lae.cc

glCreateTextures(GL_TEXTURE_2D, 1, &headptr_tex_);
glTextureStorage2D(headptr_tex_, 1, GL_R32UI, window_width, window_height);
glBindImageTexture(0, headptr_tex_, 0, GL_FALSE, 0, GL_READ_WRITE, GL_R32UI);

// glsl
layout(binding=0, r32ui) uniform uimage2D headptrs;
...
for (uint kthnode = imageLoad(headptrs, ivec2(gl_FragCoord.xy)).r;
        kthnode != 0xffffffff;
        kthnode = nodes[kthnode]) {
    frags[num_frags++] = nodes[kthnode];  
}