lighttroupe/luz

require 'gl_shapes'

module DrawingShapes
    def unit_square
        @unit_square_list = GL.RenderCached(@unit_square_list) {
            GL.Begin(GL::TRIANGLE_FAN)
                GL.TexCoord(0.0, 0.0) ; GL.Vertex(-0.5, 0.5)
                GL.TexCoord(1.0, 0.0) ; GL.Vertex(0.5, 0.5)
                GL.TexCoord(1.0, 1.0) ; GL.Vertex(0.5, -0.5)
                GL.TexCoord(0.0, 1.0) ; GL.Vertex(-0.5, -0.5)
            GL.End
        }
    end
    alias :fullscreen_rectangle :unit_square

    def unit_square_outline
        @unit_square_outline_list = GL.RenderCached(@unit_square_outline_list) {
            GL.Begin(GL::LINE_LOOP)
                GL.Vertex(-0.5, 0.5)
                GL.Vertex(0.5, 0.5)
                GL.Vertex(0.5, -0.5)
                GL.Vertex(-0.5, -0.5)
            GL.End
        }
    end

    def render_progress_bar_with_cache(value)
        cache_key = (1000 * value).to_i        # TODO: 1000 display lists to draw bars might be overkill
        @@value_list_cache ||= Hash.new
        @@value_list_cache[cache_key] ||= GL.RenderToList { render_progress_bar_without_cache(value) }
        GL.CallList(@@value_list_cache[cache_key])
    end

    def render_progress_bar_without_cache(value)
        if value > 0.0
            with_translation(-0.5 + value/2.0, 0.0) {
                with_scale_unsafe(value, 1.0) {
                    unit_square
                }
            }
        end
    end
end