1 00:00:08,640 --> 00:00:12,070 So, we're halfway through module 11. 2 00:00:12,070 --> 00:00:15,980 Continuing along, here are the learning objectives for the module. 3 00:00:18,850 --> 00:00:22,550 Last time we finished up with our console dye 4 00:00:22,550 --> 00:00:26,550 class and so it's time for us to move forward 5 00:00:26,550 --> 00:00:29,620 and to develop a class that is designed specifically for 6 00:00:29,620 --> 00:00:33,990 use in XNA game rather than in a console application. 7 00:00:33,990 --> 00:00:38,990 So, in this lecture we will be designing that class and we'll 8 00:00:38,990 --> 00:00:44,170 be implementing the fields and properties, so the state, again in 9 00:00:44,170 --> 00:00:45,500 that class. 10 00:00:45,500 --> 00:00:48,510 Before we do, you should go take an in-lecture quiz. 11 00:00:54,290 --> 00:00:58,910 Now I know we've discussed using a rubber chicken as a weapon before, way back 12 00:00:58,910 --> 00:01:03,590 in module four. I have cut back a little bit on the scope 13 00:01:03,590 --> 00:01:11,040 of that weapon so it can't be used for, as melee weapon, it's only a ranged weapon. 14 00:01:11,040 --> 00:01:15,750 So we'll use it as a ranged weapon and we're going to focus today, 15 00:01:15,750 --> 00:01:19,970 well, we'll do all the design but we'll focus on implementing the state stuff. 16 00:01:19,970 --> 00:01:23,870 So here are the things that we really need to keep track of for the state. 17 00:01:24,950 --> 00:01:29,390 We need to keep track of whether or not the rubber chicken is active. 18 00:01:29,390 --> 00:01:35,470 Because we're going to use it as a weapon, essentially a projectile, and so when the 19 00:01:35,470 --> 00:01:39,950 projectile destroys something we should probably destroy the projectile as well. 20 00:01:39,950 --> 00:01:45,220 So we're going to deactivate the rubber chicken just as we deactivated teddy bears 21 00:01:45,220 --> 00:01:47,160 when they got destroyed. 22 00:01:47,160 --> 00:01:50,220 We're also going to need other two things here. 23 00:01:50,220 --> 00:01:53,540 We're going to need both a sprite so we can draw 24 00:01:53,540 --> 00:01:58,140 the rubber chicken in our XNA game and a draw rectangle. 25 00:01:58,140 --> 00:02:00,390 Now, as I've mentioned in passing before, there 26 00:02:00,390 --> 00:02:03,320 are actually lots of ways to draw sprites. 27 00:02:03,320 --> 00:02:07,030 The Sprite Batch draw method has lots of overloads. 28 00:02:07,030 --> 00:02:09,295 We're going to continue using a draw rectangle roll. 29 00:02:09,295 --> 00:02:10,315 And I said draw 30 00:02:10,315 --> 00:02:14,990 slash collision rectangle because inside the class we'll think 31 00:02:14,990 --> 00:02:18,440 of it and refer to it as the draw rectangle. 32 00:02:18,440 --> 00:02:22,120 But again, just as with the teddy bear, we're going to consider 33 00:02:22,120 --> 00:02:26,670 consumers of the class will think about that rectangle as a collision rectangle. 34 00:02:26,670 --> 00:02:30,010 So we'll handle that when it's time to build the appropriate property. 35 00:02:32,340 --> 00:02:34,610 Rubber chickens that are used as ranged weapons 36 00:02:34,610 --> 00:02:37,650 will have a velocity once they are launched and 37 00:02:37,650 --> 00:02:39,850 so we need that velocity so we can 38 00:02:39,850 --> 00:02:43,220 update the rubber chicken's position, or location, over time. 39 00:02:44,310 --> 00:02:48,620 And then finally, the amount of damage that the rubber chicken inflicts. 40 00:02:48,620 --> 00:02:51,600 So when we hit something with the rubber, when we hit something with the 41 00:02:51,600 --> 00:02:55,270 rubber chicken it causes some damage and 42 00:02:55,270 --> 00:02:57,630 maybe some rubber chickens are more powerful 43 00:02:57,630 --> 00:03:02,160 than others and so we'll keep track of the damage that we can apply as well. 44 00:03:06,450 --> 00:03:09,620 Because, we're going to look at the UML for the fields in a 45 00:03:09,620 --> 00:03:15,150 moment, but because we're going to save all this state information inside the 46 00:03:15,150 --> 00:03:19,710 object as fields you should go do an in-lecture quiz telling me 47 00:03:19,710 --> 00:03:24,920 that you understand our conversation about fields when we did the console class. 48 00:03:29,660 --> 00:03:31,430 So here's the UML. 49 00:03:31,430 --> 00:03:38,490 And it should come as no surprise to you that we have five different fields here 50 00:03:38,490 --> 00:03:43,260 that are going to store the five pieces of state that we talked about before. 51 00:03:43,260 --> 00:03:46,380 The additional detail that's included in here is the 52 00:03:46,380 --> 00:03:49,500 data types for each of those pieces of state. 53 00:03:49,500 --> 00:03:53,740 So active will be a bool, true or false, right? 54 00:03:53,740 --> 00:03:54,490 That makes sense. 55 00:03:54,490 --> 00:03:54,870 It's either 56 00:03:54,870 --> 00:03:58,770 active or it isn't. The damage will be an integer amount. 57 00:03:58,770 --> 00:04:01,590 We won't need the granularity that says it 58 00:04:01,590 --> 00:04:04,350 does, you know, 48.2 or anything like that. 59 00:04:05,388 --> 00:04:07,050 The draw rectangle will be just as we've 60 00:04:07,050 --> 00:04:09,340 been doing before, it will be a rectangle object. 61 00:04:10,520 --> 00:04:13,560 The sprite will be a Texture2D, as we're used to 62 00:04:13,560 --> 00:04:17,940 in XNA games, and the velocity will be a Vector2. 63 00:04:17,940 --> 00:04:20,910 So as a reminder, a vector2 has 64 00:04:20,910 --> 00:04:24,530 two components, or two properties that we can access. 65 00:04:24,530 --> 00:04:26,850 It has an X, and it has a Y. 66 00:04:26,850 --> 00:04:29,334 So if we have this two dimensional vector is 67 00:04:29,334 --> 00:04:32,025 really what it is then it will tell us, what's 68 00:04:32,025 --> 00:04:35,544 the velocity in the x direction, positive or negative, and 69 00:04:35,544 --> 00:04:40,100 what's the velocity in the y direction, positive or negative. 70 00:04:40,100 --> 00:04:42,900 So those are, in addition to the field 71 00:04:42,900 --> 00:04:46,000 names, we now have captured the data types we're 72 00:04:46,000 --> 00:04:50,340 going to use for those fields which helps us when we get to the implementation part. 73 00:04:53,820 --> 00:04:56,438 So I'm going to actually start a new project. 74 00:04:56,438 --> 00:05:00,882 So I've double-clicked the, my, my shortcut and 75 00:05:00,882 --> 00:05:04,550 now I'm going to create this new project. 76 00:05:04,550 --> 00:05:11,300 So I say new project, it is an XNA game studio game, it is a Windows game. 77 00:05:11,300 --> 00:05:14,910 I'm going to browse to the place where I want to save it. 78 00:05:14,910 --> 00:05:17,600 So I'll cut here and be back momentarily. 79 00:05:17,600 --> 00:05:18,990 Okay, I have saved 80 00:05:18,990 --> 00:05:21,820 it and we have the code here. 81 00:05:21,820 --> 00:05:27,620 And I'll zoom in even though we're going to immediately go and create a new class. 82 00:05:27,620 --> 00:05:32,200 And so we do this exactly the same way that we did it in the console application. 83 00:05:32,200 --> 00:05:33,480 You need to be a little careful. 84 00:05:33,480 --> 00:05:37,650 Make sure you don't create the class down here in the content area. 85 00:05:37,650 --> 00:05:40,060 That's for content not code. 86 00:05:40,060 --> 00:05:41,452 You want to create a big class up 87 00:05:41,452 --> 00:05:44,140 here where we're storing all of our source code. 88 00:05:44,140 --> 00:05:48,160 All of our C sharp files. So we right click, I've 89 00:05:48,160 --> 00:05:52,180 named this namespace rubber chicken by the way, I right click it. 90 00:05:52,180 --> 00:06:01,145 I say that I wants to add a class and my class is going to be a rubber chicken. 91 00:06:01,145 --> 00:06:09,760 [SOUND] 92 00:06:09,760 --> 00:06:13,765 I'll zoom in immediately and put the class comment. 93 00:06:13,765 --> 00:06:15,940 [SOUND] 94 00:06:15,940 --> 00:06:16,440 And 95 00:06:19,000 --> 00:06:20,515 I'll add a region for Fields. 96 00:06:20,515 --> 00:06:21,320 [SOUND] 97 00:06:21,320 --> 00:06:25,989 And I'm going to sort of group these 98 00:06:25,989 --> 00:06:31,302 together as we go along for, you know, 99 00:06:31,302 --> 00:06:36,454 drawing support and movement support 100 00:06:36,454 --> 00:06:41,606 and so on but you can put these fields in 101 00:06:41,606 --> 00:06:46,960 any order you want really. And, 102 00:06:46,960 --> 00:06:48,300 and some I won't even comment. 103 00:06:48,300 --> 00:06:52,840 So typically I comment the drawing support fields even though there's only 104 00:06:52,840 --> 00:06:58,950 two of them but I don't necessarily comment the active field, for example. 105 00:06:58,950 --> 00:07:02,540 So, I actually will put that active field, remember we decided it was 106 00:07:02,540 --> 00:07:07,490 going to be a Bool and to this one we can just initialize to true. 107 00:07:07,490 --> 00:07:12,100 Just like at the end of the lecture last time we had 108 00:07:12,100 --> 00:07:15,650 a random number generator that we made a field 109 00:07:15,650 --> 00:07:17,790 in the die class instead of just using a 110 00:07:17,790 --> 00:07:21,320 local variable, that's what a variable that's declared inside 111 00:07:21,320 --> 00:07:24,980 a method is called, because it's local to the method. 112 00:07:24,980 --> 00:07:27,150 Instead of using a local variable we used a 113 00:07:27,150 --> 00:07:31,010 field and we initialized it when we declared it. 114 00:07:31,010 --> 00:07:34,290 And so that's a perfectly valid approach to use 115 00:07:34,290 --> 00:07:37,200 and so I'm setting active to true here because rubber 116 00:07:37,200 --> 00:07:43,440 chickens should always start as active. Okay, I'll add some drawing support. 117 00:07:45,370 --> 00:07:50,460 So I need a Texture2D and I know that it's hard to see and there's no way for me to 118 00:07:50,460 --> 00:07:57,360 zoom in on the intellesense but Texture2D is not showing up as one of my choices. 119 00:07:57,360 --> 00:08:02,770 What that means is that I am not, I do not currently have direct 120 00:08:02,770 --> 00:08:07,660 access to that class. Well, we, we have seen 121 00:08:07,660 --> 00:08:13,650 this in the programming assignments where you needed to add a using statement 122 00:08:13,650 --> 00:08:19,090 and so we need to add a using statement to get at Texture2D. 123 00:08:19,090 --> 00:08:23,340 So we need to type in using whatever the name space Texture2D appears 124 00:08:23,340 --> 00:08:28,140 in and you may not have memorized yet what name space that's in. 125 00:08:28,140 --> 00:08:32,225 Good news is we can go to help and we can search on 126 00:08:32,225 --> 00:08:40,210 Texture2D, and we will sort of click around for awhile until 127 00:08:40,210 --> 00:08:45,250 we get to where we need to be but the Texture2D class, 128 00:08:45,250 --> 00:08:50,160 it says right up here at the top, which namespace it appears in. 129 00:08:50,160 --> 00:08:53,631 And so the Texture2D is found in the Microsoft 130 00:08:53,631 --> 00:08:57,013 dot xna dot framework dot graphics namespace 131 00:08:57,013 --> 00:09:00,110 so that's the namespace we need to add. 132 00:09:01,610 --> 00:09:08,280 So Microsoft and Intellisense will help us a little bit here, graphics. 133 00:09:09,520 --> 00:09:13,159 Now that I've added that namespace, when I come back here, I 134 00:09:13,159 --> 00:09:18,540 hit Ctrl Space, by the way, to make Intellisense pop back up. 135 00:09:18,540 --> 00:09:21,400 Now all those textures show up, which is good. 136 00:09:22,470 --> 00:09:26,880 So, I'll need a sprite and I'll also need a rectangle for 137 00:09:26,880 --> 00:09:31,980 the draw rectangle and we say well, that one's not showing up either. 138 00:09:31,980 --> 00:09:36,705 So unless you've memorized which namespace rectangle appears in, back we go to Help. 139 00:09:36,705 --> 00:09:37,200 [SOUND] 140 00:09:37,200 --> 00:09:37,700 And 141 00:09:41,050 --> 00:09:43,230 I can click on any of these until I can click on 142 00:09:43,230 --> 00:09:48,380 the Rectangle Structure and this one is found in the Framework namespace. 143 00:09:48,380 --> 00:09:52,320 Not Microsoft dot XNA dot Framework dot Graphics. 144 00:09:52,320 --> 00:09:55,750 Just Microsoft dot XNA dot framework. 145 00:09:55,750 --> 00:10:01,804 So back to the code again. Another using statement. 146 00:10:01,804 --> 00:10:04,274 [SOUND] 147 00:10:04,274 --> 00:10:10,620 And now again, control space 148 00:10:10,620 --> 00:10:16,410 and rectangle is the only one that fits so it automatically filled it in for me and 149 00:10:16,410 --> 00:10:21,490 we now have our draw rectangle. So, that's good. 150 00:10:21,490 --> 00:10:24,690 We have three of the fields taken care of already. 151 00:10:24,690 --> 00:10:27,940 We still need to handle damage and velocity. 152 00:10:27,940 --> 00:10:30,058 So let's take care of 153 00:10:30,058 --> 00:10:31,758 [SOUND] 154 00:10:31,758 --> 00:10:37,170 damage first. And again, your order doesn't matter. 155 00:10:37,170 --> 00:10:41,190 I'm just sort of grouping them in a way that seems intuitive to me. 156 00:10:42,890 --> 00:10:45,670 So we'll say there's some damage field we're going to have. 157 00:10:46,790 --> 00:10:51,450 And I'll even change this comment to say drawing and moving support so I can just 158 00:10:51,450 --> 00:10:56,880 put the vector two that I need for my velocity right here as well. 159 00:11:00,930 --> 00:11:07,260 And that's it for the fields. We need an active field, that's a Boolean. 160 00:11:07,260 --> 00:11:10,432 Damage, that's an INT. Sprite is a Texture2D. 161 00:11:10,432 --> 00:11:12,650 Draw rectangle is a rectangle and velocity is 162 00:11:12,650 --> 00:11:15,760 that two dimensional vector that we talked about. 163 00:11:15,760 --> 00:11:20,070 So now it's time to actually start adding the properties. 164 00:11:21,170 --> 00:11:24,860 So first, go do an in-lecture quiz about properties. 165 00:11:28,710 --> 00:11:35,150 And now that you're back you can see that I've added properties here to the UML. 166 00:11:35,150 --> 00:11:38,270 So these are the three properties that we need. 167 00:11:38,270 --> 00:11:39,330 We need active. 168 00:11:42,160 --> 00:11:45,430 And we talked about properties last time. 169 00:11:45,430 --> 00:11:48,960 By the way, properties can be read, they can be write, or they can 170 00:11:48,960 --> 00:11:51,900 be read-write depending on the combination of 171 00:11:51,900 --> 00:11:55,930 get accessors and set accessors that we provide. 172 00:11:55,930 --> 00:12:00,590 And so in this particular case, for the Active property, 173 00:12:00,590 --> 00:12:04,600 we've said it's going to be Active with a capital A. 174 00:12:04,600 --> 00:12:07,000 We're going to provide both a get accessor, 175 00:12:07,000 --> 00:12:09,600 so the game can determine whether or not the 176 00:12:09,600 --> 00:12:13,640 rubber chicken is active, and a set accessor, so 177 00:12:13,640 --> 00:12:15,800 that the game that's using the rubber chicken can 178 00:12:15,800 --> 00:12:19,000 deactivate the rubber chicken when it should be destroyed. 179 00:12:20,310 --> 00:12:24,270 And finally that last little piece right here says 180 00:12:24,270 --> 00:12:27,300 that it is in fact going to be a bool property. 181 00:12:27,300 --> 00:12:28,240 Which makes sense right? 182 00:12:28,240 --> 00:12:32,197 Because the active field is a Boolean, it can either be true or 183 00:12:32,197 --> 00:12:34,670 false, it makes sense that the property is a Boolean as well. 184 00:12:35,880 --> 00:12:39,030 Our second property, the collision rectangle. 185 00:12:39,030 --> 00:12:43,620 Remember, I have renamed what we're calling draw rectangle in our 186 00:12:43,620 --> 00:12:48,240 field to be collision rectangle for the property because the consumer of 187 00:12:48,240 --> 00:12:51,670 the property is really thinking of it as something to be used 188 00:12:51,670 --> 00:12:57,420 for collision detection not something to be used for drawing the sprite. 189 00:12:57,420 --> 00:13:02,110 Because that's internal to the class so a consumer of the class doesn't care. 190 00:13:02,110 --> 00:13:04,910 It is a get accesser only. 191 00:13:04,910 --> 00:13:07,450 It makes no sense for the game to be 192 00:13:07,450 --> 00:13:10,560 able to change the collision rectangle for this thing. 193 00:13:10,560 --> 00:13:13,410 It's based on the sprite and I'll, well, it's based on the 194 00:13:13,410 --> 00:13:20,170 sprite and the draw rectangle so only read access for this particular property. 195 00:13:20,170 --> 00:13:22,660 And then finally we have the damage property 196 00:13:25,110 --> 00:13:28,030 and integer as, as we'd expect. 197 00:13:28,030 --> 00:13:34,660 Only a get accessor so only a read, read access for this property as well. 198 00:13:34,660 --> 00:13:39,730 So there are no power ups that will make the rubber chicken inflict more damage. 199 00:13:39,730 --> 00:13:43,520 This will be a really basic rubber chicker, chicken game. 200 00:13:43,520 --> 00:13:47,490 Not the deep play experience that you might have been expecting. 201 00:13:47,490 --> 00:13:51,230 Alright, so back to the code, I am adding 202 00:13:51,230 --> 00:13:53,690 a region for those properties that we were juts 203 00:13:53,690 --> 00:13:56,742 talking about, and I'll add them one at a time. 204 00:13:56,742 --> 00:13:58,650 So, we'll make them public. 205 00:13:58,650 --> 00:13:59,950 Remember the access modifier. 206 00:14:01,120 --> 00:14:03,930 This particular property, I'm doing active first, so 207 00:14:03,930 --> 00:14:07,370 it's a bool and Active with a capital A. 208 00:14:08,740 --> 00:14:12,640 And I said that we were going to provide both get and set accessors. 209 00:14:14,690 --> 00:14:16,930 And I'll add the comment now before I forget. 210 00:14:18,870 --> 00:14:25,762 Gets and sets whether the rubber chicken is active. 211 00:14:25,762 --> 00:14:32,790 So re, recall from the other properties that we have 212 00:14:32,790 --> 00:14:40,410 done so far that we're going to end up returning the value of the active field. 213 00:14:40,410 --> 00:14:43,180 And to return things we type return. 214 00:14:45,290 --> 00:14:49,060 The set accessor, which we looked at before and I showed you an 215 00:14:49,060 --> 00:14:53,850 example and then got rid of, looks similar to the example I showed you. 216 00:14:53,850 --> 00:15:00,080 We're going to be setting the active field equal to whatever value is provided 217 00:15:01,410 --> 00:15:07,350 when the game accesses this property, this set accessor for the property. 218 00:15:07,350 --> 00:15:10,770 Remember, it will say something like rubber chicken 219 00:15:10,770 --> 00:15:16,252 zero dot active equals false. And so inside here, inside the 220 00:15:16,252 --> 00:15:21,980 set accessor, that false is value. Alright, so that's the first property. 221 00:15:23,310 --> 00:15:25,520 The second property is collision rectangle. 222 00:15:25,520 --> 00:15:27,430 So, public again. 223 00:15:27,430 --> 00:15:28,805 This time it's a rectangle. 224 00:15:28,805 --> 00:15:33,850 [SOUND] 225 00:15:33,850 --> 00:15:38,055 And recall, this one we're only providing a get accessor for. 226 00:15:38,055 --> 00:15:39,660 [SOUND] 227 00:15:39,660 --> 00:15:45,740 And here's where using properties rather than just giving consumers of 228 00:15:45,740 --> 00:15:49,330 the class direct access to the field is useful because we 229 00:15:49,330 --> 00:15:53,980 can rename this to Collision Rectangle instead of Draw Rectangle based 230 00:15:53,980 --> 00:15:58,160 on how the consumer of the class thinks about this property. 231 00:15:58,160 --> 00:16:03,550 Gets the collision rectangle for the rubber chicken, 232 00:16:06,210 --> 00:16:11,930 and finally, we had one more property in our UML, and that property was Damage. 233 00:16:11,930 --> 00:16:14,205 So it's public int Damage. 234 00:16:14,205 --> 00:16:15,035 [SOUND] 235 00:16:15,035 --> 00:16:18,190 Get access here only. 236 00:16:21,630 --> 00:16:27,255 Gets the damage rubber chicken 237 00:16:27,255 --> 00:16:32,340 inflicts. And get works exactly like the 238 00:16:32,340 --> 00:16:37,850 other get accessors we've been doing. We just return damage. 239 00:16:41,250 --> 00:16:47,900 So now we have the properties included inside our implementation. 240 00:16:47,900 --> 00:16:50,980 we, just as with the dye class after 241 00:16:50,980 --> 00:16:53,050 we did fields and properties, we couldn't do any 242 00:16:53,050 --> 00:16:55,240 testing on it yet, and we can't here 243 00:16:55,240 --> 00:16:59,570 either because we can't construct any rubber chickens yet. 244 00:16:59,570 --> 00:17:02,340 But we'll be able to do that next lecture and we'll implement the 245 00:17:02,340 --> 00:17:05,780 constructor and then we can construct and make sure they work and so on. 246 00:17:05,780 --> 00:17:06,230 So, 247 00:17:06,230 --> 00:17:09,120 we'll get there, we're just not there quite yet. 248 00:17:10,340 --> 00:17:10,890 Okay. 249 00:17:10,890 --> 00:17:12,450 So back to the slides. 250 00:17:12,450 --> 00:17:15,290 The last piece of the design, I know I sort of 251 00:17:15,290 --> 00:17:19,610 snuck in some implementation during the design, and that's okay too. 252 00:17:19,610 --> 00:17:24,850 We, it is very rare to do all your design and then all your implementation. 253 00:17:24,850 --> 00:17:26,740 This is a really iterative thing. 254 00:17:26,740 --> 00:17:29,710 We design some, we implement some, we design some, we implement some. 255 00:17:29,710 --> 00:17:31,260 And sometimes we go 256 00:17:31,260 --> 00:17:33,760 back after starting to implement and say wow our 257 00:17:33,760 --> 00:17:36,250 design was not correct and we need to fix it. 258 00:17:36,250 --> 00:17:39,930 And so this going back and forth is a really common thing. 259 00:17:39,930 --> 00:17:41,300 Nothing wrong with it. 260 00:17:41,300 --> 00:17:43,510 But now that we're back here on the slides talking 261 00:17:43,510 --> 00:17:47,220 about design we have behavior for the rubber chicken too. 262 00:17:47,220 --> 00:17:50,520 And I have simplified that behavior as well, I, we, 263 00:17:50,520 --> 00:17:53,790 talked back in module four about playing animations and so on. 264 00:17:53,790 --> 00:17:55,310 We won't do that here. 265 00:17:55,310 --> 00:17:56,810 What we'll do instead is 266 00:17:56,810 --> 00:17:58,530 we will do two things. 267 00:17:58,530 --> 00:18:02,410 We will update the rubber chicke, and this one will be a fairly interesting and 268 00:18:02,410 --> 00:18:07,090 reasonably complicated thing because we'll move it along 269 00:18:07,090 --> 00:18:10,260 its velocity vector based on the elapsed time. 270 00:18:10,260 --> 00:18:12,640 That's not the complicated part. 271 00:18:12,640 --> 00:18:15,630 And we will also process mouse input. 272 00:18:15,630 --> 00:18:18,700 So the way we're going to launch rubber chickens, I mean, you, you, 273 00:18:18,700 --> 00:18:21,940 I think we'd have rubber chicken cannons or something like that because it's really 274 00:18:21,940 --> 00:18:24,490 a projectile. But we're not going to have that. 275 00:18:24,490 --> 00:18:28,440 We're, in fact, going to launch the rubber chicken by clicking on it. 276 00:18:28,440 --> 00:18:30,750 Now this is a very stupid rubber chicken. 277 00:18:30,750 --> 00:18:33,490 It's not a homing rubber chicken or anything. 278 00:18:33,490 --> 00:18:35,290 When we click on it it's just going to go 279 00:18:35,290 --> 00:18:37,980 straight up is how this rubber chicken will work. 280 00:18:39,240 --> 00:18:41,610 If you wanted to, you could of 281 00:18:41,610 --> 00:18:47,730 course implement far more complicated schemes where you 282 00:18:47,730 --> 00:18:50,410 click a rubber chicken to activate it and then click somewhere on 283 00:18:50,410 --> 00:18:53,620 the screen and that's where it's going to launch itself toward and so on. 284 00:18:53,620 --> 00:18:55,758 You know, send it, send the rubber chicken over there. 285 00:18:55,758 --> 00:18:56,101 Right? 286 00:18:56,101 --> 00:18:58,700 And th, and that's a perfectly reasonable thing to do 287 00:18:58,700 --> 00:19:01,530 that obviously people have figured out how to do in games. 288 00:19:01,530 --> 00:19:05,530 We're just not going to do it here today. We're not going to do it at all. 289 00:19:05,530 --> 00:19:10,770 But we'll do a really simplified rubber chicken goes up when we launch it. 290 00:19:10,770 --> 00:19:13,190 So that's this part. 291 00:19:13,190 --> 00:19:15,050 So we're going to have to detect a mouse click, 292 00:19:15,050 --> 00:19:17,860 not a mouse press, a mouse click on the chicken. 293 00:19:17,860 --> 00:19:23,570 And we've learned how to do that already when we were processing mouse buttons 294 00:19:23,570 --> 00:19:28,230 in the X and A input lectures. 295 00:19:28,230 --> 00:19:30,490 And the other behavior we're going to have is 296 00:19:30,490 --> 00:19:33,340 we're going to have the rubber chicken draw itself. 297 00:19:33,340 --> 00:19:37,070 And that one's going to be a really easy one to do. 298 00:19:37,070 --> 00:19:38,418 So if we look at 299 00:19:38,418 --> 00:19:43,820 the final UML for our diagram from today's lecture 300 00:19:43,820 --> 00:19:47,570 we see that we've added these methods down here. 301 00:19:49,110 --> 00:19:53,650 And so we also have identified the fact that to be able 302 00:19:53,650 --> 00:19:57,270 to draw we're going to need a sprite batch to get passed in. 303 00:19:57,270 --> 00:20:00,640 So we can call the sprite batch dot draw method. 304 00:20:00,640 --> 00:20:03,580 And to update, because there's 305 00:20:03,580 --> 00:20:06,310 both the velocity which needs the elapsed game 306 00:20:06,310 --> 00:20:11,290 time and the click processing which needs the mouse, 307 00:20:13,440 --> 00:20:19,250 we'll need both of those things. Just like our roll method had a return 308 00:20:19,250 --> 00:20:25,880 type of void both of these methods also have a return type of void. 309 00:20:25,880 --> 00:20:28,420 So we're not writing any methods in this class 310 00:20:28,420 --> 00:20:31,910 that will actually return a value when we call it. 311 00:20:34,060 --> 00:20:36,450 And that's all we're going to do for today. 312 00:20:36,450 --> 00:20:38,810 We did all of our design work and we 313 00:20:38,810 --> 00:20:42,230 did our implementation work for the fields and properties 314 00:20:42,230 --> 00:20:47,590 so we've got off to a great start on our rubber chicken for the X and A game. 315 00:20:47,590 --> 00:20:53,180 And next time, we'll actually implement both the constructor and the 316 00:20:53,180 --> 00:20:56,580 two methods that we need for the behaviors of the rubber chicken.