WEBVTT 00:00.180 --> 00:04.260 Hello again! In this video, we are going to add some more features to our game. 00:05.310 --> 00:10.710 We are going to add some lives, player lives. So the player can win or lose the game. 00:11.070 --> 00:15.150 And we are also going to give some text messages, so we can communicate with the player. 00:16.680 --> 00:18.090 SFML has a text 00:18.090 --> 00:25.170 class. This represents graphical text, which can be drawn on a render target. Such as our game window. 00:25.950 --> 00:27.870 And it also has a font class. 00:28.350 --> 00:33.720 A Text object will have a Font object associated with it, and that will control how the characters 00:33.720 --> 00:34.890 appear on the screen. 00:37.860 --> 00:44.880 This is quite similar to sprites and textures. So we start off by loading the font from disk. And this 00:44.880 --> 00:46.050 can be problematical. 00:48.030 --> 00:52.140 The first problem is that different systems provide different fonts. 00:52.140 --> 00:55.140 So it may be that your system does not actually have this font. 00:55.800 --> 00:58.980 And also different systems keep their fonts in different places. 00:58.980 --> 01:02.850 So the font may be available, but not in the directory where your program expects it. 01:03.090 --> 01:08.880 So if you are going to be distributing your game to other people, then a good thing to do is to copy 01:08.880 --> 01:15.240 the fonts file into the same directory as the images. So your program will be able to find it easily. 01:15.570 --> 01:18.630 And I should add that there are copyright issues with some fonts. 01:20.450 --> 01:25.880 So assuming that you have loaded up your Font objects, you can then associate it with a Text object. 01:25.880 --> 01:33.380 So you call setFont(). And then setString() will populate the Text object with some characters. And then 01:33.380 --> 01:36.980 you can draw the text, and display on the window as usual. 01:39.020 --> 01:39.890 In the game manager, 01:39.890 --> 01:43.070 we are going to add a member for the number of lives the player has. 01:43.580 --> 01:48.680 Each time the ball hits the bottom of the screen, the player is going to lose a life. And if they 01:48.680 --> 01:52.340 lose all their lives, then the game is over and the player has lost. 01:53.000 --> 01:58.220 On the other hand, if the player manages to destroy all the bricks, then they win the game. 01:59.030 --> 02:04.880 We have two more values for the game state enumeration: game over, player losing, and the player 02:04.880 --> 02:05.360 winning. 02:06.620 --> 02:12.230 And we are also going to have some members which are SFML text objects. And those will be used for displaying 02:12.230 --> 02:13.490 messages to the player. 02:15.180 --> 02:18.870 We need to change how the ball reacts, when it hits the bottom of the window. 02:19.110 --> 02:21.280 In the update() member function of ball. 02:21.300 --> 02:25.770 So far, we have been bouncing off the bottom of the window, back into the window. But we do not want to 02:25.770 --> 02:26.670 do that anymore. 02:27.360 --> 02:29.160 We are going to destroy the ball. 02:29.160 --> 02:33.450 So that will make it look as though the ball has disappeared off the bottom of the window. 02:34.710 --> 02:37.890 And then, in the game loop, we can check if the ball has been destroyed. 02:37.890 --> 02:40.410 And that will tell us that the player has lost a life. 02:42.790 --> 02:45.330 In constants, we have a new parameter. 02:45.340 --> 02:50.200 This is the number of lives the player has, at the start of the game. So the player will have three 02:50.200 --> 02:52.480 opportunities to demolish all the bricks. 02:55.020 --> 02:56.040 In the game class, 02:56.040 --> 02:59.670 we have the extra members for the game_state enumeration. 03:00.420 --> 03:04.200 We have the objects for the fonts and the text messages. 03:04.380 --> 03:10.530 text_state will tell the player about the state of the game, and text_lives will tell the player how 03:10.530 --> 03:11.820 many lives they have left. 03:13.730 --> 03:18.560 And we also have a member function which will keep track of how many lives the player has left. And 03:18.560 --> 03:21.810 the initial value will be the total number of lives they have. 03:21.830 --> 03:23.090 So that would be three. 03:25.080 --> 03:26.400 In the game constructor, 03:26.400 --> 03:29.010 we need to initialize these text objects. 03:29.160 --> 03:33.690 So we start off by loading the font. We call loadFromFile(). 03:34.260 --> 03:38.040 I chose one which is available on Windows, to make life easier. 03:39.690 --> 03:44.970 If you're using a Unix system or Mac, then the path will look something like that. 03:45.480 --> 03:47.610 webfonts is in fact a package, 03:47.610 --> 03:52.770 I think. This is FreeBSD, so Verdana is not part of the default X installation. 03:52.980 --> 03:59.310 So you could use another font if you want, or just install this one. And then we can configure the objects. 03:59.310 --> 04:01.470 So we set the font to be Verdana. 04:01.890 --> 04:07.770 We search the position, which is going to be near the middle of the screen. And, as usual, this is just 04:07.770 --> 04:08.460 trial and error. 04:08.910 --> 04:14.520 Then we can set the size of the characters and their colour. And then we provide some characters for 04:14.520 --> 04:18.840 the text object. And similar for the text_lives. 04:19.290 --> 04:23.220 And the characters will give the number of lives that the player has left. 04:23.220 --> 04:27.600 So we are using C++11's to_string(), to convert this int to a string. 04:29.640 --> 04:33.150 If we restart the game, then we want the player to have all their lives back. 04:33.150 --> 04:36.210 So we set the lives member back to the maximum. 04:40.440 --> 04:41.310 In the game loop, 04:41.310 --> 04:46.500 we have these extra states. So we need to change the logic slightly. And we also need to display the 04:46.500 --> 04:47.400 text messages. 04:48.480 --> 04:52.950 If the game is paused, then we draw the entities, but we do not update them. 04:53.790 --> 04:57.660 If the game is not running, then we tell the user what the state is. 04:57.840 --> 05:00.570 So this could be paused, game over or player wins. 05:00.960 --> 05:05.010 And I have made these all the same size, with some padding spaces. 05:06.720 --> 05:09.690 And then we draw the text objects on the window. 05:12.020 --> 05:15.380 Otherwise, if the game is running, then we update the entities. 05:15.410 --> 05:18.740 But, before we do that, we need to check some things. 05:19.520 --> 05:22.460 We need to check if the ball has been destroyed. 05:22.490 --> 05:27.350 If it has, then the entity manager will have a vector of ball entities, which is empty. 05:27.860 --> 05:36.050 So we decrement the player lives. And we also create a new ball, so the player can continue playing. And 05:36.050 --> 05:40.850 we set the game state to paused, so the player has some time to recover from their state of shock! 05:43.080 --> 05:47.460 If all the bricks have been destroyed, then the entity manager will have a vector of brick entities 05:47.460 --> 05:48.300 which is empty. 05:48.570 --> 05:50.700 So the player has won. 05:53.040 --> 05:56.580 If the player has no lives left, then they have lost the game. 05:57.630 --> 06:01.770 Then we update the text_lives, so it has the correct number of lives. 06:02.070 --> 06:06.750 And then we do the usual: update manager, handle collision, refresh, draw and display. 06:10.250 --> 06:10.990 So there we are. 06:11.000 --> 06:14.390 We know that the game is paused and we have three lives. 06:16.460 --> 06:17.960 And now I have two lives! 06:17.960 --> 06:20.690 So when the ball goes off the bottom, I lose a life. 06:27.100 --> 06:27.330 (Huh!) 06:27.860 --> 06:28.930 Now I lose another one. 06:30.450 --> 06:31.040 And that is it. 06:31.070 --> 06:31.760 Game over! 06:32.120 --> 06:32.680 (Boo hoo!) 06:34.250 --> 06:40.570 If you want to test the case where the player wins, then you do not have to actually win the game and 06:40.580 --> 06:41.750 destroy all the bricks. 06:41.960 --> 06:43.370 You can take a shortcut. 06:43.490 --> 06:50.270 If you go up to the reset member function, this line here will populate the entity manager's brick vector. 06:50.720 --> 06:56.210 So if we comment this out, then the entity manager will have an empty vector of bricks. 06:56.540 --> 07:00.620 So when we start playing, there are no bricks and the player has won. 07:06.880 --> 07:11.920 One other thing that is worth knowing, and perhaps I should have mentioned earlier. If there is an error 07:11.920 --> 07:18.400 in this loadFromFile() function, so that could be either sprites or fonts, then SFML will print 07:18.400 --> 07:20.340 a message to standard output. 07:20.350 --> 07:26.260 So if you are running in a command line, or your development environment has a console, then you will see 07:26.260 --> 07:31.300 that if you're running in a standalone window like I am, then you will not be able to see that. 07:31.510 --> 07:33.820 So here is how to do this for Visual Studio. 07:33.820 --> 07:40.210 So go into Project Properties, and then Linker, System. And this is controlled by Subsystem. 07:40.240 --> 07:41.980 So currently it is Windows. 07:42.550 --> 07:48.040 If I change this to console, then I will get a console when I start playing the game. 07:49.840 --> 07:54.430 So obviously, that is not something you want when you are releasing your application, but it is useful 07:54.430 --> 07:56.200 for testing and debugging. 07:56.830 --> 08:00.640 For example, if I change this so the load file will fail. 08:03.180 --> 08:05.010 And there we are, we get an error message. 08:05.580 --> 08:05.850 Okay. 08:05.850 --> 08:07.080 So that is it for this video. 08:07.440 --> 08:08.550 So I will see you next time. 08:08.550 --> 08:11.070 But until then, keep coding!