AP_Scripting: Add Location get_distance_NED and get_distance_NE

Fixes a regression with nil punning which broke Location:offset() and
adds a test script that is suitable for CI to test this sort of thing

libraries/AP_Scripting/examples/scripting_test.lua

@@ -0,0 +1,48 @@
+-- this is a script which is primarily intended to test the scripting bindings and be used with autotest
+-- however it may be useful to some as a demo of how the API's can be used, this example is much less
+-- heavily commented, and may require quite a bit more RAM to run in
+
+local loop_time = 500 -- number of ms between runs
+
+function is_equal(v1, v2, tolerance)
+  return math.abs(v1 - v2) < (tolerance or 0.0001)
+end
+
+function test_offset(ofs_e, ofs_n)
+  local manipulated_pos = Location()
+  manipulated_pos:offset(ofs_e, ofs_n)
+  local distance_offset = manipulated_pos:get_distance(Location())
+  if distance_offset < 0 then
+    gcs:send_text(0, "Location:get_distance() returned a negative number")
+    return false
+  end
+  local error_dist = distance_offset - math.sqrt((ofs_e*ofs_e)+(ofs_n*ofs_n))
+  if error_dist > 0.1 then
+    gcs:send_text(0, string.format("Failed offset %.1f, %.1f with an error of %f", ofs_e, ofs_n, error_dist))
+    return false
+  end
+  local from_origin_NE = Location():get_distance_NE(manipulated_pos)
+  if (not is_equal(ofs_e, from_origin_NE:x(), 0.01)) or (not is_equal(ofs_n, from_origin_NE:y(), 0.01)) then
+    gcs:send_text(0, string.format("Failed to offset %.1f, %.1f %.1f %.1f", ofs_e, ofs_n, from_origin_NE:x(), from_origin_NE:y()))
+    return false
+  end
+  local from_origin_NED = Location():get_distance_NED(manipulated_pos)
+  if (not is_equal(from_origin_NED:x(), from_origin_NE:x())) or (not is_equal(from_origin_NED:y(), from_origin_NE:y())) then 
+    gcs:send_text(0, string.format("Distance NED != NE %.1f, %.1f %.1f %.1f", from_origin_NED:x(), from_origin_NED:y(), from_origin_NE:x(), from_origin_NE:y()))
+    return false
+  end
+  return true
+end
+
+function update()
+  local all_tests_passed = true
+  -- each test should run then and it's result with the previous ones
+  all_tests_passed = test_offset(500, 200) and all_tests_passed
+
+  if all_tests_passed then
+    gcs:send_text(3, "Internal tests passed")
+  end
+  return update, loop_time
+end
+
+return update() -- run immediately before starting to reschedule

libraries/AP_Scripting/generator/description/bindings.desc

@@ -13,6 +13,8 @@ userdata Location method get_distance float Location
 userdata Location method offset void float -FLT_MAX FLT_MAX float -FLT_MAX FLT_MAX
 userdata Location method get_vector_from_origin_NEU boolean Vector3f'Null
 userdata Location method get_bearing float Location
+userdata Location method get_distance_NED Vector3f Location
+userdata Location method get_distance_NE Vector2f Location
 
 include AP_AHRS/AP_AHRS.h
 

libraries/AP_Scripting/generator/src/main.c

@@ -1191,7 +1191,7 @@ void emit_userdata_method(const struct userdata *data, const struct method *meth
       emit_checker(arg->type, arg_count, skipped, "    ", "argument");
       arg_count++;
     }
-    if (arg->type.type != TYPE_LITERAL || arg->type.flags & TYPE_FLAGS_NULLABLE) {
+    if (arg->type.type == TYPE_LITERAL || arg->type.flags & TYPE_FLAGS_NULLABLE) {
       skipped++;
     }
     arg = arg->next;

libraries/AP_Scripting/lua_generated_bindings.cpp

@@ -390,6 +390,30 @@ static int Vector3f___sub(lua_State *L) {
     return 1;
 }
 
+static int Location_get_distance_NE(lua_State *L) {
+    binding_argcheck(L, 2);
+    Location * ud = check_Location(L, 1);
+    Location & data_2 = *check_Location(L, 2);
+    const Vector2f &data = ud->get_distance_NE(
+            data_2);
+
+    new_Vector2f(L);
+    *check_Vector2f(L, -1) = data;
+    return 1;
+}
+
+static int Location_get_distance_NED(lua_State *L) {
+    binding_argcheck(L, 2);
+    Location * ud = check_Location(L, 1);
+    Location & data_2 = *check_Location(L, 2);
+    const Vector3f &data = ud->get_distance_NED(
+            data_2);
+
+    new_Vector3f(L);
+    *check_Vector3f(L, -1) = data;
+    return 1;
+}
+
 static int Location_get_bearing(lua_State *L) {
     binding_argcheck(L, 2);
     Location * ud = check_Location(L, 1);
@@ -423,7 +447,7 @@ static int Location_offset(lua_State *L) {
     const float raw_data_2 = luaL_checknumber(L, 2);
     luaL_argcheck(L, ((raw_data_2 >= MAX(-FLT_MAX, -INFINITY)) && (raw_data_2 <= MIN(FLT_MAX, INFINITY))), 2, "argument out of range");
     const float data_2 = raw_data_2;
-    const float raw_data_3 = luaL_checknumber(L, 2);
+    const float raw_data_3 = luaL_checknumber(L, 3);
     luaL_argcheck(L, ((raw_data_3 >= MAX(-FLT_MAX, -INFINITY)) && (raw_data_3 <= MIN(FLT_MAX, INFINITY))), 3, "argument out of range");
     const float data_3 = raw_data_3;
     ud->offset(
@@ -478,6 +502,8 @@ const luaL_Reg Location_meta[] = {
     {"relative_alt", Location_relative_alt},
     {"lng", Location_lng},
     {"lat", Location_lat},
+    {"get_distance_NE", Location_get_distance_NE},
+    {"get_distance_NED", Location_get_distance_NED},
     {"get_bearing", Location_get_bearing},
     {"get_vector_from_origin_NEU", Location_get_vector_from_origin_NEU},
     {"offset", Location_offset},
@@ -513,10 +539,10 @@ static int GCS_set_message_interval(lua_State *L) {
     const lua_Integer raw_data_2 = luaL_checkinteger(L, 2);
     luaL_argcheck(L, ((raw_data_2 >= MAX(0, 0)) && (raw_data_2 <= MIN(MAVLINK_COMM_NUM_BUFFERS, UINT8_MAX))), 2, "argument out of range");
     const uint8_t data_2 = static_cast<uint8_t>(raw_data_2);
-    const uint32_t raw_data_3 = *check_uint32_t(L, 2);
+    const uint32_t raw_data_3 = *check_uint32_t(L, 3);
     luaL_argcheck(L, ((raw_data_3 >= MAX(0U, 0U)) && (raw_data_3 <= MIN(UINT32_MAX, UINT32_MAX))), 3, "argument out of range");
     const uint32_t data_3 = static_cast<uint32_t>(raw_data_3);
-    const lua_Integer raw_data_4 = luaL_checkinteger(L, 2);
+    const lua_Integer raw_data_4 = luaL_checkinteger(L, 4);
     luaL_argcheck(L, ((raw_data_4 >= MAX(-1, INT32_MIN)) && (raw_data_4 <= MIN(INT32_MAX, INT32_MAX))), 4, "argument out of range");
     const int32_t data_4 = raw_data_4;
     const MAV_RESULT &data = ud->set_message_interval(