OpenGL で正多面体を回転させる

miniopengl_sample6.rb

require './miniopengl'
require 'parallel'

filenames = []
1.upto(5) {|i| filenames << "./polyhedrons_obj/r" + ("%02d" % i) + ".obj"}
data = []

filenames.each do |fn|
  open(fn, "r") do |io|
    ar = [[], []]
    io.each_line do |l|
      l.chomp!
      a = l[2..-1].split(" ")
      (l[0] == "v") ? ar[0] << a.map(&:to_f) : ar[1] << a.map {|i| i.to_i - 1}
    end
    data << ar
  end
end


Parallel.each(data, in_processes: 5) do |vertex, apexes|
  MiniOpenGL.app width: 400, height: 400, depth_buffer: :on do    #depth_buffer を on に（隠面消去のため）
    clear_color(0, 0, 0)
    num = apexes.size
    col = []
    num.times {|i| col[i] = [rand, rand, rand]}
    
    draw do
      clear
      glEnable(GL_DEPTH_TEST)    #隠面消去に必要
      glEnableClientState(GL_VERTEX_ARRAY)
      glVertexPointer(3, GL_DOUBLE, 0, vertex.flatten)
      num.times do |i|
        color(col[i][0], col[i][1], col[i][2])
        glDrawElements(GL_POLYGON, apexes[i].size, GL_UNSIGNED_BYTE, apexes[i])
      end
      display
    end
  
    reshape do |w, h|
      viewport(0, 0, w, h)
      init_projection
      perspective(30, w / h.to_f, 3, 10)
      init_modelview
      look_at(3 * 0.8, 4 * 0.8, 5 *0.8, 0, 0, 0, 0, 1, 0)
    end
  
    repeat(30) do
      modelview
      rotate(5, 0, 1, 0)
      redisplay
    end
  end
end


# miniopengl.rb
#    http://d.hatena.ne.jp/obelisk2+marginalia/20170414/1492139406
#polyhedrons_obj
#    http://mitani.cs.tsukuba.ac.jp/polyhedron/