# Stanford .ply file loader

from raytracer import Triangle, NormalVertex

def LoadStanfordPlyFile(rt, filename, mat, scale=(1,1,1), trans=(0,0,0)):

	if (type(scale) == float or type(scale) == int):

		scale = (scale,)*3

	vertices = []

	normals = []

	vertex_face_num = []

	fp = file(filename)

	# read header

	tokens = (0,)

	while (tokens[0] != "end_header"):

		tokens = fp.readline().split()

		if (tokens[0] == "element"):

			if (tokens[1] == "vertex"):

				vertex_num = int(tokens[2])

			if (tokens[1] == "face"):

				face_num = int(tokens[2])

	# read vertices

	num = vertex_num

	while (num):

		tokens = fp.readline().split()

		v = [float(x) for x in tokens[0:3]]

		v[0] = scale[0]*v[0] + trans[0]

		v[1] = scale[1]*v[1] + trans[1]

		v[2] = scale[2]*v[2] + trans[2]

		vertices.append(NormalVertex(tuple(v)))

		normals.append([0.,0.,0.])

		vertex_face_num.append(0)

		num -= 1

	# read faces

	while (face_num):

		tokens = fp.readline().split()

		if (tokens[0] != "3"):

			print "ply warning: faces of %d vertices not supported" % tokens[0]

		v = [vertices[int(x)] for x in tokens[1:4]]

		face = Triangle(v[0], v[2], v[1], mat)

		n = face.getNormal()

		for x in tokens[1:4]:

			for i in range(3):

				normals[int(x)][i] += n[i]

			vertex_face_num[int(x)] += 1

		rt.addShape(face)

		face_num -= 1

	# interpolate normals at vertices

	num = 0

	while (num < vertex_num):

		if (vertex_face_num[num] > 0):

			for i in range(3):

				normals[num][i] /= vertex_face_num[num]

		vertices[num].setNormal(tuple(normals[num]))

		num += 1