I answer myself
it seems that with AppGameKit ,you can't display an image alone
we have to create a Sprite to display the image!
this code works
#renderer "Advanced"
// show all errors
SetErrorMode(2)
// set window properties
SetWindowTitle( "test" )
SetWindowSize( 1024, 768, 0 )
SetWindowAllowResize( 1 ) // allow the user to resize the window
// set display properties
SetVirtualResolution( 1024, 768 ) // doesn't have to match the window
SetOrientationAllowed( 1, 1, 1, 1 ) // allow both portrait and landscape on mobile devices
SetSyncRate( 60, 0 )
//SetScissor( 0,0,0,0 ) // use the maximum available screen space, no black borders
UseNewDefaultFonts( 1 )
img=CreateRenderImage( 1024, 768, 0, 0 )
SetRenderToImage( img,0 )
For y=1 to 768 -1 step 10
For x= 1 to 1024 -1 step 10
coul=random(127,255)
coul2=random(127,255)
coul3=random(127,255)
DrawBox(x,y,x+10,y+10,MakeColor(coul,coul2,coul3), MakeColor(coul,coul2,coul3),MakeColor(coul,coul2,coul3),MakeColor(coul,coul2,coul3),1)
//DrawLine(x,y,x+10,y+10,255,0,0)
render()
Next x
Next y
setRenderToScreen()
CreateSprite(1,img)
SetPrintColor(255, 120, 12 )
do
Print( ScreenFPS() )
sync()
loop
