1 00:00:04,290 --> 00:00:05,650 ‫Hey, welcome back. 2 00:00:05,670 --> 00:00:09,900 ‫In this video, we're concerned with winning and losing conditions. 3 00:00:10,320 --> 00:00:14,520 ‫This is one of the last things we're going to handle in this game project. 4 00:00:14,550 --> 00:00:16,860 ‫Now let's take a look at our section plan. 5 00:00:16,860 --> 00:00:23,430 ‫Now, we've already checked off the first five items on our section plan, and the last two are the 6 00:00:23,430 --> 00:00:26,580 ‫special effects and winning and losing conditions. 7 00:00:26,580 --> 00:00:32,250 ‫And I'd like to switch these last two around and handle winning and losing conditions just because this 8 00:00:32,250 --> 00:00:39,300 ‫is the last of our gameplay programming logic and the special effects are cosmetic and more like finishing 9 00:00:39,300 --> 00:00:42,420 ‫touches so we can handle those at the very end. 10 00:00:42,420 --> 00:00:48,300 ‫So in this video we're going to create a game over function so that we know when the game has been either 11 00:00:48,300 --> 00:00:49,950 ‫won or lost. 12 00:00:49,950 --> 00:00:55,410 ‫And in order to win the game, we're going to need to count the number of towers in the world, because 13 00:00:55,410 --> 00:00:59,730 ‫once we've destroyed all of the towers, then we know we have won the game. 14 00:00:59,730 --> 00:01:05,670 ‫And if the tank itself gets destroyed, then we can consider that to be the lose condition. 15 00:01:05,670 --> 00:01:11,760 ‫So I'm back here in the game mode and the first thing I'd like to do is create another blueprint implementable 16 00:01:11,760 --> 00:01:12,540 ‫event. 17 00:01:12,570 --> 00:01:19,980 ‫We have this start game function, which we can call from C++, but we're implementing its logic in 18 00:01:19,980 --> 00:01:20,520 ‫the game mode. 19 00:01:20,520 --> 00:01:27,120 ‫Blueprint Thanks to Blueprint Implementable Event, I'd like to create another one of these for losing 20 00:01:27,120 --> 00:01:27,720 ‫the game. 21 00:01:27,720 --> 00:01:31,530 ‫So I'm going to create a void function called Game Over. 22 00:01:31,530 --> 00:01:37,530 ‫And for this one, I'd like to take a boolean input parameter called B one game. 23 00:01:37,530 --> 00:01:43,020 ‫And of course this is going to be a blueprint implementable event because the only thing I'd like to 24 00:01:43,020 --> 00:01:50,130 ‫handle with this function is displaying that we've lost or won the game and that we can do from blueprints. 25 00:01:50,130 --> 00:01:52,410 ‫So we have a game over function. 26 00:01:52,410 --> 00:01:55,350 ‫Now we need to know when we should call this function. 27 00:01:55,350 --> 00:02:00,450 ‫Well, first of all, we know we can call this function when we've lost the game, and that's going 28 00:02:00,450 --> 00:02:02,550 ‫to be if the tank has died. 29 00:02:02,550 --> 00:02:10,050 ‫So let's go into our actor died function here in tune tanks game mode CP And we see that if dead actor 30 00:02:10,050 --> 00:02:15,840 ‫is the tank, then we're handling the destruction of the tank and we're setting the enabled state to 31 00:02:15,840 --> 00:02:16,680 ‫false. 32 00:02:16,710 --> 00:02:25,020 ‫Another thing we can do here is end the game by simply calling game over and this boolean be one game 33 00:02:25,020 --> 00:02:27,240 ‫we can pass in false for this. 34 00:02:27,240 --> 00:02:31,770 ‫So that takes care of losing the game, at least from the C++ side. 35 00:02:31,800 --> 00:02:34,770 ‫Now we need to know when we should win the game. 36 00:02:34,800 --> 00:02:36,540 ‫Now here an actor died. 37 00:02:36,540 --> 00:02:43,050 ‫If the dead actor can be cast to a tower, we know that we've just destroyed a tower. 38 00:02:43,050 --> 00:02:49,740 ‫Now, this would be the perfect place to update a tower count or a variable of integer type that keeps 39 00:02:49,740 --> 00:02:53,220 ‫track of how many towers in the world there currently are. 40 00:02:53,250 --> 00:02:53,580 ‫Now. 41 00:02:53,580 --> 00:02:59,310 ‫In order to do that, we need a variable to keep track of the number of towers so we can add a private 42 00:02:59,310 --> 00:03:02,250 ‫variable here in the H file. 43 00:03:02,250 --> 00:03:03,960 ‫And I'd like to do that down here. 44 00:03:03,960 --> 00:03:08,880 ‫So I'm going to create an INT 32 and I'm going to call this target towers. 45 00:03:09,120 --> 00:03:15,840 ‫Now we can initialize this right off the bat to a value of zero, but we need to update this as the 46 00:03:15,840 --> 00:03:17,760 ‫number of towers decreases. 47 00:03:17,760 --> 00:03:22,350 ‫And we also need to set this to the number of towers there are in the world. 48 00:03:22,470 --> 00:03:28,170 ‫Now we could hard code this to four, but what happens when we start adding more towers to our levels? 49 00:03:28,170 --> 00:03:30,690 ‫Well, then it gets a little bit more complicated. 50 00:03:30,690 --> 00:03:35,580 ‫So what I'd like to do instead is see how many towers in the world there are. 51 00:03:35,610 --> 00:03:43,050 ‫Now, I could create a function for this that returns 32 and this function can find out how many towers 52 00:03:43,050 --> 00:03:45,810 ‫there are in the world and return the number. 53 00:03:45,810 --> 00:03:51,450 ‫So I'm going to call this function, get a target tower count. 54 00:03:51,600 --> 00:03:55,650 ‫So let's go ahead and give this function a body in the CP file. 55 00:03:55,680 --> 00:04:02,130 ‫I'm going to go all the way down to the bottom and create the function body and I can't forget to put 56 00:04:02,130 --> 00:04:05,040 ‫the class name before the function name. 57 00:04:05,040 --> 00:04:12,270 ‫Now this is going to return an end 32 and we need to decide how we're going to find out how many towers 58 00:04:12,270 --> 00:04:13,170 ‫there are. 59 00:04:13,200 --> 00:04:19,800 ‫Now there's a function that exists in gameplay statics called Get All Actors of class. 60 00:04:19,800 --> 00:04:21,300 ‫Here's the documentation. 61 00:04:21,300 --> 00:04:25,770 ‫It says Find all actors in the world of the specified class. 62 00:04:25,770 --> 00:04:28,890 ‫So we need to specify a particular class. 63 00:04:28,920 --> 00:04:31,530 ‫Now this function has three inputs. 64 00:04:31,530 --> 00:04:33,720 ‫First is a world context object. 65 00:04:33,720 --> 00:04:34,770 ‫That one's easy. 66 00:04:34,770 --> 00:04:36,180 ‫We know how to handle that. 67 00:04:36,180 --> 00:04:41,610 ‫But next we have a PT subclass of a actor and this is called Actor Class. 68 00:04:41,610 --> 00:04:48,000 ‫Now we've seen that functions that require a PT sub class of can accept a u class as inputs and the 69 00:04:48,000 --> 00:04:49,740 ‫third parameter is a T array. 70 00:04:49,770 --> 00:04:56,940 ‫It requires a t array of actor pointers and this is passed in as a reference and it's not a const reference 71 00:04:56,940 --> 00:05:03,680 ‫which seems to suggest that this function just might change this input parameter called out act. 72 00:05:03,730 --> 00:05:08,530 ‫Here's another hint that this is the case, is that it's called out actors. 73 00:05:08,530 --> 00:05:15,820 ‫It's an out parameter, meaning we pass it in and then after the function has been called, it has values 74 00:05:15,820 --> 00:05:18,220 ‫that have been put into it by the function. 75 00:05:18,220 --> 00:05:21,340 ‫So we can think of it as a sort of output for the function. 76 00:05:21,340 --> 00:05:28,810 ‫Now it says down here for parameters, actor class is the class of actor to find must be specified or 77 00:05:28,810 --> 00:05:30,640 ‫result array will be empty. 78 00:05:30,640 --> 00:05:37,240 ‫We want to find all of the towers and out actors is an output array of actors of the specified class. 79 00:05:37,240 --> 00:05:42,670 ‫So once we've called this function and passed in an array, when the function has finished, that array 80 00:05:42,670 --> 00:05:48,160 ‫will contain pointers to all of the actors in the world of the specified class. 81 00:05:48,160 --> 00:05:51,880 ‫So we know that this function requires a world context object. 82 00:05:51,880 --> 00:05:56,500 ‫Now, if we're going to be calling this from within the game mode, we can pass in this next. 83 00:05:56,500 --> 00:06:03,490 ‫We need the PT sub class of specifying the A actor and we know that this can be a new class pointer. 84 00:06:03,490 --> 00:06:06,070 ‫Now we need to specify the class to find. 85 00:06:06,070 --> 00:06:12,010 ‫If we specify a actor, then we'll get a big array filled with pointers to each actor in the world. 86 00:06:12,010 --> 00:06:13,810 ‫But we don't need all of the actors. 87 00:06:13,810 --> 00:06:21,070 ‫We just need the towers so we can use a tower static class which will return us a new class that represents 88 00:06:21,070 --> 00:06:23,290 ‫the A Tower C++ class. 89 00:06:23,290 --> 00:06:26,770 ‫Now the third parameter is a T array of a actor pointers. 90 00:06:26,770 --> 00:06:33,760 ‫So if we create a local variable of type T array specifying the a actor pointer in the angle brackets, 91 00:06:33,760 --> 00:06:35,980 ‫then we can call you game play statics. 92 00:06:36,010 --> 00:06:41,620 ‫Get all actors of class passing in those three inputs, and the result of this action will be that our 93 00:06:41,620 --> 00:06:45,970 ‫towers array should contain pointers to all towers in our world. 94 00:06:45,970 --> 00:06:52,840 ‫Now the tray is a nice container class which can contain a number of elements as long as they all share 95 00:06:52,840 --> 00:06:53,830 ‫the same type. 96 00:06:53,830 --> 00:07:01,690 ‫And this class has quite a great deal of functions that we can use when storing items in a tray. 97 00:07:01,720 --> 00:07:08,710 ‫Now I'm going to scroll all the way down and show you this function here called Num Short four number 98 00:07:08,830 --> 00:07:12,310 ‫and it says Returns the number of elements in array. 99 00:07:12,310 --> 00:07:19,690 ‫So we can use this function to get the number of elements in our array once we have all of the towers 100 00:07:19,690 --> 00:07:20,380 ‫in the world. 101 00:07:20,380 --> 00:07:26,080 ‫So if we call Tower's num, then we can use this as the return value for our function. 102 00:07:26,080 --> 00:07:31,930 ‫And as we saw, we set our return value for this function which we call get target tower count as an 103 00:07:31,930 --> 00:07:35,980 ‫n 32, we can return the number of elements in our tower's array. 104 00:07:35,980 --> 00:07:41,230 ‫So I'd like to challenge you to implement this get target tower count function. 105 00:07:41,230 --> 00:07:44,710 ‫So create a local t array of type A actor. 106 00:07:44,710 --> 00:07:47,110 ‫You can call it towers or anything you like. 107 00:07:47,110 --> 00:07:52,930 ‫Now use the you game, play statics function, get all actors of class and make sure you pass in the 108 00:07:52,930 --> 00:07:54,220 ‫correct input parameters. 109 00:07:54,220 --> 00:08:00,310 ‫Now, after you call this function, your tray is going to contain pointers to all of the towers in 110 00:08:00,310 --> 00:08:06,850 ‫our world, so you can simply return the number of towers using that num function that belongs to the 111 00:08:06,850 --> 00:08:07,930 ‫tray class. 112 00:08:07,930 --> 00:08:10,660 ‫So go ahead and pause the video and implement. 113 00:08:10,660 --> 00:08:12,640 ‫Get target tower count now. 114 00:08:15,670 --> 00:08:16,000 ‫Okay. 115 00:08:16,000 --> 00:08:17,980 ‫So here's get target tower count. 116 00:08:18,010 --> 00:08:24,250 ‫Now, the first thing I'm going to do is create a local t array specifying a actor pointer as the type 117 00:08:24,250 --> 00:08:26,590 ‫of element that this array should store. 118 00:08:26,590 --> 00:08:31,720 ‫And I'm going to call this towers now I need to call you gameplay statics, so I need to make sure that 119 00:08:31,720 --> 00:08:33,100 ‫that header is included. 120 00:08:33,130 --> 00:08:38,830 ‫Now I see that it is since we're using it in some of our other functions, but it's good to make that 121 00:08:38,830 --> 00:08:39,340 ‫check. 122 00:08:39,370 --> 00:08:47,380 ‫Next I can use you gameplay statics and I'm going to call get all actors of class. 123 00:08:47,410 --> 00:08:54,130 ‫Now the first input is a world context object I'm going to pass in this and next is the sub class of 124 00:08:54,130 --> 00:08:55,990 ‫representing the actor class. 125 00:08:55,990 --> 00:09:03,430 ‫And I mentioned that we can use a tower static class which will return a U class that represents the 126 00:09:03,430 --> 00:09:04,270 ‫tower class. 127 00:09:04,300 --> 00:09:09,190 ‫Now again, it's a good idea to make sure that we're including towers, which we are. 128 00:09:09,220 --> 00:09:14,740 ‫Now, the third and final parameter is going to be the tray and we can pass in towers. 129 00:09:14,740 --> 00:09:21,340 ‫So once this function has been called, towers will now contain pointers to all of the towers in the 130 00:09:21,340 --> 00:09:21,880 ‫world. 131 00:09:21,880 --> 00:09:28,000 ‫In fact, if there exist any objects of a class that derives from towers, we would also get those. 132 00:09:28,000 --> 00:09:33,780 ‫So since we have a towers array, we can simply return the number of elements in that array. 133 00:09:33,790 --> 00:09:40,660 ‫So I'm going to use a return statement and use towers dot num and now we have a get target tower count. 134 00:09:40,660 --> 00:09:41,740 ‫So this is great. 135 00:09:41,740 --> 00:09:48,220 ‫We can use this to initialize our tower count, which we called target towers and we can do that when 136 00:09:48,220 --> 00:09:49,090 ‫we start the game. 137 00:09:49,090 --> 00:09:51,780 ‫So I'm going to place that here and handle game start. 138 00:09:51,790 --> 00:09:54,400 ‫In fact, I'd like it to be the first thing we do. 139 00:09:54,400 --> 00:10:02,530 ‫So I'm going to take target towers and set it equal to the return value from get target tower count. 140 00:10:02,560 --> 00:10:07,240 ‫Now target towers should be initialized to the number of towers in our world. 141 00:10:07,240 --> 00:10:13,120 ‫So this is great, but we need to update this count every time a tower dies, which means we need to 142 00:10:13,120 --> 00:10:16,000 ‫go into our actor died function. 143 00:10:16,000 --> 00:10:22,660 ‫And here, if we've cast dead actor to a destroyed tower, then after we handle destruction, we should 144 00:10:22,660 --> 00:10:30,430 ‫update our target towers variable so we can say target towers and we can use the decrement operator. 145 00:10:30,430 --> 00:10:35,560 ‫We can use either the post decrement operator or the predicament operator. 146 00:10:35,560 --> 00:10:41,620 ‫Both of these will result in the same action which is taking target towers and subtracting one from 147 00:10:41,620 --> 00:10:41,800 ‫it. 148 00:10:41,800 --> 00:10:48,220 ‫Now, as soon as we've subtracted one from target towers, now we need to check to see if Target Towers 149 00:10:48,220 --> 00:10:49,660 ‫has reached zero. 150 00:10:49,660 --> 00:10:55,150 ‫So I'm going to place an if check here to see if Target towers has reached zero. 151 00:10:55,780 --> 00:11:02,380 ‫Now, as soon as it does, we know that the game should be over so we can call the game over function 152 00:11:02,710 --> 00:11:10,660 ‫passing in true 4b1 game since we've destroyed all of the towers and we can consider this a win. 153 00:11:10,660 --> 00:11:13,180 ‫Now let's go ahead and compile our code. 154 00:11:13,180 --> 00:11:18,670 ‫Now, back here in the editor, what I'd like to do before we wrap this video up is go into our game 155 00:11:18,670 --> 00:11:19,420 ‫mode blueprint. 156 00:11:19,420 --> 00:11:21,040 ‫So here's beep tune. 157 00:11:21,040 --> 00:11:24,400 ‫Thanks game mode and we have this event start game. 158 00:11:24,400 --> 00:11:29,650 ‫And what we're doing is creating our start game widget, adding it to the viewport so that we can see 159 00:11:29,650 --> 00:11:31,780 ‫that start game countdown timer. 160 00:11:31,780 --> 00:11:39,190 ‫So we know that start game is being called, but we also need to implement our game over blueprint implementable 161 00:11:39,190 --> 00:11:39,820 ‫event. 162 00:11:39,820 --> 00:11:47,260 ‫So I'm going to right click and type in game over and here's our event, game over and check this out. 163 00:11:47,290 --> 00:11:50,860 ‫Notice we have this one game and it's a boolean. 164 00:11:50,860 --> 00:11:57,220 ‫So when we call this function from C++, we're passing in a boolean value for B one game. 165 00:11:57,220 --> 00:12:04,270 ‫The blueprint event node strips out that lowercase B and places a space between one and game as sort 166 00:12:04,270 --> 00:12:05,440 ‫of a courtesy for us. 167 00:12:05,440 --> 00:12:10,150 ‫Now we're going to create some widgets so that we can see when we've won or lost the game, but we'll 168 00:12:10,150 --> 00:12:11,650 ‫do that in a future video. 169 00:12:11,650 --> 00:12:17,770 ‫For now, I just want to confirm that this is being called and called correctly so I can do that with 170 00:12:17,770 --> 00:12:22,180 ‫a print string node and we can print the value based on this boolean. 171 00:12:22,180 --> 00:12:29,080 ‫If I click and drag this boolean straight into the in string input, we'll see that there's a convert 172 00:12:29,080 --> 00:12:30,280 ‫boolean to string. 173 00:12:30,280 --> 00:12:37,420 ‫This is another convenient conversion node that will convert a boolean into a string for us, and its 174 00:12:37,420 --> 00:12:43,690 ‫functionality is such that it will convert to the word true or false based on the truth value of the 175 00:12:43,690 --> 00:12:44,350 ‫boolean. 176 00:12:44,710 --> 00:12:46,120 ‫So why don't we test this out? 177 00:12:46,120 --> 00:12:48,040 ‫I'm going to compile and hit play. 178 00:12:49,400 --> 00:12:52,570 ‫All right, now I'm ready to try to win the game. 179 00:12:52,580 --> 00:12:55,340 ‫Hopefully I don't lose before I can do so. 180 00:12:55,430 --> 00:13:01,430 ‫And I've lost the game and you can see false printed up at the top left of the screen. 181 00:13:01,430 --> 00:13:08,570 ‫So we now know that losing the game results in event game over being called with false being passed 182 00:13:08,570 --> 00:13:12,050 ‫in, we need to make sure that true is passed in when we win the game. 183 00:13:12,050 --> 00:13:14,900 ‫So let's try to kill all of the turrets. 184 00:13:15,380 --> 00:13:18,020 ‫So I need to really try not to get a hit. 185 00:13:18,020 --> 00:13:19,250 ‫Oh, I got hit already. 186 00:13:19,910 --> 00:13:21,560 ‫This is pretty challenging. 187 00:13:22,840 --> 00:13:24,820 ‫And there we go. 188 00:13:24,820 --> 00:13:28,720 ‫And true is printed at the top left of the screen. 189 00:13:28,750 --> 00:13:31,600 ‫It only shows up for a few seconds, so you might have missed it. 190 00:13:31,630 --> 00:13:32,350 ‫Okay, great. 191 00:13:32,350 --> 00:13:35,050 ‫So now we have winning and losing conditions. 192 00:13:35,080 --> 00:13:41,380 ‫The next step is to actually show this in the form of a widget on the screen so that we're not relying 193 00:13:41,380 --> 00:13:42,850 ‫on the print string node. 194 00:13:42,880 --> 00:13:48,010 ‫So in summary, we now have winning and losing conditions, and there's just a few things we need to 195 00:13:48,010 --> 00:13:53,890 ‫do to polish this, such as creating widgets that inform the player that they've won or lost the game. 196 00:13:53,890 --> 00:13:58,900 ‫We also counted the number of towers using a tray and the gameplay statics function. 197 00:13:58,930 --> 00:14:00,600 ‫Get all actors of class. 198 00:14:00,610 --> 00:14:01,270 ‫Great job. 199 00:14:01,270 --> 00:14:03,370 ‫This game is really coming along. 200 00:14:03,370 --> 00:14:09,220 ‫In the next video we'll create those widgets and then we're ready to start adding special effects and 201 00:14:09,220 --> 00:14:10,840 ‫polishing up our game. 202 00:14:10,870 --> 00:14:12,520 ‫I'll see you in the next video.