#!/usr/bin/env python
# A translation of the gears demo that comes with mesa, modified to use
# a few GtkHScale widgets for the rotation, rather than the keyboard.
from OpenGL.GL import *
import gtk
import gtkgl
import math
# Draw a gear wheel. You'll probably want to call this function when
# building a display list since we do a lot of trig here.
#
# Input: inner_radius - radius of hole at center
# outer_radius - radius at center of teeth
# width - width of gear
# teeth - number of teeth
# tooth_depth - depth of tooth
def gear(inner_radius, outer_radius, width, teeth, tooth_depth):
cos = math.cos
sin = math.sin
r0 = inner_radius
r1 = outer_radius - tooth_depth/2.0
r2 = outer_radius + tooth_depth/2.0
da = 2.0*math.pi / teeth / 4.0
glShadeModel( GL_FLAT )
glNormal3f( 0.0, 0.0, 1.0 )
# draw front face
glBegin( GL_QUAD_STRIP )
for i in range(teeth + 1):
angle = i * 2.0*math.pi / teeth
glVertex3f( r0*cos(angle), r0*sin(angle), width*0.5 )
glVertex3f( r1*cos(angle), r1*sin(angle), width*0.5 )
glVertex3f( r0*cos(angle), r0*sin(angle), width*0.5 )
glVertex3f( r1*cos(angle+3*da), r1*sin(angle+3*da), width*0.5 )
glEnd();
# draw front sides of teeth
glBegin( GL_QUADS )
da = 2.0*math.pi / teeth / 4.0
for i in range(teeth):
angle = i * 2.0*math.pi / teeth
glVertex3f( r1*cos(angle), r1*sin(angle), width*0.5 )
glVertex3f( r2*cos(angle+da), r2*sin(angle+da), width*0.5 )
glVertex3f( r2*cos(angle+2*da), r2*sin(angle+2*da), width*0.5 )
glVertex3f( r1*cos(angle+3*da), r1*sin(angle+3*da), width*0.5 )
glEnd()
glNormal3f( 0.0, 0.0, -1.0 )
# draw back face
glBegin( GL_QUAD_STRIP )
for i in range(teeth + 1):
angle = i * 2.0*math.pi / teeth
glVertex3f( r1*cos(angle), r1*sin(angle), -width*0.5 )
glVertex3f( r0*cos(angle), r0*sin(angle), -width*0.5 )
glVertex3f( r1*cos(angle+3*da), r1*sin(angle+3*da),-width*0.5 )
glVertex3f( r0*cos(angle), r0*sin(angle), -width*0.5 )
glEnd()
# draw back sides of teeth
glBegin( GL_QUADS )
da = 2.0*math.pi / teeth / 4.0
for i in range(teeth):
angle = i * 2.0*math.pi / teeth
glVertex3f( r1*cos(angle+3*da), r1*sin(angle+3*da),-width*0.5 )
glVertex3f( r2*cos(angle+2*da), r2*sin(angle+2*da),-width*0.5 )
glVertex3f( r2*cos(angle+da), r2*sin(angle+da), -width*0.5 )
glVertex3f( r1*cos(angle), r1*sin(angle), -width*0.5 )
glEnd()
# draw outward faces of teeth
glBegin( GL_QUAD_STRIP );
for i in range(teeth):
angle = i * 2.0*math.pi / teeth
glVertex3f( r1*cos(angle), r1*sin(angle), width*0.5 )
glVertex3f( r1*cos(angle), r1*sin(angle), -width*0.5 )
u = r2*cos(angle+da) - r1*cos(angle)
v = r2*sin(angle+da) - r1*sin(angle)
len = math.sqrt( u*u + v*v )
u = u / len
v = v / len
glNormal3f( v, -u, 0.0 )
glVertex3f( r2*cos(angle+da), r2*sin(angle+da), width*0.5 )
glVertex3f( r2*cos(angle+da), r2*sin(angle+da), -width*0.5 )
glNormal3f( cos(angle), sin(angle), 0.0 )
glVertex3f( r2*cos(angle+2*da), r2*sin(angle+2*da), width*0.5 )
glVertex3f( r2*cos(angle+2*da), r2*sin(angle+2*da),-width*0.5 )
u = r1*cos(angle+3*da) - r2*cos(angle+2*da)
v = r1*sin(angle+3*da) - r2*sin(angle+2*da)
glNormal3f( v, -u, 0.0 )
glVertex3f( r1*cos(angle+3*da), r1*sin(angle+3*da), width*0.5 )
glVertex3f( r1*cos(angle+3*da), r1*sin(angle+3*da),-width*0.5 )
glNormal3f( cos(angle), sin(angle), 0.0 )
glVertex3f( r1*cos(0), r1*sin(0), width*0.5 )
glVertex3f( r1*cos(0), r1*sin(0), -width*0.5 )
glEnd()
glShadeModel( GL_SMOOTH )
# draw inside radius cylinder
glBegin( GL_QUAD_STRIP )
for i in range(teeth + 1):
angle = i * 2.0*math.pi / teeth;
glNormal3f( -cos(angle), -sin(angle), 0.0 )
glVertex3f( r0*cos(angle), r0*sin(angle), -width*0.5 )
glVertex3f( r0*cos(angle), r0*sin(angle), width*0.5 )
glEnd()
view_rotx=20.0
view_roty=30.0
view_rotz=0.0
gear1 = 0
gear2 = 0
gear3 = 0
angle = 0.0
def xchange(adj):
global view_rotx
view_rotx = adj.value
draw(glarea)
def ychange(adj):
global view_roty
view_roty = adj.value
draw(glarea)
def zchange(adj):
global view_rotz
view_rotz = adj.value
draw(glarea)
def draw(glarea, event=None):
if not glarea.make_current(): return
glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT )
glPushMatrix()
glRotatef( view_rotx, 1.0, 0.0, 0.0 )
glRotatef( view_roty, 0.0, 1.0, 0.0 )
glRotatef( view_rotz, 0.0, 0.0, 1.0 )
glPushMatrix()
glTranslatef( -3.0, -2.0, 0.0 )
glRotatef( angle, 0.0, 0.0, 1.0 )
glCallList(gear1)
glPopMatrix()
glPushMatrix()
glTranslatef( 3.1, -2.0, 0.0 )
glRotatef( -2.0*angle-9.0, 0.0, 0.0, 1.0 )
glCallList(gear2)
glPopMatrix()
glPushMatrix()
glTranslatef( -3.1, 4.2, 0.0 )
glRotatef( -2.0*angle-25.0, 0.0, 0.0, 1.0 )
glCallList(gear3)
glPopMatrix()
glPopMatrix()
glarea.swap_buffers()
def idle():
global angle
angle = angle + 2.0
draw(glarea)
return gtk.TRUE
def reshape_idle():
if not glarea.make_current(): return
x, y, width, height = glarea.get_allocation()
glViewport(0, 0, width, height)
glMatrixMode(GL_PROJECTION)
glLoadIdentity()
if width > height:
w = width / height
glFrustum( -w, w, -1.0, 1.0, 5.0, 60.0 )
else:
h = height / width
glFrustum( -1.0, 1.0, -h, h, 5.0, 60.0 )
glMatrixMode(GL_MODELVIEW)
glLoadIdentity()
glTranslatef( 0.0, 0.0, -40.0 )
glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT )
return gtk.FALSE
def reshape(glarea, allocation):
gtk.idle_add(reshape_idle)
def init(glarea):
if not glarea.make_current(): return
global gear1, gear2, gear3
pos = (5.0, 5.0, 10.0, 0.0 )
red = (0.8, 0.1, 0.0, 1.0 )
green = (0.0, 0.8, 0.2, 1.0 )
blue = (0.2, 0.2, 1.0, 1.0 )
glLightfv( GL_LIGHT0, GL_POSITION, pos )
glEnable( GL_CULL_FACE )
glEnable( GL_LIGHTING )
glEnable( GL_LIGHT0 )
glEnable( GL_DEPTH_TEST )
# make the gears
gear1 = glGenLists(1)
glNewList(gear1, GL_COMPILE)
glMaterialfv( GL_FRONT, GL_AMBIENT_AND_DIFFUSE, red )
gear( 1.0, 4.0, 1.0, 20, 0.7 )
glEndList()
gear2 = glGenLists(1)
glNewList(gear2, GL_COMPILE)
glMaterialfv( GL_FRONT, GL_AMBIENT_AND_DIFFUSE, green )
gear( 0.5, 2.0, 2.0, 10, 0.7 )
glEndList()
gear3 = glGenLists(1)
glNewList(gear3, GL_COMPILE)
glMaterialfv( GL_FRONT, GL_AMBIENT_AND_DIFFUSE, blue )
gear( 1.3, 2.0, 0.5, 10, 0.7 )
glEndList()
glEnable( GL_NORMALIZE )
if not gtkgl.query():
print "OpenGL not supported. Bye."
raise SystemExit
win = gtk.GtkWindow()
win.connect("destroy", gtk.mainquit)
win.set_title("Gears")
table = gtk.GtkTable(4, 2)
win.add(table)
table.show()
glarea = gtkgl.GtkGLArea((gtkgl.RGBA, gtkgl.DEPTH_SIZE, 1, gtkgl.DOUBLEBUFFER))
glarea.size(300, 300)
glarea.connect("realize", init)
glarea.connect("size_allocate", reshape)
glarea.connect("expose_event", draw)
gtk.idle_add(idle)
table.attach(glarea, 0,2, 0,1)
glarea.show()
for row, label, start, cb in ((1,'X Rotation', view_rotx, xchange),
(2,'Y Rotation', view_roty, ychange),
(3,'Z Rotation', view_rotz, zchange)):
l = gtk.GtkLabel(label)
table.attach(l, 0,1, row,row+1, xoptions=0, yoptions=gtk.FILL)
l.show()
adj = gtk.GtkAdjustment(start, 0, 360, 5, 5, 0)
adj.connect("value_changed", cb)
scale = gtk.GtkHScale(adj)
table.attach(scale, 1,2, row,row+1, yoptions=gtk.FILL)
scale.show()
win.show()
gtk.mainloop()
glarea.destroy()
