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-rw-r--r--apps/plugins/lua/include_lua/draw_floodfill.lua95
1 files changed, 95 insertions, 0 deletions
diff --git a/apps/plugins/lua/include_lua/draw_floodfill.lua b/apps/plugins/lua/include_lua/draw_floodfill.lua
new file mode 100644
index 0000000000..0303e711f2
--- /dev/null
+++ b/apps/plugins/lua/include_lua/draw_floodfill.lua
@@ -0,0 +1,95 @@
+--[[ 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