[require]
GLSL >= 1.10

[vertex shader]
void main()
{
	gl_Position = gl_Vertex;
}

[fragment shader]
const vec4 v = vec4(0., 1., 0., 1.);

void main()
{
	gl_FragColor = v;
	if (mod(gl_FragCoord.x, 2.0) >= 1.0)
		return;  // return for every second pixel

	gl_FragColor = vec4(1.0) - v;
}

[test]
draw rect -1 -1 2 2
probe rgb 0 0 1 0 1
probe rgb 1 0 0 1 0
probe rgb 2 0 1 0 1
probe rgb 3 0 0 1 0