require "set"

class Window
  @windows = Set.new

  class << self
    def register(window)
      @windows << window
    end

    def remove(window)
      @windows.delete(window)
    end
  end

  def initialize
    @programs = {}
    load_shaders
    Window.register(self)
  end

  def close
    Window.remove(self)
  end

  private

  def load_shaders
    program_sources = {
      text: ["text.v.glsl", "text.f.glsl"],
      basic: ["basic.v.glsl", "basic.f.glsl"],
      rect: ["rect.v.glsl", "basic.f.glsl"],
    }

    program_sources.each do |program, (v_src_fname, f_src_fname)|
      v_shader = GLShader.new(:vertex, Runtime.read(:shader, v_src_fname))
      v_shader or raise "Could not find shader #{v_src_fname}"
      f_shader = GLShader.new(:fragment, Runtime.read(:shader, f_src_fname))
      f_shader or raise "Could not find shader #{f_src_fname}"
      @programs[program] = GLProgram.new(v_shader, f_shader)
    end
  end
end