lua add rlimg.lua example script split large includes to separate files

Change-Id: I67cac5bc4ce5525ab30abf9443f6cc1a33190512

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