ozone: gbm: Add overlay support

ui/ozone/platform/dri/hardware_display_controller.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ui/ozone/platform/dri/hardware_display_controller.h"
 
 #include <drm.h>
 #include <errno.h>
 #include <string.h>
 #include <xf86drm.h>
@@ skipping 94 matching lines @@
   }
 
   return true;
 }
 
 void HardwareDisplayController::Disable() {
   drm_->SetCrtc(crtc_id_, 0, 0, NULL);
   is_disabled_ = true;
 }
 
-bool HardwareDisplayController::SchedulePageFlip() {
-  CHECK(surface_);
-  if (!is_disabled_ && !drm_->PageFlip(crtc_id_,
-                                       surface_->GetFramebufferId(),
-                                       this)) {
+ScanoutSurface* HardwareDisplayController::AssignOverlayPlanes(
+    std::vector<OzoneOverlayPlane>* overlays) {
+  ScanoutSurface* primary = surface_.get();

[dnicoara, 2014/07/07 19:17:54]

It seems that surface is going to be ignored. Can we recycle it when
SchedulePageFlip is called with overlays?

I'm thinking that when running on the overlay path |surface_| could be replaced
by the new ScanoutSurface on every SchedulePageFlip(). You probably also want to
optimize the GBM path to create a GbmBuffer rather than a GbmSurface through the
ScanoutSurfaceGenerator (see ozone_platform_gbm.cc).

[achaulk, 2014/07/07 20:18:04]

It can't be *directly* replaced since HDC owns the surface via a scoped_ptr. It
can probably be NULLed though

I tried creating only GbmBuffer objects, but that doesn't seem to work, maybe
something with the initial modeset actually requires a gbm_surface?

+  if (!overlays)
+    return primary;
+  for (size_t i = 0; i < overlays->size(); i++) {
+    const OzoneOverlayPlane& plane = (*overlays)[i];
+    if (plane.z_order == 0) {
+      primary = plane.scanout;
+    } else {
+      // TODO: assign overlay planes.
+    }
+  }
+
+  return primary;
+}
+
+bool HardwareDisplayController::SchedulePageFlip(
+    std::vector<OzoneOverlayPlane>* overlays) {
+  ScanoutSurface* primary = AssignOverlayPlanes(overlays);
+  CHECK(primary);
+
+  primary->PreSwapBuffers();
+
+  if (!is_disabled_ &&
+      !drm_->PageFlip(crtc_id_, primary->GetFramebufferId(), this)) {
     LOG(ERROR) << "Cannot page flip: " << strerror(errno);
     return false;
   }
 
+  if (overlays) {
+    for (size_t i = 0; i < overlays->size(); i++) {
+      const OzoneOverlayPlane& plane = (*overlays)[i];
+      if (!plane.overlay_plane)
+        continue;
+      if (!drm_->PageFlipOverlay(crtc_id_,
+                                 plane.scanout->GetFramebufferId(),
+                                 plane.display_bounds,
+                                 plane.crop_rect,
+                                 plane.overlay_plane)) {
+        LOG(ERROR) << "Cannot display on overlay: " << strerror(errno);
+        return false;
+      }
+    }
+  }
+
   return true;
 }
 
 void HardwareDisplayController::WaitForPageFlipEvent() {
   TRACE_EVENT0("dri", "WaitForPageFlipEvent");
 
   if (is_disabled_)
     return;
 
   drmEventContext drm_event;
@@ skipping 29 matching lines @@
 }
 
 bool HardwareDisplayController::MoveCursor(const gfx::Point& location) {
   if (is_disabled_)
     return true;
 
   return drm_->MoveCursor(crtc_id_, location.x(), location.y());
 }
 
 }  // namespace ui