From 49572e3438c3108b84f8cca99039a9ca1e1d0d4b Mon Sep 17 00:00:00 2001
From: Magnus Jedvert <magjed@webrtc.org>
Date: Tue, 28 Mar 2023 09:43:22 +0000
Subject: [PATCH] Add support for JavaToNativeFloatArray

Change-Id: I75482debc163d2c5f173cad644cd25ceb2996b38

Bug: webrtc:15047
Change-Id: I75482debc163d2c5f173cad644cd25ceb2996b38
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/299240
Reviewed-by: Paulina Hensman <phensman@webrtc.org>
Commit-Queue: Magnus Jedvert <magjed@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#39713}
---
 sdk/android/native_api/jni/java_types.cc | 15 +++++++++++++++
 sdk/android/native_api/jni/java_types.h  |  2 ++
 2 files changed, 17 insertions(+)

diff --git a/sdk/android/native_api/jni/java_types.cc b/sdk/android/native_api/jni/java_types.cc
index 24f247e73b..87406d15c4 100644
--- a/sdk/android/native_api/jni/java_types.cc
+++ b/sdk/android/native_api/jni/java_types.cc
@@ -265,6 +265,21 @@ std::vector<int32_t> JavaToNativeIntArray(JNIEnv* env,
   return container;
 }
 
+std::vector<float> JavaToNativeFloatArray(JNIEnv* env,
+                                          const JavaRef<jfloatArray>& jarray) {
+  // jfloat is a "machine-dependent native type" which represents a 32-bit
+  // float. C++ makes no guarantees about the size of floating point types, and
+  // some exotic architectures don't even have 32-bit floats (or even binary
+  // floats), but on all architectures we care about this is a float.
+  static_assert(std::is_same<float, jfloat>::value, "jfloat must be float");
+  float* array_ptr =
+      env->GetFloatArrayElements(jarray.obj(), /*isCopy=*/nullptr);
+  size_t array_length = env->GetArrayLength(jarray.obj());
+  std::vector<float> container(array_ptr, array_ptr + array_length);
+  env->ReleaseFloatArrayElements(jarray.obj(), array_ptr, /*mode=*/JNI_ABORT);
+  return container;
+}
+
 ScopedJavaLocalRef<jobjectArray> NativeToJavaBooleanArray(
     JNIEnv* env,
     const std::vector<bool>& container) {
diff --git a/sdk/android/native_api/jni/java_types.h b/sdk/android/native_api/jni/java_types.h
index 556c5e44ca..44ade0d06e 100644
--- a/sdk/android/native_api/jni/java_types.h
+++ b/sdk/android/native_api/jni/java_types.h
@@ -242,6 +242,8 @@ std::vector<int8_t> JavaToNativeByteArray(JNIEnv* env,
                                           const JavaRef<jbyteArray>& jarray);
 std::vector<int32_t> JavaToNativeIntArray(JNIEnv* env,
                                           const JavaRef<jintArray>& jarray);
+std::vector<float> JavaToNativeFloatArray(JNIEnv* env,
+                                          const JavaRef<jfloatArray>& jarray);
 
 ScopedJavaLocalRef<jobjectArray> NativeToJavaBooleanArray(
     JNIEnv* env,