WEBVTT 00:06.960 --> 00:07.740 Welcome. 00:07.740 --> 00:13.380 In this video, we're going to add a player level to our player state class, and then we'll create 00:13.380 --> 00:17.580 a combat interface and implement that in our project. 00:17.820 --> 00:26.160 So first, let's go to our public folder into player and open up Aura Player State. 00:26.250 --> 00:31.710 And in Aura Player State, we can have a variable for the level. 00:31.710 --> 00:33.960 And I'd like this to be a private variable. 00:33.960 --> 00:39.060 This will be private here in the player state and it's going to be an int 32. 00:39.060 --> 00:46.710 So level is just going to be an integer and it'll have a default value of one and I'm going to give 00:46.710 --> 00:54.210 it a new property with visible anywhere just in case we want to see it in our blueprint Now level is 00:54.210 --> 00:55.860 going to be replicated. 00:55.860 --> 01:03.720 I'd like it to have its own rep notify as well, so that later on when we're going to be showing this 01:03.750 --> 01:08.680 in the HUD, we're going to want to make a broadcast whenever this replicates. 01:09.140 --> 01:15.020 Now to replicate anything, we need to override git lifetime replicated props, don't we? 01:15.020 --> 01:18.140 So we're going to do that here in the public section. 01:18.140 --> 01:22.130 We're going to say Virtualvoid git lifetime replicated props. 01:22.130 --> 01:30.410 We'll go ahead and create the definition for it and allow the super call and then we can add a rep notify 01:30.440 --> 01:33.770 right here in the private section for level. 01:33.770 --> 01:42.110 So this will be void on rep underscore level and we're going to have an INT 32 as the input called old 01:42.110 --> 01:42.800 level. 01:42.800 --> 01:48.800 That way we can have access to that old level and this gets a new function property. 01:48.830 --> 01:51.200 Otherwise it can't be a rep notify. 01:51.380 --> 02:00.230 And so now we can mark level as replicated and we're going to use replicated using equals on rep level. 02:02.450 --> 02:03.260 Okay. 02:03.260 --> 02:09.270 So we can generate the definition for on rep level and we're going to use that soon enough. 02:09.270 --> 02:16.320 But for now let's just mark it as replicated here and get lifetime replicated props. 02:16.470 --> 02:19.710 Now for this we're just going to use do rep lifetime. 02:19.710 --> 02:27.060 This is the most basic macro for marking something as replicated and writer is going to tell us that 02:27.060 --> 02:27.580 we need. 02:27.600 --> 02:34.320 Net slash unreal network H so I'm going to hit Alt enter to go ahead and include that header file. 02:34.320 --> 02:36.210 And now this is defined. 02:36.360 --> 02:44.850 So we need to use our class name or a player state followed by level the name of the replicated variable. 02:44.850 --> 02:50.040 And now with this level is a replicated variable and we're good. 02:50.040 --> 02:53.820 So the player state is where our level will reside. 02:53.820 --> 02:58.140 But I'd like that to be the case only for the player controlled character. 02:58.140 --> 03:03.750 For enemy characters, their level should not reside on a player state because they're not using or 03:03.750 --> 03:06.540 a player state for enemy characters. 03:06.540 --> 03:12.540 I'd like the level to be on the enemy character itself, on Ora Enemy. 03:12.570 --> 03:20.190 So for that case, let's go back to the character folder and open ora enemy and we'll give Ora Enemy 03:20.220 --> 03:25.140 a private section with its own level variable. 03:25.140 --> 03:33.480 So this will be an int 32, we'll call it level, we'll set it to a default value of one and we'll give 03:33.480 --> 03:34.320 it a new property. 03:34.320 --> 03:45.750 And for this I'd like it to be edit anywhere blueprint read only and I'll give it a category of character 03:45.750 --> 03:47.880 class defaults. 03:47.970 --> 03:52.890 Now the reason I'm not going to make this replicated for the enemy is because we're only going to be 03:52.890 --> 03:57.690 concerned with checking the level on the server for AI controlled enemies. 03:57.690 --> 04:04.200 And that's because important things that will require that level in calculations will only be done on 04:04.200 --> 04:05.010 the server. 04:05.160 --> 04:08.400 So that's all we need to do for the enemies level. 04:08.760 --> 04:12.640 Now for the interface we were talking about earlier. 04:12.660 --> 04:20.820 Ora enemy has a level variable and or a player state has a level variable, and I'd like to create an 04:20.820 --> 04:26.940 interface that can retrieve the level and we can implement that on our character class. 04:26.940 --> 04:31.920 And then any character can call that function to retrieve the level. 04:31.920 --> 04:36.960 And it's up to the individual character to determine how to get that, whether we get it from the player 04:36.960 --> 04:42.300 state or just return that value from the character itself in the case of the enemy. 04:42.300 --> 04:50.220 So we're going to go ahead and launch the editor And of course, Blueprint Read only should not be on 04:50.220 --> 04:52.290 private members, right? 04:52.380 --> 04:55.650 Of course, that's something that is going to pop up. 04:55.650 --> 05:01.200 So rather than trying to get around that, I'm going to move it actually up to the protected section. 05:01.200 --> 05:03.360 I think that's totally fine. 05:04.410 --> 05:07.710 So level is now protected instead of private. 05:07.740 --> 05:09.960 Let's go ahead and launch the editor. 05:11.490 --> 05:13.920 Okay, so what we need is an interface. 05:13.920 --> 05:20.730 So I'm going to go into our C plus plus classes ora public, and we have an interaction folder for our 05:20.730 --> 05:22.050 enemy interface. 05:22.050 --> 05:27.870 We're now going to have a combat interface that will be shared between both enemies and the player controlled 05:27.870 --> 05:28.710 character. 05:28.710 --> 05:33.780 Enemy interface is unique to enemies only, so this one will be shared. 05:33.780 --> 05:40.770 We're going to have this class in the same folder interaction and it will be an unreal interface. 05:40.770 --> 05:46.530 Let's click next, and here in interaction we'll create our combat interface. 05:49.170 --> 05:55.790 So we'll go ahead and close the editor and let writer populate our folders with our new interface. 05:55.800 --> 05:57.990 And we should see it here in interaction. 05:57.990 --> 06:00.090 Here it is combat interface. 06:00.270 --> 06:07.230 And I just want to implement one function here in combat interface right here in the public section. 06:07.230 --> 06:13.230 So it's going to be virtual and it's going to return an INT 32 and we're going to call this get level. 06:13.710 --> 06:18.000 I don't want it to be required that we implement this. 06:18.000 --> 06:22.650 If we don't implement it, I want to simply return zero. 06:22.740 --> 06:24.900 So I'm going to generate a definition. 06:24.900 --> 06:31.860 This will be a default definition that returns zero here and then we can implement this in, say, the 06:31.860 --> 06:35.580 base character class who doesn't need to implement it. 06:35.580 --> 06:41.850 But because the base character class has combat interface, then we don't have to implement it individually 06:41.850 --> 06:45.120 in each subclass of the base character. 06:45.120 --> 06:52.810 So let's go to Aura character base in the character folder and let's implement this interface. 06:52.810 --> 06:58.840 So not only I ability system interface, we're also going to inherit from i combat interface. 07:00.200 --> 07:04.370 And writer should give me the opportunity to include the header file. 07:04.370 --> 07:06.120 And there we go. 07:06.140 --> 07:12.830 So now our base character class or a character base is also a combat interface. 07:12.830 --> 07:19.160 And then we can implement get level in both aura character and aura enemy. 07:19.430 --> 07:23.540 We'll first do it in Aura Enemy, and this is going to be public. 07:23.540 --> 07:32.930 And right here I'm going to make a multi-line comment that says combat interface and beneath it. 07:34.000 --> 07:43.030 We'll close it out with end combat interface and we'll implement that function virtual int 32, get 07:43.030 --> 07:45.490 level override. 07:46.270 --> 07:51.160 And for the enemy, we're simply going to return the level variable. 07:51.160 --> 07:56.260 So let's go ahead and generate this definition and return level. 07:56.260 --> 07:57.850 We don't need to call super. 07:57.880 --> 08:01.240 We're going to return the level variable. 08:01.510 --> 08:05.320 And for a character it's going to be different, isn't it? 08:05.320 --> 08:08.020 Because our level will be on the player state. 08:08.020 --> 08:13.210 So let's go to a character and we'll override that function here. 08:13.210 --> 08:14.680 It's in the public section. 08:14.680 --> 08:20.710 So we're going to have a multi-line comment that says combat interface. 08:22.680 --> 08:29.490 And we'll have another multi-line comment beneath it that says end combat interface and we'll override 08:29.490 --> 08:34.410 the function virtual int 32, get level override. 08:34.950 --> 08:41.070 Let's go ahead and generate a function definition and this one will return something else, won't it? 08:41.100 --> 08:43.650 We have to get our player state. 08:43.680 --> 08:49.260 We're doing that right here in init ability actor info so we can copy that line right here. 08:49.740 --> 08:52.140 We can simply copy that. 08:52.260 --> 08:59.530 We can even do the check for a player state here and we can simply get the level from a player state. 08:59.550 --> 09:07.200 Now an aura player, state level is private, so we should make a public getter to retrieve that level 09:07.200 --> 09:07.770 variable. 09:07.770 --> 09:08.840 So right here, we'll do it. 09:08.850 --> 09:14.340 We're going to say int 32, not 43, but 32 get level. 09:15.660 --> 09:19.320 It'll be const and it'll return level. 09:20.140 --> 09:23.860 Now, in this case, we're hiding a function. 09:23.980 --> 09:28.360 There's a function called get level on the actor class. 09:28.360 --> 09:32.140 Now, that tells me it's going to be a problem for all the other classes. 09:32.140 --> 09:39.520 So for that reason, I'd like to change the function name to get player level on all fronts. 09:39.520 --> 09:41.700 So I'm going to change it here. 09:41.710 --> 09:44.470 I'm going to change it in the interface itself. 09:44.500 --> 09:46.600 Let's go to Combat Interface. 09:46.600 --> 09:52.270 Let's just go ahead and change this to get player level and that means I need to change it here in Combat 09:52.270 --> 09:53.470 Interface TCP. 09:53.950 --> 09:59.050 We also have to change it in Ora enemy dot H and CPP. 09:59.050 --> 10:01.990 So let's change it to get player level there. 10:02.020 --> 10:07.600 CPP will change it to get player level there and an Ora character will change it to get player level 10:07.600 --> 10:11.890 here and get player level here and we can call that getter. 10:11.890 --> 10:16.600 And before we do, let's just go back to Ora Player State for a second. 10:16.690 --> 10:21.380 And I was going to say that this is a nice simple little function. 10:21.380 --> 10:23.270 We can mark it with force inline. 10:23.270 --> 10:29.270 Now you'll notice that I'm not using force inline very much in this course, and I've used it quite 10:29.270 --> 10:31.780 a bit in other courses with getters. 10:31.790 --> 10:39.560 This is one of those micro-optimizations that you tend to kind of see overused a lot and it doesn't 10:39.560 --> 10:42.320 make a huge difference at runtime. 10:42.320 --> 10:44.600 It is a small optimization. 10:44.600 --> 10:52.610 It basically means that whenever we call get player level, the preprocessor is going to replace that 10:52.610 --> 10:58.850 function call when preprocessing before the compilation step with the function body, in this case the 10:58.850 --> 11:00.830 level variable itself. 11:00.830 --> 11:05.930 So ultimately the compiler has the say over whether it ends up doing that or not. 11:05.960 --> 11:12.170 For small things like this, it's usually okay, you're not really going to cause any harm by overusing 11:12.170 --> 11:15.320 it, but that's why I don't use it very much. 11:15.320 --> 11:17.210 I'm going to go ahead and use it here though. 11:17.210 --> 11:23.030 And since we have a getter, we can go back to Ora character and we can get that level. 11:23.030 --> 11:33.680 So we can return with lowercase, of course, return or a player state get player level like so. 11:33.680 --> 11:36.530 And this could be a const local variable here. 11:37.310 --> 11:43.280 So now ora character implements get player level or an enemy implements get player level. 11:43.280 --> 11:44.810 It just returns level. 11:44.840 --> 11:48.800 This could really be on one line know as a matter of style. 11:48.800 --> 11:52.250 You could change it if you wanted all in one line like that. 11:52.250 --> 12:00.320 But now that our character and enemy can have get player level called and in the case of the enemy, 12:00.320 --> 12:03.680 they'll return the level variable that's on the enemy class. 12:03.680 --> 12:09.560 In the case of Ora character, it'll return the player level that's on the player state class. 12:09.560 --> 12:11.000 That's all great. 12:11.030 --> 12:18.590 Now we have an interface we can use to easily get the player level if we want to. 12:18.590 --> 12:24.950 In a custom calculation class and the custom calculation class is what we will make next. 12:24.950 --> 12:29.030 So let's go ahead and make sure our code compiles here. 12:29.930 --> 12:34.580 And suddenly my player controller doesn't like to object. 12:34.580 --> 12:37.900 Pointer being used for last actor in this actor. 12:37.910 --> 12:45.140 It was legal before, but now it's telling me to stop using object pointer for the enemy interface. 12:45.410 --> 12:50.780 So that means we're going to need to use raw pointers for the enemy interface. 12:50.780 --> 12:55.310 We'll go ahead and leave that as a raw pointer. 12:55.310 --> 12:58.340 Instead, let's go ahead and compile again. 12:59.740 --> 13:00.850 And there we go. 13:00.850 --> 13:02.950 We have a successful compile. 13:02.980 --> 13:03.880 Great. 13:04.240 --> 13:05.350 So great job. 13:05.350 --> 13:07.510 And I'll see you in the next video.