reBounce - softfp-to-hardfp LD_PRELOAD hack for Bounce on N9
From http://thpmaemo.blogspot.com/2021/02/rebounce-soft
Posted on 2021-02-11 07:41:00 UTC.
This depends on Bounce (the N900 .deb) and SDL 1.2 being installed. Google "bounce_1.0.0_armel.deb" for the former, and use n9repomirror for the latter.
#if 0
gcc -Os -shared -fPIC -lSDL -o librebounce.so rebounce.c
LD_PRELOAD=$(pwd)/librebounce.so /opt/bounce/bin/bounce
exit 0
#endif
/**
* reBounce -- softfp-to-hardfp LD_PRELOAD hack for Bounce on N9
*
* Bounce was a really nice 2009 tech demo on the N900. This
* makes this tech demo work on an N9 by translating the calls
* that use floating point arguments to the hardfp ABI. It also
* fixes input using SDL1.2 to get sensor values from sensorfw.
*
* Known issues: Audio is muted on startup until mute is toggled.
*
* 2021-02-11 Thomas Perl <m@thp.io>
**/
#define _GNU_SOURCE
#include <stdio.h>
#include <dlfcn.h>
#include <pthread.h>
#include <SDL/SDL.h>
#define SFP __attribute__((pcs("aapcs")))
typedef unsigned int GLuint;
static void *
sensor_thread(void *user_data)
{
SDL_Init(SDL_INIT_JOYSTICK | SDL_INIT_VIDEO);
SDL_Joystick *accelerometer = SDL_JoystickOpen(0);
while (1) {
SDL_JoystickUpdate();
float x = 0.053888f * SDL_JoystickGetAxis(accelerometer, 0);
float y = 0.053888f * SDL_JoystickGetAxis(accelerometer, 1);
float z = 0.053888f * SDL_JoystickGetAxis(accelerometer, 2);
FILE *out = fopen("/dev/shm/bounce.sensor.tmp", "wb");
fprintf(out, "%f %f %f\n", -y, x, z);
fclose(out);
rename("/dev/shm/bounce.sensor.tmp", "/dev/shm/bounce.sensor");
SDL_Delay(10);
}
return NULL;
}
FILE *
fopen(const char *filename, const char *mode)
{
FILE *(*fopen_orig)(const char *, const char *) = dlsym(RTLD_NEXT, "fopen");
if (strcmp(filename, "/sys/class/i2c-adapter/i2c-3/3-001d/coord") == 0) {
static int sensor_inited = 0;
if (!sensor_inited) {
sensor_inited = 1;
pthread_t thread;
pthread_create(&thread, NULL, sensor_thread, NULL);
}
filename = "/dev/shm/bounce.sensor";
}
return fopen_orig(filename, mode);
}
#define f_f(name) float SFP name(float x) { return ((float (*)(float))dlsym(RTLD_NEXT, #name))(x); }
#define d_d(name) double SFP name(double x) { return ((double (*)(double))dlsym(RTLD_NEXT, #name))(x); }
#define f_ff(name) float SFP name(float x, float y) { return ((float (*)(float, float))dlsym(RTLD_NEXT, #name))(x, y); }
#define d_dd(name) double SFP name(double x, double y) { return ((double (*)(double, double))dlsym(RTLD_NEXT, #name))(x, y); }
f_f(sinhf) f_f(coshf) f_f(tanhf) f_f(asinf) f_f(acosf) f_f(atanf) f_f(sinf) f_f(cosf) f_f(tanf) f_f(expf) f_f(logf)
f_f(log10f) f_f(ceilf) f_f(floorf) d_d(log) d_d(sin) f_ff(atan2f) f_ff(fmodf) d_dd(atan2) d_dd(pow) d_dd(fmod)
double SFP
frexp(double value, int *exp)
{
return ((double (*)(double, int *))dlsym(RTLD_NEXT, "frexp"))(value, exp);
}
double SFP
ldexp(double x, int n)
{
return ((double (*)(double, int))dlsym(RTLD_NEXT, "ldexp"))(x, n);
}
double SFP
modf(double value, double *iptr)
{
return ((double (*)(double, double *))dlsym(RTLD_NEXT, "modf"))(value, iptr);
}
void SFP
glClearColor(float r, float g, float b, float a)
{
((void (*)(float, float, float, float))dlsym(RTLD_NEXT, "glClearColor"))(r, g, b, a);
}
void SFP
glUniform4f(GLuint location, float v0, float v1, float v2, float v3)
{
((void (*)(GLuint, float, float, float, float))dlsym(RTLD_NEXT, "glUniform4f"))(location, v0, v1, v2, v3);
}
void SFP
glUniform1f(GLuint location, float v0)
{
((void (*)(GLuint, float))dlsym(RTLD_NEXT, "glUniform1f"))(location, v0);
}