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[golanu21]

local screenx,screeny = guiGetScreenSize() 
-- animation 
local state = 'starting' 
local phase = 0 
local alpha = 0 
local lastTick = getTickCount() 
  
local function getProgress( addtick ) 
    local now = getTickCount() 
    local elapsedTime = now - lastTick 
    local duration = lastTick+addtick - lastTick 
    local progress = elapsedTime / duration 
    return progress 
end 
  
function drawlogpan() 
     local RectangleX,RectangleY = interpolateBetween(x/3.8, y/3.8, 0, x/1.97, y/2.75, 0, getProgress(500), 'InQuad') 
    dxDrawRectangle(RectangleX, RectangleY, x/4, y/3, tocolor(0, 0, 0, 150)) 
    showCursor(false) 
end 
  
addEventHandler ( "onClientGUIClick", loginbtn, 
function ( ) 
    addEventHandler("onClientRender", getRootElement(), drawlogpan) 
end, false ) 

why the interpolateBetween it's not working... the rectangle just appear