# 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 itertools import chain
from array import array
from math import cos, sin
from engine import create_triangles, draw_triangles, destroy_triangles

class Triangles:
    __slots__ = '_triangles'

    def __init__(self, triangles):
        self._triangles = create_triangles(triangles)

    def __del__(self):
        destroy_triangles(self._triangles)

    def draw(self):
        draw_triangles(self._triangles)

class SkyTriangles(Triangles):
    # TODO: with FOV
    def __init__(self, vsubdivs, distance, projection_ratio):
        assert vsubdivs > 0
        vertices = []
        hsubdivs = round(vsubdivs * projection_ratio)
        z = -distance
        width = distance * projection_ratio
        height = distance
        startx = width * -0.5
        starty = height * -0.5
        stepx = width / hsubdivs
        stepy = height / vsubdivs
        y1 = starty
        y2 = y1 + stepy
        for sy in range(vsubdivs):
            x1 = startx
            x2 = x1 + stepx
            for sx in range(hsubdivs):
                a = (x1, y2, z)
                b = (x2, y1, z)
                vertices.append((x1, y1, z))
                vertices.append(b)
                vertices.append(a)
                vertices.append((x2, y2, z))
                vertices.append(a)
                vertices.append(b)
                x1 = x2
                x2 += stepx
            y1 = y2
            y2 += stepy
        super().__init__(array('f', chain.from_iterable(vertices)))