From 248a08b18c005637e91d77f674408fe8f5d2b01b Mon Sep 17 00:00:00 2001
From: Rodrigo Gomes <rodgomesc@gmail.com>
Date: Tue, 12 Dec 2023 07:21:21 -0300
Subject: [PATCH] feat: Support for C++ Frame Processor Plugins by publishing
 VisionCamera as a prefab (#2251)

* update docs

* add prefabs support
---
 docs/docs/guides/FRAME_PROCESSORS.mdx | 30 +++++++++++++++++++++++++++
 package/android/build.gradle          | 15 ++++++++++++++
 2 files changed, 45 insertions(+)

diff --git a/docs/docs/guides/FRAME_PROCESSORS.mdx b/docs/docs/guides/FRAME_PROCESSORS.mdx
index a9c0961..046fbea 100644
--- a/docs/docs/guides/FRAME_PROCESSORS.mdx
+++ b/docs/docs/guides/FRAME_PROCESSORS.mdx
@@ -98,6 +98,36 @@ const frameProcessor = useFrameProcessor((frame) => {
 It is however recommended to use native **Frame Processor Plugins** for processing, as those are much faster than JavaScript and can sometimes operate with the GPU buffer directly.
 You can simply pass a `Frame` to a native Frame Processor Plugin directly.
 
+## Advanced Frame Handling in C++
+
+**vision-camera** is built using prefabs, which allow you to easily extend the library with your own native code.
+you can link it in your `CMakeLists.txt` like this:
+
+```make
+find_package(react-native-vision-camera REQUIRED CONFIG)
+# ...
+target_link_libraries(
+  ${PACKAGE_NAME}
+  # ... other libs
+  react-native-vision-camera::VisionCamera
+)
+```
+
+then pass a `jsi::Object` to your C++ code. and then use the `FrameHostObject` to access the frame data:
+
+```cpp
+ #include "frameprocessor/FrameHostObject.h"
+
+# in your jsi::Function
+jni::global_ref <JFrame> unwrappedFrame = frame->frame;
+auto frameWidth = unwrappedFrame->getWidth();
+__android_log_print(ANDROID_LOG_DEBUG, "VisionCamera",
+                    "frame width: %d", frameWidth);
+auto frameHeight = unwrappedFrame->getHeight();
+__android_log_print(ANDROID_LOG_DEBUG, "VisionCamera",
+                    "frame height: %d", frameHeight);
+```
+
 ## Interacting with Frame Processors
 
 ### Access JS values
diff --git a/package/android/build.gradle b/package/android/build.gradle
index 4dc216c..44c89cc 100644
--- a/package/android/build.gradle
+++ b/package/android/build.gradle
@@ -92,6 +92,13 @@ android {
 
   buildFeatures {
     prefab true
+    prefabPublishing true
+  }
+
+  prefab {
+    VisionCamera {
+      headers "${project.buildDir}/headers/visioncamera/"
+    }
   }
 
   defaultConfig {
@@ -171,6 +178,14 @@ task deleteCmakeCache() {
   }
 }
 
+task prepareHeaders(type: Copy) {
+  from fileTree('./src/main/cpp').filter { it.isFile() }
+  into "${project.buildDir}/headers/visioncamera/react-native-vision-camera/"
+  includeEmptyDirs = false
+}
+
+preBuild.dependsOn(prepareHeaders)
+
 tasks.configureEach { task ->
   // C++ build
   if (task.name.contains("configureCMakeDebug")) {