Performance Issues with Rendering Primitives

[BjornHallstedt]

Hi, I am trying to render a lot of procedurally animated spiders and insects in my game which are made up of circles and thick lines. Using a profiler, I discovered that most of my computer's resources are spent on the primitive rendering functions. I start getting serious frame drops when rendering about 60+ circles every frame.

Is it normal for primitive rendering to take up so many resources and should I find a different way to render my entities? I already checked the other issues on this page and I couldn't find anything else explaining the performance problem

[MarkelZ]

Hi @CabbageMan420! Primitive rendering is a relatively new feature. I believe render_triangles and render_lines are fast, but the other functions are unoptimized. To draw circles, you could load the texture of a circle and draw it normally with engine.render().

I provided a script in another issue that renders 1000 circles in real time with this exact method: #2 (comment)

I'll eventually optimize primitive rendering of course.

[BjornHallstedt]

Thanks for the quick reply! I actually did some testing where I replaced the circles with rectangles or a texture loaded from a png. I believe the rendering ran about 2 times faster in both cases which was still too slow for me though. I then tried drawing rectangles onto a pygame surface (pygame.draw.rect()) which was about 100 times faster I think. But then transforming the surface into a texture with your function once per frame was about as costly as originally rendering those 100 circles directly.

The solution I found for now was to use DaFluffyPotato's framework (from this video : https://www.youtube.com/watch?v=LFbePt8i0DI) He also draws everything onto a pygame surface and then transforms it into a texture before passing it into the shader. His surface to texture method (timestamp: 35:00) runs much faster though. Unfortunately, I am a noob when it comes to graphics programming so i have no clue why the performance differs so much, but maybe it could be interesting for you to look at.

I really appreciate this library. It makes shaders so much more accessible to people like me.

PS: I can get you more details on my performance tests if that is at all helpful.

[MarkelZ]

@CabbageMan420 thank you so much for the detailed message :) DaFluffyPotato's framework is a bit limited compared to this engine since it only lets you apply shaders as a post-processing effect. I'll definitely try his surface to texture method when I have more time to thoroughly benchmark it, I'm excited, hope it's indeed much faster. I'll also work on speeding up primitive rendering and will send an update here once I get nice results. I'm very glad you like this library!

[sevi78]

i tested the fluffy potatos surface to texture method, its about 20% faster, BUT: it also did not display the colors correctly, i might made something wrong.
But anyway: this library is absolutely great! i now run hundreds of objects instead of 40 with blitting onto screen (of course a proper LOD is very important too) It is very well structured, me as a glsl noob, can now use shaders, and its a good point to start with this library for me to get into the glsl stuff. Thank you very much !

i draw 250 primitives with 60 FPS, these are only pixels:

engine.render_lines(engine.screen, colors.frame_color, [(obj.rect.centerx, obj.rect.centery), (obj.rect.centerx+1,obj.rect.centery + 1)])

i wondering, how i could even speed that up ?