blur.lua

local blur = Material("pp/blurscreen", "noclamp")
function draw.DrawBlur(x, y, w, h, amount)
	render.ClearStencil()
	render.SetStencilEnable( true )
	render.SetStencilReferenceValue( 1 )
	render.SetStencilTestMask( 1 )
	render.SetStencilWriteMask( 1 )

	render.SetStencilCompareFunction( STENCILCOMPARISONFUNCTION_NEVER )
	render.SetStencilFailOperation( STENCILOPERATION_REPLACE )
	render.SetStencilPassOperation( STENCILOPERATION_REPLACE )
	render.SetStencilZFailOperation( STENCILOPERATION_REPLACE )

	surface.SetDrawColor( 255, 255, 255, 255 )
	surface.DrawRect(x,y,w,h)

	render.SetStencilCompareFunction( STENCILCOMPARISONFUNCTION_EQUAL )
	render.SetStencilFailOperation( STENCILOPERATION_KEEP )
	render.SetStencilPassOperation( STENCILOPERATION_KEEP )
	render.SetStencilZFailOperation( STENCILOPERATION_KEEP )

	surface.SetMaterial( blur )
	surface.SetDrawColor( 255, 255, 255, 255 )

	for i = 0, 1, 0.33 do
		blur:SetFloat( '$blur', i * (amount or 0.2) )
		blur:Recompute()
		render.UpdateScreenEffectTexture()

		surface.DrawTexturedRect( 0, 0, ScrW(), ScrH() )
	end
	render.SetStencilEnable( false )
end

function draw.StencilBlur( panel, w, h )
	render.ClearStencil()
	render.SetStencilEnable( true )
	render.SetStencilReferenceValue( 1 )
	render.SetStencilTestMask( 1 )
	render.SetStencilWriteMask( 1 )

	render.SetStencilCompareFunction( STENCILCOMPARISONFUNCTION_NEVER )
	render.SetStencilFailOperation( STENCILOPERATION_REPLACE )
	render.SetStencilPassOperation( STENCILOPERATION_REPLACE )
	render.SetStencilZFailOperation( STENCILOPERATION_REPLACE )

	surface.SetDrawColor( 255, 255, 255, 255 )
	surface.DrawRect( 0, 0, w, h )

	render.SetStencilCompareFunction( STENCILCOMPARISONFUNCTION_EQUAL )
	render.SetStencilFailOperation( STENCILOPERATION_KEEP )
	render.SetStencilPassOperation( STENCILOPERATION_KEEP )
	render.SetStencilZFailOperation( STENCILOPERATION_KEEP )

		surface.SetMaterial( blur )
		surface.SetDrawColor( 255, 255, 255, 255 )

		for i = 0, 1, 0.33 do
			blur:SetFloat( '$blur', 5 *i )
			blur:Recompute()
			render.UpdateScreenEffectTexture()

			local x, y = panel:GetPos()

			surface.DrawTexturedRect( -x, -y, ScrW(), ScrH() )
		end

	render.SetStencilEnable( false )
end