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# -*- coding: utf-8 -*-
# vispy: gallery 30
# -----------------------------------------------------------------------------
# Copyright (c) Vispy Development Team. All Rights Reserved.
# Distributed under the (new) BSD License. See LICENSE.txt for more info.
# -----------------------------------------------------------------------------
"""Display markers at different sizes and line thicknesses.
Keyboard options:
* spacebar: Cycle through possible marker symbols.
* "s": Switch between "fixed" marker scaling (initial setting) and "scene"
scaling.
"""
import numpy as np
from vispy import app, visuals
from vispy.visuals.transforms import STTransform
n = 500
pos = np.zeros((n, 2))
colors = np.ones((n, 4), dtype=np.float32)
radius, theta, dtheta = 1.0, 0.0, 5.5 / 180.0 * np.pi
for i in range(500):
theta += dtheta
x = 256 + radius * np.cos(theta)
y = 256 + radius * np.sin(theta)
r = 10.1 - i * 0.02
radius -= 0.45
pos[i] = x, y
colors[i] = (i/500, 1.0-i/500, 0, 1)
class Canvas(app.Canvas):
def __init__(self):
app.Canvas.__init__(self, keys='interactive', size=(512, 512),
title="Marker demo [press space to change marker]")
self.index = 0
self.markers = visuals.MarkersVisual()
self.markers.set_data(pos, face_color=colors)
self.markers.symbol = self.markers.symbols[self.index]
self.markers.transform = STTransform()
self.show()
def on_draw(self, event):
self.context.clear(color='white')
self.markers.draw()
def on_mouse_wheel(self, event):
"""Use the mouse wheel to zoom."""
self.markers.transform.zoom((1.25**event.delta[1],)*2,
center=event.pos)
self.update()
def on_resize(self, event):
# Set canvas viewport and reconfigure visual transforms to match.
vp = (0, 0, self.physical_size[0], self.physical_size[1])
self.context.set_viewport(*vp)
self.markers.transforms.configure(viewport=vp, canvas=self)
def on_key_press(self, event):
if event.text == ' ':
self.index = (self.index + 1) % (len(self.markers.symbols))
self.markers.symbol = self.markers.symbols[self.index]
self.update()
elif event.text == 's':
self.markers.scaling = "fixed" if self.markers.scaling != "fixed" else "scene"
self.update()
if __name__ == '__main__':
print(__doc__)
canvas = Canvas()
app.run()
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