor tree and draws it using OpenGL.

[Daniel Erat, 2011/04/02 14:54:36]

s/OpenGL/the X Render extension/

[marcheu, 2011/04/04 19:55:58]

Done.

+class XRenderDrawVisitor : virtual public RealCompositor::ActorVisitor {
+ public:
+  XRenderDrawVisitor(RealCompositor* compositor,
+                    Compositor::StageActor* stage);

[Daniel Erat, 2011/04/02 14:54:36]

nit: should be indented one more space

[marcheu, 2011/04/04 19:55:58]

Done.

+  virtual ~XRenderDrawVisitor();
+
+  XConnection* xconn() { return xconn_; }
+  void set_has_fullscreen_actor(bool has_fullscreen_actor) {
+    has_fullscreen_actor_ = has_fullscreen_actor;
+  }
+  void set_damaged_region(Rect damaged_region) {
+    damaged_region_ = damaged_region;
+  }
+
+  void BindImage(const ImageContainer* container,
+                 RealCompositor::ImageActor* actor);
+
+  virtual void VisitActor(RealCompositor::Actor* actor) {}
+  virtual void VisitStage(RealCompositor::StageActor* actor);
+  virtual void VisitContainer(RealCompositor::ContainerActor* actor);
+  virtual void VisitImage(RealCompositor::ImageActor* actor);
+  virtual void VisitTexturePixmap(RealCompositor::TexturePixmapActor* actor);
+  virtual void VisitQuad(RealCompositor::QuadActor* actor);
+
+ private:
+  XWindow root_window;
+  XConnection::WindowGeometry root_geometry;
+
+  XPicture backPicture;

[Daniel Erat, 2011/04/02 14:54:36]

these should be named back_picture_, back_pixmap_, and stage_picture_.  please
also add a comment describing what 'back' refers to (a back buffer, i'm
assuming)

[marcheu, 2011/04/04 19:55:58]

Done.

+  XPixmap backPixmap;
+
+  XPicture stagePicture;
+
+  // So it can get access to the config data.
+  friend class XRenderPixmapData;

[Daniel Erat, 2011/04/02 14:54:36]

move this to the top of the private section

[marcheu, 2011/04/04 19:55:58]

Done.

+
+  // Finds an appropriate framebuffer configurations for the current
+  // display.  Sets framebuffer_config_rgba_ and framebuffer_config_rgb_.

[Daniel Erat, 2011/04/02 14:54:36]

nit: put pipes around variable references in comments, like
|framebuffer_config_rgba_|

[marcheu, 2011/04/04 19:55:58]

Or delete the whole thing since it's useless...

+  void FindFramebufferConfigurations();
+
+  // The visitor should not change settings in the compositor while visiting
+  // actors throughout the drawing process because the compositor may decide
+  // to skip drawing frames as an optimization.
+  RealCompositor* compositor_;  // Not owned.
+  XConnection* xconn_;  // Not owned.
+  RealCompositor::StageActor* stage_; // Not owned.
+
+  // This is the cumulative opacity of all the ancestors of the
+  // currently visited node. It is recalculated each time we enter or
+  // leave a container node.
+  float ancestor_opacity_;
+
+  // This keeps track of the number of frames drawn so we can draw the

[Daniel Erat, 2011/04/02 14:54:36]

update this comment; you don't draw a debugging needle

[marcheu, 2011/04/04 19:55:58]

Done.

+  // debugging needle.
+  int num_frames_drawn_;
+
+  // The rectangular region of the screen that is damaged in the frame.
+  // This information allows the draw visitor to perform partial updates.
+  Rect damaged_region_;
+
+  // This is used to indicate whether the entire screen will be covered by an
+  // actor so we can optimize by not clearing the COLOR_BUFFER_BIT.

[Daniel Erat, 2011/04/02 14:54:36]

update this comment so it doesn't refer to GL

[marcheu, 2011/04/04 19:55:58]

Done.

+  bool has_fullscreen_actor_;
+
+  DISALLOW_COPY_AND_ASSIGN(XRenderDrawVisitor);
+};
+
+}  // namespace window_manager
+
+#endif  // WINDOW_MANAGER_XRENDER_XRENDER_VISITOR_H_