"""Teste de profundidade e descarte de faces traseiras.

Aula 07 — Leitura de Objetos e Superfícies Ocultas.

Teclas: D depth test, C culling, I inverte uma face, R reinicia, setas rotação, Esc fecha.
"""

from __future__ import annotations

import sys

from PySide6.QtCore import Qt
from PySide6.QtGui import QSurfaceFormat
from PySide6.QtOpenGLWidgets import QOpenGLWidget
from PySide6.QtWidgets import QApplication

from OpenGL.GL import *
from OpenGL.GLU import gluLookAt, gluPerspective

VERTICES = [
    (0.0, 1.5, 0.0), (-1.0, 0.0, -1.0), (1.0, 0.0, -1.0),
    (1.0, 0.0, 1.0), (-1.0, 0.0, 1.0),
]
FACES = [(0, 2, 1), (0, 3, 2), (0, 4, 3), (0, 1, 4), (1, 2, 3), (1, 3, 4)]
CORES = [
    (0.95, 0.45, 0.25), (0.25, 0.70, 0.95), (0.55, 0.80, 0.30),
    (0.80, 0.40, 0.85), (0.95, 0.75, 0.25), (0.25, 0.75, 0.65),
]


class Visibilidade(QOpenGLWidget):
    def __init__(self, parent=None):
        super().__init__(parent)
        self.reiniciar()
        self.setFocusPolicy(Qt.FocusPolicy.StrongFocus)

    def reiniciar(self):
        self.depth, self.culling = True, False
        self.inverter_face = False
        self.rot_x, self.rot_y = -15.0, 35.0

    def initializeGL(self) -> None:
        glClearColor(0.08, 0.09, 0.12, 1.0)

    def resizeGL(self, w: int, h: int) -> None:
        dpr = self.devicePixelRatioF()
        w, h = max(1, round(w * dpr)), max(1, round(h * dpr))
        glViewport(0, 0, w, h)
        glMatrixMode(GL_PROJECTION)
        glLoadIdentity()
        gluPerspective(50.0, w / float(h), 0.1, 100.0)
        glMatrixMode(GL_MODELVIEW)

    def paintGL(self) -> None:
        (glEnable if self.depth else glDisable)(GL_DEPTH_TEST)
        (glEnable if self.culling else glDisable)(GL_CULL_FACE)
        glCullFace(GL_BACK)
        glFrontFace(GL_CCW)
        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT)
        glLoadIdentity()
        gluLookAt(0.0, 2.2, 5.5, 0.0, 0.6, 0.0, 0.0, 1.0, 0.0)
        glRotatef(self.rot_x, 1.0, 0.0, 0.0)
        glRotatef(self.rot_y, 0.0, 1.0, 0.0)
        glBegin(GL_TRIANGLES)
        for numero, (face, cor) in enumerate(zip(FACES, CORES)):
            if self.inverter_face and numero == 2:
                face = (face[0], face[2], face[1])
            glColor3f(*cor)
            for indice in face:
                glVertex3f(*VERTICES[indice])
        glEnd()
        self.setWindowTitle(
            f"D depth={'on' if self.depth else 'off'} | "
            f"C culling={'on' if self.culling else 'off'} | I face invertida={self.inverter_face} | R reinicia"
        )

    def keyPressEvent(self, event) -> None:
        tecla = event.key()
        if tecla == Qt.Key.Key_Escape:
            self.close()
            return
        if tecla == Qt.Key.Key_D:
            self.depth = not self.depth
        elif tecla == Qt.Key.Key_R:
            self.reiniciar()
        elif tecla == Qt.Key.Key_I:
            self.inverter_face = not self.inverter_face
        elif tecla == Qt.Key.Key_C:
            self.culling = not self.culling
        elif tecla == Qt.Key.Key_Left:
            self.rot_y -= 5.0
        elif tecla == Qt.Key.Key_Right:
            self.rot_y += 5.0
        elif tecla == Qt.Key.Key_Up:
            self.rot_x -= 5.0
        elif tecla == Qt.Key.Key_Down:
            self.rot_x += 5.0
        else:
            return
        self.update()


def main() -> int:
    fmt = QSurfaceFormat()
    fmt.setVersion(2, 1)
    fmt.setProfile(QSurfaceFormat.OpenGLContextProfile.NoProfile)
    fmt.setDepthBufferSize(24)
    QSurfaceFormat.setDefaultFormat(fmt)
    app = QApplication(sys.argv)
    janela = Visibilidade()
    janela.resize(800, 600)
    janela.show()
    return app.exec()


if __name__ == "__main__":
    raise SystemExit(main())