from OpenGL.GL import *
from OpenGL.GLU import *
from OpenGL.GLUT import *
import sys

W,H = 300,300

class glPrinter:
    def __init__(self):
        self.size  = 0.02
        self.color = [0,0,0]
        self.font  = GLUT_BITMAP_HELVETICA_10
    def __call__(self, x, y, message):
        glPushMatrix();
        glPushAttrib(GL_LIGHTING_BIT | GL_CURRENT_BIT)
        glDisable(GL_LIGHTING);
        glColor3(self.color)
        if self.font in [GLUT_STROKE_ROMAN, GLUT_STROKE_MONO_ROMAN]:
            glLineWidth(2.0)
            glTranslatef(x, y, 0);
            glScalef(self.size,self.size,self.size);
            for m in message:
                glutStrokeCharacter(self.font, ord(m))
        else:
            glRasterPos2(x,y)
            for m in message:
                glutBitmapCharacter(self.font, ord(m))
        glPopAttrib()
        glPopMatrix();

pr_bitmap = glPrinter()
pr_stroke = glPrinter()
pr_stroke.font = GLUT_STROKE_ROMAN
pr_stroke.size = .2

cnt = 0
def display():
    global cnt
    cnt += 1
    glutSetWindowTitle('Rendering #%d' % cnt)

    glClear(GL_COLOR_BUFFER_BIT)
    pr_bitmap.font = GLUT_BITMAP_HELVETICA_10
    pr_bitmap.color = (1,0,0)
    pr_bitmap(W*.5,H*.5,'Some bitmapped text')
    pr_stroke(W*.1,H*.1,'Some stroked text')
    # glut.py lists all the available fonts
    pr_bitmap.font = GLUT_BITMAP_TIMES_ROMAN_24
    pr_bitmap.color = (0,1,0)
    pr_bitmap(W*.03,H*.8,'Some more bitmapped text')
    glFlush()

def myInit():
    glClearColor(1,1,1,0)
    
def reshape(w,h):
    # need this global declaration to be able to change the
    # global variables
    global W,H         
    W,H = w,h
    glViewport(0,0,w,h)
    glMatrixMode(GL_PROJECTION)
    glLoadIdentity()
    gluOrtho2D(0,w,0,h)
    glMatrixMode(GL_MODELVIEW)

def main():
    glutInit([])
    glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB)
    glutInitWindowSize(W,H)
    glutInitWindowPosition(300,100)
    glutCreateWindow(sys.argv[0])
    glutReshapeFunc (reshape)
    glutDisplayFunc (display)
    myInit()
    glutMainLoop()

if __name__ == '__main__':
    main()