commit ee6d843ef8960d656d48f379f66b07cc2b27801c
author Roman Stratiienko <r.stratiienko@gmail.com> Fri Feb 14 06:25:30 2025 +0200
committer Roman Stratiienko <r.stratiienko@gmail.com> Tue Feb 18 22:58:58 2025 +0200
tree 5ffc7171856fb5c130c2ba4213db4cd1d1ad1ad9
parent 67b85a625ad5e39fcab43bf67193edc050c3b261

drm_hwcomposer: Rework CreateLayer/DestroyLayer

- Make HwcDisplay CreateLayer/DestroyLayer frontend-agnostic.
- Provide LayerId as an input for CreateLayer. It is necessary to add
  the HWC3 LayerLifecycleBatchCommand feature, where layer ID is
  generated by the client.

Change-Id: I317dcf22461fe4390ced9f0c0c780cffaa3b8f5d
Signed-off-by: Roman Stratiienko <r.stratiienko@gmail.com>

hwc3/ComposerClient.cpp

diff --git a/hwc3/ComposerClient.cpp b/hwc3/ComposerClient.cpp
index a1a1e26..09d8817 100644
--- a/hwc3/ComposerClient.cpp
+++ b/hwc3/ComposerClient.cpp
@@ -494,13 +494,16 @@
     return ToBinderStatus(hwc3::Error::kBadDisplay);
   }
 
-  hwc2_layer_t hwc2_layer_id = 0;
-  auto err = Hwc2toHwc3Error(display->CreateLayer(&hwc2_layer_id));
-  if (err != hwc3::Error::kNone) {
-    return ToBinderStatus(err);
+  auto hwc3display = DrmHwcThree::GetHwc3Display(*display);
+
+  if (!display->CreateLayer(hwc3display->next_layer_id)) {
+    return ToBinderStatus(hwc3::Error::kBadDisplay);
   }
 
-  *layer_id = Hwc2LayerToHwc3(hwc2_layer_id);
+  *layer_id = hwc3display->next_layer_id;
+
+  hwc3display->next_layer_id++;
+
   return ndk::ScopedAStatus::ok();
 }
 
@@ -534,12 +537,11 @@
     return ToBinderStatus(hwc3::Error::kBadDisplay);
   }
 
-  auto err = Hwc2toHwc3Error(display->DestroyLayer(Hwc3LayerToHwc2(layer_id)));
-  if (err != hwc3::Error::kNone) {
-    return ToBinderStatus(err);
+  if (!display->DestroyLayer(layer_id)) {
+    return ToBinderStatus(hwc3::Error::kBadLayer);
   }
 
-  return ToBinderStatus(err);
+  return ToBinderStatus(hwc3::Error::kNone);
 }
 
 ndk::ScopedAStatus ComposerClient::destroyVirtualDisplay(int64_t display_id) {
@@ -698,8 +700,7 @@
         changed_layers = display->ValidateStagedComposition();
     DisplayChanges changes{};
     for (auto [layer_id, composition_type] : changed_layers) {
-      changes.AddLayerCompositionChange(command.display,
-                                        Hwc2LayerToHwc3(layer_id),
+      changes.AddLayerCompositionChange(command.display, layer_id,
                                         static_cast<Composition>(
                                             composition_type));
     }
@@ -743,8 +744,7 @@
 
     std::unordered_map<int64_t, unique_fd> hal_release_fences;
     for (const auto& [layer_id, release_fence] : release_fences) {
-      hal_release_fences[Hwc2LayerToHwc3(layer_id)] =  //
-          unique_fd(::android::DupFd(release_fence));
+      hal_release_fences[layer_id] = unique_fd(::android::DupFd(release_fence));
     }
     cmd_result_writer_->AddReleaseFence(display_id, hal_release_fences);
   }

hwc3/DrmHwcThree.h

diff --git a/hwc3/DrmHwcThree.h b/hwc3/DrmHwcThree.h
index 44168aa..10470ea 100644
--- a/hwc3/DrmHwcThree.h
+++ b/hwc3/DrmHwcThree.h
@@ -26,6 +26,8 @@
 class Hwc3Display : public ::android::FrontendDisplayBase {
  public:
   bool must_validate = false;
+
+  int64_t next_layer_id = 1;
 };
 
 class DrmHwcThree : public ::android::DrmHwc {

hwc3/Utils.h

diff --git a/hwc3/Utils.h b/hwc3/Utils.h
index 642c777..e892832 100644
--- a/hwc3/Utils.h
+++ b/hwc3/Utils.h
@@ -57,12 +57,6 @@
   return ToBinderStatus(Hwc2toHwc3Error(error));
 }
 
-// ID conversion. HWC2 uses typedef'd unsigned integer types while HWC3 uses
-// signed integer types. static_cast in between these.
-inline int64_t Hwc2LayerToHwc3(hwc2_layer_t layer) {
-  return static_cast<int64_t>(layer);
-}
-
 inline int64_t Hwc2DisplayToHwc3(hwc2_display_t display) {
   return static_cast<int64_t>(display);
 }
@@ -71,10 +65,6 @@
   return static_cast<int32_t>(config_id);
 }
 
-inline hwc2_layer_t Hwc3LayerToHwc2(int64_t layer) {
-  return static_cast<hwc2_layer_t>(layer);
-}
-
 inline hwc2_display_t Hwc3DisplayToHwc2(int64_t display) {
   return static_cast<hwc2_display_t>(display);
 }