triangles2d.py

''' Displays the given triangles in the passed triangle file
    as flat color triangles using barycentric coordinates.
    Clockwise oriented triangles are ignored
'''

import sys

from pyglet import window
from pyglet.gl import *

from shapes import *
from util import load_triangle_file

WINDOW_WIDTH  = 1024
WINDOW_HEIGHT = 768

def draw_triangle(tri):
    ''' Draws a single triangle onto the screen '''
    glLoadIdentity()
    glBegin(GL_TRIANGLES)
    for vec, col in tri.as_pairs():
        glColor3f(*col)
        glVertex3f(vec.x, vec.y, 0)
    glEnd()

def main(name, args):
    ''' Creates the main window, initializes the OpenGL
        environment, and draws the triangles
    '''
    win = window.Window(WINDOW_WIDTH, WINDOW_HEIGHT)
    # Initialize the opengl camera
    glViewport(0, 0, WINDOW_WIDTH, WINDOW_HEIGHT)
    glMatrixMode(GL_PROJECTION)
    glLoadIdentity()
    glOrtho(WINDOW_WIDTH / -2, WINDOW_WIDTH / 2,
            WINDOW_HEIGHT / -2, WINDOW_HEIGHT / 2,
            WINDOW_WIDTH / -2, WINDOW_HEIGHT / 2)
    glMatrixMode(GL_MODELVIEW)
    glClear(GL_COLOR_BUFFER_BIT)
    glLoadIdentity()

    triangles = load_triangle_file(name, args)
    valid_triangles = [tri for tri in triangles if tri.is_ccw]

    for tri in valid_triangles:
        draw_triangle(tri)

    pyglet.app.run()

if __name__ == "__main__":
    main(sys.argv[0], sys.argv[1:])