From bf0771af59019f6a7554868f620d7d57c8993361 Mon Sep 17 00:00:00 2001
From: Chris Lomont <chrislomont@meta.com>
Date: Thu, 28 Sep 2023 18:28:52 -0700
Subject: [PATCH] Exporting Android native hardware buffers out of IGL

Summary: This diff exposes an Android shared CPU+GPU memory buffer on EGL.

Differential Revision: D49734694

fbshipit-source-id: 5d84543cb5ece77ced184ba1f173ac05fb6d76a4
---
 src/igl/opengl/egl/PlatformDevice.cpp         | 32 +++++++++++++++++++
 src/igl/opengl/egl/PlatformDevice.h           |  9 ++++++
 src/igl/opengl/egl/android/NativeHWBuffer.cpp |  2 +-
 src/igl/opengl/egl/android/NativeHWBuffer.h   |  2 +-
 4 files changed, 43 insertions(+), 2 deletions(-)

diff --git a/src/igl/opengl/egl/PlatformDevice.cpp b/src/igl/opengl/egl/PlatformDevice.cpp
index ccec01baa5..71bb244370 100644
--- a/src/igl/opengl/egl/PlatformDevice.cpp
+++ b/src/igl/opengl/egl/PlatformDevice.cpp
@@ -10,6 +10,9 @@
 #include <igl/opengl/egl/Context.h>
 #include <igl/opengl/egl/Device.h>
 #include <igl/opengl/egl/PlatformDevice.h>
+#if IGL_PLATFORM_ANDROID && __ANDROID_MIN_SDK_VERSION__ >= 26
+#include <igl/opengl/egl/android/NativeHWBuffer.h>
+#endif
 #include <sstream>
 #include <utility>
 
@@ -142,6 +145,35 @@ std::shared_ptr<ITexture> PlatformDevice::createTextureFromNativeDepth(Result* o
   return texture;
 }
 
+#if IGL_PLATFORM_ANDROID && __ANDROID_MIN_SDK_VERSION__ >= 26
+
+/// returns a android::NativeHWTextureBuffer on platforms supporting it
+/// this texture allows CPU and GPU to both read/write memory
+std::shared_ptr<ITexture> PlatformDevice::createTextureWithSharedMemory(const TextureDesc& desc,
+                                                                        Result* outResult) {
+  auto context = static_cast<Context*>(getSharedContext().get());
+  if (context == nullptr) {
+    Result::setResult(outResult, Result::Code::InvalidOperation, "No EGL context found!");
+    return nullptr;
+  }
+
+  Result subResult;
+
+  auto texture = std::make_shared<android::NativeHWTextureBuffer>(getContext(), desc.format);
+  subResult = texture->create(desc, false);
+  Result::setResult(outResult, subResult.code, subResult.message);
+  if (!subResult.isOk()) {
+    return nullptr;
+  }
+
+  if (auto resourceTracker = owner_.getResourceTracker()) {
+    texture->initResourceTracker(resourceTracker);
+  }
+
+  return texture;
+}
+#endif
+
 void PlatformDevice::updateSurfaces(EGLSurface readSurface,
                                     EGLSurface drawSurface,
                                     Result* outResult) {
diff --git a/src/igl/opengl/egl/PlatformDevice.h b/src/igl/opengl/egl/PlatformDevice.h
index cb16dee9fe..2c5dc53a53 100644
--- a/src/igl/opengl/egl/PlatformDevice.h
+++ b/src/igl/opengl/egl/PlatformDevice.h
@@ -39,6 +39,15 @@ class PlatformDevice : public opengl::PlatformDevice {
   /// Returns a texture representing the EGL depth texture associated with this device's context.
   std::shared_ptr<ITexture> createTextureFromNativeDepth(Result* outResult);
 
+#if IGL_PLATFORM_ANDROID && __ANDROID_MIN_SDK_VERSION__ >= 26
+
+  /// returns a android::NativeHWTextureBuffer on platforms supporting it
+  /// this texture allows CPU and GPU to both read/write memory
+  std::shared_ptr<ITexture> createTextureWithSharedMemory(const TextureDesc& desc,
+                                                          Result* outResult);
+
+#endif
+
   /// This function must be called every time the currently bound EGL read and/or draw surfaces
   /// change, in order to notify IGL of these changes.
   void updateSurfaces(EGLSurface readSurface, EGLSurface drawSurface, Result* outResult);
diff --git a/src/igl/opengl/egl/android/NativeHWBuffer.cpp b/src/igl/opengl/egl/android/NativeHWBuffer.cpp
index 2840011854..565fc55316 100644
--- a/src/igl/opengl/egl/android/NativeHWBuffer.cpp
+++ b/src/igl/opengl/egl/android/NativeHWBuffer.cpp
@@ -16,7 +16,7 @@
 #include <igl/opengl/Errors.h>
 #include <igl/opengl/GLIncludes.h>
 
-#if defined(__ANDROID_API__) && __ANDROID_MIN_SDK_VERSION__ >= 26
+#if IGL_PLATFORM_ANDROID && __ANDROID_MIN_SDK_VERSION__ >= 26
 
 #if defined(IGL_API_LOG) && (IGL_DEBUG || defined(IGL_FORCE_ENABLE_LOGS))
 #define APILOG_DEC_DRAW_COUNT() \
diff --git a/src/igl/opengl/egl/android/NativeHWBuffer.h b/src/igl/opengl/egl/android/NativeHWBuffer.h
index f64899a429..ee10796cc6 100644
--- a/src/igl/opengl/egl/android/NativeHWBuffer.h
+++ b/src/igl/opengl/egl/android/NativeHWBuffer.h
@@ -9,7 +9,7 @@
 
 #include <igl/opengl/TextureBufferBase.h>
 
-#if defined(__ANDROID_API__) && __ANDROID_MIN_SDK_VERSION__ >= 26
+#if IGL_PLATFORM_ANDROID && __ANDROID_MIN_SDK_VERSION__ >= 26
 
 struct AHardwareBuffer;