Game Development Reference
In-Depth Information
The static options are added to the
map
using the
[]
operator. The key being used is postincremented
on each insert call. The
AddDynamicOption
method uses the
vector::push_back
method to push the
new option into the
vector
. Both methods have a call to
assert
in their first line that will trigger if the
Option
pointer being added is a
nullptr
. This will allow you to track down invalid options while your
program is running.
Now that the options are stored within a
Room
instance, the class is required to have a method to
print the available options to the player, which is shown in Listing 19-4.
Listing 19-4. Printing the Available Options
void Room::PrintOptions() const
{
for (unsigned int i = 0; i < m_dynamicOptions.size(); ++i)
{
const Option* option = m_dynamicOptions[i];
std::cout << i + 1 << ": " << option->GetOutputText() << std::endl << std::endl;
}
for (StaticOptions::const_iterator iter = m_staticOptions.cbegin();
iter != m_staticOptions.cend();
++iter)
{
const Option* option = iter->second;
const unsigned int chosenOption = iter->first + m_dynamicOptions.size();
std::cout << chosenOption << ": "
<< option->GetOutputText() << std::endl << std::endl;
}
}
The
PrintOptions
method must print out all of the dynamic options followed by the static options.
Each option is preceded by an index number that the player will then be asked to enter. A
for
loop
is used to track the option number to be printed for the dynamic options, and you can see this in the
cout
statement where we add 1 to
i
when printing.
Constant iterators are used to loop over the static options. Each static option is keyed starting from
1 so we can add the size of
m_dynamicOptions
to each key to find the appropriate index for each
static option. The iterators represent key-data pairs with the key stored in the
first
member of the
pair and the
Option
pointer stored in
second
.
The
Room
class will also be responsible for evaluating the player's input. Listing 19-4 shows the
Room::EvaluateInput
method.
Listing 19-5.
Room::EvaluateInput
Option* Room::EvaluateInput(unsigned int playerInput)
{
Option* option = nullptr;
const unsigned int numDynamicOptions = m_dynamicOptions.size();
if (playerInput <= numDynamicOptions)
