zoom-crosshairs-tool.rb

if not defined?(JF::ZoomCrosshairs)
  UI.menu("Camera").add_item("Zoom Crosshairs") {
    Sketchup.active_model.select_tool(JF::ZoomCrosshairs.new)
  }
end

module JF

  class ZoomCrosshairs

    # Move the Camera
    def do_zoom(view)
      reset()
      camera    = view.camera
      eye       = camera.eye
      up        = camera.up
      target    = camera.target
      direction = camera.direction
      height    = camera.height

      # The corners of the selection are
      # @pt1 and @pt2
      rect_width = (@pt2.x - @pt1.x).abs
      rect_height = (@pt2.y - @pt1.y).abs

      camera.set(eye, target, up)

      if not camera.perspective?
        camera.height = height
      end
    end


    def activate()
      @h = Sketchup.active_model.active_view.vpheight
      @w = Sketchup.active_model.active_view.vpwidth
      @state = 1
    end

    def onMouseMove(flags, x, y, view)
      @x = x
      @y = y
      if @down
        if @pt1.distance([x, y]) > 10
          @dragging = true
          @pt2 = [x, y]
        else
          @dragging = false
        end
      end
      view.invalidate
    end

    def onLButtonUp(flags, x, y, view)
      @down = false
      if @state == 2 && @dragging
        @pt2 = [x, y]
        view.invalidate
        do_zoom(view)
      end
      if @state == 2
        @state = 1
      end
    end

    def onLButtonDown(flags, x, y, view)
      @down = true
      if @state == 1
        @pt1 = [x, y]
        @state = 2
      end
    end

    def deactivate(view)
      view.invalidate
    end

    def suspend(view)
      view.invalidate
    end

    def draw(view)
      if @x && @y
        view.draw2d(GL_LINES, [@x, 1], [@x, @h-1])
        view.draw2d(GL_LINES, [0, @y], [@w-1, @y])
        if @dragging
          pt3 = [@pt2.x, @pt1.y]
          pt4 = [@pt1.x, @pt2.y]
          view.drawing_color = 'red'
          view.draw2d(GL_LINE_LOOP, @pt1, pt3, @pt2, pt4)
        end
      end
    end

    def reset
      @state = 1
      @dragging = false
    end

  end
end