Category: Programming

Today I fixed the cube texture warping: The perspective correction uses interpolated Z values to do a sort of perspective divide in the texture space. I don’t entirely understand how it works yet, so I’ll add a note here if this is all wrong.Here’s what I have so far: The problem is that the texture…

Barycentric coordinates: they’re great for squishing squares into triangles. Here’s a wobbly textured cube: An overview of how it works The goal is to draw a triangle on the screen with pixels from a texture. I have three vertices and a texture in memory. The vertices describe two triangles: a triangle in the screen with…

Today I worked on adding texture mapping to the renderer so that it can display textured objects, which took about two and a half hours. It isn’t done yet, though, so here’s the classic missing texture color using the new code: Right now the code loops through each pixel of each screen space triangle and…

Today I spent about two and a half hours implementing the perspective matrix and better flat shading. Now the renderer supports different aspect ratios and fields of view: At one point I messed up the color shading code and this happened (warning, flashing colors): Also, the site now has an icon and dark mode! I…

More matrix math today. I spent about an hour and a half implementing matrix rotation and scaling: Perspective matrix is up next, I’ll see you tomorrow!

Matrix math. I added types and functions for matrix scaling and translation, which took about two hours. I’m thinking I might not use matrices in the PICO-8 port because they seem to add a bunch of overhead. I guess I’ll see. An update on Vim: sometimes I find myself pressing “j” to go down in…

Today I got triangle fill and basic z-depth order working! It took about four hours (o.O), but it looks really cool: I also fixed a bug with key inputs being delayed. I needed to get all the SDL events each frame instead of just the first one. It’s really nice to not have to wait…

I spent about two and a half hours today on the course (more vector math) and I got back-face culling working! The next part of the course is filling the triangles, which is something I’ve been wondering how to do for a while. I can’t wait to see what I can make with the engine…

Today I worked on vector math to eventually implement back-face culling. I spent about an hour on that and then I ported the renderer so far to PICO-8: And it only took about 30 minutes! Working in C really makes me appreciate how much PICO-8 does behind the scenes. PICO-8 can’t load files directly, so…

Today I spent about two and a half hours on the course and I got my renderer loading OBJ files! So I had to render the Blender Suzanne monkey: I’m pretty sure my method of parsing OBJ files is awful, so I’ll probably rewrite it at some point. Here’s the code snippet: I’ll see you…

I spent about four hours on the course today and I made a new cube: Things I worked on: Fixing the game loop to run at a constant speed Adding types for working with triangles DDA line drawing Maybe it doesn’t look as cool as the last one, but this one uses a system of…

Finally some 3D today! But first, Vim. I spent about half an hour just messing around in Vim and after that I used it for the rest of the day. Vim is so cool. It has shortcuts and commands for everything. A few times I found myself guessing commands correctly. For example, “$” means “move…

About an hour and a half learning C and 3D graphics today. I’m really enjoying the course so far. Not a whole lot to report on, I just refactored the code and wrote functions for drawing rectangles, grids, and single pixels. Note: I’ve got to learn vim. The course instructor is zooming in vim. Makes…

Recently I’ve been playing some 3D PICO-8 games and I’m intrigued as to how the game creators squished 3D graphics into PICO-8’s limitations. I have experience with Blender, so I’m familiar with the high level concepts of 3D graphics, but I don’t understand how they work at a low level. So… I got a course…