# Copyright (C) 2022 RozK
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU Affero General Public License for more details.
#
# You should have received a copy of the GNU Affero General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

from array import array

from engine import (
    INSTANCE_FLAG_SPAWNED, BATCH_MAX_SIZE, BATCH_ORIENTATION_FORMAT_NONE, create_batch, draw_batch, destroy_batch)

class Batch:
    __slots__ = '_batch', 'max_size', 'flags', 'texlevels', 'meshes', 'translations', 'orientations'

    def __init__(self, max_size, translation_format, orientation_format):
        assert max_size <= BATCH_MAX_SIZE
        self._batch = create_batch(max_size, translation_format, orientation_format)
        self.max_size = max_size
        self.flags = array('B')
        self.texlevels = array('H')
        self.meshes = array('I')
        self.translations = array('f')
        if orientation_format != BATCH_ORIENTATION_FORMAT_NONE:
            self.orientations = array('f')
        else:
            self.orientations = None

    def __del__(self):
        destroy_batch(self._batch)

    def append(self, flags, texlevel, mesh, translation, orientation):
        assert len(translation) == 3
        assert orientation is None or len(orientation) == 3
        index = len(self.flags)
        assert index < self.max_size
        self.flags.append(flags | INSTANCE_FLAG_SPAWNED)
        self.texlevels.append(texlevel)
        self.meshes.append(mesh)
        self.translations.extend(translation)
        if self.orientations is not None:
            self.orientations.extend(orientation)
        return index

    def set_translation(self, index, translation):
        self.translations[index * 3 : index * 3 + 3] = translation

    def set_orientation(self, index, orientation):
        self.orientations[index * 3 : index * 3 + 3] = orientation

    def draw(self):
        draw_batch(self._batch, self.flags, self.texlevels, self.meshes, self.translations, self.orientations)