Update examples

Update the coding style used in the examples and fixes some undesired
behaviors (eg. overwriting versioned files, polluting the directory,
etc.).

.gitignore

@@ -1,3 +1,8 @@
 *.so
 *.lo
 *.tar.gz
+
+demos/out.png
+demos/out.gif
+demos/counter.txt
+

demos/brush.lua

@@ -1,12 +1,12 @@
 local gd = require("gd")
 
-im = gd.createTrueColor(400, 400)
+local im = gd.createTrueColor(400, 400)
 assert(im)
 
-black = im:colorAllocate(0, 0, 0)
-white = im:colorAllocate(255, 255, 255)
+local black = im:colorAllocate(0, 0, 0)
+local white = im:colorAllocate(255, 255, 255)
 
-brush = gd.createFromPng("paper.png")
+local brush = gd.createFromPng("paper.png")
 im:setBrush(brush)
 im:line(60, 60, 70, 70, gd.BRUSHED)
 im:line(120, 120, 130, 130, gd.BRUSHED)

demos/circle.lua

@@ -2,10 +2,10 @@
 
 local gd = require("gd")
 
-im = gd.createTrueColor(100, 100)
+local im = gd.createTrueColor(100, 100)
 
-white = im:colorAllocate(255, 255, 255)
-blue = im:colorAllocate(0, 0, 255)
+local white = im:colorAllocate(255, 255, 255)
+local blue = im:colorAllocate(0, 0, 255)
 
 im:filledRectangle(0, 0, 100, 100, white)
 im:stringFTCircle(50, 50, 40, 10, 0.9, "./Vera.ttf", 24, "Powered", "by Lua", blue)

demos/clock.lua

@@ -5,7 +5,7 @@
 
 local gd = require("gd")
 
-function createClock(size, hours, minutes)
+local function createClock(size, hours, minutes)
   local im = gd.createTrueColor(size, size)
   local white = im:colorAllocate(255, 255, 255)
   local gray = im:colorAllocate(128, 128, 128)
@@ -55,8 +55,8 @@ function createClock(size, hours, minutes)
   return im
 end
 
-dh = os.date("*t")
-im = createClock(100, dh.hour, dh.min)
+local dh = os.date("*t")
+local im = createClock(100, dh.hour, dh.min)
 
 print("Content-type: image/png")
 print("Refresh: 60")            -- Ask browser to reload the image after 60s

demos/counter.lua

@@ -4,26 +4,26 @@
 
 local gd = require("gd")
 
-datafile = "counter.txt"
-fp = io.open(datafile, "r+")
+local datafile = "counter.txt"
+local fp = io.open(datafile, "r+")
+local cnt = 0
 if fp then
   cnt = tonumber(fp:read("*l")) or 0
   fp:seek("set", 0)
 else
-  cnt = 0
   fp = io.open(datafile, "w")
   assert(fp)
 end
 cnt = cnt + 1
 fp:write(cnt .."\n")
 fp:close()
 
-sx = math.max(string.len(tostring(cnt)), 1) * 8
-im = gd.create(sx, 15)
+local sx = math.max(string.len(tostring(cnt)), 1) * 8
+local im = gd.create(sx, 15)
 -- first allocated color defines the background.
-white = im:colorAllocate(255, 255, 255)
+local white = im:colorAllocate(255, 255, 255)
 im:colorTransparent(white)
-black = im:colorAllocate(0, 0, 0)
+local black = im:colorAllocate(0, 0, 0)
 im:string(gd.FONT_MEDIUM, 1, 1, cnt, black)
 
 print("Content-type: image/png\n")

demos/ellipse.lua

@@ -1,9 +1,9 @@
 local gd = require("gd")
-im = gd.createTrueColor(80, 80)
+local im = gd.createTrueColor(80, 80)
 assert(im)
 
-black = im:colorAllocate(0, 0, 0)
-white = im:colorAllocate(255, 255, 255)
+local black = im:colorAllocate(0, 0, 0)
+local white = im:colorAllocate(255, 255, 255)
 im:filledEllipse(40, 40, 70, 50, white)
 
 im:png("out.png")

demos/fontconfig.lua

@@ -3,10 +3,10 @@
 
 local gd = require("gd")
 
-im = gd.createTrueColor(220, 190)
-white = im:colorAllocate(255, 255, 255)
-black = im:colorAllocate(0, 0, 0)
-x, y = im:sizeXY()
+local im = gd.createTrueColor(220, 190)
+local white = im:colorAllocate(255, 255, 255)
+local black = im:colorAllocate(0, 0, 0)
+local x, y = im:sizeXY()
 im:filledRectangle(0, 0, x, y, white)
 
 gd.useFontConfig(true)

demos/gifanim.lua

@@ -1,10 +1,10 @@
 local gd = require("gd")
 
-im = gd.createPalette(80, 80)
+local im = gd.createPalette(80, 80)
 assert(im)
 
-black = im:colorAllocate(0, 0, 0)
-white = im:colorAllocate(255, 255, 255)
+local black = im:colorAllocate(0, 0, 0)
+local white = im:colorAllocate(255, 255, 255)
 im:gifAnimBegin("out.gif", true, 0)
 
 for i = 1, 10 do

demos/gifanim2.lua

@@ -1,10 +1,10 @@
 local gd = require("gd")
 
-im = gd.createPalette(120, 120)
+local im = gd.createPalette(120, 120)
 assert(im)
 
-black = im:colorAllocate(0, 0, 0)
-blue = {}
+local black = im:colorAllocate(0, 0, 0)
+local blue = {}
 for i = 1, 20 do
   blue[i] = im:colorAllocate(0, 0, 120+6*i)
 end

demos/gifanim3.lua

@@ -1,15 +1,15 @@
 local gd = require("gd")
 
-im = gd.createPalette(120, 120)
+local im = gd.createPalette(120, 120)
 assert(im)
 
-black = im:colorAllocate(0, 0, 0)
-blue = {}
+local black = im:colorAllocate(0, 0, 0)
+local blue = {}
 for i = 1, 20 do
   blue[i] = im:colorAllocate(0, 0, 120+6*i)
 end
 
-fp = io.open("out.gif", "w")
+local fp = io.open("out.gif", "w")
 assert(fp, "Failed to open file for writting")
 
 fp:write(im:gifAnimBeginStr(true, 0))

demos/lualogo.lua

@@ -33,7 +33,6 @@ function makelogo(size)
   im:filledArc(cxy, cxy, ediam, ediam, 0, 360, blue, gd.ARC)
 
   im:setThickness(math.max(0.02 * ediam, 1))
-  local i
   for i = 0, 360, 10 do
     im:arc(cxy, cxy, odiam, odiam, i, i+5, gray)
   end
@@ -57,5 +56,5 @@ function makelogo(size)
   return im2
 end
 
-makelogo(140):png("lualogo.png")
-os.execute("display lualogo.png")
+makelogo(140):png("out.png")
+os.execute("display out.png")

demos/poly.lua

@@ -1,10 +1,10 @@
 local gd = require("gd")
 
-im = gd.createTrueColor(80, 80)
+local im = gd.createTrueColor(80, 80)
 assert(im)
 
-black = im:colorAllocate(0, 0, 0)
-white = im:colorAllocate(255, 255, 255)
+local black = im:colorAllocate(0, 0, 0)
+local white = im:colorAllocate(255, 255, 255)
 
 im:polygon( { { 10, 10 }, { 10, 20 }, { 20, 20 }, { 20, 10 } }, white)
 im:filledPolygon( { { 30, 30 }, { 30, 40 }, { 40, 40 }, { 40, 30 } }, white)

demos/setstyle.lua

@@ -29,6 +29,7 @@ for i = 0, 100, 2 do
     im:line(i, i, i+50, i, gd.STYLED)
 end
 
-im:png("styled.png")
+im:png("out.png")
+os.execute("display out.png")
 
 

demos/stdfont.lua

@@ -1,10 +1,10 @@
 local gd = require("gd")
 
-x, y = 140, 110
+local x, y = 140, 110
 
-im = gd.createPalette(x, y)
-white = im:colorAllocate(255, 255, 255)
-black = im:colorAllocate(0, 0, 0)
+local im = gd.createPalette(x, y)
+local white = im:colorAllocate(255, 255, 255)
+local black = im:colorAllocate(0, 0, 0)
 
 im:string(gd.FONT_TINY, 10, 10, "gd.FONT_TINY", black)
 im:string(gd.FONT_SMALL, 10, 20, "gd.FONT_SMALL", black)
@@ -15,5 +15,6 @@ im:string(gd.FONT_GIANT, 10, 65, "gd.FONT_GIANT", black)
 im:line(60, 93, 70, 93, black)
 im:string(gd.FONT_SMALL, 80, 86, "= 10 px", black)
 
-im:png("stdfonts.png")
+im:png("out.png")
+os.execute("display out.png")
 

demos/steg.lua

@@ -90,13 +90,13 @@ to stop. Of course, this program will also do this boring job for Bob.
 local gd = require("gd")
 
 
-function getLSB(n)
+local function getLSB(n)
   return math.mod(n, 2) ~= 0
 end
 
 
 -- Bizarre way to do some bit-level operations without bitlib.
-function setLSB(n, b)
+local function setLSB(n, b)
   if type(b) == "number" then
     if b == 0 then
       b = false
@@ -124,7 +124,7 @@ function setLSB(n, b)
 end
 
 
-function intToBitArray(n)
+local function intToBitArray(n)
   local ret = {}
   local i = 0
   while n ~= 0 do
@@ -137,7 +137,7 @@ function intToBitArray(n)
 end
 
 
-function printBitArray(a)
+local function printBitArray(a)
   local i
   for i = a.size,0,-1 do
     if a[i] then
@@ -149,7 +149,7 @@ function printBitArray(a)
 end
 
 
-function mergeMessage(im, msg)
+local function mergeMessage(im, msg)
   local w, h = im:sizeXY()
   msg = msg .. string.char(0)
   local len = string.len(msg)
@@ -204,7 +204,7 @@ function mergeMessage(im, msg)
 end
 
 
-function getMessage(im)
+local function getMessage(im)
   local msg = {}
   local w, h = im:sizeXY()
   local x, y = 0, 0
@@ -245,7 +245,7 @@ function getMessage(im)
 end
 
 
-function compare(fimg1, fimg2)
+local function compare(fimg1, fimg2)
   local im1 = gd.createFromPng(fimg1)
   if not im1 then
     print("ERROR: " .. fimg1 .. " bad PNG data.")
@@ -288,7 +288,7 @@ function compare(fimg1, fimg2)
 end
 
 
-function usage()
+local function usage()
   print("Usage:")
   print(" lua steg.lua hide <input file> <output file>")
   print(" lua steg.lua show <input file>")
@@ -308,7 +308,7 @@ if not arg[1] or not arg[2] then
 end
 
 if arg[1] == "show" then
-  im = gd.createFromPng(arg[2])
+  local im = gd.createFromPng(arg[2])
   if not im then    
     print("ERROR: Bad image data.")
     os.exit(1)
@@ -322,14 +322,14 @@ if arg[1] == "hide" then
     usage()
     os.exit(1)
   end
-  im = gd.createFromPng(arg[2])
+  local im = gd.createFromPng(arg[2])
   if not im then
     print("ERROR: Bad image data.")
     os.exit(1)
   end
   print("Type your message and press CTRL+D to finish.")
-  msg = io.read("*a")
-  oim, l, t = mergeMessage(im, msg)
+  local msg = io.read("*a")
+  local oim, l, t = mergeMessage(im, msg)
   if not oim then
     print("ERROR: Image is too small for the message.")
     os.exit(1)
@@ -348,7 +348,7 @@ if arg[1] == "diff" then
     usage()
     os.exit(1)
   end
-  oim = compare(arg[2], arg[3])
+  local oim = compare(arg[2], arg[3])
   if not oim:png(arg[4]) then
     print("ERROR: Failed to write output file.")
     os.exit(1)

demos/test.lua

@@ -2,29 +2,29 @@ local gd = require("gd")
 
 math.randomseed(os.time())
 
-im = gd.createFromJpeg("./bugs.jpg")
+local im = gd.createFromJpeg("./bugs.jpg")
 assert(im)
-sx, sy = im:sizeXY()
+local sx, sy = im:sizeXY()
 
-im2 = gd.createTrueColor(2*sx, sy)
-black = im2:colorAllocate(0, 0, 0)
-white = im2:colorAllocate(255, 255, 255)
+local im2 = gd.createTrueColor(2*sx, sy)
+local black = im2:colorAllocate(0, 0, 0)
+local white = im2:colorAllocate(255, 255, 255)
 gd.copy(im2, im, 0, 0, 0, 0, sx, sy, sx, sy)
 
-sx2, sy2 = im2:sizeXY()
+local sx2, sy2 = im2:sizeXY()
 im2:stringUp(gd.FONT_SMALL, 5, sy2-10, gd.VERSION, white)
 
 for i = 0, 14 do
   for j = 0, 24 do
-    rcl = im2:colorAllocate(math.random(255), math.random(255), 
+    local rcl = im2:colorAllocate(math.random(255), math.random(255), 
             math.random(255))
     im2:filledRectangle(sx+20+j*10, i*20+40, sx+30+j*10, i*20+50, rcl)
   end
 end
 
 im2:string(gd.FONT_GIANT, sx+80, 10, "Powered by Lua", white)
 
-blackTr = im2:colorAllocateAlpha(0, 0, 0, 80)
+local blackTr = im2:colorAllocateAlpha(0, 0, 0, 80)
 im2:stringFT(blackTr, "./Vera.ttf", 140, 0, 70, 130, "gd")
 im2:stringFT(white, "./Vera.ttf", 45, math.pi/5, 340, 250, "FreeType")