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mirror of https://github.com/kepler155c/opus synced 2024-11-16 05:34:49 +00:00
opus/sys/apis/ui/region.lua
2018-01-24 17:39:38 -05:00

263 lines
6.7 KiB
Lua

--
-- tek.lib.region
-- Written by Timm S. Mueller <tmueller at schulze-mueller.de>
--
-- Copyright 2008 - 2016 by the authors and contributors:
--
-- * Timm S. Muller <tmueller at schulze-mueller.de>
-- * Franciska Schulze <fschulze at schulze-mueller.de>
-- * Tobias Schwinger <tschwinger at isonews2.com>
--
-- https://opensource.org/licenses/MIT
--
-- Some comments have been removed to reduce file size, see:
-- https://github.com/technosaurus/tekui/blob/master/etc/region.lua
-- for the full source
local insert = table.insert
local ipairs = ipairs
local max = math.max
local min = math.min
local setmetatable = setmetatable
local unpack = unpack or table.unpack
local Region = { }
Region._VERSION = "Region 11.3"
Region.__index = Region
-- x0, y0, x1, y1 = Region.intersect(d1, d2, d3, d4, s1, s2, s3, s4):
-- Returns the coordinates of a rectangle where a rectangle specified by
-- the coordinates s1, s2, s3, s4 overlaps with the rectangle specified
-- by the coordinates d1, d2, d3, d4. The return value is '''nil''' if
-- the rectangles do not overlap.
function Region.intersect(d1, d2, d3, d4, s1, s2, s3, s4)
if s3 >= d1 and s1 <= d3 and s4 >= d2 and s2 <= d4 then
return max(s1, d1), max(s2, d2), min(s3, d3), min(s4, d4)
end
end
-- insertrect: insert rect to table, merging with an existing one if possible
local function insertrect(d, s1, s2, s3, s4)
for i = 1, min(4, #d) do
local a = d[i]
local a1, a2, a3, a4 = a[1], a[2], a[3], a[4]
if a2 == s2 and a4 == s4 then
if a3 + 1 == s1 then
a[3] = s3
return
elseif a1 == s3 + 1 then
a[1] = s1
return
end
elseif a1 == s1 and a3 == s3 then
if a4 + 1 == s2 then
a[4] = s4
return
elseif a2 == s4 + 1 then
a[2] = s2
return
end
end
end
insert(d, 1, { s1, s2, s3, s4 })
end
-- cutrect: cut rect d into table of new rects, using rect s as a punch
local function cutrect(d1, d2, d3, d4, s1, s2, s3, s4)
if not Region.intersect(d1, d2, d3, d4, s1, s2, s3, s4) then
return { { d1, d2, d3, d4 } }
end
local r = { }
if d1 < s1 then
insertrect(r, d1, d2, s1 - 1, d4)
d1 = s1
end
if d2 < s2 then
insertrect(r, d1, d2, d3, s2 - 1)
d2 = s2
end
if d3 > s3 then
insertrect(r, s3 + 1, d2, d3, d4)
d3 = s3
end
if d4 > s4 then
insertrect(r, d1, s4 + 1, d3, d4)
end
return r
end
-- cutregion: cut region d, using s as a punch
local function cutregion(d, s1, s2, s3, s4)
local r = { }
for _, dr in ipairs(d) do
local d1, d2, d3, d4 = dr[1], dr[2], dr[3], dr[4]
for _, t in ipairs(cutrect(d1, d2, d3, d4, s1, s2, s3, s4)) do
insertrect(r, t[1], t[2], t[3], t[4])
end
end
return r
end
-- region = Region.new(r1, r2, r3, r4): Creates a new region from the given
-- coordinates.
function Region.new(r1, r2, r3, r4)
if r1 then
return setmetatable({ region = { { r1, r2, r3, r4 } } }, Region)
end
return setmetatable({ region = { } }, Region)
end
-- self = region:setRect(r1, r2, r3, r4): Resets an existing region
-- to the specified rectangle.
function Region:setRect(r1, r2, r3, r4)
self.region = { { r1, r2, r3, r4 } }
return self
end
-- region:orRect(r1, r2, r3, r4): Logical ''or''s a rectangle to a region
function Region:orRect(s1, s2, s3, s4)
self.region = cutregion(self.region, s1, s2, s3, s4)
insertrect(self.region, s1, s2, s3, s4)
end
-- region:orRegion(region): Logical ''or''s another region to a region
function Region:orRegion(s)
for _, r in ipairs(s) do
self:orRect(r[1], r[2], r[3], r[4])
end
end
-- region:andRect(r1, r2, r3, r4): Logical ''and''s a rectange to a region
function Region:andRect(s1, s2, s3, s4)
local r = { }
for _, d in ipairs(self.region) do
local t1, t2, t3, t4 =
Region.intersect(d[1], d[2], d[3], d[4], s1, s2, s3, s4)
if t1 then
insertrect(r, t1, t2, t3, t4)
end
end
self.region = r
end
-- region:xorRect(r1, r2, r3, r4): Logical ''xor''s a rectange to a region
function Region:xorRect(s1, s2, s3, s4)
local r1 = { }
local r2 = { { s1, s2, s3, s4 } }
for _, d in ipairs(self.region) do
local d1, d2, d3, d4 = d[1], d[2], d[3], d[4]
for _, t in ipairs(cutrect(d1, d2, d3, d4, s1, s2, s3, s4)) do
insertrect(r1, t[1], t[2], t[3], t[4])
end
r2 = cutregion(r2, d1, d2, d3, d4)
end
self.region = r1
self:orRegion(r2)
end
-- self = region:subRect(r1, r2, r3, r4): Subtracts a rectangle from a region
function Region:subRect(s1, s2, s3, s4)
local r1 = { }
for _, d in ipairs(self.region) do
local d1, d2, d3, d4 = d[1], d[2], d[3], d[4]
for _, t in ipairs(cutrect(d1, d2, d3, d4, s1, s2, s3, s4)) do
insertrect(r1, t[1], t[2], t[3], t[4])
end
end
self.region = r1
return self
end
-- region:getRect - gets an iterator on the rectangles in a region [internal]
function Region:getRects()
local index = 0
return function(object)
index = index + 1
if object[index] then
return unpack(object[index])
end
end, self.region
end
-- success = region:checkIntersect(x0, y0, x1, y1): Returns a boolean
-- indicating whether a rectangle specified by its coordinates overlaps
-- with a region.
function Region:checkIntersect(s1, s2, s3, s4)
for _, d in ipairs(self.region) do
if Region.intersect(d[1], d[2], d[3], d[4], s1, s2, s3, s4) then
return true
end
end
return false
end
-- region:subRegion(region2): Subtracts {{region2}} from {{region}}.
function Region:subRegion(region)
if region then
for r1, r2, r3, r4 in region:getRects() do
self:subRect(r1, r2, r3, r4)
end
end
end
-- region:andRegion(r): Logically ''and''s a region to a region
function Region:andRegion(s)
local r = { }
for _, s in ipairs(s.region) do
for _, d in ipairs(self.region) do
local t1, t2, t3, t4 =
Region.intersect(d[1], d[2], d[3], d[4],
s[1], s[2], s[3], s[4])
if t1 then
insertrect(r, t1, t2, t3, t4)
end
end
end
self.region = r
end
-- region:forEach(func, obj, ...): For each rectangle in a region, calls the
-- specified function according the following scheme:
-- func(obj, x0, y0, x1, y1, ...)
-- Extra arguments are passed through to the function.
function Region:forEach(func, obj, ...)
for x0, y0, x1, y1 in self:getRects() do
func(obj, x0, y0, x1, y1, ...)
end
end
-- region:shift(dx, dy): Shifts a region by delta x and y.
function Region:shift(dx, dy)
for _, r in ipairs(self.region) do
r[1] = r[1] + dx
r[2] = r[2] + dy
r[3] = r[3] + dx
r[4] = r[4] + dy
end
end
-- region:isEmpty(): Returns '''true''' if a region is empty.
function Region:isEmpty()
return #self.region == 0
end
-- minx, miny, maxx, maxy = region:get(): Get region's min/max extents
function Region:get()
if #self.region > 0 then
local minx = 1000000 -- ui.HUGE
local miny = 1000000
local maxx = 0
local maxy = 0
for _, r in ipairs(self.region) do
minx = min(minx, r[1])
miny = min(miny, r[2])
maxx = max(maxx, r[3])
maxy = max(maxy, r[4])
end
return minx, miny, maxx, maxy
end
end
return Region