Koch curve generator
false
false
true
macros_menu.examples>end("Examples").end
ruby
# @title Creating layouts: the Koch curve
#
# This application creates a <a href="http://en.wikipedia.org/wiki/Koch_snowflake">Koch curve</a> which
# is constructed by the recursive application
# of a generation recipe. In our case, this recipe is implemented by instantiating cells. An exact
# implementation would require a cell to call itself, but this is not allowed in this framework. Instead,
# a set of up to 20 cells is created with each cell calling the successive one in the same fashion.
#
# When zooming deeply into the curve, the viewer gets pretty slow which is a consequence of the
# performance degradation of the underlying quad tree when the quads get really small. However, since this application is a pretty
# artificial one, I hope that this is not a serious imperfection ...
module Examples
# create one level of recursion
# unless the level is deeper than the maximum level, create a new cell and instantiate this in
# the given upper cell four times rendering the Sierpinski curve.
def self.create_recursion(layout, cell_id, layer_id, rec_level)
if rec_level > 20
# max. recursion depth reached: just paint a straight line
edge = RBA::Edge.new(RBA::Point::new(0, 0), RBA::Point::new(3000, 0))
layout.cell(cell_id).shapes(layer_id).insert_edge(edge)
else
# create a new cell
new_cell = layout.add_cell("level" + rec_level.to_s)
cell = layout.cell(cell_id)
# and add four instances of it
insts = [
RBA::CellInstArray::new(new_cell, RBA::CplxTrans::new(1.0 / 3.0, 0.0, false, RBA::DPoint::new(0.0, 0.0))),
RBA::CellInstArray::new(new_cell, RBA::CplxTrans::new(1.0 / 3.0, 60.0, false, RBA::DPoint::new(1000.0, 0.0))),
RBA::CellInstArray::new(new_cell, RBA::CplxTrans::new(1.0 / 3.0, -60.0, false, RBA::DPoint::new(1500.0, 1000 * Math::sin(Math::PI / 3.0)))),
RBA::CellInstArray::new(new_cell, RBA::CplxTrans::new(1.0 / 3.0, 0.0, false, RBA::DPoint::new(2000.0, 0.0)))
]
insts.each { |i| cell.insert(i) }
# recursively create new cells on this one
create_recursion(layout, new_cell, layer_id, rec_level + 1)
end
end
app = RBA::Application.instance
mw = app.main_window
# create a new layout
mw.create_layout(0)
view = mw.current_view
# create a new layer in that layout
layout = view.cellview(0).layout
linfo = RBA::LayerInfo.new
layer_id = layout.insert_layer(linfo)
# create a layer view for that layer
ln = RBA::LayerPropertiesNode::new
ln.dither_pattern = 0
ln.fill_color = 0xffff00
ln.frame_color = 0xffff00
ln.width = 1
ln.source_layer_index = layer_id
view.insert_layer(view.end_layers, ln)
# create a top cell and start the recursion on this
topcell_id = layout.add_cell("top")
create_recursion(layout, topcell_id, layer_id, 1)
# select his cell as the top cell, fit all and switch on all hierarchy levels
view.select_cell_path([topcell_id], 0)
view.update_content
view.zoom_fit
view.max_hier
end