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>
 
 #include "base/basictypes.h"
 #include "base/debug/trace_event.h"
 #include "base/logging.h"
 #include "base/time/time.h"
 #include "third_party/skia/include/core/SkCanvas.h"
 #include "ui/gfx/geometry/point.h"
 #include "ui/gfx/geometry/size.h"
 #include "ui/ozone/platform/dri/dri_buffer.h"
 #include "ui/ozone/platform/dri/dri_wrapper.h"
 #include "ui/ozone/platform/dri/scanout_surface.h"
+#include "ui/ozone/public/native_pixmap.h"
 
 namespace ui {
 
 namespace {
 
 // DRM callback on page flip events. This callback is triggered after the
 // page flip has happened and the backbuffer is now the new frontbuffer
 // The old frontbuffer is no longer used by the hardware and can be used for
 // future draw operations.
 //
@@ skipping 73 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::GetPrimaryPlane(
+    const std::vector<OzoneOverlayPlane>& overlays) {
+  ScanoutSurface* primary = surface_.get();
+  for (size_t i = 0; i < overlays.size(); i++) {
+    const OzoneOverlayPlane& plane = overlays[i];
+    if (plane.z_order == 0) {

[dnicoara, 2014/07/10 17:00:56]

Should replace |surface_| in this case otherwise later calls which do not
specify a primary will use a stale buffer.

[achaulk, 2014/07/10 17:07:50]

We could NULL it, but we can't store any of the overlay planes in |surface_|
because that implies explicit ownership and these pointers can't be deleted.

[dnicoara, 2014/07/10 17:25:47]

You can't NULL it otherwise SchedulePageFlip will fail.

I'm a bit fuzzy on why you can't take a reference? HDC is already doing that for
the other overlay planes. Reading the calling code in gl_renderer.cc is
confusing me a bit. We're explicitly skipping the primary plane in CC. (So CC is
treating the primary plane in a special manner?).

What are all the supported overlay (+primary) combinations?

[achaulk, 2014/07/10 17:42:29]

References are only taken on NativePixmap objects - that's the list that is
passed in to SchedulePageFlip. |surface_| is a scoped_ptr and implies ownership.
Since the NativePixmap object will delete the ScanoutSurface object (and in fact
for gbm overlay planes the ScanoutSurface object is a member of the NativePixmap
object, not allocated) we will crash horribly if it is deleted through
|surface_|.

If you're worried about having a reference at all, it will be in the list that
gets passed in.

[dnicoara, 2014/07/10 19:17:13]

We clarified this offline :)

+      return plane.scanout;
+    }
+  }
+
+  return primary;
+}
+
+bool HardwareDisplayController::SchedulePageFlip(
+    const std::vector<OzoneOverlayPlane>& overlays,
+    NativePixmapList* references) {
+  ScanoutSurface* primary = GetPrimaryPlane(overlays);
+  CHECK(primary);
+
+  primary->PreSwapBuffers();
+
+  if (!is_disabled_ &&
+      !drm_->PageFlip(crtc_id_, primary->GetFramebufferId(), this)) {
     LOG(ERROR) << "Cannot page flip: " << strerror(errno);
     return false;
   }
 
+  current_overlay_references_.clear();
+  if (references)
+    current_overlay_references_.swap(*references);
+
+  for (size_t i = 0; i < overlays.size(); i++) {
+    const OzoneOverlayPlane& plane = overlays[i];
+    if (!plane.overlay_plane)
+      continue;
+    const gfx::Size& size = plane.scanout->Size();
+    const gfx::SizeF sizef(size.width(), size.height());
+    const gfx::RectF& crop_rect = plane.crop_rect;
+    gfx::RectF draw_rect(crop_rect.x() * sizef.width(),

[dnicoara, 2014/07/10 19:53:52]

I think you can just make crop_rect non-const and replace all of this with:

crop_rect.Scale(size.width(), size.height());

[achaulk, 2014/07/11 16:57:49]

Acknowledged.

+                         crop_rect.y() * sizef.height(),
+                         crop_rect.width() * sizef.width(),
+                         crop_rect.height() * sizef.height());
+    if (!drm_->PageFlipOverlay(crtc_id_,
+                               plane.scanout->GetFramebufferId(),
+                               plane.display_bounds,
+                               draw_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