WEBVTT 00:06.780 --> 00:07.980 Welcome back. 00:08.190 --> 00:14.580 Now, here in our Attributes set, we're checking to see if the changed attribute here in post gameplay 00:14.580 --> 00:19.440 effect execute is incoming XP our meta attribute. 00:19.470 --> 00:28.110 Now, if it is, we're adding to XP using the player interface that allows us to actually change our 00:28.110 --> 00:29.880 XP on the player state. 00:29.880 --> 00:35.970 But now that we're concerned with leveling up, we need to check to see if this is enough for a level 00:35.970 --> 00:36.480 up. 00:36.510 --> 00:39.780 If it is, we want to level up the character. 00:39.780 --> 00:43.440 Now what happens as a result of that depends. 00:43.440 --> 00:51.780 Yes, we're going to award certain values to various classes so that we can increase our level of progression, 00:51.780 --> 00:58.500 but also we're going to most likely have some visual effects and in particular some effects related 00:58.500 --> 01:00.270 to the player specifically. 01:00.390 --> 01:04.580 So I'd like to add another player interface function for leveling up. 01:04.590 --> 01:11.470 So I'm going to go into my public folder, into interaction and into player interface, and we're going 01:11.470 --> 01:15.400 to add another function to this, and this one will be for leveling up. 01:15.490 --> 01:20.650 Now it's going to be void and I'm just going to call it level up and we can implement this however we 01:20.650 --> 01:23.290 like in our Aura character. 01:23.290 --> 01:26.200 And I'm also going to make it a Blueprint Native event. 01:27.490 --> 01:32.830 So we can override this in aura character however we like. 01:32.860 --> 01:38.680 For now, I'm just going to override it and then we'll decide what happens as a result of calling this 01:38.680 --> 01:39.350 later. 01:39.370 --> 01:46.900 So we can say virtual void level up implementation override and we can generate an empty definition. 01:46.900 --> 01:48.640 We don't need to call super for this. 01:48.670 --> 01:51.760 We're going to do whatever we want here. 01:51.790 --> 01:54.340 Most likely going to be cosmetic. 01:54.490 --> 02:01.240 But now that we have this function, we can decide in our attributes set if we've just gained enough 02:01.240 --> 02:05.950 XP to level up and that's going to involve some kind of calculation. 02:05.980 --> 02:08.020 That's why we have our to do here. 02:08.020 --> 02:09.660 So we'll do that. 02:09.670 --> 02:12.520 I'd like to do that next in our next video. 02:12.520 --> 02:16.840 But before we wrap up this one, I'd like to do one more thing. 02:16.840 --> 02:24.490 I'd like to go into my interaction folder again into combat interface and notice that we have a lot 02:24.490 --> 02:30.710 of Blueprint Native events and we've seen that this is really nice because it allows us to avoid the 02:30.710 --> 02:34.130 cast to the interface and call a static function. 02:34.160 --> 02:41.000 The execute version related to this, but get player level is not one of these and we're using get player 02:41.000 --> 02:46.790 level all over the place and I really prefer that it be one of these blueprint native events so that 02:46.790 --> 02:51.110 we can execute it without a cast just like the others. 02:51.140 --> 02:57.950 That way in our aura attributes set where we're calling get player level, we can be consistent about 02:57.950 --> 03:00.470 it here and send Exp event. 03:00.470 --> 03:06.200 For example, we're casting to the combat interface just so we can call get player level. 03:06.260 --> 03:11.150 If get player level were a blueprint native event, we wouldn't have to do that. 03:11.150 --> 03:17.600 We could just check to see if the target character implements the interface and then call execute get 03:17.600 --> 03:18.380 character class. 03:18.380 --> 03:19.940 Now this isn't a problem. 03:19.940 --> 03:21.920 This is a totally legit way to do it. 03:21.920 --> 03:27.800 It's not bad practice or anything like that, but I would prefer if this were consistent here, if I 03:27.800 --> 03:30.410 got both of these in a consistent manner. 03:30.410 --> 03:32.960 That's one reason I'd like to change it. 03:32.990 --> 03:41.060 But another reason I'd like to change it is because complications can occur when we're relying on something 03:41.090 --> 03:42.680 to implement an interface. 03:42.680 --> 03:44.960 And I'm going to show you one of those. 03:45.050 --> 03:50.720 If we go into the private folder and ability system and open exec calc damage. 03:51.120 --> 03:58.200 Here in exact calc damage all the way up at the top where casting the source, Avatar and target Avatar 03:58.200 --> 04:00.960 both to these combat interfaces. 04:00.990 --> 04:06.420 Now, that's fine if they both implement those and if they didn't, well, we could perform a null check 04:06.420 --> 04:07.320 or something like that. 04:07.320 --> 04:10.350 But why are we using the combat interface? 04:10.350 --> 04:17.010 Well, if we search this file for interface, we can see that we're calling get player level here and 04:17.010 --> 04:22.650 we're evaluating curves from curve tables based on the player level that we get. 04:22.830 --> 04:23.880 Now, this is great. 04:23.880 --> 04:30.300 Again, if both the damage causer and the receiver implement this combat interface, this works just 04:30.300 --> 04:30.960 fine. 04:30.960 --> 04:34.830 But if let's say we're getting damage from an effect. 04:34.830 --> 04:35.900 Actor Right. 04:35.940 --> 04:43.080 A fire area, well, that fire area may or may not implement this interface, at which point we'd be 04:43.080 --> 04:45.450 trying to cast to the interface. 04:45.450 --> 04:51.670 The interface would be a null pointer in this case and we'd be trying to access a null pointer again. 04:51.670 --> 05:00.310 We could perform a null check, but it'd be nicer if we could just check to see if these actors implement 05:00.310 --> 05:06.640 the interface and then have some local level variable that we can set to zero if they don't implement 05:06.640 --> 05:07.510 the interface. 05:07.510 --> 05:11.260 And then we would just have zero in our calculations. 05:11.470 --> 05:18.070 So what I'd like to do is change the function in the combat interface, get player level so that it's 05:18.070 --> 05:19.510 a blueprint native event. 05:19.510 --> 05:25.600 And of course that's going to require us to go through the project everywhere it's used and change it. 05:25.630 --> 05:33.550 We're going to have to change what we're overriding in both a character and or an enemy to the implementation 05:33.550 --> 05:34.270 version. 05:34.270 --> 05:39.700 And then everywhere we're calling the function, we have to call the static execute version instead. 05:39.700 --> 05:45.730 So this will require a little bit of a project refactor, not a big one, but a little one. 05:45.730 --> 05:48.640 So I'd like to do that in this video. 05:48.640 --> 05:54.690 And this can happen in a project from time to time where you decide to change a design. 05:54.700 --> 06:00.970 So the first thing we need to do is we're going to remove virtual from the function and we're going 06:00.970 --> 06:04.150 to add a new function with Blueprint Native event. 06:04.180 --> 06:05.680 That's the first thing. 06:06.010 --> 06:10.120 Now as soon as we've done that, we're going to create lots of errors. 06:10.120 --> 06:14.640 If we go ahead and compile right now, we'll get compiler errors. 06:14.650 --> 06:21.490 So the first errors we get are in or character and or enemy like I just mentioned, get player level. 06:21.490 --> 06:24.250 This is no longer something we override. 06:24.250 --> 06:28.720 Instead we override the underscore implementation version of this. 06:28.720 --> 06:36.430 So we have to do this both in the H file and we have to go into the CPP file and change it here as well. 06:36.430 --> 06:43.210 So I just did for or a character we can do so for Ora Enemy as well, changing it from get player level 06:43.240 --> 06:50.230 to get player level implementation, there's the header file and here is the CPP file. 06:50.260 --> 06:53.050 So that takes care of those errors. 06:53.050 --> 06:56.800 But if we compile again now we get other errors. 06:56.800 --> 07:00.010 So how are we going to fix this? 07:00.040 --> 07:05.530 Well, what I'm going to do is do a project wide search for get player level and I'm going to see everywhere 07:05.530 --> 07:06.790 where we're using it. 07:06.970 --> 07:12.190 The first place I see is the MSI, Max Mana, so I'm going to start there. 07:12.190 --> 07:19.090 We're calling it right here After casting to the combat interface, instead of casting our spec, get 07:19.090 --> 07:22.480 context, get source object to the combat interface. 07:22.480 --> 07:27.160 What I'd rather do is check to see if it implements the interface and set player level. 07:27.160 --> 07:31.690 And if it doesn't, player level can be set to say one. 07:31.690 --> 07:33.250 So I'm going to do this. 07:33.250 --> 07:41.980 I'm going to create a local non-const int 32 called player level and set it equal to one and remove 07:41.980 --> 07:49.660 that line where I've declared that const int 32 and instead of casting to I combat interface, I'm going 07:49.660 --> 07:51.370 to use an if statement. 07:51.370 --> 07:59.500 And in the if statement I'm going to take this source object spec, get context dot get source object 07:59.590 --> 08:01.480 and I'm going to paste it here. 08:01.480 --> 08:07.810 And on this source object I'm going to call implements and implements allows me to check to see if it 08:07.810 --> 08:09.190 implements the interface. 08:09.280 --> 08:10.570 But very important. 08:10.570 --> 08:15.760 We have to remember that if we call implements, we use the U version and not the I version. 08:15.760 --> 08:21.340 So we use U combat interface for this implements function call. 08:21.340 --> 08:28.570 Now, if we make it inside this, then that source object does implement the interface and then we can 08:28.570 --> 08:35.140 set our player level by calling the static execute version on I combat interface. 08:35.140 --> 08:37.210 So it can be a little confusing. 08:37.210 --> 08:42.760 When we're using implements, we use U combat interface, but when we call that function on it, we 08:42.760 --> 08:49.510 use I combat interface and the function is execute, underscore, get player level and when we call 08:49.510 --> 08:50.680 the execute version. 08:50.780 --> 08:54.090 Since it's static, it needs to know which object we're calling it on. 08:54.110 --> 08:56.660 That's going to be this source object. 08:56.660 --> 08:59.150 So we're going to pass that in as well. 08:59.330 --> 09:03.340 And now we don't need this cast to eye combat interface. 09:03.350 --> 09:05.450 We're going to go ahead and remove that. 09:05.450 --> 09:07.910 And now we have just this line here. 09:07.970 --> 09:16.730 So these lines where I create the player level and set them, we can use these instead in MK Maxhealth 09:16.730 --> 09:17.320 as well. 09:17.330 --> 09:26.570 So I'm going to copy them and go into my MKs folder into MK Maxhealth and replace these two lines here 09:26.570 --> 09:30.770 where we're casting to the interface and creating this player level local variable. 09:30.860 --> 09:37.220 I'm going to replace them with this function call where we check to see if the source object implements 09:37.220 --> 09:41.050 the interface and then we call the execute version of get player level. 09:41.060 --> 09:46.100 So that's going to take care of the usage of get player level in the MKs. 09:46.100 --> 09:48.140 I'm going to go ahead and close out of those. 09:48.140 --> 09:53.610 We're done with those and I'm going to search project wide for get player level again and see where 09:53.610 --> 09:54.930 else we're calling it. 09:54.990 --> 09:59.100 I see that I'm using it in the attribute set, but we'll get to that. 09:59.100 --> 10:07.080 I'd like to skip to the exec calc as we're using get player level a couple times here when we're accessing 10:07.080 --> 10:12.290 the player level to calculate our armor penetration coefficient and so on. 10:12.300 --> 10:19.680 Now what I'd like to do is scroll up to the top because we're storing pointers to the combat interface. 10:19.710 --> 10:26.460 What I'd rather do instead is just calculate the player level and have a couple local integers for player 10:26.460 --> 10:30.210 level instead of just calling get player level. 10:30.210 --> 10:36.030 In multiple instances here, the way we did it is totally fine, but I'd like to do it a little bit 10:36.030 --> 10:36.660 differently. 10:36.660 --> 10:42.690 So what I'm going to do is first check our source avatar and see if it implements the interface. 10:42.690 --> 10:44.130 So we're going to say if. 10:44.130 --> 10:45.630 Source Avatar. 10:46.250 --> 10:49.730 Implements you combat interface. 10:51.200 --> 10:54.350 And if it does, we can get the player level for it. 10:54.440 --> 10:59.930 So I'm going to make a local int 32 called source player level. 11:00.590 --> 11:08.420 I'm going to start it off at one without a dot f and now I'm realizing, I think I went into my mix 11:08.420 --> 11:11.540 and I made an int 32 with dot f. 11:11.540 --> 11:12.920 That's just habit. 11:12.920 --> 11:17.420 I tend to put a dot f after a lot of things, so it's an n 32. 11:17.450 --> 11:20.720 We don't need a dot f there that would result in an implicit conversion. 11:20.960 --> 11:23.440 So I'm going to remove those from there. 11:23.480 --> 11:30.020 A little tangent there, but I'm going to have this source player level and I'm going to take my source 11:30.020 --> 11:37.520 player level here and set it equal to eye combat interface, execute get player level passing in source 11:37.520 --> 11:38.360 Avatar. 11:38.360 --> 11:40.340 So I'd rather do it this way. 11:40.340 --> 11:44.960 And now we have just an int 32 for source player level. 11:45.140 --> 11:49.290 I'm going to have the same thing for the target as well. 11:49.290 --> 11:55.950 So we're going to have a target player level and this will be checking if the target Avatar implements 11:55.950 --> 11:56.760 the interface. 11:56.760 --> 12:03.810 And if it does, then we're going to set target player level equal to get player level passing in Target 12:03.810 --> 12:04.620 Avatar. 12:04.620 --> 12:10.530 Now that we have source player level and target player level, we can delete these pointers as we don't 12:10.530 --> 12:15.210 really need them anymore and we can find where we're calling get player level here. 12:15.450 --> 12:21.990 So instead of calling source combat interface, get player level here, we can just pass in source player 12:21.990 --> 12:22.590 level. 12:23.140 --> 12:27.550 And right here we're calling target Combat interface, get player level. 12:27.550 --> 12:28.150 Instead. 12:28.150 --> 12:33.430 I'm going to pass in target player level and I believe we're using it again here. 12:33.640 --> 12:40.210 I'm going to replace this function call with target player level as well, and that is the only place 12:40.210 --> 12:41.230 we use that interface. 12:41.230 --> 12:44.530 So now we don't need to cast to the interface. 12:44.530 --> 12:47.440 We're just checking to see if we implement the interface. 12:47.590 --> 12:48.130 Okay. 12:48.130 --> 12:54.910 So searching project wide again, I see that aura attribute set looks like just about the last place 12:54.910 --> 12:56.860 we're calling get player level. 12:56.860 --> 12:57.910 Actually almost. 12:57.910 --> 13:00.880 We're calling it an aura ability system library as well. 13:00.880 --> 13:04.870 So first the attribute set and send Exp event. 13:04.900 --> 13:08.830 So here we don't have to cast to the combat interface. 13:08.830 --> 13:13.870 Instead, we're going to take props dot target character and see if it implements the interface. 13:13.870 --> 13:16.180 So we'll replace the conditional here with props. 13:16.180 --> 13:19.690 Dot target character call implements. 13:21.660 --> 13:24.150 You combat interface. 13:24.150 --> 13:32.730 And if it does, then here we'll call that function I combat interface execute get player level passing 13:32.730 --> 13:34.830 in props dot target character. 13:37.580 --> 13:44.570 So now these two local variables are obtained in consistent manners and it looks a little bit more professional. 13:44.900 --> 13:45.320 All right. 13:45.320 --> 13:50.710 So the last place I think we're using this is in our Ability system library. 13:50.720 --> 13:56.150 Let's go to that and that's here and give startup abilities where again, we're casting to the combat 13:56.150 --> 13:59.840 interface, but instead I think we can just check. 13:59.840 --> 14:05.270 So we're going to take our ASCs get Avatar actor function call. 14:05.300 --> 14:10.700 We'll replace this conditional with get Avatar actor calling implements. 14:10.820 --> 14:13.400 We'll check you combat interface. 14:13.400 --> 14:19.940 And then instead of calling get player level on the combat interface directly, we'll call eye combat 14:19.940 --> 14:26.630 interface, execute get player level and pass in ASC, get Avatar actor. 14:26.750 --> 14:30.530 So that's going to replace our cast there. 14:30.830 --> 14:37.740 Now I'm going to quickly just give this a compile and see what we get and we get a linker error. 14:37.770 --> 14:44.190 Okay, So here's one that might have tripped you up if you tried to compile and do this. 14:44.190 --> 14:50.250 Refactor yourself a linker error that says that a function is already defined. 14:50.280 --> 14:56.250 This can be a little bit tricky, but it all comes back to this get player level function and how it 14:56.250 --> 14:57.300 used to be. 14:57.330 --> 14:59.280 Not a blueprint native event. 14:59.310 --> 15:00.420 Now it is one. 15:00.420 --> 15:07.020 So if we go to combat interface here, now we have get player level right and when we have this get 15:07.020 --> 15:15.450 player level function as blueprint native event, we have to go into the CPP file here as we've defined 15:15.450 --> 15:17.730 a function definition for it. 15:17.760 --> 15:24.000 We can't do this because this get player level definition will be auto generated by the unreal header 15:24.000 --> 15:24.480 tool. 15:24.480 --> 15:31.410 So the unreal header tool sees that blueprint native event macro specifier and generates the implementation 15:31.410 --> 15:32.880 for get player level. 15:33.000 --> 15:38.940 For that reason, this get player level is a redefinition which is not okay. 15:38.940 --> 15:43.320 So for that reason we have to remove this function call altogether. 15:44.040 --> 15:48.600 If we do that, we should be able to compile just fine and we do. 15:49.260 --> 15:49.680 Okay. 15:49.680 --> 15:51.900 So that was a pretty good refactor. 15:51.900 --> 15:56.040 We can do a quick play test and make sure that everything works okay. 15:56.430 --> 15:59.610 Everything should still work the same as it did before. 15:59.700 --> 16:03.390 We've just kind of cleaned up our code so it's a little bit more consistent. 16:07.570 --> 16:13.600 So really quickly, I'm just going to press play caused some damage, make sure that things are working. 16:13.600 --> 16:15.460 I can even take some damage. 16:15.460 --> 16:17.320 And we see that things are working. 16:17.320 --> 16:19.180 Everything works just fine. 16:20.050 --> 16:23.050 We'll do a really quick multiplayer test as well. 16:25.740 --> 16:28.890 Take some damage, caused some damage. 16:30.480 --> 16:32.010 And things are working. 16:34.150 --> 16:37.180 And I'll play his client as well just to try. 16:39.550 --> 16:41.170 Dedicated server setup. 16:43.460 --> 16:44.300 Perfect. 16:44.570 --> 16:45.140 Okay. 16:45.140 --> 16:52.130 So with that, we've just done a little bit of a refactor and we're ready to continue implementing level 16:52.130 --> 16:56.360 up capabilities and we'll level up in the next video. 16:56.780 --> 16:59.420 Excellent job and I'll see you soon.