Simple raycaster in Go using SDL.
There's plenty of comments in the code. Check it out if you are interested and just email me if you have any questions.
The textures in the images directory are from Wolfenstein 3D and all copyrights belong to ID Software.
Through trial and error mostly i got the Raycaster running from an average of 10fps to an average of 48fps.
As a first pass i went through all the instances of images that i had and made sure everything was in the same format i.e. NRGBA. Then i went through and i replaced all the calls to .Set with .SetNRGBA. Those two changes alone bumped the fps up to 20!
It seems that there are a lot of interface checks or type assertions i suppose on the .Set method and using the .SetNRGBA method is A LOT faster. To make sure that was an issue i simply changed a single call from .SetNRGBA to just .Set and the fps dropped by 7fps.
I also tried using the draw.Image interface instead but that didn't do anything.
Eventually i switched to having a fixed sized uint32 array ([WindowWidth*WindowHeight]uint32) which i converted to a []byte slice every time i updated the texture in SDL. Funny enough that gave me another 10fps and got the total average up to 30fps!
As a last pass i just implemented everything using a []byte slice and added some convenience methods. In fact it actually resembles the image.NRGBA struct. That brought up the average FPS to 40 i believe.
And the last optimization i made was removing the call to .Clear(). I can't tell a difference. To be honest although all the tutorials say you should clear out the buffer every time, in my scenario the entire buffer is re-rendered every time so i skipped it :). Now it went up to an average of 50fps. I'll stop there. Let me know if there are more things i could do or if you think there is something wrong with what i am doing.
I am very curious as to why the image.NRGBA was so much slower. I actually went back and just used an image.NRGBA again just to make sure i wasn't doing anything wrong and the FPS dropped again.
- Load levels from external file
- Remove extra global VARS
- Determine texture size dynamically or set as a constant
- Add textures for floor and ceiling
- Add .At method on Gamemap to simplify it rather than going through the Level
- Clean up FPS calculation code
- Don't use the global gameMap variable in Ray.cast
- Use static sdl.Renderer instead of passing it everywhere. Create Game struct to hold all the statics
- Optimize the code. Figure out a way to make it run faster. It's very slow...
- The raycasting algorithm can be improved and simplified.