Sonic Engine

Instructions

Welp... I'm starting over. This engine doesn't work quite well enough to my tastes, and it'll be easier to start over and do it right then to spend weeks troubleshooting bugs. So, I'm starting over and I'm going to follow the docs I've been working with a little more closely (check the credits for the Sonic Retro website, I've been borrowing ideas from there). I'll be leaving this up for learning/documentation purposes, but otherwise this engine is outdated and hopefully you'll see a new one soon. Welcome to the sonic engine! It's a from the ground up engine that I've been working on for a couple weeks now. It is still in active development though so definitely check back later if you are interested in seeing changes. Scroll down for controls and dev information. Controls are WASD to move, crouch, and look down or up, j to jump or spindash while crouching, and r to reset if you get stuck or fall off the stage. FOR DEVELOPERS, click see inside, I tried to comment this project as well as I could and so there are lots of explanations inside. You might also find additional info in the notes and credits. If you just want to edit levels though, just go to the collision and overlay sprites and you can draw collision and visuals in the vector editor. A couple helpful tips: If you are editing the code, I tried to leave lots of comments and point out variables that can be easily edited (jump height, acceleration, deceleration, etc.). If you think any sections need commenting please let me know. Collision is made up of dots and you can visually see where collision is taking place on screen, I put in a stamp block at certain points in the code so you can see the slope detection points, the player position point, and the wall sensor points. They are a little hard to see though because they are very tiny, only 2x2 pixels in size. Try resizing them if you need to see better, just don't make it too large (probably around 200 is best) because it will affect collision detection. In addition, please note that collision with the ground does not use a traditional hitbox, instead it tests single points for collision to check for slopes and so on. Use this website for information on how sonic physics work: https://info.sonicretro.org/Sonic_Physics_Guide I pulled a lot of information from here and it could be helpful in explaining some of what's going on. Finally, feel free to ask any questions or report issues found, although I can't guaruntee I'm able to fix anything because I'm still just a guy and might just not know the answer. It's worth asking anyways though, I'm always happy to help out. Known Bugs: - sonic sometimes gets stuck in a rolling state, not allowing him to jump and usually forcing the camera to look down. - very sharp corners don't work very well. I don't think I'm going to fix this either, that is just a limitation with the engine and the extra sharp corners usually aren't necessary in level design anyways. I might want to add squishing though. - Occasionally sonic will get stuck in the ground for some reason, and then teleport somewhere else on screen. Happens most often on straight, slanted surfaces (straight lines that are at a decently steep incline) - Sonic will occasionally not go up curves, instead stopping in his tracks. Usually happens with very small curves, since instead of thinking it is a curve, it will thinks its a corner because it is too tight. Probably won't be fixing this either, if this happens in one of your levels make the curve a little bit larger. - a couple of visual bugs with walls. Not sure how to fix these. - jumping into a corner sometimes gives the player a significant amount of speed, very rare though. Definitely want to focus on bugs that are either game breaking or could softlock, because those will be most frustrating for developers and players. Future additions: - does not yet have level overlays - no layer 1/2 switching (used for loops and intersecting pathways) - squishing - badniks - hazards, spikes, etc. - death for when you fall off the stage - peel out maybe? - extended idle animations (just need to draw them) - more level design would be nice. - backgrounds - zoom - level scale (one screen of level design would take up more space, but might look more blurry/pixelated because of scaling issues) Lots of stuff that I would still like to do. As usual, any help or suggestions would be greatly appreciated. Have fun!