[require]
GLSL >= 1.30

[vertex shader]
#version 130
void main()
{
	gl_Position = gl_Vertex;
}

[fragment shader]
#version 130

void main()
{
	int i = (int(gl_FragCoord.x) & 1) + (int(gl_FragCoord.y) & 1) * 2;

	switch (i) {
	case 0:
		gl_FragColor = vec4(1.0, 0.0, 0.0, 0.0);
		break;
	case 1:
		gl_FragColor = vec4(0.0, 1.0, 0.0, 0.0);
		break;
	case 2:
		gl_FragColor = vec4(0.0, 0.0, 1.0, 0.0);
		break;
	case 3:
		gl_FragColor = vec4(1.0, 1.0, 1.0, 0.0);
		break;
	default:
		gl_FragColor = vec4(1.0, 0.0, 1.0, 0.0);
	}
}

[test]
draw rect -1 -1 2 2

# test a couple of 2x2 blocks.

probe rgba 0 0 1.0 0.0 0.0 0.0
probe rgba 1 0 0.0 1.0 0.0 0.0
probe rgba 0 1 0.0 0.0 1.0 0.0
probe rgba 1 1 1.0 1.0 1.0 0.0

probe rgba 2 0 1.0 0.0 0.0 0.0
probe rgba 3 0 0.0 1.0 0.0 0.0
probe rgba 2 1 0.0 0.0 1.0 0.0
probe rgba 3 1 1.0 1.0 1.0 0.0