$:.unshift File.expand_path(File.dirname(__FILE__) + "/../../lib")
$:.unshift File.expand_path(File.dirname(__FILE__) + "/../../ext")

require 'ray'

def path_of(res)
  File.expand_path(res, File.join(File.dirname(__FILE__), '../../test/res'))
end

class Model < Ray::Drawable
  include Ray::GL

  Vertex = Ray::GL::Vertex.make [
    [:pos,    "in_Position", :vector3],
    [:normal, "in_Normal",   :vector3],
    [:col,    "in_Color",    :color]
  ]

  def initialize(filename)
    super Vertex

    @vertices  = []

    positions = []
    normals   = []

    open(filename) do |io|
      io.each_line do |line|
        next if line[0] == "#" or line !~ /\S/

        word, *args = line.split(" ")

        case word # lacks many features.
        when "v"  then positions << Ray::Vector3[*args.map(&:to_f)]
        when "vn" then normals   << Ray::Vector3[*args.map(&:to_f)]
        when "f"  then
          args.each do |arg|
            pos, normal = arg.split("//").map { |s| s.to_i - 1 }
            @vertices << Vertex.new(positions[pos],
                                    normals[normal],
                                    Ray::Color.new(120, 100, 255))
          end
        end
      end
    end

    self.vertex_count = @vertices.size
    self.matrix_proc = proc do # always called with self
      mat = Ray::Matrix.translation [0, 0, -4]

      mat.rotate(@x, [1, 0, 0])
      mat.rotate(@y, [0, 1, 0])
      mat.rotate(@z, [0, 0, 1])
    end
  end

  def rotate(x, y, z)
    @x, @y, @z = x, y, z
    matrix_changed!
  end

  def fill_vertices
    @vertices
  end

  def render(first, index)
    draw_arrays :triangles, first, @vertices.size
  end
end

Ray::Shader.use_old!

Ray.game "A teapot!" do
  register { add_hook :quit, method(:exit!) }

  scene :teapot do
    @model = Model.new path_of("teapot.obj")

    window.shader.apply_vertex Model::Vertex
    window.shader.compile(:vertex => path_of("light3d.c"),
                          :frag   => path_of("frag_light3d.c"))

    window.shader["in_Light"] = Ray::Vector3[1, 0, 0]

    window.view = Ray::View.new Ray::Matrix.perspective(80, 1, 1, 10)

    n = 0
    always do
      n += 0.01
      @model.rotate(n * 50, n * 30, n * 90)
    end

    render do |win|
      win.draw @model
    end
  end

  scenes << :teapot
end