Class: Treemap::SquarifiedLayout

Inherits:
SliceLayout show all
Defined in:
lib/treemap/squarified_layout.rb

Constant Summary

Constants inherited from SliceLayout

Treemap::SliceLayout::Horizontal, Treemap::SliceLayout::Vertical

Instance Attribute Summary

Attributes inherited from LayoutBase

#color, #position

Instance Method Summary collapse

Methods inherited from SliceLayout

#flip, #horizontal?, #process_children, #sum, #vertical?

Methods inherited from LayoutBase

#initialize

Constructor Details

This class inherits a constructor from Treemap::LayoutBase

Instance Method Details

#aspect_ratio(bounds, node_prop, row_prop, axis) ⇒ Object 



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# File 'lib/treemap/squarified_layout.rb', line 93

def aspect_ratio(bounds, node_prop, row_prop, axis)
    height = bounds.height * row_prop
    width = bounds.width * node_prop
    if(axis == Vertical)
        width = bounds.width * row_prop
        height = bounds.height * node_prop
    end 

    return 0 if width == 0 and height == 0

    a = 0;
    b = 0;
    if(width > 0)
        a = height.to_f / width.to_f
    end
    if(height > 0)
        b = width.to_f / height.to_f
    end

    ratio = [a, b].max

    ratio
end

#aspect_ratio_method2(bounds, max, proportion, axis) ⇒ Object

XXX another way of computing the aspect ratio



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# File 'lib/treemap/squarified_layout.rb', line 124

def aspect_ratio_method2(bounds, max, proportion, axis)

    large = bounds.height
    small = bounds.width
    if(axis == Vertical)
        large = bounds.width
        small = bounds.height
    end 

    ratio = (large * proportion).to_f / ((small * max).to_f / proportion.to_f).to_f

    if(ratio < 1)
        ratio = 1.to_f / ratio.to_f
    end

    ratio
end

#axis(bounds) ⇒ Object 



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# File 'lib/treemap/squarified_layout.rb', line 117

def axis(bounds)
    # XXX experiment with switching
    # axis = super(bounds)
    # flip(axis)
end

#process(node, bounds, axis = nil) ⇒ Object 



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# File 'lib/treemap/squarified_layout.rb', line 17

def process(node, bounds, axis=nil)

    bounds = bounds.clone

    node.bounds = bounds.clone

    if(@position == :absolute) 
        bounds.x2 = bounds.width
        bounds.y2 = bounds.height
        bounds.x1 = 0
        bounds.y1 = 0
    end

    if(!node.leaf?)
        squarify_children(node, bounds, flip(axis))
    end
end

#squarify_children(node, bounds, axis) ⇒ Object 



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# File 'lib/treemap/squarified_layout.rb', line 35

def squarify_children(node, bounds, axis)

    parent_bounds = bounds.clone
    bounds = bounds.clone

    node.children.sort! {|a,b| b.size <=> a.size}

    if(node.children.size < 2)
        process_children(node.children, bounds, flip(axis))
    end

    parent_size = node.size
    first_child = node.children.first

    row_size = first_child.size
    row_max = row_size.to_f / parent_size.to_f
    total = row_max 

    prev_aspect = aspect_ratio(bounds, first_child.size.to_f / row_size.to_f, total, axis)
    row = [first_child]

    node.children[1 .. node.children.size-1].each do |c|
        child_prop = c.size.to_f / parent_size.to_f
        aspect = aspect_ratio(bounds, c.size.to_f / row_size.to_f, total + child_prop, axis)

        if(aspect > prev_aspect)
            newb = bounds.clone
            if(axis == Vertical)
                newb.x2 = bounds.x1 + ((bounds.width * total)).round
            else 
                newb.y2 = bounds.y1 + ((bounds.height * total)).round
            end

            process_children(row, newb, flip(axis))

            if(axis == Vertical)
                bounds.x1 = newb.x2
            else 
                bounds.y1 = newb.y2
            end

            axis = flip(axis)
            parent_size -= row_size
            row_size = c.size
            total = row_max = row_size.to_f / parent_size.to_f
            prev_aspect = aspect_ratio(bounds, c.size.to_f / row_size.to_f, total, axis)
            row = [c]
        else
            row_size += c.size
            total += child_prop
            prev_aspect = aspect
            row.push(c)
        end
    end

    process_children(row, bounds, flip(axis))
end