qzdoom/wadsrc/static/shaders/glsl/screenquad.vp

layout(location = 0) in vec4 PositionInProjection;
layout(location = 1) in vec2 UV;
layout(location = 0) out vec2 TexCoord;

void main()
{
	gl_Position = PositionInProjection;
	TexCoord = UV;
}