// should data be uploaded as an array of 3 floats, or padded to 4 floats each block?
layout (std140) uniform blockA {
    vec3 foo;
};

// should data be uploaded as an array of 4 floats, 5 floats, or 8 floats for each block?
layout (std140) uniform blockB {
    vec3  foo;
    float bar;
};

// same as above, but with a boolean
// should data be uploaded as an array of 4 floats, 5 floats, or 8 floats for each block?
layout (std140) uniform blockC {
    vec3  foo;
    bool bar;
};

// will reversing this order have any effect on possible packing?
layout (std140) uniform blockD {
    float foo;
    vec3 bar;
};

// should data be uploaded as an array of 1 byte values, padded to 4 bytes (float), or padded 16 bytes (vec4)?
layout (std140) uniform blockE {
    bool foo;
};