Examples

From GiderosMobile


Here are some examples from the Gideros forum.
All samples are ready to use. Enjoy!


STRING

A COLORED STRING @hgy29

local text = TextField.new(nil, "This is a \e[color=#f005]semi transparent red\e[color] text")
text:setPosition(32, 64)
stage:addChild(text)


GFX

DRAWING A CIRCLE @xxx

xCircle = Core.class(Sprite)

function xCircle:init(r, steps, color)
   color = color or 0xff0000
   local sin, cos, d2r = math.sin, math.cos, math.pi / 180
   local c = Shape.new()
   c:setFillStyle(Shape.SOLID, color)
   c:setLineStyle(0)
   c:beginPath()
   c:moveTo(r * sin(0 * d2r), r * cos(0 * d2r))
   for i = 0, 360, 360 / steps  do
     c:lineTo(r * sin(i * d2r), r * cos(i * d2r))
   end    
   c:endPath()
   self:addChild(c)
end

--- usage
--xCircle(10, 5, 0xFF0000)


DRAWING ANOTHER CIRCLE (stars, circles, flowers) @gemboy100

Circle = Core.class(Mesh)

function Circle:init(__, r, COLOR, STEPS, PULL, CUT)
   local r1 = r -- h radius
   local r2 = r -- v radius
   local STEPS = STEPS or math.floor((math.pi / 4) * r)
   local COLOR = COLOR or 0
   local PULL = PULL or 0
   local CUT = CUT or 2
   if STEPS < 3 then STEPS = 3 end
   if PULL > r then PULL = 0
   elseif PULL > 0 then
      if CUT then
         while STEPS % CUT ~= 0 do
            STEPS += 1
         end
      elseif STEPS % 2 ~= 0 then STEPS +=1 end
   end

   self.c = {}
   local v = {}
   local ind = {}
   local _i = 0
   local _l = 0
   local ou = 2
   local step = math.pi / (STEPS / 2)
   local pull = 0

   v[#v + 1] = 0; v[#v + 1] = 0
   self.c[#self.c + 1] = COLOR; self.c[#self.c + 1] = 1

   --for i=step,PI*2, step do -- buggy cuz of infinite PI
   for i = 1, STEPS do
      _l += 1
      if _l % CUT == 0 then pull = PULL else pull = 0 end

      v[#v + 1] = (r1 - pull) * math.cos(i * step)
      v[#v + 1] = (r2 - pull) * math.sin(i * step)

      v[#v + 1] = (r1 - pull + ou) * math.cos(i * step)
      v[#v + 1] = (r2 - pull + ou) * math.sin(i * step)
   --
      self.c[#self.c + 1] = COLOR
      self.c[#self.c + 1] = 1

      self.c[#self.c + 1] = COLOR
      self.c[#self.c + 1] = 0.0
   --
      ind[#ind + 1] = _i + 3
      ind[#ind + 1] = _i + 5
      ind[#ind + 1] = _i + 4

      ind[#ind + 1] = _i + 4
      ind[#ind + 1] = _i + 3
      ind[#ind + 1] = _i + 2

      ind[#ind + 1] = _i + 4
      ind[#ind + 1] = _i + 2
      ind[#ind + 1] = 1

      _i = _i + 2
   end

   ind[#ind - 7] = 2
   ind[#ind - 6] = 3
   ind[#ind - 5] = 2
   ind[#ind - 2] = 2

   self:setVertexArray(v)
   self:setIndexArray(ind)
   self:setColorArray(self.c)
end

function Circle:setColor(c, a)
   local a = a or 1
   self.c[1] = c
   self.c[2] = a
   for i = 3, #self.c, 4 do
      self.c[i + 0] = c
      self.c[i + 1] = a
   end
   self:setColorArray(self.c)
end

-- usage
--star
local c1 = Circle.new(false, 80, 0xffaa55, 9, 50)
c1:setColor(0xff0000, 0.75)
c1:setPosition(1 * 64, 1 * 64)
stage:addChild(c1)

--circle
local c2 = Circle.new(false, 32, 0xffaa55)
c2:setPosition(3 * 64, 1 * 64)
stage:addChild(c2)

--flowers
local c3 = Circle.new(false, 32, 0xffaa55, 80, 10, 8)
c3:setPosition(1 * 64, 3 * 64)
stage:addChild(c3)
local c4 = Circle.new(false, 64, 0xffaa55, 100, 5)
c4:setPosition(3 * 64, 3 * 64)
stage:addChild(c4)


DRAWING AN ARC @hgvyas123

function drawArc(xc,yc,xradius,yradius,startAngle,endAngle,isFill)
   if yradius == nil then
      yradius = xradius
   end
   if startAngle == nil then
      startAngle = 0
   end
   if endAngle == nil then
      endAngle = 360
   end
   if isFill == nil then
      isFill = true
   end

   local shape = Shape.new()
   if isFill then
      shape:setFillStyle(Shape.SOLID, 0xff0000, 0.5)
   else
      shape:setLineStyle(3, 0x000000)
   end
   shape:beginPath()
   for i=startAngle,endAngle do
      if i == 1 then
         shape:moveTo(math.sin(math.rad(i)) * xradius, math.cos(math.rad(i)) * yradius)
      else
         shape:lineTo(math.sin(math.rad(i)) * xradius, math.cos(math.rad(i)) * yradius)
      end
   end
   if isFill then
      shape:closePath()
   end
   shape:endPath()

   shape:setPosition(xc, yc)
   return shape
end

--- usage
--function drawArc(xc,yc,xradius,yradius,startAngle,endAngle,isFill)
local myarc = drawArc(128, 128, 64, 64, 0, 5 * 45, false)
stage:addChild(myarc)


CIRCULAR PROGRESS @hgy29

CircularProgress = Core.class(Sprite)
 
function CircularProgress:init(radius, width, color, font, fontscale)
   self.radiusMin, self.radiusMax = radius - width / 2, radius + width / 2
   self.color = color
   self.font = font
   self:addChild(Path2D.new())
   local text = TextField.new(font, "-")
   text:setTextColor(color)
   text:setScale(fontscale or 1)
   self:addChild(text)
--   self:setValue(0.4)
end

function CircularProgress:setValue(val, xcolor, xalpha)
   local angs, ange = 0, math.pi * val * 1.999
   local rl, rh = self.radiusMin, self.radiusMax
   local ta = self:getChildAt(1)
   local ra = math.floor(val * 2)
--   ta:setLineColor(self.color, xalpha)
--   ta:setFillColor(self.color, xalpha)
   ta:setLineColor(xcolor, xalpha)
   ta:setFillColor(xcolor, xalpha)
   ta:setPath("MALAZ",
      math.sin(angs) * rl, -math.cos(angs) * rl,
      rl, rl, 0, ra, 1,
      math.sin(ange) * rl, -math.cos(ange) * rl,
      math.sin(ange) * rh, -math.cos(ange) * rh,
      rh, rh, 0, ra, 0,
      math.sin(angs) * rh, -math.cos(angs) * rh
      )
   ta:setLineThickness(4, 0.5)
   ta = self:getChildAt(2)
   ta:setText(("%d%%"):format(math.floor(val * 100)))
   ta:setTextColor(xcolor)
   ta:setAlpha(xalpha)
   local tax, tay, taw, tah = ta:getBounds(ta)
   ta:setAnchorPosition(tax + taw / 2, tay + tah / 2)
   return ta
end

--- usage
-- meter = CircularProgress.new(40, 5, 0x770000, nil, 2)


SAVING IMAGE TO FILE @mokalux

Saving an image or part of an image to disk.

function xsaveJPGtoDoc(xoriginalimgfile, xposx, xposy, xsizew, xsizeh, xdestimgname)
   local mytexture = Texture.new(xoriginalimgfile)
   local mybmp = Bitmap.new(mytexture)
   local rt = RenderTarget.new(mybmp:getWidth(), mybmp:getHeight())
   rt:draw(mybmp)
   rt:save("|D|tex_"..xdestimgname..".jpg", xposx, xposy, xsizew, xsizeh)
   
   return "|D|tex_"..xdestimgname..".jpg"
end

--- usage
--local xsavedjpg = xsaveJPGtoDoc("gfx/bg/dark.jpg", 0, 0, 64, 64, "dark")


PREVENT FROM DRAGGING A SHAPE OVER OTHER SHAPE @hgvyas123

--[[
Drag the shapes around with your mouse or fingers
This code is MIT licensed, see http://www.opensource.org/licenses/mit-license.php
(C) 2010 - 2011 Gideros Mobile
]]
 
local myShapes = {}

function Sprite:collidesWith(sprite2)
   local x,y,w,h = self:getBounds(stage)
   local x2,y2,w2,h2 = sprite2:getBounds(stage)

   return not ((y+h < y2) or (y > y2+h2) or (x > x2+w2) or (x+w < x2))
end

local function onMouseDown(self, event)
   if self:hitTestPoint(event.x, event.y) then
      self.isFocus = true
      self.x0 = event.x
      self.y0 = event.y

      event:stopPropagation()
   end
end

local function onMouseMove(self, event)
   if self.isFocus then
      self.lastX,self.lastY = self:getPosition()
      local dx = event.x - self.x0
      local dy = event.y - self.y0
      self:setX(self:getX() + dx)
      self:setY(self:getY() + dy)
      self.x0 = event.x
      self.y0 = event.y
      for i=1,#myShapes do
         if myShapes[i] ~= self then
            if self:collidesWith(myShapes[i]) then
               self:setPosition(self.lastX,self.lastY)
            end
         end
      end
      event:stopPropagation()
   end
end

local function onMouseUp(self, event)
   if self.isFocus then
      self.isFocus = false
      event:stopPropagation()
   end
end

for i=1,5 do
   local shape = Shape.new()
   shape:setLineStyle(3, 0x000000)
   shape:setFillStyle(Shape.SOLID, 0xff0000, 0.5)
   shape:beginPath()
   shape:moveTo(0, 0)
   shape:lineTo(100, 0)
   shape:lineTo(100, 50)
   shape:lineTo(0, 50)
   shape:closePath()
   shape:endPath()

   shape:setX(math.random(0, 320 - 100))
   shape:setY(math.random(0, 480 - 50))

   shape.isFocus = false

   shape:addEventListener(Event.MOUSE_DOWN, onMouseDown, shape)
   shape:addEventListener(Event.MOUSE_MOVE, onMouseMove, shape)
   shape:addEventListener(Event.MOUSE_UP, onMouseUp, shape)

   stage:addChild(shape)
   table.insert(myShapes, shape)
end

local info = TextField.new(nil, "drag the shapes around with your mouse or fingers")
info:setPosition(23, 50)
stage:addChild(info)


CHECK POINT IS IN POLYGON @atilim

function pointInPolygon(vertices, x, y)
   local intersectionCount = 0

   local x0 = vertices[#vertices].x - x
   local y0 = vertices[#vertices].y - y

   for i= 1, #vertices do
      local x1 = vertices[i].x - x
      local y1 = vertices[i].y - y

      if y0 > 0 and y1 <= 0 and x1 * y0 > y1 * x0 then
         intersectionCount = intersectionCount + 1
      end

      if y1 > 0 and y0 <= 0 and x0 * y1 > y0 * x1 then
         intersectionCount = intersectionCount + 1
      end

      x0 = x1
      y0 = y1
   end

   return (intersectionCount % 2) == 1
end

local vertices = {
   {x = 0, y = 0},
   {x = 0, y = 100},
   {x = 100, y = 100},
   {x = 0, y = 0},
}

local shape = Shape.new()
shape:setFillStyle(Shape.SOLID, 0xff0000)
shape:setLineStyle(5, 0x0000ff, 1)
shape:beginPath()
shape:moveTo(vertices[1].x,vertices[1].y)
shape:lineTo(vertices[2].x,vertices[2].y)
shape:lineTo(vertices[3].x,vertices[3].y)
shape:lineTo(vertices[4].x,vertices[4].y)
shape:endPath()

shape:setPosition(64, 64)
stage:addChild(shape)

local vertices_shape = {}
for i = 1, #vertices do
   vertices_shape[i] = {x = vertices[i].x + shape:getX(), y = vertices[i].y + shape:getY()}
end

shape:addEventListener(Event.MOUSE_HOVER, function(e)
   if pointInPolygon(vertices_shape, e.x, e.y) then
      print("hovering the shape")
   else
      print("not hovering the shape")
   end
end)


STENCIL OPERATION @hgy29

Stencil operation ex01.png

local star = Bitmap.new(Texture.new("gfx/star.png", true))
stage:addChild(star)

local bluestar_tex = RenderTarget.new(star:getWidth(), star:getHeight())
local bluestar = Bitmap.new(bluestar_tex)
stage:addChild(bluestar) bluestar:setPosition(0, 128)

-- Here is the magic!
-- Clear our render target to all alpha
bluestar_tex:clear(0x000000, 0)
--[[Gideros don't draw pixels with alpha value of 0,
they are discarded at early stage. Use the stencil to get a
footprint of visible pixels of source image]]
star:setStencilOperation {
	stencilClear = true,
	stencilWriteMask = 1,
	stencilFunc = Sprite.STENCIL_ALWAYS,
	depthPass = Sprite.STENCIL_INCR
}
bluestar_tex:draw(star)
-- Render the footprint in the color we want
local mask = Pixel.new(0x00FFFF, 1, star:getWidth(), star:getHeight())
mask:setStencilOperation {
	stencilClear = false,
	stencilMask = 1,
	stencilWriteMask = 1, 
	stencilRef = 0,
	stencilFunc = Sprite.STENCIL_NOTEQUAL,
	depthPass = Sprite.STENCIL_KEEP,
	stencilFail = Sprite.STENCIL_KEEP
}
bluestar_tex:draw(mask)
 
--[[ The result is possibly enough here, but we lost the smoothed edges of
the original texture in the process. We can restore them with a smart alpha
blending trick:]]
star:setBlendMode(Sprite.ZERO, Sprite.SRC_ALPHA)
bluestar_tex:draw(star)
 
-- Restore our initial bitmap blending mode, to show it on screen as usual
star:setBlendMode(Sprite.ALPHA)


ANIMATION

FPS @atilim

local fps = TextField.new(nil, "")
fps:setScale(2)
fps:setPosition(16, 16)
fps:setTextColor(0xff0000)
stage:addChild(fps)

local frame = 0
local timer = os.timer()
local qFloor = math.floor
local function displayFps(event)
   frame = frame + 1
   if frame == 60 then
      local currentTimer = os.timer()
      fps:setText(qFloor(60 / (currentTimer - timer)))
      frame = 0
      timer = currentTimer
      -- optional
      --print ("memory used: "..qFloor(collectgarbage("count")/1000),"Mb")
   end
end

-- Add FPS Counter to stage
stage:addEventListener(Event.ENTER_FRAME, displayFps)


MOVING A SPRITE IN AN ARC PATH @Disciple

local bone = Sprite.new()
--local boneImg = Bitmap.new(Texture.new("gfx/enemy01.png")) -- add your gfx!
-- or use this one (Pixel)
local boneImg = Pixel.new(0x0000ff, 0.75, 32, 48)
stage:addChild(bone)
bone:addChild(boneImg)
boneImg:setAnchorPoint(0.5, 0.5)

local grav = -15 / 2
local velx = -3 / 2
local rotvel = -3 / 2
local x = 300 / 2
local y = 400 / 2
local rotation = 0

function enterFrame ()
   grav = grav + 0.3
   x = x + velx
   y = y + grav
   rotation = rotation + rotvel
   bone:setRotation(rotation)
   bone:setPosition(x, y)
end

stage:addEventListener(Event.ENTER_FRAME, enterFrame)


MOVING A SPRITE IN AN HORIZONTAL SINE WAVE @Harrison

local blimp1 = Pixel.new(0x0000ff, 0.5, 32, 64)
blimp1:setAnchorPoint(0.5, 0.5)
blimp1:setPosition(0, 128)
blimp1.speedx = 1.2
stage:addChild(blimp1)

function onEnterFrame(event)
   local posx = blimp1:getX() + blimp1.speedx
   local posy = blimp1:getY() + (1.5 * math.sin(0.075 * posx))
   if blimp1:getX() > application:getContentWidth() + blimp1:getWidth() / 2 then
      blimp1:setPosition(-blimp1:getWidth() / 2, 128)
      posx = blimp1:getX()
      posy = blimp1:getY()
   end
   blimp1:setPosition(posx, posy)
end

stage:addEventListener(Event.ENTER_FRAME, onEnterFrame)


MOVING A SPRITE IN A VERTICAL COS WAVE @Harrison

local blimp2 = Pixel.new(0x00ff00, 0.5, 64, 32)
blimp2:setAnchorPoint(0.5, 0.5)
blimp2:setPosition(128, 0)
blimp2.speedy = 1.3
stage:addChild(blimp2)

function onEnterFrame(event)
   local posy = blimp2:getY() + blimp2.speedy -- posy first
   local posx = blimp2:getX() + 2.5 * math.cos(0.1 * posy) -- posy first
   if blimp2:getY() > application:getContentHeight() + blimp2:getHeight() then
      blimp2:setPosition(128, -blimp2:getHeight())
      posx = blimp2:getX()
      posy = blimp2:getY()
   end
   blimp2:setPosition(posx, posy)
end

stage:addEventListener(Event.ENTER_FRAME, onEnterFrame)


FILES

CSV @hgy29

Load a CSV file.

function loadCSV(file)
   local function csvsplit(line)
      local t, w, l2 = {}, nil, nil
      while #line > 0 do
         w, l2 = line:match("\"([^\"]*)\"[,\r\n]?(.*)") -- Check for quoted string
         if not w then w, line = line:match("([^,]*)[,\r\n]?(.*)") -- Non quoted 
         else line = l2 end
         if not w then break end --Nothing or issue, break
         t[#t + 1] = w
      end
      return t
   end
   local headers, csv = nil, {}
   for line in io.lines(file) do
      f = csvsplit(line)
      if not headers then -- Assume first line is headers
         headers = {} for n, v in ipairs(f) do headers[v] = n end
      else
         csv[#csv + 1] = f
      end
   end
   csv.getField = function(self, row, field) return self[row][headers[field]] end
   return csv
end

--- usage
--csv=loadCSV("135-bis-bt.csv")
--print(csv:getField(4,"Value"))
--print(csv:getField(7,"Time")


JSON @xxx

Loading and saving preferences.

require "json" -- you must add JSON plugin to your app

function saveData(filepath, value)
   local contents = json.encode(value)
   local file = io.open("|D|"..filepath, "w") -- create file
   file:write(contents) -- save json string in file
   io.close(file)
end

function getData(filepath)
   local value
   local file = io.open("|D|"..filepath, "r")
   if file then
      local contents = file:read("*a") -- read contents
      value = json.decode(contents) -- decode json
      io.close(file)
   end
   return value
end

-- globals
g_configfilepath = "myplayground.txt"
g_language = application:getLanguage()
g_theme = "dark"
g_isaudio = true
g_level = 1

-- init prefs
local mydata = getData(g_configfilepath) -- try to read information from file

-- if no prefs file, create it
if not mydata then
   mydata = {g_language, g_theme, g_isaudio, g_level}
   saveData(g_configfilepath, mydata) -- create file and save datas
else
   g_language = mydata[1]
   g_theme = mydata[2]
   g_isaudio = mydata[3]
   g_level = mydata[4]
end

-- save prefs
function mySavePrefs(xlanguage, xtheme, xisaudio, xlevel)
   local mydata = {xlanguage or g_language, xtheme or g_theme, xisaudio or g_isaudio, xlevel or g_level}
   saveData(g_configfilepath, mydata) -- save new datas
   g_language = mydata[1]
   g_theme = mydata[2]
   g_isaudio = mydata[3]
   g_level = mydata[4]
end

--- usage
--mySavePrefs("en", "dark", true, 1)
--print(g_language)
--print(g_theme)











More to come God's willing...