From 015592f534b68b8f281f9d7a2ab9733bf58031a1 Mon Sep 17 00:00:00 2001
From: hschlueter <hschlueter@google.com>
Date: Mon, 14 Feb 2022 14:34:37 +0000
Subject: [PATCH] Add glClear call before drawing.

PiperOrigin-RevId: 428492031
---
 .../src/main/java/androidx/media3/transformer/FrameEditor.java  | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/libraries/transformer/src/main/java/androidx/media3/transformer/FrameEditor.java b/libraries/transformer/src/main/java/androidx/media3/transformer/FrameEditor.java
index 9bcc97def0..1a6f7c619b 100644
--- a/libraries/transformer/src/main/java/androidx/media3/transformer/FrameEditor.java
+++ b/libraries/transformer/src/main/java/androidx/media3/transformer/FrameEditor.java
@@ -352,6 +352,8 @@ import java.util.concurrent.atomic.AtomicInteger;
   /** Focuses the specified surface with the specified width and height, then draws a quad. */
   private void focusAndDrawQuad(EGLSurface eglSurface, int width, int height) {
     GlUtil.focusEglSurface(eglDisplay, eglContext, eglSurface, width, height);
+    GLES20.glClearColor(/* red= */ 0, /* green= */ 0, /* blue= */ 0, /* alpha= */ 0);
+    GLES20.glClear(GLES20.GL_COLOR_BUFFER_BIT);
     // The four-vertex triangle strip forms a quad.
     GLES20.glDrawArrays(GLES20.GL_TRIANGLE_STRIP, /* first= */ 0, /* count= */ 4);
   }