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#!/usr/bin/env python
# -*- coding: utf-8 -*-
# vispy: gallery 2
# Copyright (c) Vispy Development Team. All Rights Reserved.
# Distributed under the (new) BSD License. See LICENSE.txt for more info.
"""
Multiple digital signals.
"""
from vispy import gloo
from vispy import app
import numpy as np
import math
m = 20
n = 25000
x = np.tile(np.linspace(-1., 1., n), m)
y = .1 * np.random.randn(m, n)
y += np.arange(m).reshape((-1, 1))
data = np.zeros(n*m, dtype=[
('a_position', np.float32, 2),
('a_color', np.float32, 3),
('a_index', np.float32),
])
data['a_position'] = np.zeros((n*m, 2), dtype=np.float32)
data['a_position'][:, 0] = x
data['a_position'][:, 1] = .9*(y.ravel()/y.max()*2-1)
data['a_color'] = np.repeat(np.random.uniform(size=(m, 3), low=.5, high=.9),
n, axis=0)
data['a_index'] = np.repeat(np.arange(m), n)
VERT_SHADER = """
#version 120
attribute vec2 a_position;
attribute float a_index;
varying float v_index;
attribute vec3 a_color;
varying vec3 v_color;
uniform vec2 u_pan;
uniform vec2 u_scale;
void main() {
vec2 position_tr = u_scale * (a_position + u_pan);
gl_Position = vec4(position_tr, 0.0, 1.0);
v_color = a_color;
v_index = a_index;
}
"""
FRAG_SHADER = """
#version 120
varying vec3 v_color;
varying float v_index;
void main() {
gl_FragColor = vec4(v_color, 1.0);
if ((fract(v_index) > .00001) && (fract(v_index) < .99999))
gl_FragColor.a = 0.;
}
"""
class Canvas(app.Canvas):
def __init__(self):
app.Canvas.__init__(self, keys='interactive')
self.program = gloo.Program(VERT_SHADER, FRAG_SHADER)
self.program.bind(gloo.VertexBuffer(data))
self.program['u_pan'] = (0., 0.)
self.program['u_scale'] = (1., 1.)
gloo.set_viewport(0, 0, *self.physical_size)
gloo.set_state(clear_color=(1, 1, 1, 1), blend=True,
blend_func=('src_alpha', 'one_minus_src_alpha'))
self.show()
def on_resize(self, event):
gloo.set_viewport(0, 0, *event.physical_size)
def on_draw(self, event):
gloo.clear(color=(0.0, 0.0, 0.0, 1.0))
self.program.draw('line_strip')
def _normalize(self, x_y):
x, y = x_y
w, h = float(self.size[0]), float(self.size[1])
return x/(w/2.)-1., y/(h/2.)-1.
def on_mouse_move(self, event):
if event.is_dragging:
x0, y0 = self._normalize(event.press_event.pos)
x1, y1 = self._normalize(event.last_event.pos)
x, y = self._normalize(event.pos)
dx, dy = x - x1, -(y - y1)
button = event.press_event.button
pan_x, pan_y = self.program['u_pan']
scale_x, scale_y = self.program['u_scale']
if button == 1:
self.program['u_pan'] = (pan_x+dx/scale_x, pan_y+dy/scale_y)
elif button == 2:
scale_x_new, scale_y_new = (scale_x * math.exp(2.5*dx),
scale_y * math.exp(2.5*dy))
self.program['u_scale'] = (scale_x_new, scale_y_new)
self.program['u_pan'] = (pan_x -
x0 * (1./scale_x - 1./scale_x_new),
pan_y +
y0 * (1./scale_y - 1./scale_y_new))
self.update()
def on_mouse_wheel(self, event):
dx = np.sign(event.delta[1])*.05
scale_x, scale_y = self.program['u_scale']
scale_x_new, scale_y_new = (scale_x * math.exp(2.5*dx),
scale_y * math.exp(2.5*dx))
self.program['u_scale'] = (scale_x_new, scale_y_new)
self.update()
if __name__ == '__main__':
c = Canvas()
app.run()
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