[require]
GLSL >= 1.10

[vertex shader]
varying vec2 texcoord;

void main()
{
	gl_Position = gl_Vertex;
	texcoord = (gl_Vertex.xy + 1.0) / 2.0;
}

[fragment shader]
varying vec2 texcoord;
uniform sampler2D tex;

void main()
{
	vec4 t1 = texture2D(tex, texcoord) * 0.5;
	vec4 t2 = texture2D(tex, texcoord) * 0.5;
	gl_FragColor = t1 + t2;
}

[test]
uniform int tex 0
texture rgbw 0 (8, 8)

draw rect -1 -1 2 2
relative probe rgb (0.0, 0.0) (1.0, 0.0, 0.0, 1.0)
relative probe rgb (1.0, 0.0) (0.0, 1.0, 0.0, 1.0)
relative probe rgb (0.0, 1.0) (0.0, 0.0, 1.0, 1.0)
relative probe rgb (1.0, 1.0) (1.0, 1.0, 1.0, 1.0)