<!-- Generated from sdk/bindings/fortran/README.md and protocol/v2/api.json by protocol/v2/codegen/docs.js; do not edit. Run `make api`. -->
# The Fortran binding

The generated `clunkyard` module uses `ISO_C_BINDING` for the core's C ABI.
Records are interoperable derived types, enums are integer constants, and
procedures return statuses and copy results into the caller's variables.
`CY_NONE` means absent; negative statuses are errors. `cy_last_error` gives
the error message. Text is UTF-8 with explicit byte lengths. A list takes an
array, its capacity and a count; `CY_SHORT` gives the required capacity.
The binding contains no protocol parser, tracker or physics implementation.

Install with `make install SDK=/opt/clunkyard/sdk`. Build with
`gfortran -std=f2018 -O2 -ffree-line-length-none
-I/opt/clunkyard/sdk/bindings/fortran bot.f90
/opt/clunkyard/sdk/bindings/fortran/clunkyard.o
/opt/clunkyard/sdk/lib/libclunkyard.a -lpthread -ldl -lm -o bot`.
Only the native executable is shipped in the artifact.

`cy_open` opens standard I/O and protects the protocol pipe. For tests, use
`cy_open_memory`, `cy_session_feed` and `cy_session_reply`. Each successful
`cy_session_next` reads a hello, state or end event. Send a reply with
`cy_session_send`. After `CY_E_INTERNAL`, send the core's empty reply and
continue; the next state recovers the session. `cy_session_forfeit` reports
a robot forfeit.

## A tiny robot

```fortran
program tiny
use clunkyard
implicit none
type(c_ptr) :: robot
type(cy_contact) :: target
type(cy_solution) :: aim
type(cy_scan) :: last
integer(c_int32_t) :: status,event,can_fire
real(c_double) :: heading,power,delta,control
status=cy_open(2,0,'clunkyard-fortran',17,'2.0.0',5,robot)
do
  status=cy_session_next(robot,event)
  if(status==CY_E_INTERNAL)then
    status=cy_session_send(robot)
    if(status<0)exit
    cycle
  end if
  if(status/=CY_OK.or.event==CY_EVENT_END)exit
  if(event==CY_EVENT_STATE)then
    status=cy_me_heading(robot,heading)
    if(cy_sensors_nearest(robot,target)/=CY_OK)then
      status=cy_drive_throttle(robot,0.75_c_double);status=cy_drive_turn(robot,0.25_c_double)
      status=cy_scanner_heading(robot,heading);status=cy_scanner_arc(robot,40.0_c_double)
      status=cy_scanner_last(robot,last);status=cy_status_text(robot,'SEARCH',6);status=cy_status_value(robot,last%arc)
    else
      status=cy_gun_power_for_flight_time(robot,target%range,1.0_c_double,power)
      if(cy_gun_lead(robot,target,power,aim)/=CY_OK)then
        aim%heading=target%bearing;aim%pitch=target%elevation
      end if
      status=cy_gun_aim_heading(robot,aim%heading);status=cy_gun_aim_pitch(robot,aim%pitch)
      status=cy_gun_can_fire(robot,power,10.0_c_double,can_fire)
      if(can_fire/=0)then
        status=cy_gun_fire(robot);status=cy_gun_power(robot,power)
      end if
      status=cy_angles_angle_diff(target%bearing,heading,delta)
      status=cy_angles_clamp(delta,-1.0_c_double,1.0_c_double,control)
      status=cy_drive_throttle(robot,0.5_c_double);status=cy_drive_turn(robot,control)
      status=cy_scanner_heading(robot,target%bearing);status=cy_scanner_arc(robot,10.0_c_double)
      status=cy_status_text(robot,'TRACK',5);status=cy_status_value(robot,target%range)
    end if
  end if
  status=cy_session_send(robot)
end do
call cy_close(robot)
end program
```

`make test` calls every generated Fortran declaration against the core's
conformance vectors. It verifies the foreign record layout and marshalling,
exact floating-point results, optional values and serialized acts.

## Names

Every entry of the robot API 2.0.0 in Fortran.
[names.md](names.md) has every language side by side.

| Canonical | Form | Fortran |
| --- | --- | --- |
| `match.mode` | property | cy_match_mode |
| `match.ruleset` | property | cy_match_ruleset |
| `match.control` | property | cy_match_control |
| `match.robots` | property | cy_match_robots |
| `match.is_3d` | property | cy_match_is_3d |
| `match.tick_rate` | property | cy_match_tick_rate |
| `match.max_ticks` | property | cy_match_max_ticks |
| `match.robot_id` | call | cy_robot_id |
| `clock.tick` | property | cy_clock_tick |
| `clock.seconds` | property | cy_clock_seconds |
| `clock.remaining_ticks` | property | cy_clock_remaining_ticks |
| `arena.size` | property | cy_arena_size |
| `arena.gravity` | property | cy_arena_gravity |
| `arena.terrain_kind` | property | cy_arena_terrain_kind |
| `arena.ground_height` | call | cy_arena_ground_height |
| `me.health` | property | cy_me_health |
| `me.position` | property | cy_me_position |
| `me.velocity` | property | cy_me_velocity |
| `me.heading` | property | cy_me_heading |
| `me.pitch` | property | cy_me_pitch |
| `me.roll` | property | cy_me_roll |
| `me.angular_velocity` | property | cy_me_angular_velocity |
| `me.attitude` | property | cy_me_attitude |
| `me.grounded` | property | cy_me_grounded |
| `me.altitude` | property | cy_me_altitude |
| `me.applied` | property | cy_me_applied |
| `battery.charge` | property | cy_battery_charge |
| `battery.capacity` | property | cy_battery_capacity |
| `battery.regen` | property | cy_battery_regen |
| `battery.sustainable_drive` | property | cy_battery_sustainable_drive |
| `battery.compute` | property | cy_battery_compute |
| `battery.drive_cost` | call | cy_battery_drive_cost |
| `drive.hover_lift` | property | cy_drive_hover_lift |
| `drive.set` | control | cy_drive_throttle, cy_drive_turn, cy_drive_pitch_turn |
| `drive.forces` | control | cy_drive_thrust, cy_drive_strafe, cy_drive_lift, cy_drive_yaw_torque, cy_drive_pitch_torque, cy_drive_roll_torque, cy_drive_brake |
| `drive.get` | call | cy_drive_get_throttle, cy_drive_get_turn, cy_drive_get_pitch_turn, cy_drive_get_thrust, cy_drive_get_strafe, cy_drive_get_lift, cy_drive_get_yaw_torque, cy_drive_get_pitch_torque, cy_drive_get_roll_torque, cy_drive_get_brake |
| `gun.aim_now` | property | cy_gun_aim_now |
| `gun.cooldown_ticks` | property | cy_gun_cooldown_ticks |
| `gun.spread` | property | cy_gun_spread |
| `gun.max_power` | property | cy_gun_max_power |
| `gun.damage_scale` | property | cy_gun_damage_scale |
| `gun.can_fire` | call | cy_gun_can_fire |
| `gun.shot_speed` | call | cy_gun_shot_speed |
| `gun.shot_cost` | call | cy_gun_shot_cost |
| `gun.reload_ticks` | call | cy_gun_reload_ticks |
| `gun.shot_damage` | call | cy_gun_shot_damage |
| `gun.power_for_speed` | call | cy_gun_power_for_speed |
| `gun.power_for_flight_time` | call | cy_gun_power_for_flight_time |
| `gun.lead` | call | cy_gun_lead |
| `gun.lead_point` | call | cy_gun_lead_point |
| `gun.aim` | control | cy_gun_aim_heading, cy_gun_aim_pitch |
| `gun.fire` | control | cy_gun_fire, cy_gun_power |
| `gun.get` | call | cy_gun_get_aim_heading, cy_gun_get_aim_pitch, cy_gun_get_fire, cy_gun_get_power |
| `scanner.last` | property | cy_scanner_last |
| `scanner.proximity_range` | property | cy_scanner_proximity_range |
| `scanner.reach` | call | cy_scanner_reach |
| `scanner.arc_for_reach` | call | cy_scanner_arc_for_reach |
| `scanner.set` | control | cy_scanner_heading, cy_scanner_arc, cy_scanner_pitch |
| `scanner.get` | call | cy_scanner_get_heading, cy_scanner_get_arc, cy_scanner_get_pitch |
| `sensors.contacts` | property | cy_sensors_contacts |
| `sensors.nearest` | property | cy_sensors_nearest |
| `sensors.cues` | property | cy_sensors_cues |
| `sensors.contact` | call | cy_sensors_contact |
| `sensors.position_of` | call | cy_sensors_position_of |
| `tracker.cue` | property | cy_tracker_cue |
| `tracker.nearest_bearing_rate` | property | cy_tracker_nearest_bearing_rate |
| `tracker.velocity` | call | cy_tracker_velocity |
| `tracker.position` | call | cy_tracker_position |
| `tracker.last_seen` | call | cy_tracker_last_seen |
| `tracker.configure` | call | cy_tracker_configure |
| `nav.zone` | property | cy_nav_zone |
| `nav.zone.margin` | call | cy_nav_zone_margin |
| `nav.zone.contains` | call | cy_nav_zone_contains |
| `nav.zone.distance_from` | call | cy_nav_zone_distance_from |
| `nav.storm` | property | cy_nav_storm |
| `nav.storm.margin` | call | cy_nav_storm_margin |
| `nav.storm.contains` | call | cy_nav_storm_contains |
| `nav.storm.distance_from` | call | cy_nav_storm_distance_from |
| `nav.hill` | property | cy_nav_hill |
| `nav.hill.margin` | call | cy_nav_hill_margin |
| `nav.hill.contains` | call | cy_nav_hill_contains |
| `nav.hill.distance_from` | call | cy_nav_hill_distance_from |
| `nav.pickups` | property | cy_nav_pickups |
| `nav.nearest_pickup` | call | cy_nav_nearest_pickup |
| `nav.field_distance` | call | cy_nav_field_distance |
| `score.me` | property | cy_score_me |
| `score.best` | property | cy_score_best |
| `score.armour` | property | cy_score_armour |
| `angles.normalize` | call | cy_angles_normalize |
| `angles.angle_diff` | call | cy_angles_angle_diff |
| `angles.bearing_to` | call | cy_angles_bearing_to |
| `angles.elevation_to` | call | cy_angles_elevation_to |
| `angles.direction` | call | cy_angles_direction |
| `angles.distance` | call | cy_angles_distance |
| `angles.clamp` | call | cy_angles_clamp |
| `status.set` | control | cy_status_text, cy_status_value |
| `status.get` | call | cy_status_get_text, cy_status_get_value |
| `raw.number` | call | cy_raw_number |
| `raw.text` | call | cy_raw_text |
| `raw.has` | call | cy_raw_has |
| `raw.flag` | call | cy_raw_flag |
| `raw.count` | call | cy_raw_count |
| `raw.line` | call | cy_raw_line |
| `raw.extra` | call | cy_raw_extra |
| `session.event` | property | cy_session_event |
| `session.next` | call | cy_session_next |
| `session.send` | call | cy_session_send |
| `session.forfeit` | call | cy_session_forfeit |
| `session.log` | call | cy_session_log |
| `session.feed` | call | cy_session_feed |
| `session.reply` | call | cy_session_reply |