CATSFC/README.md

CATSFC version 1.36, 2013-06-16

A Super Nintendo emulator for the Supercard DSTWO.

Based on:
* Snes9x 1.43, by the Snes9x team (with research by the ZSNES folks, anomie,
  zsKnight, etc.)
* NDSSFC 1.06, by the Supercard team (porting to the MIPS processor)
* BAGSFC, by BassAceGold (improving over NDSSFC)
* CATSFC, by ShadauxCat and Nebuleon (improving over BAGSFC)

Contains:
* Language files written by the GBAtemp community: Dutch by Aeter, French
  by Nebuleon, German by SignZ, Portuguese (Brazilian) by Diego Liberal,
  Spanish by Boriar
* Language files written by GitHub users: Italian by alexinfurs

# Installing

(If you got the source code and want to compile it, see the `Compiling` section
 at the end of the file.)

To install the plugin to your storage card, copy `catsfc.plg`, `catsfc.ini` and
`catsfc.bmp` from the release archive to the card's `_dstwoplug` directory.
Then, copy the `CATSFC` subdirectory to the root of the card.

# Cheats

The format accepted by the "Load a cheat file" function is equivalent to the
old format used in Mightymo's BSNES Cheat Code Pack.

1. Download the BSNES Cheat Code Pack at
   <http://www.mightymo.net/downloads.html>. It will be a zip archive.
2. Open the zip file, with WinZip, WinRAR or the built-in zip extension in
   the operating system on your computer.
3. In the zip file, open the folder called *BSNES Cheat Code Pack*, then
   the one called *BSNES v0.51-0.74 Cheat Code Pack*.
4. Open your storage card's CATSFC folder, then descend into gamecht.
5. Drag the cheat code files from the zip archive to the card's gamecht
   folder.

To add cheats to the menu in a game, first load the game, then use the Cheats
menu's "Load a cheat file" option.

# Frame skipping

In the Video & audio menu, the **Frame skipping** option allows you to select
a number of frames to skip between rendered frames.

As of version 1.29, the default is - (Keep up with the game). For most games,
this setting keeps video and audio fluid, without the sudden slowdowns of
previous versions when many sprites fill the screen. The DS controller buttons
are also responsive at this setting.

For some games, you may need to adjust frame skipping.
* If a game runs at 5 frames per second, like *Yoshi's Island*,
  *Kirby Super Star*, *Star Fox* or *Super Mario RPG*, setting frame skipping
  to 1 will allow you to jump, move or shoot at the right times.
* If you want to show more frames per second in a game that already shows 20,
  setting frame skipping to 1 or 0 will cause more frames to appear,
  but your DS button input may stop responding for 2 entire seconds every so
  often. The audio may also be stretched. (This is similar to NDSGBA.)
* Setting this to 10 will skip 10 frames and render one, but this will
  severely desynchronise the audio. You will also find yourself unable to
  perform actions during the correct frame with the DS buttons. It is advised
  to set frame skipping to the lowest value with which you can play a game.

# Fluidity

Fluidity is an option you can find under the Video & audio menu in a game.
By default, video fluidity is preferred over audio fluidity in games.

* Preferring video fluidity makes audio skip certain notes, up to
  23 milliseconds, in order to render more video. In many games, this
  difference is not audible, but you may hear certain audio glitches if a game
  depends highly on timing for its audio.
  Use this option if you want to play games that require fluid imagery more
  than precise audio emulation. You can also use this option when watching game
  introductions, endings and cutscenes.
* Preferring audio fluidity makes video skip certain images, up to
  46 milliseconds, in order to render audio closer to 32,000 times per second.
  Use this option if you want to play games mainly for their soundtracks, or in
  a game's sound test mode. You can also use this option to experiment with the
  green berry glitch in Super Mario World that makes TIME go over and under 100
  units constantly and makes the music play very fast.

# Hotkeys

You can set buttons to press to perform certain actions. For each action,
there is a *global hotkey* and a *game-specific override hotkey*. You might,
for example, want to have the R button bound to Temporary fast-forward, but
a specific game uses R for something important. In that case, you can set the
global hotkey to R and make an override with X for that game.

Hotkeys are sent to the current game as well as to their corresponding action.
The criterion for a hotkey is met when **at least** all of its buttons are
held. Additional keys are sent to the game and can trigger another hotkey.
For example, setting a hotkey to L and another to R+X, then pressing L+R+X+Y
will trigger both and send L+R+X+Y to the game.

Available actions are:
* Go to main menu. In addition to tapping the Touch Screen to return to
  the main menu, you can set a hotkey to do the same.
* Temporary fast-forward. While this hotkey is held, the fast-forward option
  will be forced on.
* Toggle sound. Each time this hotkey is held, the sound will be disabled if
  it's currently enabled, and vice-versa.
* Save state #1. Each time this hotkey is held, saved state #1 will be written,
  without confirmation if it exists.
* Load state #1. Each time this hotkey is held, saved state #1 will be loaded.
* Toggle full-screen. Each time this hotkey is held:
  * If the current display mode *is* a full-screen mode, then the display mode
    is set to 3 (Middle, square pixels) and the top and bottom will be cut off.
  * If the current display mode *is not* a full-screen mode, then the display
    mode is set to 4 (Entire screen, smoothed).

# The font

The font used by CATSFC is similar to the Pictochat font. To modify it,
see `source/font/README.txt`.

# Translations

Translations for CATSFC may be submitted to the author(s) under many forms,
one of which is the Github pull request. To complete a translation, you will
need to do the following:

* Open `CATSFC/system/language.msg`.
* Copy what's between `STARTENGLISH` and `ENDENGLISH` and paste it at the end
  of the file.
* Change the tags. For example, if you want to translate to Japanese, the tags
  will become `STARTJAPANESE` and `ENDJAPANESE`.
* Translate each of the messages, using the lines starting with `#MSG_` as a
  guide to the context in which the messages will be used.

If you are not comfortable editing C code, or cannot compile CATSFC after your
changes, you may instead test your translation in the English block and submit
it. That allows you to look for message length issues and to align the option
names and values to your liking with spaces.

If you wish to also hook your language into the user interface, you will need
to do the following:

* Edit `source/nds/message.h`. Find `enum LANGUAGE` and add the name of your
  language there. For the example of Japanese, you would add this at the end of
  the list:
  ```
	,
	JAPANESE
  ```
* Still in `source/nds/message.h`, just below `enum LANGUAGE`, you will find
  `extern char* lang[` *some number* `]`. Add 1 to that number.
* Edit `source/nds/gui.c`. Find `char *lang[` *some number* `] =`.
  Add the name of your language, in the language itself. For the example of
  Japanese, you would add this at the end of the list:
  ```
	,
	"日本語"
  ```
* Still in `source/nds/gui.c`, find `char* language_options[]`, which is below
  the language names. Add an entry similar to the others, with the last number
  plus 1. For example, if the last entry is `, (char *) &lang[7]`, yours would
  be `, (char *) &lang[8]`.
* Still in `source/nds/gui.c`, find `case CHINESE_SIMPLIFIED`. Copy the lines
  starting at the `case` and ending with `break`, inclusively. Paste them
  before the `}`. Change the language name and tags. For the example of
  Japanese, you would use:
  ```
	case JAPANESE:
		strcpy(start, "STARTJAPANESE");
		strcpy(end, "ENDJAPANESE");
		break;
  ```

Compile again, copy the plugin and your new `language.msg` to your card
under `CATSFC/system`, and you can now select your new language in CATSFC!

# Compiling

Compiling CATSFC is best done on Linux. Make sure you have access to a Linux
system to perform these steps.

## The DS2 SDK
To compile CATSFC, you need to have the Supercard team's DS2 SDK.
The Makefile expects it at `/opt/ds2sdk`, but you can move it anywhere,
provided that you update the Makefile's `DS2SDKPATH` variable to point to it.

For best results, download version 0.13 of the DS2 SDK, which will have the
MIPS compiler (`gcc`), extract it to `/opt/ds2sdk`, follow the instructions,
then download version 1.2 of the DS2 SDK and extract its files into
`opt/ds2sdk`, overwriting version 0.13.

Additionally, you will need to add the updated `zlib`, DMA
(Direct Memory Access) and filesystem access routines provided by BassAceGold
and recompile `libds2a.a`. To do this:

> sudo rm -r /opt/ds2sdk/libsrc/{console,core,fs,key,zlib,Makefile} /opt/ds2sdk/include
> sudo cp -r sdk-modifications/{libsrc,include} /opt/ds2sdk
> sudo chmod -R 600 /opt/ds2sdk/{libsrc,include}
> sudo chmod -R a+rX /opt/ds2sdk/{libsrc,include}
> cd /opt/ds2sdk/libsrc
> sudo rm libds2a.a ../lib/libds2a.a
> sudo make

## The MIPS compiler (`gcc`)
You also need the MIPS compiler from the DS2 SDK.
The Makefile expects it at `/opt/mipsel-4.1.2-nopic`, but you can move it
anywhere, provided that you update the Makefile's `CROSS` variable to point to
it.

## Making the plugin
To make the plugin, `catsfc.plg`, use the `cd` command to change to the
directory containing your copy of the CATSFC source, then type
`make clean; make`. `catsfc.plg` should appear in the same directory.