Additive Blending Without Glclear

I want to do additive blending on camera preview's surface texture binded to my opengl context. I am getting weirdly rendered texture when i enable blending(20 noisy squares gettin

Solution 1:

Most Android devices have a PowerVR, Mali, Adreno or Vivante GPU core which are all deferred, tiled-based renderers. This architecture requires the glClear operation at the start of each frame to tell the OpenGL ES driver when to clear internal triangle binning queues as well as the frame buffer. If you don't do the glClear, this caching design does not work properly and you will get weird results that will differ from one GPU type to another. So, you really must do the glClear.