34 lines
1.1 KiB
Plaintext
34 lines
1.1 KiB
Plaintext
intersect_with_centroid = function(node, sx,sy)
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local h = node_height(node)
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local c = centroid(node)
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-- collect nearest intersection with all 4 boundaries
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local candidates = {}
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local y = y_at_x(sx,sy, c.sx,c.sy, node.x-10)
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if y and y >= node.y-10 and y < node.y+h+10 then
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table.insert(candidates, {sx=node.x-10, sy=y})
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end
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y = y_at_x(sx,sy, c.sx,c.sy, node.x+node.w+10)
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if y and y >= node.y-10 and y < node.y+h+10 then
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table.insert(candidates, {sx=node.x+node.w+10, sy=y})
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end
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local x = x_at_y(sx,sy, c.sx,c.sy, node.y-10)
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if x and x >= node.x-10 and x < node.x+node.w+10 then
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table.insert(candidates, {sx=x, sy=node.y-10})
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end
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x = x_at_y(sx,sy, c.sx,c.sy, node.y+h+10)
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if x and x >= node.x-10 and x < node.x+node.w+10 then
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table.insert(candidates, {sx=x, sy=node.y+h+10})
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end
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if #candidates == 0 then
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-- no intersection; just return the same point
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return {sx=sx, sy=sy}
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end
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if #candidates == 1 then
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return candidates[1]
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end
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table.sort(candidates,
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function(a, b)
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return distance_sq(sx,sy, a.sx,a.sy) < distance_sq(sx,sy, b.sx,b.sy)
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end)
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return candidates[1]
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end |