95 lines
3.5 KiB
Lua
95 lines
3.5 KiB
Lua
--[[ Lua Floodfill function
|
|
/***************************************************************************
|
|
* __________ __ ___.
|
|
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
|
|
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
|
|
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
|
|
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
|
|
* \/ \/ \/ \/ \/
|
|
* $Id$
|
|
*
|
|
* Copyright (C) 2017 William Wilgus
|
|
*
|
|
* This program is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU General Public License
|
|
* as published by the Free Software Foundation; either version 2
|
|
* of the License, or (at your option) any later version.
|
|
*
|
|
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
|
|
* KIND, either express or implied.
|
|
*
|
|
****************************************************************************/
|
|
]]
|
|
-- floods an area of targetclr with fillclr x, y specifies the start seed
|
|
-- flood_fill(img, x, y, targetclr, fillclr)
|
|
if not rb.lcd_framebuffer then rb.splash(rb.HZ, "No Support!") return nil end
|
|
do
|
|
|
|
local rocklib_image = getmetatable(rb.lcd_framebuffer())
|
|
local _NIL = nil -- nil placeholder
|
|
local _get = rocklib_image.get
|
|
local _line = rocklib_image.line
|
|
local _marshal = rocklib_image.marshal
|
|
|
|
return function(img, x, y, targetclr, fillclr)
|
|
-- scanline 4-way flood algorithm
|
|
-- ^
|
|
-- <--------x--->
|
|
-- v
|
|
-- check that target color doesn't = fill and the first point is target color
|
|
if targetclr == fillclr or targetclr ~= _get(img, x, y, true) then return end
|
|
local max_w = img:width()
|
|
local max_h = img:height()
|
|
|
|
local qpt = {} -- FIFO queue
|
|
-- rather than moving elements around in our FIFO queue
|
|
-- for each read; increment 'qhead' by 2
|
|
-- set both elements to nil and let the
|
|
-- garbage collector worry about it
|
|
-- for each write; increment 'qtail' by 2
|
|
-- x coordinates are in odd indices while
|
|
-- y coordinates are in even indices
|
|
|
|
local qtail = 0
|
|
|
|
local function check_ns(val, x, y)
|
|
if targetclr == val then
|
|
y = y - 1
|
|
if targetclr == _get(img, x, y, true) then -- north
|
|
qtail = qtail + 2
|
|
qpt[qtail - 1] = x
|
|
qpt[qtail] = y
|
|
end
|
|
y = y + 2
|
|
if targetclr == _get(img, x, y, true) then -- south
|
|
qtail = qtail + 2
|
|
qpt[qtail - 1] = x
|
|
qpt[qtail] = y
|
|
end
|
|
return fillclr
|
|
end
|
|
return _NIL -- signal marshal to stop
|
|
end
|
|
|
|
local function seed_pt(x, y)
|
|
-- should never hit max but make sure not to end early
|
|
for qhead = 2, 0x40000000, 2 do
|
|
|
|
if targetclr == _get(img, x, y, true) then
|
|
_marshal(img, x, y, 1, y, _NIL, _NIL, true, check_ns) -- west
|
|
_marshal(img, x + 1, y, max_w, y, _NIL, _NIL, true, check_ns) -- east
|
|
end
|
|
|
|
x = qpt[qhead - 1]
|
|
qpt[qhead - 1] = _NIL
|
|
|
|
if not x then break end
|
|
|
|
y = qpt[qhead]
|
|
qpt[qhead] = _NIL
|
|
end
|
|
end
|
|
|
|
seed_pt(x, y) -- Begin
|
|
end -- flood_fill
|
|
end
|