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bryanthaboi
36 lines
981 B
Lua
36 lines
981 B
Lua
---@class ZIndex
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local ZIndex = {}
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-- The effective z-index formula used for sorting is:
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-- rootZ * ROOT_WEIGHT + depth * DEPTH_WEIGHT + ownZ
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-- where rootZ is the z-index of the top-level ancestor, depth is the
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-- nesting level, and ownZ is the element's own z property.
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--
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-- Constraints enforced by these weights:
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-- |ownZ| <= MAX_Z (must fit within DEPTH_WEIGHT digits)
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-- DEPTH_WEIGHT has enough room for depths well beyond any practical tree
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-- ROOT_WEIGHT has enough room for the rootZ without exceeding double-precision
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---
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---@type integer
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ZIndex.MIN_Z = -999
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---@type integer
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ZIndex.MAX_Z = 999
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---@type integer
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ZIndex.ROOT_WEIGHT = 10000000000
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---@type integer
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ZIndex.DEPTH_WEIGHT = 1000
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--- Clamp a z-index value to the valid range
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---@param value number
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---@return integer
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function ZIndex.clamp(value)
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if value < ZIndex.MIN_Z then
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return ZIndex.MIN_Z
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elseif value > ZIndex.MAX_Z then
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return ZIndex.MAX_Z
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end
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return value
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end
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return ZIndex
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