# ----------------------------------------------------------------------------- # Python & OpenGL for Scientific Visualization # www.labri.fr/perso/nrougier/python+opengl # Copyright (c) 2017, Nicolas P. Rougier # Distributed under the 2-Clause BSD License. # ----------------------------------------------------------------------------- import numpy as np from glumpy import app, gloo, gl vertex = """ attribute vec2 position; varying vec2 v_position; void main(){ v_position = position; gl_Position = vec4(position, 0.0, 1.0); } """ fragment = """ float SDF_fake_box(vec2 p, vec2 size) { return max(abs(p.x)-size.x, abs(p.y)-size.y); } vec4 color(float d) { vec3 white = vec3(1.0, 1.0, 1.0); vec3 blue = vec3(0.1, 0.4, 0.7); vec3 color = white - sign(d)*blue; color *= (1.0 - exp(-4.0*abs(d))) * (0.8 + 0.2*cos(140.0*d)); color = mix(color, white, 1.0-smoothstep(0.0,0.02,abs(d)) ); return vec4(color, 1.0); } varying vec2 v_position; uniform vec2 size; void main() { float d = SDF_fake_box(v_position, size); gl_FragColor = color(d); } """ window = app.Window(512, 512) quad = gloo.Program(vertex, fragment, count=4) quad['position'] = (-1,+1), (+1,+1), (-1,-1), (+1,-1) phi = 0 @window.event def on_draw(dt): global phi window.clear() phi0 = np.pi*phi/180.0 quad["size"] = 0.5+0.25*np.cos(phi0), 0.5+0.25*np.sin(2*phi0) quad.draw(gl.GL_TRIANGLE_STRIP) phi += 1.0 app.run(framerate=60, framecount=360)