render.Spin
render.Spin()
Description
Swaps the frame buffers/cycles the frame. In other words, this updates the screen.
If you take a really long time during a single frame render, it is a good idea to use this and let the user know that the game isn't stuck.
Example
Code from Super DOF; Push the current progress of rendering onto the screen and display a percentage of completion near the bottom right.
-- Restore RT
render.SetRenderTarget( OldRT )
-- Render our result buffer to the screen
matFSB:SetFloat( "$alpha", 1 )
matFSB:SetTexture( "$basetexture", texFSB )
render.SetMaterial( matFSB )
render.DrawScreenQuad()
cam.Start2D()
local add = ( i / ( math.pi*2 ) ) * ( 1 / passes )
local percent = string.format( "%.1f", ( mul - ( 1 / passes ) + add ) * 100 )
draw.DrawText( percent .. "%", "GModWorldtip", view.w - 100, view.h - 100, Color( 0, 0, 0, 255 ), TEXT_ALIGN_CENTER )
draw.DrawText( percent .. "%", "GModWorldtip", view.w - 101, view.h - 101, Color( 255, 255, 255, 255 ), TEXT_ALIGN_CENTER )
cam.End2D()
render.Spin()
Output: 
