Work-around for Kerbal Space Program under 10-bit displays (or any Unity game, really)

kspfix.c

// Compile as kspfix.so and load with LD_PRELOAD

#define _GNU_SOURCE

#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#include <dlfcn.h>
#include <GL/glx.h>

GLXFBConfig *glXChooseFBConfig(Display *dpy, int screen, const int *attrib_list, int *nelements)
{
    for (int *attr = (int *)attrib_list; *attr != None; attr += 2) {
        if (attr[0] == GLX_ALPHA_SIZE) {
            attr[1] = 0;
        }
    }

    typeof(glXChooseFBConfig) *old_fbconfig;
    old_fbconfig = dlsym(RTLD_NEXT, "glXChooseFBConfig");
    return (*old_fbconfig)(dpy, screen, attrib_list, nelements);
}

__GLXextFuncPtr glXGetProcAddressARB(const GLubyte *name)
{
    if (strcmp((const char *) name, "glXChooseFBConfig") == 0)
        return glXChooseFBConfig;

    typeof(glXGetProcAddressARB) *old_getproc;
    old_getproc = dlsym(RTLD_NEXT, "glXGetProcAddressARB");
    return (*old_getproc)(name);
}