python
from vispy import app, gloo
canvas = app.Canvas(title='VisPy Example', size=(800, 600), show=True)
vertices = gloo.Program("""
attribute vec2 position;
void main()
{
gl_Position = vec4(position, 0.0, 1.0);
}
""")
vertices['position'] = [[-0.6, -0.6], [0.6, -0.6], [0.0, 0.6]]
@canvas.connect
def on_draw(event):
gloo.clear()
vertices.draw('triangles')
app.run()
