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# -*- coding: utf-8 -*-
# vispy: testskip
# -----------------------------------------------------------------------------
# Copyright (c) Vispy Development Team. All Rights Reserved.
# Distributed under the (new) BSD License. See LICENSE.txt for more info.
# -----------------------------------------------------------------------------
"""Display a live webcam feed. Require OpenCV (Python 2 only).
"""
try:
import cv2
except Exception:
raise ImportError("You need OpenCV for this example.")
import numpy as np
from vispy import app
from vispy import gloo
vertex = """
attribute vec2 position;
attribute vec2 texcoord;
varying vec2 v_texcoord;
void main()
{
gl_Position = vec4(position, 0.0, 1.0);
v_texcoord = texcoord;
}
"""
fragment = """
uniform sampler2D texture;
varying vec2 v_texcoord;
void main()
{
gl_FragColor = texture2D(texture, v_texcoord);
// HACK: the image is in BGR instead of RGB.
float temp = gl_FragColor.r;
gl_FragColor.r = gl_FragColor.b;
gl_FragColor.b = temp;
}
"""
class Canvas(app.Canvas):
def __init__(self):
app.Canvas.__init__(self, size=(640, 480), keys='interactive')
self.program = gloo.Program(vertex, fragment, count=4)
self.program['position'] = [(-1, -1), (-1, +1), (+1, -1), (+1, +1)]
self.program['texcoord'] = [(1, 1), (1, 0), (0, 1), (0, 0)]
self.program['texture'] = np.zeros((480, 640, 3)).astype(np.uint8)
width, height = self.physical_size
gloo.set_viewport(0, 0, width, height)
self.cap = cv2.VideoCapture(0)
if not self.cap.isOpened():
raise Exception("There's no available camera.")
self._timer = app.Timer('auto', connect=self.on_timer, start=True)
self.show()
def on_resize(self, event):
width, height = event.physical_size
gloo.set_viewport(0, 0, width, height)
def on_draw(self, event):
gloo.clear('black')
_, im = self.cap.read()
self.program['texture'][...] = im
self.program.draw('triangle_strip')
def on_timer(self, event):
self.update()
c = Canvas()
app.run()
c.cap.release()
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