From 9558ac18302221591eab7fa754463e26ba4c13e2 Mon Sep 17 00:00:00 2001
From: Pavol Rusnak <stick@gk2.sk>
Date: Mon, 28 Mar 2016 18:30:53 +0200
Subject: [PATCH] introduce TOI grayscale 4-bit format

---
 assets/lock.png | Bin 0 -> 710 bytes
 assets/lock.toi | Bin 0 -> 323 bytes
 tools/png2toi   |  42 ++++++++++++++++++++++++++++++++----------
 3 files changed, 32 insertions(+), 10 deletions(-)
 create mode 100644 assets/lock.png
 create mode 100644 assets/lock.toi

diff --git a/assets/lock.png b/assets/lock.png
new file mode 100644
index 0000000000000000000000000000000000000000..35d0b9080ea061cc2bc6dfadbd938d06fb4f16f9
GIT binary patch
literal 710
zcmV;%0y+JOP)<h;3K|Lk000e1NJLTq001li002M;00000MA^#x0007wNkl<ZNXPA#
zO=uHA6vzLwn=hMa(pX}eMvG8rtq9tJ0VPo|fr^)Y;lWGs(1UnT5IlQnkLsyXJ&1_f
zgB0|jf*)8aITVWZ;-M<^!vwLFCV@utwa>$DLuPi8CLnm}Tz22gkJ<PBJM-RSg!+d?
zHkrx7<*Em!_)KCo4R5eLa@<4{KPG#8OkYs_p{K$k4}Uwt?-X9E3TqEd-?hD{0vE<*
z!QPX@cT^edsBoN>bzbPzjJLkiy~VjVvxc?%%RaLjTd`fp==Ms?kman|jl24ar{b#<
zP5Ru72@V1P_DoksKj8oX^oZ~~D*z~$_`fj70Khsgz#|L*9BCf@Xa@kxgaDrc01OHL
zm%0D|QNvR77*c5fz&TOn5dc8munahv0RS8oVIKgXz{9yB0KhN8RscXT&%wrEB5X{M
z4Blom1oPL*Sz2CO&k_M(%+=y+w{zZDxJN5A(#rlars#2NtbFS7i&p~MInaGQSs((@
zt@<2(Or)SNTOa%$P^#n^sTB1~$7I`DRF#29E0${LeApS-Z)1wf*<@FhQZcu=nI$c^
z{3Ekyf;|tq?ah*8m`?p!jfrqapH1qi+l@}s*-+?TAEX_42mXJsqBa00e^y0)nc$VS
zlhZl#eb#bsPqavGcRap#=;DFa%6z__c=Y5u*PP_fS6HE|FH>8UDt_ZkC3u-gfC2BZ
z(N9E_8jG~?9_jFan5S%=w}%}jbw>4~ITdkRYis8447@5=*roAUusYf`IGN^}lib4m
z^Vgb$^!A5Chs>?o#?n}ai1tq<vejBO`aJAl<@)2lxlyaHBO<yV4qAZbgV#QomY5_V
setk9<h(_&_<S)&hzjw(iMI$ZoU!d+bE*fIX3jhEB07*qoM6N<$f}>njD*ylh

literal 0
HcmV?d00001

diff --git a/assets/lock.toi b/assets/lock.toi
new file mode 100644
index 0000000000000000000000000000000000000000..e3d557f6f5821b54e4d299bf2fd032d2c67468f4
GIT binary patch
literal 323
zcmV-J0lfZHPf2G0EC4|J{~tg2_a0O1Pn)x8#(6ZspN0%TAiN$$@UH>`7%-!lvVZ{!
zxRC^ZFu=ilgy;l>C>O$h5SOKUhXII&oBRpLVFkI^0m$%2GJp~6rk_Aj9+;>A+&G{-
zGgR<5P(?n3`4z}Kk6<F%3w7IPh+SZy0JrWj0|O^aw1I)a9>ThWWbp*J=s^YsKBNGl
zrYQg4)2o1B&wGUEMFtcA7X6#ZfCkjxgWZh|fI$_2DauAAQ6|&$@{XCSR?a9dPcedt
zGVVo6F>g0OMVV0&*N0Kj0Tg9?k1YBC7MslL5rUf$G0&I-RsOaRB|Vt$2ML~VKuaaU
zx&Qw+3t*-l%>bmd^UDA|L5YG)``03XEXEWGb<If!grL}5xFg>+!33jFd~_8o#@P2C
V75p@0U{pW<A07N{t^Q9I006rGkE#Fw

literal 0
HcmV?d00001

diff --git a/tools/png2toi b/tools/png2toi
index 23a59b82ec..915b73a796 100755
--- a/tools/png2toi
+++ b/tools/png2toi
@@ -5,11 +5,15 @@ import struct
 import zlib
 
 if len(sys.argv) < 2:
-    print('Usage png2toi image.png')
+    print('Usage png2toi image.png [mode]')
     sys.exit(1)
 
 ifn = sys.argv[1]
 
+gray = False
+if len(sys.argv) >= 3 and sys.argv[2] == 'g':
+    gray = True
+
 if not ifn.endswith('.png'):
     print('Must provide PNG file')
     sys.exit(2)
@@ -18,22 +22,40 @@ im = Image.open(ifn)
 w, h = im.size
 print('Opened  %s ... %d x %d @ %s' % (ifn, w, h, im.mode))
 
-if not im.mode == 'RGB':
-    print('PNG file must use RGB mode')
-    sys.exit(3)
+if not gray:
+    if not im.mode == 'RGB':
+        print('PNG file must use RGB mode')
+        sys.exit(3)
+else:
+    if not im.mode == 'L':
+        print('PNG file must use grayscale mode')
+        sys.exit(3)
+    if w % 2 > 0:
+        print('PNG file must have width divisible by 2')
+        sys.exit(4)
 
 pix = im.load()
 
 ofn = '%s.toi' % ifn[:-4]
 with open(ofn, 'wb') as f:
-    f.write(bytes('TOIa', 'ascii'))
+    if not gray:
+        f.write(bytes('TOIa', 'ascii'))
+    else:
+        f.write(bytes('TOIg', 'ascii'))
     f.write(struct.pack('>HH', w, h))
     data = bytes()
-    for j in range(h):
-        for i in range(w):
-            r, g, b = pix[i, j]
-            c = ((r & 0xF8) << 8) | ((g & 0xFC) << 3) | ((b & 0xF8) >> 3)
-            data += struct.pack('>H', c)
+    if not gray:
+        for j in range(h):
+            for i in range(w):
+                r, g, b = pix[i, j]
+                c = ((r & 0xF8) << 8) | ((g & 0xFC) << 3) | ((b & 0xF8) >> 3)
+                data += struct.pack('>H', c)
+    else:
+        for j in range(h):
+            for i in range(w // 2):
+                l1, l2 = pix[i * 2, j], pix[i * 2 + 1, j]
+                c = (l1 & 0xF0) | (l2 >> 4)
+                data += struct.pack('>B', c)
     z = zlib.compressobj(level=9, wbits=10)
     zdata = z.compress(data) + z.flush()
     zdata = zdata[2:-4] # strip header and checksum