Adaptation of the original DOOM based on this fork that adds framebuffer support and adjusted by implementing my Quad Cortex stomp tools into the source code to get full control over the game using the stomps.
cd qcdoom
make CROSS_COMPILE=<path-to-cross-compiler>/arm-linux-gnueabi-
To run DOOM you will need a .wad file. You can get a working file from here. From what I understand there are loads of these that people created on their own and shared. You could also use one of those.
Once you have this file, copy the built qcdoom executable and doom1.wad (or whatever yours is called) file somewhere on the Quad Cortex. I personally put it in /media/doom since the /media folder is persistent over updates.
Then first, for the best experience, go to the top right corner on the Quad Cortex, open the menu, and select New Neural Capture. The reason for this is that this view does't render any UI, but rather just displays .png images like a slide show (yes this is exactly how they do it). This means the framebuffer does not get any updates, allowing DOOM to render over all UI.
Now you can launch DOOM by running:
./qcdoom -iwad doom1.wad
You should be able to start playing now!
To quit, you'll have to quit manually through your ssh shell. You'll see that the screen freezes and still displays DOOM. This is normal. That's because the framebuffer is not receiving any updates at this point. You can just press the exit button and all will be back normal.
- A: Turn left
- B: Move forward
- C: Move right
- D: Fire
- E: Move left
- F: Move back
- G: Move right
- H: Use
- Preset down: Enter
- Tempo: Backspace (Open menu)
Here it is, at long last. The DOOM source code is released for your non-profit use. You still need real DOOM data to work with this code. If you don't actually own a real copy of one of the DOOMs, you should still be able to find them at software stores.
Many thanks to Bernd Kreimeier for taking the time to clean up the project and make sure that it actually works. Projects tends to rot if you leave it alone for a few years, and it takes effort for someone to deal with it again.
The bad news: this code only compiles and runs on linux. We couldn't release the dos code because of a copyrighted sound library we used (wow, was that a mistake -- I write my own sound code now), and I honestly don't even know what happened to the port that microsoft did to windows.
Still, the code is quite portable, and it should be straightforward to bring it up on just about any platform.
I wrote this code a long, long time ago, and there are plenty of things that seem downright silly in retrospect (using polar coordinates for clipping comes to mind), but overall it should still be a usefull base to experiment and build on.
The basic rendering concept -- horizontal and vertical lines of constant Z with fixed light shading per band was dead-on, but the implementation could be improved dramatically from the original code if it were revisited. The way the rendering proceded from walls to floors to sprites could be collapsed into a single front-to-back walk of the bsp tree to collect information, then draw all the contents of a subsector on the way back up the tree. It requires treating floors and ceilings as polygons, rather than just the gaps between walls, and it requires clipping sprite billboards into subsector fragments, but it would be The Right Thing.
The movement and line of sight checking against the lines is one of the bigger misses that I look back on. It is messy code that had some failure cases, and there was a vastly simpler (and faster) solution sitting in front of my face. I used the BSP tree for rendering things, but I didn't realize at the time that it could also be used for environment testing. Replacing the line of sight test with a bsp line clip would be pretty easy. Sweeping volumes for movement gets a bit tougher, and touches on many of the challenges faced in quake / quake2 with edge bevels on polyhedrons.
Some project ideas:
Port it to your favorite operating system.
Add some rendering features -- transparency, look up / down, slopes, etc.
Add some game features -- weapons, jumping, ducking, flying, etc.
Create a packet server based internet game.
Create a client / server based internet game.
Do a 3D accelerated version. On modern hardware (fast pentium + 3DFX) you probably wouldn't even need to be clever -- you could just draw the entire level and get reasonable speed. With a touch of effort, it should easily lock at 60 fps (well, there are some issues with DOOM's 35 hz timebase...). The biggest issues would probably be the non-power of two texture sizes and the walls composed of multiple textures.
I don't have a real good guess at how many people are going to be playing with this, but if significant projects are undertaken, it would be cool to see a level of community cooperation. I know that most early projects are going to be rough hacks done in isolation, but I would be very pleased to see a coordinated 'net release of an improved, backwards compatable version of DOOM on multiple platforms next year.
Have fun.
John Carmack 12-23-97