What is this?
=============

This is a Mugen stage edit that converts it to a wide-screen aspect.
The edit itself is made by Kasasagi (https://tilde.town/~kasasagi/).

The original stage is a part of the full-game project named
'Hyper Street Fighter Zero' by Ehnyd (https://ehnyd.deviantart.com).

Other such edits and updated versions of this edit can be downloaded
from here: https://drive.proton.me/urls/PDERG8YN00#RwM3MVN730fv


What engines is this edit intended for?
---------------------------------------

The edited stages are made for Mugen 1.1 and/or Ikemen Go engines.

The required Mugen version is strictly Mugen 1.1, because the
stage edits use zoom to implement the wide-screen conversion.

The required Ikemen Go version is **newer** than 0.99, e.g. Nightly,
because Ikemen Go 0.99 and older is highly incompatible with Mugen,
when it comes to low and high camera bounds of the stages.

To download Ikemen Go Nightly, go here:
https://github.com/ikemen-engine/Ikemen-GO/releases/tag/nightly

Some (but **not all**) of these edits are available for Ikemen Go 0.99
and possibly older Ikemen versions, if you really need them:
https://drive.proton.me/urls/5WFX1RTQVM#8txeFDYlJxkG


Where can I download the original stage?
----------------------------------------

You can see the original full game release thread here:

https://mugenguild.com/forum/topics/hsfz-by-ehnyd-190800.html

Or if you want the direct download links (2021.04.28 1.2 Update):

https://www.4shared.com/rar/A9MJFXOTiq/HSFZ_U1-2part1.html
https://www.4shared.com/rar/LztEHChEiq/HSFZ_U1-2part2.html
https://www.4shared.com/rar/ynCTOo7_ea/HSFZ_U1-2part3.html
https://www.4shared.com/rar/lAb5Tlorea/HSFZ_U1-2part4.html

Patch fix 1: https://www.4shared.com/archive/guaL5qgKea/Patch_fix_1.html
Patch fix 2: https://www.4shared.com/archive/I01o3TTZiq/Patch_Fix_2.html



What kind of edit is this?
==========================

This edit does three main things:

1) it converts the original stage from the original game-specific
   aspect ratio, to a 16:9 wide-screen (e.g. 1080p/FHD or 4K) aspect
   for full display with 16:9 screen packs and/or wide-screen monitors;
   this makes the stage playable in generic wide-screen Mugen
   installations, just **turn off 'StageFit'**,
   
2) it contains variants of the stage that have been aspect-corrected
   for the CPS resolution and screen aspect, making the stage appear
   much more like it did on the original arcade hardware,

3) for the CPS aspect-corrected stage variants, this edit also restores
   the vertical deltas and vertical scrolling to the stage; this is
   possible, because these variants have the vertical resolution of 224p
   (like the original CPS hardware, as opposed to the Mugen standard of 240p).

Some additional changes and edits might have also been applied to the stage.
If so, they will be listed in a separate section below.


Why are there several *.def files included?
-------------------------------------------

There are several stage variants:

1) '*-wide.def', a 16:9 wide-screen variant, 240p, 1:1 square pixels,
   no vertical scrolling; this is the wide-screen equivalent of a
   traditional Mugen conversion, without aspect ratio correction,
   
2) '*-wide-cps.def' a 16:9 wide-screen variant, but CPS aspect-corrected;
   224p, 7:9 non-square pixels, with vertical scrolling and deltas;
   these variants are aspect-corrected for the resolution and
   screen/pixel shape of the original CPS arcade hardware,

3) '*-hsfz.def', a stage variant intended to be used in
   the original full-game project 'Hyper Street Fighter Zero' by Ehnyd,
   with the addition of vertical deltas and possibly other small tweaks;
   *not* to be used in a generic Mugen / Ikemen installation.


Why is there no 4:3 variant?
----------------------------

Because there was no such variant of this stage to begin with and 
the aim of this particular edit does not include making one.



Where is the music?
===================

The music is not included in this edit release. However, you can simply
download the original game that includes the music for all of the stages. 



What is this about the aspect-corrected variants?
=================================================

Traditional Mugen conversions of classic arcade stages generally
use the 320x240 resolution and assume a 4:3 screen aspect, which
results in 1:1 square pixels. Then the stage is simply converted
from the arcade version in a pixel-for-pixel manner, disregarding
any differences in both the pixel shape and the vertical resolution.

The above approach is a trade-off. The main advantage is that it allows
for a pixel-perfect display (with no scaling artifacts or blur) in
low-to-mid, 4:3 screen resolutions, such as 320x240 or 640x480, which
were the PC standard at the time that Mugen was created.

The main disadvantage of this approach is that the actual image of
the stage can be severely stretched or squashed, in comparison to the
original arcade hardware, which often uses resolutions that are not 4:3,
resulting in non-square pixels.

This problem of the lack of aspect-correction and the resulting
stretching/squashing of the stage image is especially egregious in
the case of the CPS-series arcade hardware (e.g. all of the classic
Street Fighter series games, Darkstalkers series etc), as the original
arcade screen pixels in this case have a severely non-square aspect
of 7:9, i.e. they are tall rectangles.

The included 'cps' stage variants aim to solve this problem.

You can see several examples of the aspect-correction in action here:
https://images2.imgbox.com/38/9c/GBmOx3L3_o.png


Do non-CPS arcade conversions need aspect-correction too? 
---------------------------------------------------------

It depends on the specific hardware.

At least in the case of the Neo Geo arcades (e.g. game series such as
Fatal Fury, King of Fighters, The Last Blade, Samurai Showdown etc),
the need for aspect-correction is much less pressing, as the pixels
of these machines are almost square (off by 5%). However, it would
still make sense to convert these stages to the original 224p
vertical resolution, if it makes the difference between a working
vertical scrolling/deltas and a total lack thereof.


What is the disadvantage of aspect-correction?
----------------------------------------------

The problem with aspect-correction is that displaying non-square
pixels on a low-to-mid resolution PC screen (which has square pixels),
will introduce either scaling artifacts, scaling blur or both,
depending on the applied scaling method. In other words, the image
displayed on the screen will not be pixel-perfect.

This problem is actually not even limited only to aspect-correction,
as just using a modern 16:9 wide-screen resolution, already results
in non-integer scaling of the old 4:3 PC resolutions (at least in
the vertical dimension) so some scaling artifacts will already
have been introduced in this case.

Moreover, Mugen 1.1 allows for sub-pixel positioning of sprites
and this will also introduce drawing artifacts all by itself.

The above mentioned problems can be mitigated in several ways.

Arcade emulators for example usually have a variety of options that
allow to fine-tune the scaling method and the resulting image quality,
using different filters and shaders. They usually even allow to apply
strict integer scaling, at the cost of displaying a smaller image at
the center of the screen. Such options can be used to find a sweet-spot
between blurriness and drawing/scaling artifacts. Mugen and Ikemen
however currently lack such sophisticated scaling solutions.

Nevertheless, there is also a brute-force approach to reduce scaling
artifacts, and it is to go as high as possible with the screen
resolution, preferably up to 4K for example.