from OpenGL.GL import *
from OpenGL.GLU import *
from OpenGL.GLUT import *
import numpy as np
import sys

global lp, lq, rp, rq, z, eyeX, eyeY, eyeZ
lp = 0.0
lq = 2.5
rp = 0.0
rq = 2.5
z = 0.0

# gluLookAt 'eye' coordinates
eyeX = 0.0 
eyeY = 0.0
eyeZ = 10.0

def init():
    global eyeX, eyeY, eyeZ
    glClearColor(0.0, 0.0, 0.0, 1.0)
    glMatrixMode(GL_PROJECTION)
    glOrtho(-10.0, 10.0, -10.0, 10.0, -10.0, 10.0)
    glClear(GL_COLOR_BUFFER_BIT)
    glMatrixMode(GL_MODELVIEW)
    glLoadIdentity()
    gluLookAt(eyeX, eyeY, eyeZ, 0.0, 0.0, 0.0, 0.0, 1.0, 0.0)

def plotdial():
    global lp, lq, rp, rq, eyeX, eyeY, eyeZ
    #lOrigin = np.array((0.0, 0.0, 0.0))
    rOrigin = np.array((5.0, 0.0, 0.0))
    radius = 2.5

    glClear(GL_COLOR_BUFFER_BIT)
    glMatrixMode(GL_MODELVIEW)
    glLoadIdentity()
    gluLookAt(eyeX, eyeY, eyeZ, 0.0, 0.0, 0.0, 0.0, 1.0, 0.0)  

    # Left arm unit vector calculation
    lVec =  np.array((lp, lq, z))
    lMag = np.linalg.norm(lVec)
    lVec = (lVec/lMag)*radius
    glColor3f(1.0, 0.0, 0.0)
    glLineWidth(3.0)
    glBegin(GL_LINES)
    glVertex3f(0.0, 0.0, z)
    glVertex3f(lVec[0], lVec[1], z)
    glEnd()
    glLineWidth(1.0)
    glColor3f(0.0, 0.0, 1.0)
    glutWireSphere(2.5, 25, 25)

    # Right 
    glPushMatrix()
    glTranslatef(rOrigin[0], rOrigin[1], z)
    glColor3f(0.0, 1.0, 0.0)
    glLineWidth(3.0)
    glBegin(GL_LINES)
    glVertex3f(0.0, 0.0, z)
    rVec =  np.array((rp, rq, z))
    rMag = np.linalg.norm(rVec)
    rVec = (rVec/rMag)*radius 
    glVertex3f(rVec[0], rVec[1], z)
    glEnd()
    glLineWidth(1.0)
    glColor3f(0.0, 0.0, 1.0)
    glutWireSphere(2.5, 25, 25)
    glPopMatrix()

    glFlush()

def keyboard(key, x, y):
    global glutshape, solid, eyeX, eyeY, eyeZ
    step = 0.01
    if key == chr(27) or key == "q":
        sys.exit()
    if key == "x":
        eyeX -= step
    if key == "X":
        eyeX += step
    if key == "y":
        eyeY -= step
    if key == "Y":
        eyeY += step
    if key == "z":
        eyeZ -= step
    if key == "Z":
        eyeZ -= step
    glutPostRedisplay()

def mouse(button, state, x, y):
    global lp, lq, rp, rq
    o_lp = lp    
    o_lq = lq
    o_rp = rp
    o_rq = rq
    if button == GLUT_LEFT_BUTTON and state == GLUT_DOWN:
        lp = -10.0 + x/500.0 * 20
        lq = 10 - y/500.0 * 20   
        if lq < 0.0:
            lp = o_lp
            lq = o_lq
    if button == GLUT_RIGHT_BUTTON and state == GLUT_DOWN:
        rp = -10.0 + x/500.0 * 20 - 5 # -5 is 2*radius
        rq = 10 - y/500.0 * 20 
        if rq < 0.0:
            rp = o_rp
            rq = o_rq
    glutPostRedisplay()

def main():
    glutInit(sys.argv)
    glutInitDisplayMode(GLUT_SINGLE|GLUT_RGB)
    glutInitWindowSize(500,500)
    glutInitWindowPosition(50,50)
    glutCreateWindow('Dial Trial')
    glutDisplayFunc(plotdial)
    glutKeyboardFunc(keyboard)
    glutMouseFunc(mouse)
    init()
    glutMainLoop()

main()