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

in vec4 AttrPosition;
in vec4 AttrColor0;
in vec4 AttrColor1;
in vec4 AttrTexCoord0;

out vec4 PixelColor0;
out vec4 PixelColor1;
out vec4 PixelTexCoord0;

uniform vec4 ScreenSize;

void main()
{
	gl_Position = vec4(AttrPosition.xy / ScreenSize.xy * 2.0 - 1.0, 1.0, 1.0);
	gl_Position.y = -gl_Position.y;
	PixelColor0 = AttrColor0.bgra;
	PixelColor1 = AttrColor1.bgra;
	PixelTexCoord0 = AttrTexCoord0;
}