mirror of https://github.com/bsnes-emu/bsnes.git
126 lines
4.0 KiB
Markdown
126 lines
4.0 KiB
Markdown
Most of the consoles higan emulates
|
|
were designed for the low resolution of NTSC televisions,
|
|
and their video output is often chunky and blocky
|
|
by today's standards.
|
|
Shaders customise how a console's video output
|
|
is drawn to the computer screen,
|
|
and can apply just about any effect you can imagine.
|
|
|
|
For most [drivers](drivers.md),
|
|
the only shaders available are:
|
|
|
|
- **None** draws each computer pixel
|
|
in the same colour as the nearest console pixel.
|
|
This is sometimes called "nearest neighbour scaling",
|
|
and produces crisp, blocky output.
|
|
- **Blur** draws each computer pixel
|
|
as the weighted average colour
|
|
of the four nearest console pixels.
|
|
This is sometimes called "bilinear scaling",
|
|
and hides some of the blockiness
|
|
at the expense of blurring edges.
|
|
|
|
However,
|
|
the OpenGL driver supports custom shaders,
|
|
in addition to the above.
|
|
|
|
**Note:**
|
|
For technical reasons,
|
|
higan's emulation of certain consoles
|
|
can produce surprising behaviour
|
|
in certain shaders,
|
|
particularly shaders that compare each console pixel
|
|
with its neigbours.
|
|
See [Console-specific Notes](../notes.md) for details.
|
|
|
|
# Where to get shaders
|
|
|
|
- higan includes some simple example shaders.
|
|
If your copy of higan did not come with shaders,
|
|
you can get them from
|
|
[the unofficial higan repository](https://gitlab.com/higan/higan/tree/master/shaders).
|
|
- [quark-shaders](https://github.com/hizzlekizzle/quark-shaders)
|
|
contains many high-quality shaders for use with higan.
|
|
- You can write your own.
|
|
|
|
# How to install shaders
|
|
|
|
Make sure the shader you want to install
|
|
is in the correct format:
|
|
it should be a folder whose name ends in `.shader`,
|
|
it should contain a file named `manifest.bml`,
|
|
and probably some `*.fs` or `*.vs` files.
|
|
|
|
Place the shader folder inside
|
|
the `Video Shaders` directory
|
|
of your higan installation.
|
|
If you don't have a `Video Shaders` directory,
|
|
create it beside the `*.sys` directories
|
|
like `Game Boy Advance.sys` and `Super Famicom.sys`.
|
|
|
|
- On Windows,
|
|
this is probably the directory containing `higan.exe`
|
|
- On Linux,
|
|
this is probably `~/.local/share/higan`
|
|
|
|
Launch higan,
|
|
open the Settings menu,
|
|
and choose "Advanced ..."
|
|
to open [the Advanced tab](../interface/higan-config.md#advanced)
|
|
of the Settings dialog.
|
|
Under "Driver Selection",
|
|
make sure "Video" is set to "OpenGL".
|
|
If you changed the video driver,
|
|
you'll need to restart higan
|
|
for the change to take effect.
|
|
|
|
Open the Settings menu again,
|
|
choose the "Video Shader" submenu,
|
|
and now the shaders you installed
|
|
should be listed at the bottom of the menu.
|
|
|
|
Load a game
|
|
(so you can see the results)
|
|
and switch between shaders
|
|
to see what they do
|
|
and pick your favourite!
|
|
|
|
# Notable examples
|
|
|
|
The quark-shaders repository
|
|
contains lots of carefully-crafted shaders,
|
|
but some are particularly noteworthy:
|
|
|
|
- **AANN** implements "anti-aliased nearest neighbour" scaling.
|
|
If the console's video is not displayed
|
|
at an exact multple of the console's native resolution,
|
|
rounding errors cause normal nearest-neighbour scaling
|
|
to draw some rows and columns wider than others,
|
|
which many people find ugly and distracting.
|
|
This is very common when
|
|
higan's aspect-ratio correction mode
|
|
is enabled.
|
|
AANN uses very slight anti-aliasing
|
|
to hide the rounding errors,
|
|
leaving the overall image as crisp as nearest-neighbour.
|
|
- **Gameboy** emulates the squarish aspect-ratio
|
|
greenish-colours
|
|
and limited palette
|
|
of the original Game Boy.
|
|
At larger scales,
|
|
you can even see the fine gaps between each pixel,
|
|
and the shadow that dark colours would cast
|
|
on the LCD background.
|
|
- **NTSC** performs NTSC encoding,
|
|
bandwidth limiting,
|
|
and NTSC decoding of the video image to recreate
|
|
the colour fringing,
|
|
blurring
|
|
and shimmer
|
|
that most game players would have seen
|
|
on real televisions.
|
|
This is important because
|
|
some games depended on NTSC artifacts
|
|
to display colours outside the console's official palette
|
|
or to create effects like transparency.
|