fix: Fix flutter texture rendering downscale on Android

android/src/main/cpp/iris_rtc_rendering_android.cc

@@ -303,6 +303,8 @@ class Texture2DRendering final : public RenderingOp {
         CHECK_GL_ERROR()
         glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
         CHECK_GL_ERROR()
+        glViewport(0, 0, video_frame->width, video_frame->height);
+        CHECK_GL_ERROR()
 
         // Bind 2D texture
         glActiveTexture(GL_TEXTURE0);
@@ -409,6 +411,8 @@ class OESTextureRendering final : public RenderingOp {
         CHECK_GL_ERROR()
         glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
         CHECK_GL_ERROR()
+        glViewport(0, 0, video_frame->width, video_frame->height);
+        CHECK_GL_ERROR()
 
         // Bind external oes texture
         glActiveTexture(GL_TEXTURE0);
@@ -528,6 +532,8 @@ class YUVRendering final : public RenderingOp {
     CHECK_GL_ERROR()
     glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
     CHECK_GL_ERROR()
+    glViewport(0, 0, width, height);
+    CHECK_GL_ERROR()
 
     glEnableVertexAttribArray(aPositionLoc_);
     CHECK_GL_ERROR()
@@ -538,8 +544,8 @@ class YUVRendering final : public RenderingOp {
 
     // Adjust the tex coords to avoid green edge issue
     float sFactor = 1.0f;
-    if (video_frame->width != video_frame->yStride) {
-      sFactor = (float) video_frame->width / (float) video_frame->yStride - 0.02f;
+    if (width != yStride) {
+      sFactor = (float) width / (float) yStride - 0.02f;
     }
 
     float fragment[] = {sFactor, 0.0f, 0.0f, 0.0f, sFactor, 1.0f, 0.0f, 1.0f};
@@ -704,6 +710,8 @@ class NativeTextureRenderer final
       strcpy(config.channelId, "");
     }
     config.video_view_setup_mode = video_view_setup_mode;
+    config.observed_frame_position = agora::media::base::VIDEO_MODULE_POSITION::POSITION_POST_CAPTURER
+            | agora::media::base::VIDEO_MODULE_POSITION::POSITION_PRE_RENDERER;
 
     if (iris_rtc_rendering_) {
       delegate_id_ =

android/src/main/cpp/third_party/include/iris/iris_rtc_rendering_c.h

@@ -46,7 +46,7 @@ typedef struct IrisRtcVideoFrameConfig {
   int video_view_setup_mode;
 
   /// int value of agora::media::base::VIDEO_MODULE_POSITION.
-  /// Default value is
+  /// Default value is 
   /// `agora::media::base::VIDEO_MODULE_POSITION::POSITION_PRE_ENCODER | agora::media::base::VIDEO_MODULE_POSITION::POSITION_PRE_RENDERER`
   uint32_t observed_frame_position;
 } IrisRtcVideoFrameConfig;

android/src/main/java/io/agora/agora_rtc_ng/TextureRenderer.java

@@ -5,12 +5,9 @@
 import android.os.Looper;
 import android.view.Surface;
 
-import androidx.annotation.NonNull;
-
 import java.util.HashMap;
 
 import io.flutter.plugin.common.BinaryMessenger;
-import io.flutter.plugin.common.MethodCall;
 import io.flutter.plugin.common.MethodChannel;
 import io.flutter.view.TextureRegistry;
 
@@ -23,9 +20,6 @@ public class TextureRenderer {
     private SurfaceTexture flutterSurfaceTexture;
     private Surface renderSurface;
 
-    int width = 0;
-    int height = 0;
-
     public TextureRenderer(
             TextureRegistry textureRegistry,
             BinaryMessenger binaryMessenger,
@@ -42,33 +36,6 @@ public TextureRenderer(
         this.renderSurface = new Surface(this.flutterSurfaceTexture);
 
         this.methodChannel = new MethodChannel(binaryMessenger, "agora_rtc_engine/texture_render_" + flutterTexture.id());
-        this.methodChannel.setMethodCallHandler(new MethodChannel.MethodCallHandler() {
-            @Override
-            public void onMethodCall(@NonNull MethodCall call, @NonNull MethodChannel.Result result) {
-                if (call.method.equals("setSizeNative")) {
-                    if (call.arguments() == null) {
-                        result.success(false);
-                        return;
-                    }
-
-                    int width = 0;
-                    int height = 0;
-                    if (call.hasArgument("width")) {
-                        width = call.argument("width");
-                    }
-                    if (call.hasArgument("height")) {
-                        height = call.argument("height");
-                    }
-
-                    startRendering(width, height);
-
-                    result.success(true);
-                    return;
-                }
-
-                result.notImplemented();
-            }
-        });
 
         this.irisRenderer = new IrisRenderer(
                 irisRtcRenderingHandle,
@@ -79,6 +46,11 @@ public void onMethodCall(@NonNull MethodCall call, @NonNull MethodChannel.Result
         this.irisRenderer.setCallback(new IrisRenderer.Callback() {
             @Override
             public void onSizeChanged(int width, int height) {
+                final SurfaceTexture st = TextureRenderer.this.flutterSurfaceTexture;
+                if (null != st) {
+                    st.setDefaultBufferSize(width, height);
+                }
+
                 handler.post(() -> {
                     methodChannel.invokeMethod(
                             "onSizeChanged",
@@ -89,29 +61,8 @@ public void onSizeChanged(int width, int height) {
                 });
             }
         });
-    }
-
-    private void startRendering(int width, int height) {
-        if (width == 0 && height == 0) {
-            return;
-        }
-
-        final SurfaceTexture st = TextureRenderer.this.flutterSurfaceTexture;
-        if (null == st) {
-            return;
-        }
-
-        if (this.width != width || this.height != height) {
-            st.setDefaultBufferSize(width, height);
 
-            // Only call `irisRenderer.startRenderingToSurface` in the first time.
-            if (this.width == 0 && this.height == 0) {
-                this.irisRenderer.startRenderingToSurface(renderSurface);
-            }
-
-            this.width = width;
-            this.height = height;
-        }
+        this.irisRenderer.startRenderingToSurface(renderSurface);
     }
 
     public long getTextureId() {

example/lib/components/config_override.dart

@@ -45,4 +45,8 @@ class ExampleConfigOverride {
   void set(String name, String value) {
     _overridedConfig[name] = value;
   }
+
+  /// Internal testing flag
+  bool get isInternalTesting =>
+      const bool.fromEnvironment('INTERNAL_TESTING', defaultValue: false);
 }

example/lib/examples/basic/index.dart

@@ -1,3 +1,5 @@
+import 'package:agora_rtc_engine_example/components/config_override.dart';
+import 'package:agora_rtc_engine_example/examples/basic/join_channel_video/flutter_texture_android_internal_test.dart';
 import 'package:agora_rtc_engine_example/examples/basic/string_uid/string_uid.dart';
 
 import 'join_channel_audio/join_channel_audio.dart';
@@ -9,5 +11,11 @@ final basic = [
   {'name': 'Basic'},
   {'name': 'JoinChannelAudio', 'widget': const JoinChannelAudio()},
   {'name': 'JoinChannelVideo', 'widget': const JoinChannelVideo()},
+  if (defaultTargetPlatform == TargetPlatform.android &&
+      ExampleConfigOverride().isInternalTesting)
+    {
+      'name': 'FlutterTextureAndroidTest',
+      'widget': const FlutterTextureAndroidTest()
+    },
   {'name': 'StringUid', 'widget': const StringUid()}
 ];