#!python
# -*- mode: python; Encoding: utf-8; coding: utf-8 -*-
# Last updated: <2024/11/23 09:33:38 +0900>
"""
Draw wavefront obj by OpenGL, GLFW3, PyWavefront

Usage:
    python draw_opengl_glfw.py [-m N] [--obj INPUT.obj] [--scale N]

    -m N, --model N     : model type [0 - 2]
    -o FILE, --obj FILE : set .obj filename
    -s N, --scale N     : set scale

* Windows10 x64 22H2
* Python 3.10.10 64bit
* PyOpenGL 3.1.7
* PyOpenGL-accelerate 3.1.7
* glfw 2.7.0
* PyWavefront 1.3.3
"""

import glfw
from OpenGL.GL import *
from OpenGL.GLU import *
import pywavefront
import argparse

model_kind = 1

modeldata = [
    {"file": "./models/cube01.obj", "scale": 2.0},
    {"file": "./models/suzanne01.obj", "scale": 5.0},
    {"file": "./models/car.obj", "scale": 7.0},
]

SCRW, SCRH = 1280, 720
WDWTITLE = "Draw wavefront obj"
FOV = 50.0

winw, winh = SCRW, SCRH
ang = 0.0
obj = None


def init_animation(infile):
    global ang, obj
    ang = 0.0
    obj = pywavefront.Wavefront(infile)


def render(scale):
    global ang, obj
    ang += 45.0 / 60.0

    # init OpenGL
    glViewport(0, 0, winw, winh)
    glMatrixMode(GL_PROJECTION)
    glLoadIdentity()
    gluPerspective(FOV, float(winw) / float(winh), 1.0, 1000.0)

    # clear screen
    glClearDepth(1.0)
    glClearColor(0, 0, 0, 1)
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT)

    glMatrixMode(GL_MODELVIEW)
    glLoadIdentity()

    glDepthFunc(GL_LESS)
    glEnable(GL_DEPTH_TEST)
    glEnable(GL_BLEND)
    glEnable(GL_NORMALIZE)

    glEnable(GL_CULL_FACE)
    glFrontFace(GL_CCW)
    # glCullFace(GL_FRONT)
    glCullFace(GL_BACK)

    # set lighting
    light_pos = [1.0, 1.0, 1.0, 0.0]

    # light_ambient = [0.2, 0.2, 0.2, 1.0]
    light_ambient = [0.5, 0.5, 0.5, 1.0]

    light_diffuse = [1.0, 1.0, 1.0, 1.0]
    light_specular = [0.8, 0.8, 0.8, 1.0]

    glLightfv(GL_LIGHT0, GL_POSITION, light_pos)
    glLightfv(GL_LIGHT0, GL_AMBIENT, light_ambient)
    glLightfv(GL_LIGHT0, GL_DIFFUSE, light_diffuse)
    glLightfv(GL_LIGHT0, GL_SPECULAR, light_specular)
    glEnable(GL_LIGHTING)
    glEnable(GL_LIGHT0)

    # obj move and rotate
    glTranslatef(0.0, 0.0, -20.0)
    glScalef(scale, scale, scale)
    glRotatef(20.0, 1, 0, 0)
    # glRotatef(ang * 0.5, 1, 0, 0)
    glRotatef(ang, 0, 1, 0)

    # set material
    glColorMaterial(GL_FRONT, GL_AMBIENT_AND_DIFFUSE)
    # glColorMaterial(GL_FRONT, GL_DIFFUSE)
    glEnable(GL_COLOR_MATERIAL)

    # draw obj
    for mesh in obj.mesh_list:
        for mat in mesh.materials:
            # glMaterialfv(GL_FRONT, GL_AMBIENT, mat.ambient)
            # glMaterialfv(GL_FRONT, GL_DIFFUSE, mat.diffuse)
            # glMaterialfv(GL_FRONT, GL_SPECULAR, mat.specular)
            glColor4fv(mat.diffuse)
            gl_floats = (GLfloat * len(mat.vertices))(*mat.vertices)
            count = len(mat.vertices) / mat.vertex_size
            glInterleavedArrays(GL_T2F_N3F_V3F, 0, gl_floats)
            glDrawArrays(GL_TRIANGLES, 0, int(count))


def key_callback(window, key, scancode, action, mods):
    if action == glfw.PRESS:
        if key == glfw.KEY_ESCAPE or key == glfw.KEY_Q:
            # ESC or Q key to exit
            glfw.set_window_should_close(window, True)


def resize(window, w, h):
    if h == 0:
        return
    set_view(w, h)


def set_view(w, h):
    global winw, winh
    winw, winh = w, h
    glViewport(0, 0, w, h)


def main():
    global model_kind

    objname = ""
    scale = 1.0
    parser = argparse.ArgumentParser()
    parser.add_argument("-m", "--model", type=int, help="Model type 0 - 2")
    parser.add_argument("-o", "--obj", type=str, help=".obj filename")
    parser.add_argument("-s", "--scale", type=float, help="Scale")
    args = parser.parse_args()

    objname = modeldata[model_kind]["file"]
    scale = modeldata[model_kind]["scale"]

    if args.model is not None:
        model_kind = args.model
        if model_kind < len(modeldata):
            objname = modeldata[model_kind]["file"]
            scale = modeldata[model_kind]["scale"]
    else:
        if args.obj is not None:
            objname = args.obj
        if args.scale is not None:
            scale = args.scale

    if not glfw.init():
        raise RuntimeError("Could not initialize GLFW3")
        return

    window = glfw.create_window(SCRW, SCRH, WDWTITLE, None, None)
    if not window:
        glfw.terminate()
        raise RuntimeError("Could not create an window")
        return

    # set OpenGL 1.1
    glfw.window_hint(glfw.CONTEXT_VERSION_MAJOR, 1)
    glfw.window_hint(glfw.CONTEXT_VERSION_MINOR, 1)

    glfw.window_hint(glfw.OPENGL_PROFILE, glfw.OPENGL_CORE_PROFILE)
    glfw.window_hint(glfw.DEPTH_BITS, 24)

    glfw.set_key_callback(window, key_callback)
    glfw.set_window_size_callback(window, resize)
    glfw.make_context_current(window)
    glfw.swap_interval(1)

    set_view(SCRW, SCRH)

    init_animation(objname)

    # main loop
    while not glfw.window_should_close(window):
        render(scale)
        glfw.swap_buffers(window)
        glfw.poll_events()

    glfw.destroy_window(window)
    glfw.terminate()


if __name__ == "__main__":
    main()