/**
* Determines the next articulated part to attach
* @param index Position in chain
* @param front_type Front engine type
* @param front Front engine
* @param mirrored Returns whether the part shall be flipped.
* @return engine to add or INVALID_ENGINE
*/
static EngineID GetNextArticPart(uint index, EngineID front_type, Vehicle *front = NULL, bool *mirrored = NULL)
{
assert(front == NULL || front->engine_type == front_type);
uint16 callback = GetVehicleCallback(CBID_VEHICLE_ARTIC_ENGINE, index, 0, front_type, front);
if (callback == CALLBACK_FAILED || GB(callback, 0, 8) == 0xFF) return INVALID_ENGINE;
if (mirrored != NULL) *mirrored = HasBit(callback, 7);
return GetNewEngineID(GetEngineGRF(front_type), Engine::Get(front_type)->type, GB(callback, 0, 7));
}
/**
* Determines the next articulated part to attach
* @param index Position in chain
* @param front_type Front engine type
* @param front Front engine
* @param mirrored Returns whether the part shall be flipped.
* @return engine to add or INVALID_ENGINE
*/
static EngineID GetNextArticulatedPart(uint index, EngineID front_type, Vehicle *front = NULL, bool *mirrored = NULL)
{
assert(front == NULL || front->engine_type == front_type);
const Engine *front_engine = Engine::Get(front_type);
uint16 callback = GetVehicleCallback(CBID_VEHICLE_ARTIC_ENGINE, index, 0, front_type, front);
if (callback == CALLBACK_FAILED) return INVALID_ENGINE;
if (front_engine->GetGRF()->grf_version < 8) {
/* 8 bits, bit 7 for mirroring */
callback = GB(callback, 0, 8);
if (callback == 0xFF) return INVALID_ENGINE;
if (mirrored != NULL) *mirrored = HasBit(callback, 7);
callback = GB(callback, 0, 7);
} else {
/* 15 bits, bit 14 for mirroring */
if (callback == 0x7FFF) return INVALID_ENGINE;
if (mirrored != NULL) *mirrored = HasBit(callback, 14);
callback = GB(callback, 0, 14);
}
return GetNewEngineID(front_engine->GetGRF(), front_engine->type, callback);
}
