[require]
GL >= 2.0
GLSL >= 1.10

[fragment shader]


void main(void)
{
mat2 m = mat2(0.5, 0.5, 0.5, 0.5);
m[0][0] = m[0][0] + 0.3;
m[0][0] = m[0][0] - 0.3;
     gl_FragColor = vec4(m[0][0], m[0][1], m[1][0], m[1][1]); 
}

[test]
draw rect -1 -1 2 2
probe all rgba 0.5 0.5 0.5 0.5