testing.glsl

    vec4 result = vec4(0, 0, 0, 1);
    int abc = 0;
    for (int i = 0; i < 2000; i ++) {
        abc += i;
    }

    result.x = float(abc) / 200000.0;
    ivec2 storePos = ivec2(gl_GlobalInvocationID.xy);
    imageStore(destTex, storePos, result);