ardupilot/libraries/AP_Mission/AP_Mission_ChangeDetector.cpp

63 lines
2.4 KiB
C++

/// @file AP_Mission_ChangeDetector.cpp
/// @brief Detects changes in the next few nav commands in the mission
#include "AP_Mission_ChangeDetector.h"
#if HAL_MISSION_ENABLED
// detect external changes to mission
bool AP_Mission_ChangeDetector::check_for_mission_change()
{
AP_Mission *mission = AP::mission();
if (mission == nullptr) {
return false;
}
// check if mission has been updated
const uint32_t change_time_ms = mission->last_change_time_ms();
const bool update_time_changed = (change_time_ms != mis_change_detect.last_change_time_ms);
// check if active command index has changed
const uint16_t curr_cmd_idx = mission->get_current_nav_index();
const bool curr_cmd_idx_changed = (curr_cmd_idx != mis_change_detect.curr_cmd_index);
// no changes if neither mission update time nor active command index has changed
if (!update_time_changed && !curr_cmd_idx_changed) {
return false;
}
// the mission has been updated (but maybe not changed) and/or the current command index has changed
// check the contents of the next three commands to ensure they have not changed
// and update storage so we can detect future changes
bool cmds_changed = false; // true if upcoming command contents have changed
// retrieve cmds from mission and compare with mis_change_detect
uint8_t num_cmds = 0;
uint16_t cmd_idx = curr_cmd_idx;
AP_Mission::Mission_Command cmd[mis_change_detect_cmd_max];
while ((num_cmds < ARRAY_SIZE(cmd)) && mission->get_next_nav_cmd(cmd_idx, cmd[num_cmds])) {
num_cmds++;
if ((num_cmds > mis_change_detect.cmd_count) || (cmd[num_cmds-1] != mis_change_detect.cmd[num_cmds-1])) {
cmds_changed = true;
mis_change_detect.cmd[num_cmds-1] = cmd[num_cmds-1];
}
cmd_idx = cmd[num_cmds-1].index+1;
}
// mission has changed if number of upcoming commands does not match mis_change_detect
if (num_cmds != mis_change_detect.cmd_count) {
cmds_changed = true;
}
// update mis_change_detect with last change time, command index and number of commands
mis_change_detect.last_change_time_ms = change_time_ms;
mis_change_detect.curr_cmd_index = curr_cmd_idx;
mis_change_detect.cmd_count = num_cmds;
// mission has changed if upcoming command contents have changed without the current command index changing
return cmds_changed && !curr_cmd_idx_changed;
}
#endif // AP_MISSION_ENABLED