ardupilot/libraries/AP_Scripting/AP_Scripting_helpers.cpp

#include "AP_Scripting_helpers.h"
#include <AP_Scripting/lua_generated_bindings.h>

/// Fast param access via pointer helper class

// Custom lua constructor with optional param name
int lua_new_Parameter(lua_State *L) {

    const int args = lua_gettop(L);
    if (args > 1) {
        return luaL_argerror(L, args, "too many arguments");
    }
    const char * name = nullptr;
    if (args == 1) {
        name = luaL_checkstring(L, 1);
    }

    // This chunk is the same as the auto generated constructor
    luaL_checkstack(L, 2, "Out of stack");
    void *ud = lua_newuserdata(L, sizeof(Parameter));
    memset(ud, 0, sizeof(Parameter));
    new (ud) Parameter();
    luaL_getmetatable(L, "Parameter");
    lua_setmetatable(L, -2);

    if (args == 0) {
        // no arguments, nothing to do
        return 1;
    }

    if (!static_cast<Parameter*>(ud)->init(name)) {
        return luaL_error(L, "No parameter: %s", name);
    }

    return 1;
}

// init by name
bool Parameter::init(const char *name)
{
    vp = AP_Param::find(name, &vtype);
    if (vp == nullptr) {
        return false;
    }
    return true;
}

// init by info, to get the value of old params
bool Parameter::init_by_info(uint16_t key, uint32_t group_element, enum ap_var_type type)
{
    switch (type) {
    case AP_PARAM_INT8:
        vp = new AP_Int8;
        break;
    case AP_PARAM_INT16:
        vp = new AP_Int16;
        break;
    case AP_PARAM_INT32:
        vp = new AP_Int32;
        break;
    case AP_PARAM_FLOAT:
        vp = new AP_Float;
        break;
    default:
        return false;
    }
    if (vp == nullptr) {
        return false;
    }
    vtype = type;
    AP_Param::ConversionInfo info = {
        key,
        group_element,
        type,
        nullptr
    };
    return AP_Param::find_old_parameter(&info, vp);
}

// set a value
bool Parameter::set(float value)
{
    if (vp == nullptr) {
        return false;
    }
    switch (vtype) {
    case AP_PARAM_INT8:
        ((AP_Int8 *)vp)->set(value);
        return true;
    case AP_PARAM_INT16:
        ((AP_Int16 *)vp)->set(value);
        return true;
    case AP_PARAM_INT32:
        ((AP_Int32 *)vp)->set(value);
        return true;
    case AP_PARAM_FLOAT:
        ((AP_Float *)vp)->set(value);
        return true;
    default:
        break;
    }
    // not a supported type
    return false;
}

// get value
bool Parameter::get(float &value)
{
    if (vp == nullptr) {
        return false;
    }
    switch (vtype) {
    case AP_PARAM_INT8:
        value = ((AP_Int8 *)vp)->get();
        break;
    case AP_PARAM_INT16:
        value = ((AP_Int16 *)vp)->get();
        break;

    case AP_PARAM_INT32:
        value = ((AP_Int32 *)vp)->get();
        break;

    case AP_PARAM_FLOAT:
        value = ((AP_Float *)vp)->get();
        break;

    default:
        // not a supported type
        return false;
    }
    return true;
}

// set and save value
bool Parameter::set_and_save(float value)
{
    if (vp == nullptr) {
        return false;
    }
    switch (vtype) {
    case AP_PARAM_INT8:
        ((AP_Int8 *)vp)->set_and_save(value);
        return true;
    case AP_PARAM_INT16:
        ((AP_Int16 *)vp)->set_and_save(value);
        return true;
    case AP_PARAM_INT32:
        ((AP_Int32 *)vp)->set_and_save(value);
        return true;
    case AP_PARAM_FLOAT:
        ((AP_Float *)vp)->set_and_save(value);
        return true;
    default:
        break;
    }
    // not a supported type
    return false;
}

// Check if param had been configured
bool Parameter::configured()
{
    if (vp == nullptr) {
        return false;
    }
    return vp->configured();
}

// set default value
bool Parameter::set_default(float value)
{
    if (vp == nullptr) {
        return false;
    }
    switch (vtype) {
    case AP_PARAM_INT8:
        ((AP_Int8 *)vp)->set_default(value);
        return true;
    case AP_PARAM_INT16:
        ((AP_Int16 *)vp)->set_default(value);
        return true;
    case AP_PARAM_INT32:
        ((AP_Int32 *)vp)->set_default(value);
        return true;
    case AP_PARAM_FLOAT:
        ((AP_Float *)vp)->set_default(value);
        return true;
    default:
        break;
    }
    // not a supported type
    return false;
}