commit cbb1de9d4435bb78b4529518db2fecf4e36b5d1e
Author: Leszek Koltunski <leszek@koltunski.pl>
Date:   Wed Mar 30 01:23:58 2022 +0200

    Create the bandaged 3x3 icon: something works, the shape is drawn, but it's entirely black. Investigate.

diff --git a/src/main/java/org/distorted/library/main/DistortedFramebuffer.java b/src/main/java/org/distorted/library/main/DistortedFramebuffer.java
index 120e5c1..cd01083 100644
--- a/src/main/java/org/distorted/library/main/DistortedFramebuffer.java
+++ b/src/main/java/org/distorted/library/main/DistortedFramebuffer.java
@@ -344,4 +344,23 @@ public class DistortedFramebuffer extends InternalOutputSurface
     {
     return mColorH[0];
     }
+
+///////////////////////////////////////////////////////////////////////////////////////////////////
+/**
+ * Bind one of the underlying FBOs to GL_READ_FRAMEBUFFER.
+ * Useful for a subsequent glReadBuffer / glReadPixels.
+ *
+ * @param fbo which of the underlying FBOs to bind.
+ * @return <code>true</code> if successful.
+ */
+  public boolean setAsReadFramebuffer(int fbo)
+    {
+    if( fbo>=0 && fbo<mNumFBOs )
+      {
+      GLES30.glBindFramebuffer(GLES30.GL_READ_FRAMEBUFFER, mFBOH[fbo]);
+      return true;
+      }
+
+    return false;
+    }
   }