def axis(vertices, position, angle):
AXIS_SIZE = 0.1
transform = Transform(position, angle)
xaxis = transform.apply_vector(Vec2(AXIS_SIZE, 0.0))
yaxis = transform.apply_vector(Vec2(0.0, AXIS_SIZE))
c = position
cx = c + xaxis
cx = Vec3(cx.x, cx.y, 0.0)
cy = c + yaxis
cy = Vec3(cy.x, cy.y, 0.0)
c = Vec3(position.x, position.y, 0.0)
xcolor = Vec3(0.5, 0.0, 0.0)
ycolor = Vec3(0.0, 0.5, 0.0)
vertices.append((c, xcolor))
vertices.append((cx, xcolor))
vertices.append((c, ycolor))
vertices.append((cy, ycolor))
