OffScreenImage.py

# The MIT License (MIT)

# Copyright 2021,2022 HalfMarble LLC

# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:

# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.

# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
# THE SOFTWARE.


from kivy.uix.image import Image
from kivy.graphics import Fbo, ClearBuffers, ClearColor


class OffScreenImage(Image):

    def __init__(self, client, shader, **kwargs):
        super(OffScreenImage, self).__init__(**kwargs)

        self._client = client
        self._fbo = Fbo(use_parent_projection=False, mipmap=True)
        if shader is not None:
            self._fbo.shader.fs = shader

    def paint(self, size):
        if size is not None:
            self.size = size

        self._fbo.size = self.size
        with self._fbo:
            ClearColor(0, 0, 0, 0)
            ClearBuffers()
            if self._client is not None:
                self._client.paint(self._fbo, self.size)
        self._fbo.draw()
        self.texture = self._fbo.texture