# module 'block' imported by twoview demo.

from gl import n3f, bgnpolygon, varray, endpolygon, lmbind
from GL import MATERIAL

# Draw a single 2x2x2 block with its center at (0, 0, 0)
# Arguments are the material indices (0 = don't call lmbind)
#
def block(m_front, m_back, m_left, m_right, m_top, m_bottom):
	#
	# Distances defining the sides
	#
	x_left = -1.0
	x_right = 1.0
	y_top = 1.0
	y_bottom = -1.0
	z_front = 1.0
	z_back = -1.0
	#
	# Top surface points: A, B, C, D
	#
	A = x_right, y_top, z_front
	B = x_right, y_top, z_back
	C = x_left, y_top, z_back
	D = x_left, y_top, z_front
	#
	# Bottom surface points: E, F, G, H
	#
	E = x_right, y_bottom, z_front
	F = x_right, y_bottom, z_back
	G = x_left, y_bottom, z_back
	H = x_left, y_bottom, z_front
	#
	# Draw front face
	#
	if m_front: lmbind(MATERIAL, m_front)
	n3f(0.0, 0.0, 1.0)
	face(H, E, A, D)
	#
	# Draw back face
	#
	if m_back: lmbind(MATERIAL, m_back)
	n3f(0.0, 0.0, -1.0)
	face(G, F, B, C)
	#
	# Draw left face
	#
	if m_left: lmbind(MATERIAL, m_left)
	n3f(-1.0, 0.0, 0.0)
	face(G, H, D, C)
	#
	# Draw right face
	#
	if m_right: lmbind(MATERIAL, m_right)
	n3f(1.0, 0.0, 0.0)
	face(F, E, A, B)
	#
	# Draw top face
	#
	if m_top: lmbind(MATERIAL, m_top)
	n3f(0.0, 1.0, 0.0)
	face(A, B, C, D)
	#
	# Draw bottom face
	#
	if m_bottom: lmbind(MATERIAL, m_bottom)
	n3f(0.0, -1.0, 0.0)
	face(E, F, G, H)

def face(points):
	bgnpolygon()
	varray(points)
	endpolygon()