WEBVTT 00:00.590 --> 00:02.630 Welcome to your next quest. 00:03.080 --> 00:08.210 Okay, so you finished your last assignment, and the project manager says, that's great, excellent 00:08.210 --> 00:11.510 thinking when it came to taking the level into account. 00:11.540 --> 00:14.480 Now, I have another task for you. 00:14.510 --> 00:20.840 I'd like you to bind to that on XP change delegate we created in the player state and I'd like you to 00:20.840 --> 00:24.140 bind to it on the widget controller for the overlay. 00:24.170 --> 00:24.770 Why? 00:24.800 --> 00:31.100 Because our overlay is going to have an XP bar, so it needs to know when our XP changes. 00:31.490 --> 00:37.310 Now as a bonus, see if you can figure out what that percent will be for the XP bar. 00:37.340 --> 00:44.120 Now this is deceptively a little bit more difficult than you might think as the way that we calculate 00:44.120 --> 00:46.700 the percent depends on what level we are. 00:46.730 --> 00:49.010 So see if you can figure that out. 00:49.010 --> 00:55.640 And as a hint, does the overlay widget controller need level up info because level up info contains 00:55.640 --> 00:59.200 those level up requirements for XP for each level. 00:59.210 --> 01:02.400 So see if that's something you're going to need. 01:02.400 --> 01:05.880 And if you do, where should level up info go? 01:05.910 --> 01:11.720 We created the data asset blueprint, but we never set that on any of our classes, right? 01:11.730 --> 01:19.200 So try to think about where a good spot for that level up info should go and try to keep in mind that 01:19.200 --> 01:24.930 we may need that level up info in our widget controller, both on clients and server. 01:24.930 --> 01:30.960 And just remember that the game mode doesn't exist on the clients, it only exists on the server. 01:30.960 --> 01:34.910 So right away I'm telling you it probably shouldn't go in the game mode. 01:34.920 --> 01:38.700 So give it a little bit of thought, see if you can figure that out. 01:38.700 --> 01:41.520 And if you're up for a bonus challenge, give that a try. 01:41.550 --> 01:47.520 But either way, I'd like you to bind to on XP changed in the overlay widget controller. 01:47.520 --> 01:50.880 So pause the video and conquer this quest now. 01:53.800 --> 02:00.550 Now we're going to need to bind to our on XP change delegate in our widget controller. 02:00.580 --> 02:05.050 Now it's possible that we may decide to bind to on level changed as well. 02:05.050 --> 02:07.480 So that's something to keep in mind. 02:07.570 --> 02:14.380 But when we bind to on XP change, we're going to want to figure out what that XP bar percent is going 02:14.380 --> 02:14.680 to be. 02:14.680 --> 02:16.400 So we'll keep that in mind as well. 02:16.420 --> 02:22.090 Well, the first thing we should do is go to our widget controller class that's going to be in UI widget 02:22.090 --> 02:25.480 controller and it's our overlay widget controller. 02:25.690 --> 02:28.510 Here is where we're going to want to bind to the delegate. 02:28.510 --> 02:28.900 Right? 02:28.900 --> 02:35.860 So I would like to make a callback function to bind because it's going to be a little bit more complicated 02:35.860 --> 02:39.100 than just passing through that value up to widgets. 02:39.130 --> 02:42.000 We're going to be performing some calculations, right? 02:42.010 --> 02:48.250 So I'm going to make a function in the protected section, and this is going to be for when our XP changes, 02:48.250 --> 02:55.250 we're going to bind it to the delegate on the player state called on XP change delegate, which can 02:55.250 --> 02:58.970 only have functions bound to it that can receive an INT 32. 02:59.000 --> 03:03.050 So here in overlay widget controller, we're going to make a function. 03:03.050 --> 03:12.770 It's going to be void and I'm going to call this on XP changed, which will take an INT 32 called New 03:12.770 --> 03:16.520 XP and we'll go ahead and generate the definition for it. 03:16.520 --> 03:20.890 And before we figure out what to do in this function, we're going to bind it. 03:20.900 --> 03:27.680 So we need to go up to our bind callbacks to dependencies where we're binding to all of our callbacks 03:27.680 --> 03:31.400 and we have a few bound to the ability system component. 03:31.430 --> 03:36.650 We have some bound to the attributes set, but we don't have anything bound to the player state. 03:36.650 --> 03:39.410 So we're going to have to get our player state, aren't we? 03:39.410 --> 03:46.220 So up here as we're getting our aura attributes set, I'd like to cast to the Aura player state as well. 03:46.220 --> 03:53.390 So I'm going to go ahead and create a const pointer to it and it's going to be of type A or a player 03:53.390 --> 03:54.020 state. 03:56.710 --> 03:59.830 And I'm going to go ahead and include the header file. 03:59.830 --> 04:03.040 So alt enter and writer will do that for me. 04:03.460 --> 04:09.610 Adding the include for it to send player slash player state and I'm going to call this or player state. 04:12.030 --> 04:15.000 Now I'm going to use cast checked for this. 04:18.630 --> 04:21.960 By the way, in a package build, this compiles as a static cast. 04:21.960 --> 04:24.690 So you have that bit of optimization there too. 04:24.720 --> 04:31.410 Now, this will be an A or a player state and we're going to cast our player state variable that all 04:31.410 --> 04:32.850 widget controllers have. 04:34.740 --> 04:40.320 Now we know that we have the aura player state and we can bind callbacks to the aura player state. 04:40.350 --> 04:46.950 I'm going to actually move this aura player state local variable up to the first line and the first 04:46.950 --> 04:53.710 thing we'll do is bind to the player state callbacks and then the attribute set will be after that. 04:53.730 --> 05:00.720 So after getting the aura player state, we can take Aura player state and we can access that public 05:00.750 --> 05:04.950 on XRP changed delegate and we can bind to it. 05:04.980 --> 05:07.050 We're going to use Add new object. 05:08.390 --> 05:15.920 And with the user object being this and the function being the address of you overlay widget controller 05:15.950 --> 05:17.510 on XP changed. 05:17.750 --> 05:23.120 And of course we're going to get red squiggles here because now we're actually changing something on 05:23.120 --> 05:26.750 the player state so it can't be a const pointer anymore. 05:26.780 --> 05:30.200 If we're going to want to bind callbacks to delegates. 05:30.410 --> 05:30.800 Okay. 05:30.800 --> 05:37.190 So now we have a callback bound to on Change delegate so we'll know in the widget controller when our 05:37.190 --> 05:38.720 XP has changed. 05:38.750 --> 05:43.940 Now we need to broadcast something up to our progress bar in Blueprint. 05:43.940 --> 05:48.380 But the thing is, we can't just broadcast the total amount of XP. 05:48.680 --> 05:55.190 We need to find out what the percentage of that bar should be and that's going to involve the use of 05:55.190 --> 05:56.660 our level up info. 05:56.690 --> 05:59.480 So what class should have the level up info? 05:59.510 --> 06:05.630 Well, I think the player state is probably a good class to keep that level up info as it is the class 06:05.630 --> 06:10.650 that has the level stored on it and also the player state is replicated. 06:10.650 --> 06:16.950 So if we access the player state in our widget controller on the client, we can get level up info from 06:16.950 --> 06:17.610 there. 06:17.760 --> 06:24.060 So I think a great place for it is here on Aura Player State right here in the public section. 06:24.150 --> 06:27.870 So I'm going to go ahead and declare a public variable. 06:27.870 --> 06:29.940 It's going to be a T object pointer. 06:30.920 --> 06:40.280 Now its type will be you level up info and we can forward declare that we don't have to include level 06:40.280 --> 06:41.480 up info up here. 06:41.480 --> 06:43.340 We can just say class. 06:43.370 --> 06:52.490 You level up info here and we can create this variable called level up info and we can make it a new 06:52.520 --> 06:57.650 property with edit defaults only so we can set it in our player state blueprint. 06:57.650 --> 06:59.450 So we'll remember to do that. 06:59.450 --> 07:06.380 And in our widget controller we can access that when determining how much our percent bar should show. 07:06.380 --> 07:09.440 And that's going to be all in on XRP changed. 07:09.440 --> 07:15.290 And once we figure out that percent, we can broadcast something up to our widgets. 07:15.290 --> 07:17.420 Now what are we going to broadcast? 07:17.450 --> 07:21.230 Well, we're going to broadcast a float for the percent of our XRP bar. 07:21.230 --> 07:26.720 And if we want to broadcast a float, we have an on attribute change signature we can use. 07:26.750 --> 07:28.280 It's not an attribute. 07:28.310 --> 07:36.030 Our percentage for the XRP bar technically isn't a gameplay attribute, but we can still use this same 07:36.030 --> 07:36.480 delegate. 07:36.510 --> 07:42.690 If the name bothered us, we could create a new delegate with a different name capable of broadcasting 07:42.690 --> 07:43.050 a float. 07:43.050 --> 07:45.390 But that's a little bit silly. 07:45.390 --> 07:49.950 I think we could just use this delegate signature and create a new delegate. 07:49.950 --> 07:56.160 In fact, I'm going to give it a new property so I can take one of our other attribute changed signatures 07:56.160 --> 07:57.360 and copy it. 07:57.360 --> 08:02.880 And down here at the bottom of it in the public section, I'm going to paste, but change the name and 08:02.880 --> 08:05.370 this will be on XRP. 08:05.580 --> 08:15.660 Percent changed and we'll tack on delegate at the end there and this will be gas slash XRP for the category. 08:15.690 --> 08:18.090 So now we have a delegate to broadcast. 08:18.120 --> 08:24.900 Now we just need to figure out what that percent should be and broadcast that in on XRP changed. 08:24.930 --> 08:26.820 Now here in on XRP changed. 08:26.820 --> 08:33.780 We're going to want the level up info and we know that that exists on the player state so we can access 08:33.780 --> 08:35.700 the player state with a cast checked. 08:36.150 --> 08:39.240 We'll go ahead and copy that line and paste it there. 08:39.270 --> 08:43.530 Don't worry about using cast checked each time our XRP changes. 08:43.560 --> 08:49.740 As I mentioned, this turns into a static cast in builds, so this is not something to worry about performance 08:49.740 --> 08:50.370 wise. 08:50.640 --> 08:54.660 So in on XRP changed, What exactly are we going to do here? 08:54.660 --> 09:03.600 Well, we need to get our level up info, so I'm just going to say you level up info, we'll get a pointer 09:03.600 --> 09:04.470 to that. 09:04.500 --> 09:10.230 We'll call this level up info and we'll use our aura player state. 09:11.500 --> 09:13.580 And get that level up info. 09:13.600 --> 09:14.830 Public variable. 09:15.010 --> 09:21.240 And what we'll do with our level up info is we're going to perform lookups for data from it. 09:21.250 --> 09:26.350 So this can be a const pointer and if we like, we can perform a check on that. 09:26.350 --> 09:38.560 We can say check level up info and we can even use a check f if we want a descriptive message. 09:38.740 --> 09:46.210 When level up info is a null pointer, we can say unable to find level up info. 09:47.710 --> 09:49.930 Please fill out. 09:51.460 --> 09:54.310 Or a player state blueprint. 09:55.520 --> 10:02.810 So we'll definitely know if we forgot that we'll get a crash or an assertion in debug mode with that 10:02.810 --> 10:03.620 message. 10:03.800 --> 10:09.620 So how are we going to know what our percent bar should be when we know what our XP is? 10:09.650 --> 10:16.460 Well, level up info has a handy function that can tell us what level we should be for a given experience 10:16.460 --> 10:17.420 value. 10:17.720 --> 10:21.110 We can take our level up info and call that function. 10:21.110 --> 10:24.590 It's called find level for XP. 10:25.070 --> 10:28.820 It takes an int 32 we can pass in new XP. 10:29.090 --> 10:36.200 Now we made level up info, const and find level for XP could be const, so one has to change. 10:36.200 --> 10:43.220 Either this function can be const and then our pointer can be const or the function can not be const. 10:43.220 --> 10:47.030 But if it's not const then our pointer can't be const. 10:47.270 --> 10:52.100 Well, if it's just a lookup to find level for XP, it could easily be const. 10:52.130 --> 10:59.580 We can go into our public ability system data folder and to level up info and we can make find level 10:59.580 --> 11:01.650 for XP a const function. 11:01.650 --> 11:04.590 We'll have to do it in the header and the CPP file. 11:05.520 --> 11:11.550 And once we do that, then here in the widget controller we can call this function no problem. 11:11.550 --> 11:13.410 So this gives us the level. 11:13.410 --> 11:21.300 It's an int 32 returning function so we can create an int 32 called level and now we know what our level 11:21.300 --> 11:21.750 is. 11:21.780 --> 11:29.490 Now that's important because we need to know how much XP to get from the beginning of one level to the 11:29.490 --> 11:30.780 end of that level. 11:30.780 --> 11:33.780 In other words, that Delta XP requirement. 11:34.050 --> 11:39.840 And if we're going to be finding Delta XP from one level to another, we should know what that max level 11:39.840 --> 11:40.170 is. 11:40.170 --> 11:44.670 So we should have a const int 32 called max level. 11:44.700 --> 11:51.420 I said const, we'll make it constant, a second max level equals and we'll get our level up info and 11:51.420 --> 11:56.880 access that level up information and get the number of elements in it. 11:56.880 --> 12:01.770 So the number of elements in it should be the max level possible. 12:01.770 --> 12:04.410 So these both can be constants. 12:06.130 --> 12:07.750 So we know our current level. 12:07.750 --> 12:10.000 We know the max level possible. 12:10.120 --> 12:17.950 We need to figure out that delta between the amount of XP when we first reached our current level to 12:17.950 --> 12:20.170 the amount of XP at the end of that level. 12:20.170 --> 12:22.300 In other words, it's level requirement. 12:22.630 --> 12:31.300 So first I'm going to place a check here that says if level is less than or equal to max level, that 12:31.300 --> 12:33.010 way, we're in range here. 12:33.430 --> 12:37.630 But I'm also going to have an and and make sure level is greater than zero. 12:39.370 --> 12:42.130 Because it's a zero level doesn't make sense either. 12:42.430 --> 12:48.130 Now, the level requirement for our current level that can be accessed from our level up information. 12:48.130 --> 12:54.280 So I'm going to make a const int 32 called level requirement or level up requirement. 12:55.160 --> 12:58.040 And that's going to be our level up info. 12:59.590 --> 13:04.360 Accessing level up information from it and indexing it at our current level. 13:04.510 --> 13:09.730 But that's a struct which contains the level up requirements, so we have to access that. 13:09.760 --> 13:12.850 Now I want to know the previous level requirement. 13:12.850 --> 13:18.400 In other words, the XP that we were at at the very beginning of our current level, that's the level 13:18.400 --> 13:20.530 up requirement for the previous level. 13:20.650 --> 13:28.840 So I'm going to make a const int 32 called previous level up requirement and that's going to be level 13:28.840 --> 13:29.890 up info. 13:31.460 --> 13:39.020 Accessing level up information, indexing it at level minus one, the previous level, and then getting 13:39.020 --> 13:40.760 that level up requirement. 13:40.790 --> 13:42.710 So now we have both of those. 13:42.740 --> 13:45.440 Now we can see the difference between them. 13:45.440 --> 13:54.500 A delta, we can say const int 32, Delta level requirement, we'll call it, and that's simply going 13:54.500 --> 13:58.490 to be the current level requirement minus the previous one. 14:00.530 --> 14:07.310 And it's actually level up requirement minus previous level up requirement. 14:09.020 --> 14:15.020 The reason we need this delta is so that we know what to divide our current exp value by. 14:15.110 --> 14:18.610 Now current exp remember is a cumulative total. 14:18.620 --> 14:23.990 What we need is how much more from the beginning of our current level we have. 14:24.020 --> 14:31.610 In other words, if we're level two and we had to reach 300 to reach level two and now we have 400 then 14:31.610 --> 14:36.140 to calculate the percent and the level up requirement for level two is, say, 900. 14:36.170 --> 14:42.410 In other words, 600 more, then our percent would be 100 divided by 600. 14:42.440 --> 14:47.510 It would be our current Exp minus last level's requirement. 14:47.510 --> 14:59.450 So we're going to say const int 32 exp for this level equals and it's going to be new exp. 14:59.480 --> 15:06.590 That's our current value minus previous level up requirement. 15:07.070 --> 15:13.560 And finally we can calculate the exp bar percent and this is going to be a float because we're going 15:13.560 --> 15:15.900 to do a division, a const float. 15:15.930 --> 15:18.840 We're going to call this exp bar percent. 15:20.970 --> 15:24.180 And this will be our XP for this level. 15:26.160 --> 15:30.360 Divided by the Delta level requirement. 15:30.630 --> 15:33.610 Now, we don't want to perform integer division. 15:33.630 --> 15:39.090 We want to perform float division so we can static cast these to floats. 15:39.120 --> 15:44.400 Or we could have done an implicit cast and created floats for these variables. 15:44.430 --> 15:46.520 Either one, it doesn't really matter. 15:46.530 --> 15:52.320 We were working with integers up to this point, so this is the point at which we need them to be floats 15:52.320 --> 15:54.690 so we can say static cast. 15:54.690 --> 15:58.740 And this is just a regular old C plus plus static cast to float. 15:58.770 --> 16:02.310 We're going to static cast both of these to floats. 16:02.310 --> 16:08.790 So we'll static cast this one and we'll static cast this one and now we have exp bar percent we can 16:08.790 --> 16:18.000 broadcast we can take our on exp changed and actually our delegate is called on exp percent changed 16:18.000 --> 16:21.090 delegate will broadcast this. 16:21.090 --> 16:22.890 This can broadcast a float. 16:22.920 --> 16:26.290 We're going to broadcast exp bar percent. 16:29.220 --> 16:30.180 All right. 16:30.180 --> 16:32.850 Well, that was quite an experience. 16:32.850 --> 16:38.460 And if you did this all on your own, I'm pretty impressed because that was quite a problem to find 16:38.460 --> 16:39.630 a solution to. 16:39.810 --> 16:40.740 Pretty nice. 16:40.740 --> 16:47.060 And by the way, this could be a const function or a player state could be a const variable. 16:47.070 --> 16:54.660 We can just make these const correct on exp changed in the header file can be made const here. 16:55.460 --> 17:02.090 And with that, we now have our widget controller responding to XRP changes. 17:02.120 --> 17:11.360 Now it'd be great to just go into our XRP bar in Blueprint and bind to this on XRP Percent Change Delegate. 17:11.390 --> 17:14.330 You can see that I just compiled while I was talking there. 17:14.450 --> 17:17.300 But we're never actually changing our XRP. 17:17.600 --> 17:23.510 That's going to be something we have to do when we accomplish something like Slay an Enemy or whatever. 17:23.540 --> 17:30.410 So there's really nothing we can do at this point to test it unless we just change our XRP on the player 17:30.410 --> 17:32.270 state willy nilly. 17:32.270 --> 17:33.470 But that's okay. 17:33.470 --> 17:35.000 We'll test it soon enough. 17:35.000 --> 17:37.340 We're going to implement this in stages. 17:37.370 --> 17:39.800 For now, we have our callback. 17:39.800 --> 17:44.420 We even have this code to find out the XRP bar percent. 17:44.450 --> 17:47.240 We'll see very soon if that's correct. 17:47.240 --> 17:49.820 And things are looking good. 17:49.820 --> 17:54.140 So excellent job with this quest and we'll continue in the next video. 17:54.170 --> 17:55.250 I'll see you soon.