added pi constant; don't clamp the magnitude in the output texture
added pi constant; don't clamp the magnitude in the output texture

headupinclouds/ogles_gpgpu,hunter-packages/ogles_gpgpu,headupinclouds/ogles_gpgpu,headupinclouds/ogles_gpgpu,headupinclouds/ogles_gpgpu,hunter-packages/ogles_gpgpu,hunter-packages/ogles_gpgpu,hunter-packages/ogles_gpgpu