WEBVTT 00:07.090 --> 00:08.200 Welcome back. 00:08.200 --> 00:15.100 So now that we have four new attributes in our attribute set, we're going to learn how to easily create 00:15.100 --> 00:22.450 some accessor functions to retrieve and set these, even though usually we don't set these from code 00:22.450 --> 00:28.030 directly, we use gameplay effects, but we haven't learned about gameplay effects just yet, so we 00:28.030 --> 00:33.430 do need to know that we can in fact set these from code with regular old setters. 00:33.460 --> 00:42.460 Now for getters and setters, there exist some pretty handy macros that make it easy to mutate and access 00:42.460 --> 00:44.080 these attributes. 00:44.080 --> 00:47.500 And I'm just going to show you one for health. 00:47.500 --> 00:53.350 Just under health, I'm going to use the gas specific macro gameplay attribute. 00:54.070 --> 00:57.160 Underscore property getter. 00:57.250 --> 01:00.430 Now, this requires two inputs. 01:00.430 --> 01:07.810 The class name, which is you, or a attribute set, of course, and the property name, which is health. 01:07.990 --> 01:11.590 So what exactly happens when we call this? 01:11.590 --> 01:14.440 Well, let's go ahead and just jump to its definition. 01:14.440 --> 01:16.480 I'm going to right click here in writer. 01:16.480 --> 01:19.600 It's go to declaration or usages. 01:19.600 --> 01:23.770 You can just peek the definition in Visual Studio, but here it is. 01:23.770 --> 01:25.960 Gameplay attribute Property getter. 01:25.960 --> 01:27.400 It's a macro. 01:27.400 --> 01:28.540 It's defined right here. 01:28.540 --> 01:33.460 In fact, here in attribute set this big comment explains it. 01:33.490 --> 01:39.790 It says This defines a set of helper functions for accessing and initializing attributes to avoid having 01:39.790 --> 01:41.620 to manually write these functions. 01:41.620 --> 01:46.300 It would create the following functions for attribute health. 01:46.300 --> 01:49.420 It uses health as the example. 01:49.420 --> 01:57.770 It says that these macros result in creating Get Health, which is a const getter, set health which 01:57.770 --> 02:04.250 does what you'd think a set health function would do, and in it health which initializes the health, 02:04.280 --> 02:10.010 it says to use this in your game you can define something like this and then add game specific functions 02:10.010 --> 02:11.120 as necessary. 02:11.120 --> 02:15.620 And it says here, define this macro called attribute accessors. 02:15.620 --> 02:23.960 If you define this, then when you call attribute accessors, it will call these four macros which create 02:23.960 --> 02:31.010 the getter for the attribute, the getter for the value, the setter for the attribute and the emitter 02:31.010 --> 02:32.330 for the attribute. 02:32.330 --> 02:36.530 And why do we have get health attribute and get health? 02:36.530 --> 02:43.850 Well, that's because the attribute itself is its own type of gameplay attribute. 02:43.850 --> 02:51.470 That's the attribute that gameplay attribute data contains within and get health would return just the 02:51.470 --> 02:51.860 float. 02:51.860 --> 02:53.870 You could see it returns float here. 02:53.870 --> 03:01.100 So one returns the actual attribute object, the other returns the numerical value of health. 03:01.130 --> 03:02.480 See the difference? 03:02.480 --> 03:04.910 So we can take a look at these macros. 03:04.910 --> 03:08.570 It's not imperative that we understand the macros. 03:08.570 --> 03:10.760 This is macro creation magic. 03:10.790 --> 03:18.050 This macro here is generating a new function called get property attribute. 03:18.140 --> 03:23.810 So it's using macro magic to generate a getter function for us. 03:23.840 --> 03:30.830 And I'd just like to point out one quick difference between set and init. 03:30.860 --> 03:36.170 You see, set is going to set the numeric attribute base. 03:36.170 --> 03:43.010 That's the base value for the attribute, whereas init sets the base value but also sets the current 03:43.010 --> 03:45.170 value base and current. 03:45.200 --> 03:52.970 It's basically saying start off with the same base and current value, which is what we pass in. 03:52.970 --> 03:56.900 So we get these nice accessor functions. 03:56.900 --> 04:05.030 If we call these macros as we saw in aura attribute set dot h, I called gameplay attribute property 04:05.030 --> 04:05.360 getter. 04:05.360 --> 04:12.950 This is going to generate the getter for the health attribute, not its numerical value, but an object 04:12.950 --> 04:18.680 of type gameplay attribute which is contained within that attribute data. 04:18.920 --> 04:25.970 So why don't we go ahead and follow what the attribute set header recommends and that is to create this 04:26.000 --> 04:28.160 attribute Accessors macro. 04:28.160 --> 04:31.580 Let's go ahead and copy these lines. 04:32.030 --> 04:37.490 And back in our aura attributes set at the top underneath all the includes. 04:37.490 --> 04:38.810 We'll go ahead and paste them. 04:38.810 --> 04:41.840 We need to delete these stars. 04:41.840 --> 04:45.860 The asterisks that came from that multi-line comment. 04:46.010 --> 04:50.360 And now we have this attribute accessors macro. 04:50.360 --> 04:55.190 And if we call this, then we don't have to use all four of these. 04:55.190 --> 05:00.710 So just under health, I'm going to replace this with attribute accessors here. 05:00.830 --> 05:05.300 Now hovering over it says ability system component is incomplete. 05:05.330 --> 05:08.900 That means we're going to have to include it here in the header file. 05:08.900 --> 05:11.540 There's no way to get around that. 05:11.540 --> 05:18.710 So I'm going to go into aura attribute set dot CPP up at the top where I've included ability system 05:18.710 --> 05:19.310 component. 05:19.310 --> 05:25.520 I'm just going to go ahead and control X to cut that out and we're going to include it right here in 05:25.520 --> 05:26.660 the attribute set. 05:26.690 --> 05:30.710 That way we can use these macros. 05:30.830 --> 05:36.750 So the attribute accessors thing is just another one of those boilerplate things that you're going to 05:36.750 --> 05:38.220 add to your attributes. 05:38.220 --> 05:42.750 And because of this, we can now use those accessor functions. 05:42.750 --> 05:51.060 For example, if I want to initialize health to say a value of 100, I can go into my constructor and 05:51.060 --> 05:54.270 use init health and pass in 100. 05:54.540 --> 06:02.220 And even though I didn't create an init health function, I used my attribute accessors macro which 06:02.220 --> 06:08.940 calls these four macros, one of which creates the emitter and by default that's called init health. 06:09.000 --> 06:11.850 So I can use that to init the health. 06:11.850 --> 06:13.770 But how do we see that change? 06:13.770 --> 06:16.110 How can we verify that it's working? 06:16.140 --> 06:18.450 Well, we can compile and launch the editor. 06:18.450 --> 06:21.180 I'm just going to go ahead and run and debug mode. 06:21.680 --> 06:24.780 And right here in the editor, I can press play. 06:24.800 --> 06:30.410 I can click in the viewport and I'm going to hit the tilde key to bring up the console and I'm going 06:30.410 --> 06:34.580 to type the console command show debug. 06:34.580 --> 06:37.340 That's one word ability system. 06:37.340 --> 06:38.750 That's also one word. 06:38.750 --> 06:42.530 So two words total show debug ability system. 06:42.740 --> 06:49.250 Now this brings up a debug view for the ability system and it has a lot of information. 06:49.250 --> 06:53.870 It shows attributes for Avatar or a character. 06:53.900 --> 06:59.780 See, So we know that our avatar actor has been set correctly to be or a character. 06:59.870 --> 07:01.130 It says authority. 07:01.130 --> 07:03.560 That means we're looking at the authority version. 07:03.560 --> 07:10.460 Now there are no other client machines, so the only version there is is the authority version. 07:10.460 --> 07:14.270 And we see for owner BP or a player state. 07:14.270 --> 07:21.300 So it knows that our avatar actor is the character and our owner actor is the player state. 07:21.300 --> 07:29.160 That's all thanks to calling init ability actor info we see in red showing debug for BP or a character 07:29.160 --> 07:33.330 press page up and page down to cycle between targets. 07:33.330 --> 07:41.010 So if we press page up we can cycle to other targets and we see the name change right here. 07:41.010 --> 07:48.780 It says showing debug for BP Goblin Slingshot C1 But we can cycle back around to our character. 07:48.780 --> 07:50.940 It shows some other information. 07:50.940 --> 07:58.410 It shows the name of the computer, that's my computer's name, and it actually has the location and 07:58.410 --> 08:02.940 rotation right here and you can see it update as I'm moving around. 08:02.940 --> 08:07.980 We have an instigator and an owner for our ability system component. 08:08.010 --> 08:13.860 We see the controller is BP or a player controller and the pawn is BP or a character. 08:13.860 --> 08:16.350 So it knows a lot of this information. 08:16.350 --> 08:19.830 And beneath all that we see owned tags. 08:19.830 --> 08:22.920 We're going to look at that as soon as we get into gameplay tags. 08:22.920 --> 08:26.910 And yet underneath all of that, we see the four attributes. 08:26.910 --> 08:29.940 Here we have health followed by 100. 08:29.940 --> 08:31.860 That's what we initialized it to. 08:31.860 --> 08:37.920 And then Max Health Mana and Max Mana, the other attributes and we didn't initialize those. 08:37.920 --> 08:46.590 So show debug ability system is a great way to sort of debug some of our attribute values and also see 08:46.620 --> 08:48.960 what gameplay tags our character has. 08:49.110 --> 08:51.960 So that's a nice way that we can do some debug. 08:51.960 --> 08:57.270 I'm going to go ahead and close out of the editor and now we've added some boilerplate here that we 08:57.270 --> 09:05.280 can reuse for all of our attributes by using the attribute accessors and that gives us these functions 09:05.280 --> 09:07.620 we can use to initialize and set. 09:07.650 --> 09:09.780 Now I'll give you a bit of a spoiler. 09:09.810 --> 09:14.100 The constructor is too early to call the setter. 09:14.100 --> 09:16.470 That's why we have the emitter here. 09:16.470 --> 09:21.990 But now we have this attribute accessors which we could use with all of our attributes. 09:22.140 --> 09:25.500 So here's what your quest will be for this video. 09:25.620 --> 09:30.800 You're going to use that attribute accessors macro on the other attributes. 09:30.810 --> 09:33.360 So go ahead and add that. 09:33.360 --> 09:36.180 That way you'll have those accessor functions. 09:36.180 --> 09:40.890 And once you have those, you can now give initial values to all of the attributes. 09:40.890 --> 09:48.510 So do that in the constructor and then use show debug ability system by playtesting the game and then 09:48.510 --> 09:51.830 you can verify that those initial values have been set. 09:51.840 --> 09:56.130 So pause the video and conquer this quest now. 09:59.320 --> 10:03.100 Okay, so we can use our attribute accessors macro. 10:03.310 --> 10:07.150 I'm going to be nice and lazy and copy it. 10:07.180 --> 10:13.900 Being very careful to change it from health to max health for this one, I'll copy it again. 10:13.900 --> 10:18.760 And just under Mana we'll add that changing it to Manna. 10:18.760 --> 10:21.070 And finally we have Max Manna. 10:21.070 --> 10:23.440 We'll change it to Max Manna as well. 10:23.440 --> 10:25.840 So now we have attribute accessors. 10:25.840 --> 10:30.340 For the rest we can go back and call init for all of them. 10:30.340 --> 10:33.130 I'm going to call init max health. 10:33.520 --> 10:37.810 Give it a value of 100 we can call init manna. 10:37.840 --> 10:40.150 Doesn't matter what values we choose. 10:40.150 --> 10:46.450 I'll just go ahead and choose 50 for mana and we'll use init max manna. 10:46.780 --> 10:51.610 I'll go ahead and give it 50 as well and we can go ahead and run. 10:51.610 --> 10:53.200 By the way, I'm running in debug mode. 10:53.200 --> 11:00.080 We're not really debugging per se, but don't you worry, we'll be debugging a lot in this course. 11:00.080 --> 11:02.210 We're just still kind of getting started here. 11:02.210 --> 11:06.320 But don't worry, we'll learn a lot about debugging throughout the course. 11:06.320 --> 11:12.680 Right now it's not that important whether you choose to run or debug at this point in time. 11:12.680 --> 11:14.750 All right, so we're going to hit play. 11:15.020 --> 11:16.370 I'm going to bring up the console. 11:16.370 --> 11:19.010 I'm just going to press up on the keyboard. 11:19.010 --> 11:26.330 That'll bring up my last command hitting enter and I see health and Max health are both 100 mana and 11:26.330 --> 11:28.220 Max Mana are both 50. 11:28.250 --> 11:33.080 They have been initialized successfully and it's looking good. 11:33.230 --> 11:33.860 Excellent. 11:33.860 --> 11:34.940 So great job. 11:34.940 --> 11:39.260 We now have those attribute accessors yet another piece of boilerplate. 11:39.260 --> 11:41.120 But now you know what it does. 11:41.120 --> 11:43.550 You don't need to be intimidated by it when you see it. 11:43.550 --> 11:47.660 You know that it simply creates some accessor functions that we can use. 11:47.690 --> 11:52.550 And I'll say it again, we typically don't use those functions to change attributes. 11:52.550 --> 11:58.040 We can, but we like to use gameplay effects instead as those can be predicted. 11:58.040 --> 12:00.620 And we'll learn about those when we get to gameplay effects. 12:00.620 --> 12:03.290 But for now we have accessors. 12:03.290 --> 12:05.540 So great job and I'll see you soon.