/**
* A helper function for _eglMatchDriver. It finds the first driver that can
* initialize the display and return.
*/
static _EGLDriver *
_eglMatchAndInitialize(_EGLDisplay *dpy)
{
_EGLDriver *drv = NULL;
EGLint i = 0;
if (!_eglAddDrivers()) {
_eglLog(_EGL_WARNING, "failed to find any driver");
return NULL;
}
if (dpy->Driver) {
drv = dpy->Driver;
/* no re-matching? */
if (!drv->API.Initialize(drv, dpy))
drv = NULL;
return drv;
}
while (i < _eglModules->Size) {
_EGLModule *mod = (_EGLModule *) _eglModules->Elements[i];
if (!_eglLoadModule(mod)) {
/* remove invalid modules */
_eglEraseArray(_eglModules, i, _eglFreeModule);
continue;
}
if (mod->Driver->API.Initialize(mod->Driver, dpy)) {
drv = mod->Driver;
break;
}
else {
i++;
}
}
return drv;
}
/**
* Match a display to a driver. The display is initialized unless use_probe is
* true.
*
* The matching is done by finding the first driver that can initialize the
* display, or when use_probe is true, the driver with highest score.
*/
_EGLDriver *
_eglMatchDriver(_EGLDisplay *dpy, EGLBoolean use_probe)
{
_EGLModule *mod;
_EGLDriver *best_drv = NULL;
EGLint best_score = 0;
EGLint major, minor, i;
_eglLockMutex(&_eglModuleMutex);
if (!_eglAddDrivers()) {
_eglUnlockMutex(&_eglModuleMutex);
return EGL_FALSE;
}
/* match the loaded modules */
for (i = 0; i < _eglModules->Size; i++) {
mod = (_EGLModule *) _eglModules->Elements[i];
if (!mod->Driver)
break;
if (use_probe) {
EGLint score = (mod->Driver->Probe) ?
mod->Driver->Probe(mod->Driver, dpy) : 1;
if (score > best_score) {
best_drv = mod->Driver;
best_score = score;
}
}
else {
if (mod->Driver->API.Initialize(mod->Driver, dpy, &major, &minor)) {
best_drv = mod->Driver;
best_score = 100;
}
}
/* perfect match */
if (best_score >= 100)
break;
}
/* load more modules */
if (!best_drv) {
EGLint first_unloaded = i;
while (i < _eglModules->Size) {
mod = (_EGLModule *) _eglModules->Elements[i];
assert(!mod->Driver);
if (!_eglLoadModule(mod)) {
/* remove invalid modules */
_eglEraseArray(_eglModules, i, _eglFreeModule);
continue;
}
if (use_probe) {
best_score = (mod->Driver->Probe) ?
mod->Driver->Probe(mod->Driver, dpy) : 1;
}
else {
if (mod->Driver->API.Initialize(mod->Driver, dpy, &major, &minor))
best_score = 100;
}
if (best_score > 0) {
best_drv = mod->Driver;
/* loaded modules come before unloaded ones */
if (first_unloaded != i) {
void *tmp = _eglModules->Elements[i];
_eglModules->Elements[i] =
_eglModules->Elements[first_unloaded];
_eglModules->Elements[first_unloaded] = tmp;
}
break;
}
else {
_eglUnloadModule(mod);
i++;
}
}
}
_eglUnlockMutex(&_eglModuleMutex);
if (best_drv) {
_eglLog(_EGL_DEBUG, "the best driver is %s (score %d)",
best_drv->Name, best_score);
if (!use_probe) {
dpy->Driver = best_drv;
dpy->Initialized = EGL_TRUE;
dpy->APImajor = major;
dpy->APIminor = minor;
}
}
return best_drv;
}
