convert_model.py

#!/usr/bin/python3

# Title:		Create C model data from an OBJ file exported from Blender
# Author:		Dean Belfield
# Created:		03/09/2025
# Last Updated:	04/09/2025
#
# Modinfo:
# 04/09/2025:	Removed debug code, fixed bugs, added scale arg

import sys
import os
from datetime import datetime
from pathlib import Path

# The Next palette lookup
# https://wiki.specnext.dev/File:256-palette-2.png
#
palette = {
	"Black": "0x00",
	"Blue": "0x07",
	"Red": "0xE0",
	"Magenta": "0xA3",
	"Green": "0x5C",
	"Cyan": "0x1F",
	"Yellow": "0xFC",
	"White": "0xFF",
	"Grey": "0x6E",
	"Light_Grey": "0x6D",
	"Dark_Grey": "0X6C",
}

# Open the file for reading
#
name = sys.argv[1]								# Get the filename
try:
	scale = float(sys.argv[2])
except:
	scale = 100
full_path = os.path.expanduser(name)			# Expand the full path to the file and
file = open(full_path, "r")						# Open it up as a text file

file_stdout = sys.stdout						# Store the current stdout file handle for redirect output
sys.stdout = open(Path(full_path).stem + ".h", "w")

now = datetime.now()

line = ""										# Storage for line
modelName = ""									# The model name
vertices = []									# List of vertices
faces = []										# List of faces
colour = "0x12"									# Default colour palette entry on Next

# Iterate through the file
# Use print to output to file
#
while True:
	line = file.readline()						# Read 1 byte into the buffer data
	if len(line) == 0:
		break
	
	code = line[:line.find(" ")]				# Find the code
	data = line[line.find(" ")+1:].rstrip('\n').split(" ")

	if code == "o":
		modelName = data[0]
	elif code == "v":							# Vertex data	
		if len(data) != 3:
			sys.exit("Invalid vertex count")
		output = []
		for item in data:
			value = round(float(item)*scale/100)
			if value < -128 or value > 127:
				sys.exit("Coordinate data out of range")
			output.append(str(value))
		vertices.append(f"    POINT8( {', '.join(output)} ),")
	elif code == "vn:":							# Normal data
		pass
	elif code == "usemtl":						# Blender material name
		colour = palette[data[0]]
	elif code == "f":							# Face data
		if len(data) != 3:
			sys.exit("Invalid face count")
		output = []
		for item in data:
			value = item.split("//")
			output.append(str(int(value[0])-1))	# Blender indexes vertices from 1, not 0
		output.append(colour)					# Colour of face
		faces.append(f"    {{ {', '.join(output)} }},")
	elif code == "l":							# Line data
		pass
	else:
		pass

print(f"// Generated automatically by convert_model.py on {now.strftime('%m/%d/%Y, %H:%M:%S')}")
print(f"//")
print(f"// Model: {name}")
print(f"// Scale: {scale}")
print(f"//")
print(f"Model_3D {modelName}_m = {{")
print(f"    {len(vertices)},");
print(f"    {len(faces)},");
print(f"    &{modelName}_p,");
print(f"    &{modelName}_v,");
print("};")
print(f"Point8_3D {modelName}_p[] = {{")
print("\n".join(vertices))
print("};")
print(f"Vertice_3D {modelName}_v[] = {{")
print("\n".join(faces))
print("};")

file.close()									# We've done so close the files

sys.stdout.close()								# Close and restore stdout
sys.stdout = file_stdout