Sets the size of the device you have designed all your artwork for, this allows AGK to downsize the images to save memory on lower resolution devices. Note that commands such as SetSpriteAnimation that might assume image sizes must account for images that have been reduced. For example loading a 512x512 image and using SetSpriteAnimation(spr,128,128,16) should instead use SetSpriteAnimation(spr,GetImageWidth(img)/4,GetImageHeight(img)/4,16) in case the image is no longer 512 in size.
This command has been deprecated and you should use LoadImageResized to adjust image sizes depending on the device resolution, you can check the device resolution with GetDeviceWidth and GetDeviceHeight.
SetIntendedDeviceSize( width, height )