# Shader Presets
This directory contains curated shader presets that reference the [libretro/slang-shaders](https://github.com/libretro/slang-shaders) repository, which is included as a git submodule at `vendor/slang-shaders`.
## Setup
After cloning neser, initialise the submodule to enable the non-stock shaders:
```bash
git submodule update --init
```
Or clone with submodules from the start:
```bash
git clone --recurse-submodules https://github.com/rmstdope/neser
```
## Available Presets
- **stock.slangp**: Nearest neighbor (no filtering) — no submodule required
- **xbrz-freescale.slangp**: xBRZ pixel art upscaler (requires submodule)
- **crt-lottes.slangp**: CRT simulation by Timothy Lottes — scanlines, shadow mask, bloom (requires submodule, public domain)
- **ntsc-256px-composite.slangp**: NTSC composite video simulation (requires submodule)
## Usage
Use the `--filter` flag with a simplified name:
```bash
neser rom.nes --filter crt # CRT simulation
neser rom.nes --filter ntsc # NTSC composite
neser rom.nes --filter smooth # Smooth upscaling
neser rom.nes --filter none # No filter
```
Or set in config file:
```text
filter=crt
```
You can also cycle through shaders at runtime with F6.
## Why a submodule?
The shader files carry per-file licenses (public domain, MIT, GPL-3.0).
Rather than vendoring the source directly in this repository, a shallow
submodule is used so that each shader is fetched from the authoritative
upstream repository along with its original license text.