Bloom defender examples have broken offsets on development

[pushfoo]

Bug Report

System Info

$ python -m arcade

Arcade 2.7.1.dev8
-----------------
vendor: Intel
renderer: Mesa Intel(R) UHD Graphics 620 (KBL GT2)
version: (4, 6)
python: 3.9.2 (default, Feb 28 2021, 17:03:44) 
[GCC 10.2.1 20210110]
platform: linux

$ hostnamectl
 ...
  Operating System: Debian GNU/Linux 11 (bullseye)
            Kernel: Linux 5.10.0-19-amd64
      Architecture: x86-64

Actual behavior:

Expected behavior:

Steps to reproduce/example code:

Run either of the following examples on the OS / hardware version listed above:

1. arcade/examples/bloom_defender.py
2. arcade/experimental/bloom_multilayer_defender.py

[pushfoo]

This happens regardless of whether the color constant in #1425 is used.

[pushfoo]

Per discord discussion, this has been broken for a while, and it's not clear when it broke.

[einarf]

Duplicate of #946