1 files changed, 215 insertions, 0 deletions

diff --git a/apps/plugins/lua/include_lua/image_save.lua b/apps/plugins/lua/include_lua/image_save.lua
new file mode 100644
index 0000000000..4735af46d7
--- /dev/null
+++ b/apps/plugins/lua/include_lua/image_save.lua
@@ -0,0 +1,215 @@
+--[[ Lua Image save
+/***************************************************************************
+ *             __________               __   ___.
+ *   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.
+ *
+ ****************************************************************************/
+]]
+-- save(img, path/name)
+-- bmp saving derived from rockbox - screendump.c
+-- bitdepth is limited by the device
+-- eg. device displays greyscale, rgb images are saved greyscale
+if not rb.lcd_framebuffer then rb.splash(rb.HZ, "No Support!") return nil end
+
+do
+    local rocklib_image = getmetatable(rb.lcd_framebuffer())
+
+    -- internal constants
+    local _NIL = nil -- _NIL placeholder
+    local _points  = rocklib_image.points
+
+    -- saves img to file: name
+    return function(img, name)
+        local file
+        local bbuffer = {} -- concat buffer for s_bytes
+        local fbuffer = {} -- concat buffer for file writes, reused
+
+        local function s_bytesLE(bits, value)
+            -- bits must be multiples of 8 (sizeof byte)
+            local byte
+            local nbytes = bit.rshift(bits, 3)
+            for b = 1, nbytes do
+                if value > 0 then
+                    byte  = value % 256
+                    value = (value - byte) / 256
+                else
+                    byte = 0
+                end
+                bbuffer[b] = string.char(byte)
+            end
+            return table.concat(bbuffer, _NIL, 1, nbytes)
+        end
+
+        local function s_bytesBE(bits, value)
+            -- bits must be multiples of 8 (sizeof byte)
+            local byte
+            local nbytes = bit.rshift(bits, 3)
+            for b = nbytes, 1, -1 do
+                if value > 0 then
+                    byte  = value % 256
+                    value = (value - byte) / 256
+                else
+                    byte = 0
+                end
+                bbuffer[b] = string.char(byte)
+            end
+            return table.concat(bbuffer, _NIL, 1, nbytes)
+        end
+
+        local cmp = {["r"] =  function(c) return bit.band(bit.rshift(c, 16), 0xFF) end,
+                     ["g"] =  function(c) return bit.band(bit.rshift(c, 08), 0xFF) end,
+                     ["b"] =  function(c) return bit.band(c, 0xFF) end}
+
+        local function bmp_color(color)
+            return s_bytesLE(8, cmp.b(color))..
+                   s_bytesLE(8, cmp.g(color))..
+                   s_bytesLE(8, cmp.r(color))..
+                   s_bytesLE(8, 0) .. ""
+        end -- c_cmp(color, c.r))
+
+        local function bmp_color_mix(c1, c2, num, den)
+            -- mixes c1 and c2 as ratio of numerator / denominator
+            -- used 2x each save results
+            local bc1, gc1, rc1 = cmp.b(c1), cmp.g(c1), cmp.r(c1)
+
+            return s_bytesLE(8, cmp.b(c2) - bc1 * num / den + bc1)..
+                   s_bytesLE(8, cmp.g(c2) - gc1 * num / den + gc1)..
+                   s_bytesLE(8, cmp.r(c2) - rc1 * num / den + rc1)..
+                   s_bytesLE(8, 0) .. ""
+        end
+
+        local w, h = img:width(), img:height()
+        local depth  = tonumber(img:__tostring(6)) -- RLI_INFO_DEPTH   = 0x6
+        local format = tonumber(img:__tostring(7)) -- RLI_INFO_FORMAT  = 0x7
+
+        local bpp, bypl -- bits per pixel, bytes per line
+        -- bypl, pad rows to a multiple of 4 bytes
+        if depth <= 4 then
+            bpp = 8 -- 256 color image
+            bypl = (w + 3)
+        elseif depth <= 16 then
+            bpp = 16
+            bypl = (w * 2 + 3)
+        elseif depth <= 24 then
+            bpp = 24
+            bypl = (w * 3 + 3)
+        else
+            bpp = 32
+            bypl = (w * 4 + 3)
+        end
+
+        local linebytes = bit.band(bypl, bit.bnot(3))
+
+        local bytesperpixel = bit.rshift(bpp, 3)
+        local headersz = 54
+        local imgszpad = h * linebytes
+
+        local compression, n_colors = 0, 0
+        local h_ppm, v_ppm = 0x00000EC4, 0x00000EC4 --Pixels Per Meter ~ 96 dpi
+
+        if depth == 16 then
+            compression = 3 -- BITFIELDS
+            n_colors    = 3
+        elseif depth <= 8 then
+            n_colors = bit.lshift(1, depth)
+        end
+
+        headersz = headersz + (4 * n_colors)
+
+        file = io.open('/' .. name, "w+") -- overwrite, rb ignores the 'b' flag
+
+        if not file then
+            rb.splash(rb.HZ, "Error opening /" .. name)
+            return
+        end
+        -- create a bitmap header 'rope' with image details -- concatenated at end
+        local bmpheader = fbuffer
+
+              bmpheader[01] = "BM"
+              bmpheader[02] = s_bytesLE(32, headersz + imgszpad)
+              bmpheader[03] = "\0\0\0\0" -- WORD reserved 1 & 2
+              bmpheader[04] = s_bytesLE(32, headersz) -- BITMAPCOREHEADER size
+              bmpheader[05] = s_bytesLE(32, 40) -- BITMAPINFOHEADER size
+
+              bmpheader[06] = s_bytesLE(32, w)
+              bmpheader[07] = s_bytesLE(32, h)
+              bmpheader[08] = "\1\0" -- WORD color planes ALWAYS 1
+              bmpheader[09] = s_bytesLE(16, bpp) -- bits/pixel
+              bmpheader[10] = s_bytesLE(32, compression)
+              bmpheader[11] = s_bytesLE(32, imgszpad)
+              bmpheader[12] = s_bytesLE(32, h_ppm) -- biXPelsPerMeter
+              bmpheader[13] = s_bytesLE(32, v_ppm) -- biYPelsPerMeter
+              bmpheader[14] = s_bytesLE(32, n_colors)
+              bmpheader[15] = s_bytesLE(32, n_colors)
+
+        -- Color Table (#n_colors entries)
+        if depth == 1 then -- assuming positive display
+            bmpheader[#bmpheader + 1] = bmp_color(0xFFFFFF)
+            bmpheader[#bmpheader + 1] = bmp_color(0x0)
+        elseif depth == 2 then
+            bmpheader[#bmpheader + 1] = bmp_color(0xFFFFFF)
+            bmpheader[#bmpheader + 1] = bmp_color_mix(0xFFFFFF, 0, 1, 3)
+            bmpheader[#bmpheader + 1] = bmp_color_mix(0xFFFFFF, 0, 2, 3)
+            bmpheader[#bmpheader + 1] = bmp_color(0x0)
+        elseif depth == 16 then
+            if format == 555 then
+                -- red bitfield mask
+                bmpheader[#bmpheader + 1] = s_bytesLE(32, 0x00007C00)
+                -- green bitfield mask
+                bmpheader[#bmpheader + 1] = s_bytesLE(32, 0x000003E0)
+                -- blue bitfield mask
+                bmpheader[#bmpheader + 1] = s_bytesLE(32, 0x0000001F)
+                        else --565
+                -- red bitfield mask
+                bmpheader[#bmpheader + 1] = s_bytesLE(32, 0x0000F800)
+                -- green bitfield mask
+                bmpheader[#bmpheader + 1] = s_bytesLE(32, 0x000007E0)
+                -- blue bitfield mask
+                bmpheader[#bmpheader + 1] = s_bytesLE(32, 0x0000001F)
+            end
+        end
+
+        file:write(table.concat(fbuffer))-- write the header to the file now
+        for i=1, #fbuffer do fbuffer[i] = _NIL end -- reuse table
+
+        local imgdata = fbuffer
+        -- pad rows to a multiple of 4 bytes
+        local bytesleft = linebytes - (bytesperpixel * w)
+        local t_data = {}
+        local fs_bytes_E = s_bytesLE -- default save in Little Endian
+
+        if format == 3553 then -- RGB565SWAPPED
+            fs_bytes_E = s_bytesBE -- Saves in Big Endian
+        end
+
+        -- Bitmap lines start at bottom unless biHeight is negative
+        for point in _points(img, 1, h, w + bytesleft, 1) do
+            imgdata[#imgdata + 1] = fs_bytes_E(bpp, point or 0)
+
+            if #fbuffer >= 31 then -- buffered write, increase # for performance
+                file:write(table.concat(fbuffer))
+                for i=1, #fbuffer do fbuffer[i] = _NIL end -- reuse table
+            end
+
+        end
+        file:write(table.concat(fbuffer)) --write leftovers to file
+        fbuffer = _NIL
+
+        file:close()
+    end -- save(img, name)
+end