m68k-3d-penger

Watch this tutorial by Max:

One Formula That Demystifies 3D Graphics https://www.youtube.com/watch?v=qjWkNZ0SXfo

Based on: https://github.com/tsoding/formula

Penger Model: https://github.com/Max-Kawula/penger-obj

Tested with AsmPRO 1.22 on M68030 no FPU

https://aminet.net/package/dev/asm/ASMPro1.22

Quick start

From amiga shell:

assign asmpro: Work:MyAsmProFolder
asmpro:
AsmPRO

From Menu: Open ami3d.s source

RightAmiga+Shift+A (assembly)

type: j (to jump at start)

enjoy.

penger_rotate.mp4

For js example from formula you can do basic conversion in python:

#!/usr/bin/env python3
import struct

cube_verts = [
    {"x":  0.25, "y":  0.25, "z":  0.25},
    {"x": -0.25, "y":  0.25, "z":  0.25},
    {"x": -0.25, "y": -0.25, "z":  0.25},
    {"x":  0.25, "y": -0.25, "z":  0.25},
    {"x":  0.25, "y":  0.25, "z": -0.25},
    {"x": -0.25, "y":  0.25, "z": -0.25},
    {"x": -0.25, "y": -0.25, "z": -0.25},
    {"x":  0.25, "y": -0.25, "z": -0.25},
]

cube_faces = [
    [0, 1, 2, 3],
    [4, 5, 6, 7],
    [0, 4],
    [1, 5],
    [2, 6],
    [3, 7],
]

def faces_to_edges(faces):
    edges = set()
    for face in faces:
        for i in range(len(face)):
            a, b = face[i], face[(i+1) % len(face)]
            edge = (min(a,b), max(a,b))
            edges.add(edge)
    return sorted(edges)

def to_fixed88(val):    
    fixed = int(val * 256)
    return max(-32768, min(32767, fixed))

def write_binary(verts, faces, outfile):    
    edges = faces_to_edges(faces)

    with open(outfile, 'wb') as f:        
        f.write(struct.pack('>HH', len(verts), len(edges)))    
        for v in verts:
            f.write(struct.pack('>hhh',
                to_fixed88(v["x"]),
                to_fixed88(v["y"]),
                to_fixed88(v["z"])))        
        for a, b in edges:
            f.write(struct.pack('>HH', a, b))

    print(f"wrote {outfile}: {len(verts)} verts, {len(edges)} edges")

write_binary(cube_verts, cube_faces, r'cube.dat')
penger_src = open(r'penger.js').read()
penger_src = '\n'.join(l for l in penger_src.split('\n') if not l.strip().startswith('//'))
penger_src = penger_src.replace('const ', '')
penger_src = penger_src.replace('x:', '"x":').replace('y:', '"y":').replace('z:', '"z":')
exec(penger_src)
write_binary(vs, fs, r'penger.dat')