Jo Engine: 2D game engine for the Sega Saturn

[tryphon]

Announced for 2020. Not effective until 2042

[Johannes Fetz]

Hey!

I made a new version of the Jo Engine: http://www.jo-engine.org/download/

You can now create map (of tiles) programmatically and I also made some performance upgrade

Next step: Per-pixel collision

I have a couple things to do on the engine for the community and I'll switch on my Sonic game

It's important to me to share my work in order to let other homebrewer made their own game too.

Btw, now I use Twitter to communicate about the development of JoEngine : https://twitter.com/johannes_fetz

[Sik]

How do you plan to implement per-pixel collision and it not be horribly slow?

Makes me wonder what DIV did... Full blown per-pixel collision, taking into account arbitrary scaling and rotation, without any hardware acceleration and that works happily for things off-screen and regardless of size (except maybe for 32-bit overflow). That's like the holy grail of per-pixel collision o.o; How far do you think you can get with this?

[Johannes Fetz]

Hi Sik,

In my Sonic demo, I already use per-pixel collision for the ground and it's "fast" (you can see it here https://youtu.be/gV-7cA9_h-4?t=30).

Now, I try to add this feature in a generic and simple way on the Jo Engine.

The algorithm is simple:

1) Use simple and fast Hitbox detection to find "potential collision"
2) Per-pixel collision (scaling will be supported but not rotating (too slow))

Simple but efficient
Of course, you have to limited the usage only if it's necessary

[Game Taff]

I wanna look into this sometime. I mean, where do I even begin? Do I need to use some editor to modify the code and the a compiler? what does it compile in and how can I then turn it into an ISO to be burnt or run on an emulator? Would love to mess about and make something super basic on my favourite console of all time.

[Johannes Fetz]

Hi Game Taff,

Trust me, it's very simple

You just have to follow the tutorial on my website : http://www.jo-engine.org/tutorial/

When you install The Jo Engine (~120 MB uncompressed), you have everything, to build, create iso and test your homebrew.

[Johannes Fetz]

Hi,

I've published a new update with some math tools optimized for the Sega Saturn and a new function to get tick count.

Btw, I'm happy to tell you that I've been contacted by multiple homebrewer recently

I think we will see some Sega Saturn homebrews in few weeks

[Stef]

Great work Johannes ! I'm following your (fast) progresses and so far it's really impressive I'm certain it will bring many new developers to the Saturn homebrew community !
Don't know if you are aware of it, but i'm doing something similar but for the Megadrive with SGDK.
Can be a source of inspiration if you want (i speak about the API design as the hardware is too much different by itself)

[Johannes Fetz]

Great work Johannes ! I'm following your (fast) progresses and so far it's really impressive I'm certain it will bring many new developers to the Saturn homebrew community !
Don't know if you are aware of it, but i'm doing something similar but for the Megadrive with SGDK.
Can be a source of inspiration if you want (i speak about the API design as the hardware is too much different by itself)

Thanks Stef !

It's a pleasure to meet someone who is pursuing the same goal.

I'll take a look on your framework this weekend

[Sik]

Stupid thought: ever wondered about having 3D support? (even if as a separate or complement library)

[retrospiel]

This is pretty darn close to what I thought a 2d Sonic on Saturn would have looked like. Kind of sad we had to wait 20+ years to finally see its realization.

[Johannes Fetz]

Stupid thought: ever wondered about having 3D support? (even if as a separate or complement library)

It's on my todo list, but I want to proceed step by step and the 3d part is much more simple to abstract. It's just an OpenGL clone

[Johannes Fetz]

This is pretty darn close to what I thought a 2d Sonic on Saturn would have looked like. Kind of sad we had to wait 20+ years to finally see its realization.

Yes, it's true, but better late than never

[Johannes Fetz]

Hi,

I have too much requests for 3D support so I will start to implement it in 2 weeks

[Manveru]

Congratulations! great project and fast progress. Someday when Mega Drive gives me a break, i will give it a try.