Hi, I'm trying to detect the opengl object under the cursor... I have read it referred to as picking. Here is my code:
public int makeBuffer(GL10 gl, int x, int y) { ByteBuffer PixelBuffer = ByteBuffer.allocateDirect(4); PixelBuffer.order(ByteOrder.nativeOrder()); PixelBuffer.position(0); int mTemp = 0; gl.glReadPixels((int)x, (int) y, 1, 1, GL10.GL_RGBA, GL10.GL_UNSIGNED_BYTE, PixelBuffer); Log.e("Picking", " xy: x" + x + " y"+ y); byte b [] = new byte[4]; PixelBuffer.get(b); Log.e("Picking", " rgba: r"+ PixelBuffer.get(0) + " g" + PixelBuffer.get(1) + " b" + PixelBuffer.get(2) + " a" + PixelBuffer.get(3)); Log.e("Picking", " rgba: r"+ b[0] + " g" + b[1] + " b" + b[2] + " a" + b[3]); //mTemp = PixelBuffer.get(0); mTemp = b[0]; Log.e("Picking", "result:" + mTemp ); return mTemp; } See that most of the code above is logcat statements. My code prints zeros to the screen for r,g, and b. For alpha it prints '-1' which is translatable to 255 (unsigned) as 'full alpha'. I'm trying to detect a color on the screen at the given x/y position. I would be happy with a red value that's somewhere between 1 and 15, as that's the color that should be below the touch. I would expect that if I was doing it entirely wrong I would get all zeroes, but I must be doing it at least partially right, as I'm getting alpha. I have also included lines in my manifest that tell the phone that I use the permissions for the 'surface flinger' and the 'read frame buffer'. I don't know if these lines are working. <uses-permission android:name="android.permission.ACCESS_SURFACE_FLINGER" /> <uses-permission android:name="android.permission.READ_FRAME_BUFFER" / > any help would be appreciated. -- You received this message because you are subscribed to the Google Groups "Android Developers" group. To post to this group, send email to android-developers@googlegroups.com To unsubscribe from this group, send email to android-developers+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-developers?hl=en