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# -*- coding: utf-8 -*-
# Copyright (c) Vispy Development Team. All Rights Reserved.
# Distributed under the (new) BSD License. See LICENSE.txt for more info.
import struct
from .base_filter import Filter
class PickingFilter(Filter):
"""Filter used to color visuals by a picking ID.
Note that the ID color uses the alpha channel, so this may not be used
with blending enabled.
"""
FRAG_SHADER = """
void picking_filter() {
if( $enabled == 0 )
return;
if( gl_FragColor.a == 0.0 )
discard;
gl_FragColor = $id_color;
}
"""
def __init__(self, id_=None):
super(PickingFilter, self).__init__(fcode=self.FRAG_SHADER, fpos=10)
self.id = id_
self.enabled = False
@property
def id(self):
return self._id
@id.setter
def id(self, id):
if id < 1:
raise ValueError('Picking ID must be integer > 0.')
id_color = struct.unpack('<4B', struct.pack('<I', id))
self.fshader['id_color'] = [x/255. for x in id_color]
self._id = id
self._id_color = id_color
@property
def enabled(self):
return self._enabled
@enabled.setter
def enabled(self, e):
self._enabled = e
self.fshader['enabled'] = 1 if e is True else 0
@property
def color(self):
""" The RGBA color that will be drawn to the framebuffer for visuals
that use this filter.
"""
return self._id_color