WEBVTT 00:00.200 --> 00:02.150 Welcome to your next quest. 00:02.330 --> 00:08.150 Okay, So the project manager for your game project walks up to you and says, My lovely developer, 00:08.180 --> 00:11.930 we need to add XP to our player state. 00:11.960 --> 00:15.830 They then proceed to tell you that we need a member variable. 00:15.860 --> 00:21.230 On top of that, this member variable should be replicated and we're going to need a rep notify. 00:21.380 --> 00:28.610 We'll want a set function that can set the XP to a certain value and an add to XP function so that we 00:28.610 --> 00:34.040 can just pass a value in and let the player state handle adding to XP. 00:34.370 --> 00:40.970 And every time XP changes, we need a delegate that we can broadcast whenever our XP changes on the 00:40.970 --> 00:45.440 player state and our rep notify can help us to broadcast on clients. 00:45.440 --> 00:52.310 So we need some kind of broadcast that's capable of broadcasting some kind of change in stats. 00:52.310 --> 00:56.690 So your project manager says to you, Here's the job I'd like you to get done today. 00:56.720 --> 01:00.030 Thank you very much, and leaves you with these tasks. 01:00.030 --> 01:05.370 So pause the video and handle these changes to your project now. 01:08.060 --> 01:08.900 All right. 01:08.900 --> 01:12.380 So we need some XP and we're going to have that on our player state. 01:12.380 --> 01:14.660 So we have a number of things to do. 01:15.080 --> 01:20.990 I'm going to close the editor and here in writer, I'm going to open up my player folder and get our 01:21.080 --> 01:27.890 player state, both the CP and the header files so we can add this new XP variable. 01:28.220 --> 01:31.940 So first we need the XP and that's going to be an integer. 01:32.030 --> 01:39.220 So this will be right here in the header file and I'd like it to be a private variable. 01:39.230 --> 01:46.670 Now in the scenario when I gave you the quest, I was kind of roleplaying saying that you had a manager 01:46.670 --> 01:51.350 for this project and notice that they didn't give you all the information involved. 01:51.350 --> 01:55.970 And that's kind of common when it comes to being delegated a task from a manager. 01:56.120 --> 02:02.780 Sometimes a project manager doesn't know all the details or leaves the details up to you or just trusts 02:02.780 --> 02:04.600 you to make the decision yourself. 02:04.610 --> 02:06.500 So there's a little bit of uncertainty. 02:06.530 --> 02:09.450 Sometimes you aren't given all of the instructions. 02:09.570 --> 02:11.190 That's how we're going to handle this. 02:11.190 --> 02:15.150 Now our player state has level and it's already private. 02:15.180 --> 02:17.880 We can follow this convention. 02:17.880 --> 02:22.110 In fact, we can copy level and paste it and just rename this to XP. 02:22.380 --> 02:30.450 We're going to call it simply XP and we're going to make a rep notify called on Rep XP and we can really 02:30.450 --> 02:34.440 just copy on rep level and rename this as well. 02:34.440 --> 02:44.070 We'll call this on rep underscore XP with old XP being passed in and with that we can generate the function 02:44.070 --> 02:47.400 definition for it and we have our rep notify. 02:47.430 --> 02:50.160 Okay, so we have our member variable. 02:50.160 --> 02:53.490 We have it replicated now because it's replicated. 02:53.490 --> 03:01.170 There's an important step that wasn't outlined in the quest and that is to add it to Git lifetime replicated 03:01.170 --> 03:01.890 props. 03:01.890 --> 03:06.450 So this is another boilerplate step when adding a replicated variable, right? 03:06.450 --> 03:10.680 So we can add that now we know it will be replicated. 03:10.800 --> 03:18.450 Now, next, we needed to create a setter and an add to function so we can put those in our class. 03:18.450 --> 03:25.110 We're going to put them up here in the public section and perhaps you might decide while you're implementing 03:25.110 --> 03:28.380 this task that, hey, we could probably implement a getter too. 03:28.380 --> 03:29.970 And I'm just going to do that first. 03:29.970 --> 03:32.010 And if you did that, that's fine too. 03:32.040 --> 03:38.170 You could even force inline it like we did get player level and you can just have 32 get XP. 03:39.990 --> 03:44.430 Which can be const and return exp. 03:45.630 --> 03:49.170 Now we need those add two and set functions. 03:49.170 --> 03:51.770 So let's just declare them both. 03:51.780 --> 03:59.910 We're going to have a void function called add to exp which will take an int 32 called NXP and we'll 03:59.910 --> 04:08.730 have a void function set exp which will also take an int 32 called in exp as well, and we can go ahead 04:08.730 --> 04:11.550 and generate function definitions for these both. 04:13.880 --> 04:17.910 And it seems like these would be quite easy to implement, right? 04:17.930 --> 04:23.750 Add to XP means we take our XP and we add to it plus equals in XP. 04:24.350 --> 04:25.500 Pretty simple. 04:25.520 --> 04:28.670 Set XP would probably be even simpler. 04:28.670 --> 04:29.300 Right? 04:29.330 --> 04:31.400 XP equals in XP. 04:31.640 --> 04:38.240 But we know that these functions also serve another purpose because one of our tasks was to create a 04:38.240 --> 04:41.470 delegate to broadcast when these values change. 04:41.480 --> 04:46.700 So what we should do is create a delegate and broadcast it when these values change. 04:46.700 --> 04:50.240 And this probably will bring something to our attention. 04:50.270 --> 04:56.660 We also have a level, and if we want to show that in the HUD, well, we definitely know that we're 04:56.660 --> 05:01.300 going to need a delegate to broadcast when level changes as well. 05:01.310 --> 05:07.250 So as we're doing this, and this is something I've seen in a professional environment, working as 05:07.250 --> 05:13.130 a software engineer is sometimes I'll be given a task like this, and while I'm working on it, I'll 05:13.130 --> 05:18.600 see a need that's similar for another variable, in this case player level. 05:18.600 --> 05:27.090 And as I'm implementing my add to XP and set XP, I may be seeing the need for that for the player level. 05:27.090 --> 05:32.970 And while I'm at it, I'll just kind of take care of that as well by creating an add to level and a 05:32.970 --> 05:36.240 set level, things like that depending on the needs. 05:36.240 --> 05:41.610 And that's of course going to depend on your level of experience and familiarity with the needs of the 05:41.610 --> 05:42.480 project. 05:42.510 --> 05:48.660 Now, before we start going rogue, let's make sure we have our own task assigned to us completed before 05:48.660 --> 05:49.920 doing anything else. 05:49.920 --> 05:52.620 And that's going to involve creating a delegate. 05:52.650 --> 05:54.480 Now, what kind of delegate do we need? 05:54.480 --> 05:59.520 Well, we need a delegate that at least can be bound to in C plus plus. 05:59.550 --> 06:05.760 We don't need to bind to this from blueprints as we're going through our widget controllers. 06:05.790 --> 06:09.900 Those are going to broadcast to our widgets in blueprint. 06:09.900 --> 06:12.960 So this doesn't have to be a dynamic delegate. 06:12.960 --> 06:18.900 It can be multicast or just simply a delegate non dynamic, non multicast. 06:18.990 --> 06:22.020 I'm going to choose to make it a multicast delegate. 06:24.150 --> 06:26.640 That can broadcast one param. 06:27.540 --> 06:37.860 That's going to be the stat that has changed and this can be on player stat changed and it's going to 06:37.860 --> 06:45.630 use an n 32 now with multicast delegates we don't need a comma followed by the param name like this. 06:45.630 --> 06:53.400 But what we can do is an inline comment that kind of says what this is and this is going to be stat 06:53.400 --> 06:54.120 value. 06:54.720 --> 07:01.440 So when one of our stats changes will broadcast that to whoever binds to our delegate and we're going 07:01.440 --> 07:06.300 to have one of them for our XP and that will be a public delegate. 07:06.300 --> 07:09.780 So we can just put our delegates right here. 07:09.810 --> 07:18.720 We'll have an on player stat change and this can be on XP changed and we'll call it on XP change delegate. 07:19.170 --> 07:22.470 And it doesn't have to be blueprint assignable. 07:22.620 --> 07:30.390 Now this delegate can be broadcast whenever we set the value or change the value of XP. 07:30.480 --> 07:35.370 So let's go into Aura Player State and make sure we broadcast our delegate. 07:35.400 --> 07:38.910 When XP changes, that's going to be when we add two XP. 07:39.150 --> 07:46.290 So we're going to say on XP change delegate dot broadcast and we're going to just broadcast the value 07:46.290 --> 07:46.800 of XP. 07:47.460 --> 07:50.970 Now this has to happen any time it changes. 07:50.970 --> 07:53.760 So we're going to do that in set XP as well. 07:53.850 --> 08:02.560 Now XP will be actively set only on the server and since it's a replicated variable, then it'll replicate 08:02.560 --> 08:07.690 down to clients and it's on rep XP function will be called at that point. 08:07.690 --> 08:14.890 That's when we need to broadcast our delegate on the client side so that any HUD elements can respond 08:14.920 --> 08:21.160 and update themselves with the correct XP for our XP bar, for example, on clients. 08:21.460 --> 08:25.840 Now we see that this is a need for level as well. 08:25.840 --> 08:34.450 So now that we've finished our current task, we can see the need for an additional set of changes that 08:34.450 --> 08:37.240 could be added to our project for our level. 08:37.330 --> 08:43.390 Now first of all, it would be nice to have a set and an add to function for level. 08:43.600 --> 08:45.340 I think that is important. 08:45.370 --> 08:47.080 We already have a getter, right? 08:47.080 --> 08:54.310 So we need add to and set and for that reason we could have our getters here, our add two functions 08:54.310 --> 08:56.800 here and our setter functions here. 08:56.800 --> 09:02.500 So in addition to add to XP, we can also have add to level. 09:02.500 --> 09:09.670 So void add to level which can take in an int 32 called in level and I'll go ahead and generate the 09:09.670 --> 09:14.680 definition, but I'm also going to declare a set level. 09:14.680 --> 09:16.420 So void set level. 09:17.750 --> 09:20.840 Which takes an int 32 called in level as well. 09:21.140 --> 09:23.780 And I'll generate a function definition for that. 09:24.230 --> 09:28.400 And these will be similar to their counterparts for XP. 09:28.760 --> 09:37.040 Add two level is going to take level plus equals in level and we're going to need a delegate to broadcast 09:37.040 --> 09:42.530 for it to set level just takes level and sets it equal to end level. 09:42.830 --> 09:47.780 So this one is going to need to broadcast a delegate and so is the rep notify. 09:47.810 --> 09:55.760 So let's make that delegate and thanks to our delegate on player stat changed we didn't call it on XP 09:55.760 --> 10:03.680 changed it's just generic for stats so as long as that stat is an int 32 we can use this same delegate 10:03.680 --> 10:11.240 signature and we'll call this on level changed delegate and we'll broadcast this whenever the level 10:11.240 --> 10:12.020 changes. 10:12.020 --> 10:19.580 So add to level gets it, we'll say on level change delegate dot broadcast and we'll broadcast level. 10:20.150 --> 10:26.300 We'll copy this and we'll broadcast level when we set it and when it replicates. 10:26.300 --> 10:28.460 So the rep notify has it too. 10:28.970 --> 10:29.450 Okay. 10:29.450 --> 10:36.620 So we filled a need for level and that's looking pretty nice and we can follow that same trend for new 10:36.620 --> 10:41.810 stats that we add to our player state, such as attribute points and spell points. 10:41.810 --> 10:47.390 If we want to store those on the player state, we have a nice pattern going where we can create a delegate 10:47.390 --> 10:55.190 for it, make a getter and setters or add two functions and create those variables and their rep notifies 10:55.190 --> 10:56.030 and so on. 10:56.480 --> 10:57.170 Excellent. 10:57.170 --> 11:00.100 So this is the next step in our level up system. 11:00.110 --> 11:04.820 Excellent job implementing it and I'll see you in the next video.