Pixel art filter (crt, scale2x...) for preview window

[emidevops]

Problem

I use Libresprite for an SNES game. I would like to preview my sprites rendered using art filters (CRT, scale2x, hqx...) without launching an emulator or pluging a monitor.

Proposed solution

Add filters to render/render.cpp and option to activate them to ui/preview_editor.cpp.

Exemple of CRT filter algorithm: https://github.com/Kannagi/CRT

Alternative

Allow use of opengl shader in preview window ?