stlgen.py

def vmul(a, b):
	return (a[0] * b, a[1] * b, a[2] * b)

def vmin(*x):
	cur = x[0]
	for v in x[1:]:
		cur = min(v[0], cur[0]), min(v[1], cur[1]), min(v[2], cur[2])
	return cur

def vmax(*x):
	cur = x[0]
	for v in x[1:]:
		cur = max(v[0], cur[0]), max(v[1], cur[1]), max(v[2], cur[2])
	return cur

def aabb(tmin, tmax):
	box(
		(tmin[0], tmin[1], tmin[2]), 
		(tmax[0], tmin[1], tmin[2]), 
		(tmax[0], tmax[1], tmin[2]), 
		(tmin[0], tmax[1], tmin[2]), 
		(tmin[0], tmin[1], tmax[2]), 
		(tmax[0], tmin[1], tmax[2]), 
		(tmax[0], tmax[1], tmax[2]), 
		(tmin[0], tmax[1], tmax[2])
	)

# a b
# d c
# | |
# e f
# h g
def box(a, b, c, d, e, f, g, h):
	quad(a, b, c, d) # Top
	quad(a, d, h, e) # Left
	quad(a, b, f, e) # Back
	quad(b, c, g, f) # Right
	quad(d, c, g, h) # Front
	quad(e, f, g, h) # Bottom

def quad(a, b, c, d):
	tri(a, b, c)
	tri(c, d, a)

def tri(a, b, c):
	print 'facet normal 0 0 0'
	print 'outer loop'
	point(a)
	point(b)
	point(c)
	print 'endloop'
	print 'endfacet'

def withbox(func):
	def sub(*x):
		aabb(vmin(*x), vmax(*x))
		return func(*x)
	return sub

def point(x):
	print 'vertex %f %f %f' % x

def stl(func):
	print 'solid obj'
	func()
	print 'endsolid obj'

@stl
def test():
	withbox(tri)((-2501.938, -1.40625, 180.5312), (-2501.469, 65.25, 168.0625), (-2501.938, 65.25, 168.0312))
	aabb((-2803.812, -2693.156, -16179.89), (-43.29688, 36.5625, 417.9531))