1 00:00:05,890 --> 00:00:09,090 What's a bigger one Mark Price you're at death's slopes dot com. 2 00:00:09,090 --> 00:00:13,390 And let's continue building our arcade app here. 3 00:00:13,530 --> 00:00:18,900 And we want to do is get these items rotating and it may not be that complex actually and then maybe 4 00:00:18,900 --> 00:00:20,010 we'll do some refactoring. 5 00:00:20,010 --> 00:00:22,550 So first things first is how are we going to do it. 6 00:00:22,650 --> 00:00:28,220 Well we're going to need to just like you would use and spray it or seen it we're going to use an action. 7 00:00:28,530 --> 00:00:35,640 And what we're going to do is create a rotary action sort of say let rotate equals LCN action. 8 00:00:35,640 --> 00:00:45,720 So a scene action that repeat forever and then we'll put an action set of here seen action that rotate 9 00:00:45,720 --> 00:00:46,250 by. 10 00:00:46,290 --> 00:00:47,670 We want to rotate by something. 11 00:00:47,670 --> 00:00:48,380 OK. 12 00:00:48,570 --> 00:00:56,190 And we are going to say zero on the X but on the Y we're going to say C.G. float because we need to 13 00:00:56,190 --> 00:01:01,630 cast a value here 0.01 times double dot pi. 14 00:01:03,780 --> 00:01:05,510 Doubled up pi is just pi. 15 00:01:05,560 --> 00:01:08,810 So it's the way you get pi you know 3.1 for blah blah blah. 16 00:01:09,210 --> 00:01:14,400 And then on the z axis we're going to rotate that either one is zero and the duration we're going to 17 00:01:14,400 --> 00:01:15,540 say 0.1. 18 00:01:15,540 --> 00:01:23,970 So every point one of a second we want to rotate it by point zero 1 times doubled up PI along the along 19 00:01:23,970 --> 00:01:28,410 the y axis and then it'll rotate it very smoothly. 20 00:01:28,470 --> 00:01:30,300 So long as we run the action forever. 21 00:01:30,390 --> 00:01:39,200 And so we've got the action here so what we can do now is here in our node we should just be able to 22 00:01:39,200 --> 00:01:48,630 add it to that so we're going to say no dot add action or run action is what I was looking for. 23 00:01:48,700 --> 00:01:59,330 Rotate and we're just going to copy this here and we're going to paste it here and we're going to paste 24 00:01:59,330 --> 00:02:01,920 it here. 25 00:02:02,450 --> 00:02:05,840 We're using the same action and rotating by the y axis. 26 00:02:05,850 --> 00:02:08,710 And let's see if that actually works for us here. 27 00:02:08,850 --> 00:02:13,710 And look at that we have rotating objects now. 28 00:02:14,720 --> 00:02:16,100 We're going to see this as is. 29 00:02:16,220 --> 00:02:22,400 But you could make this a little more exciting by having the rotate rotation star at a different time 30 00:02:22,400 --> 00:02:24,930 period so they're all rotating differently. 31 00:02:24,950 --> 00:02:26,530 They will be rotating at the same speed. 32 00:02:26,540 --> 00:02:28,370 That's important and rotating at different speeds. 33 00:02:28,370 --> 00:02:37,100 But you might want to do delay the rotation on these by a couple of millisecond So they they are rotating 34 00:02:37,190 --> 00:02:41,280 at different angles or you could well you could also do which might even be better. 35 00:02:41,370 --> 00:02:46,550 Is rotate the object after you place it just rotate it at a certain position and then have it start 36 00:02:46,730 --> 00:02:49,920 from that position and it would look cool or two but we're not going to answer that you can play with 37 00:02:49,940 --> 00:02:51,200 our with that you get the point. 38 00:02:51,200 --> 00:02:53,450 It's not a very hard thing to do and will be a challenge for you. 39 00:02:53,450 --> 00:02:57,350 So we've got two or three objects here which is really awesome. 40 00:02:57,350 --> 00:03:06,330 So maybe the next thing to do is well let's think about this here we have these three objects here and 41 00:03:06,350 --> 00:03:10,190 I don't like the fact that the code we're copying and pasting those three times we may not be able to 42 00:03:10,190 --> 00:03:12,310 get around it but at least I think that could be a better place for that. 43 00:03:12,320 --> 00:03:17,480 We might want to refactor but I think maybe instead what we can do is the tap detection whenever items 44 00:03:17,480 --> 00:03:22,670 tapped we just detect it and then we grab its name and pass it on to the previous view controller. 45 00:03:22,670 --> 00:03:25,420 So let's work on that feature now because we know that we're going to need it. 46 00:03:25,490 --> 00:03:27,320 So here we go. 47 00:03:28,560 --> 00:03:31,430 Stop it it's our computer runs nice and fast. 48 00:03:31,530 --> 00:03:45,090 And here in our ramp picker VC let's just create the let's create a a gesture recognizer handler for 49 00:03:45,090 --> 00:03:47,730 when the screen is actually tapped. 50 00:03:48,750 --> 00:03:53,960 And we'll add a just a tap gesture to the whole scene and then we'll handle it accordingly. 51 00:03:53,970 --> 00:03:55,780 So let's create a function here. 52 00:03:55,890 --> 00:04:01,530 When you say at 0 BJC because we're going use a gesture recognizer which is going to use the selector 53 00:04:01,530 --> 00:04:06,730 syntax we have to make this an object of C runtime function meaning it's going to use Objective-C features. 54 00:04:06,900 --> 00:04:15,690 When you say func handle tap and windows can say gesture recognizer you just use recognizer and we're 55 00:04:15,690 --> 00:04:17,530 just putting the underscore here. 56 00:04:17,580 --> 00:04:23,370 So we don't have to give it a name and let's leave it empty for now and then what we're going to do 57 00:04:23,370 --> 00:04:26,600 is actually add a gesture recognizer to the scene itself. 58 00:04:26,610 --> 00:04:29,690 So we'll do it right here. 59 00:04:29,880 --> 00:04:39,060 We'll say let tat equals you tap gesture recognizer and the target is going to be self and the action 60 00:04:39,570 --> 00:04:42,680 is going to be selector handle tap 61 00:04:46,380 --> 00:04:53,010 and then all we have to do is scene view not add gesture recognizer and let's add the taps. 62 00:04:53,040 --> 00:04:59,340 Now whenever somebody taps this screen or the scene this scene gets seen. 63 00:04:59,400 --> 00:05:00,190 All we have to do. 64 00:05:00,200 --> 00:05:04,660 We're the scene view excuse me all we have to do is implement the code over here and handle tap. 65 00:05:04,740 --> 00:05:05,600 And what do we want to do. 66 00:05:05,610 --> 00:05:07,990 We want to detect which item was tapped. 67 00:05:08,280 --> 00:05:12,010 Or rather we want to even see if an item was tapped and if an item was tapped. 68 00:05:12,120 --> 00:05:17,390 What we want to do is get the name of that item and pass it back to the ramp. 69 00:05:17,400 --> 00:05:21,880 Placers So when you go to tap that screen and knows which ramp to to to place. 70 00:05:21,900 --> 00:05:22,580 OK. 71 00:05:23,100 --> 00:05:25,770 So let's get started. 72 00:05:25,860 --> 00:05:28,480 Let it kind of sounded like Lego Batman. 73 00:05:28,480 --> 00:05:31,310 I should be like Lego Batman too. 74 00:05:31,440 --> 00:05:32,890 Let's write some code. 75 00:05:33,360 --> 00:05:34,420 I'm an orphan. 76 00:05:34,800 --> 00:05:38,220 Let p equals an orphaned coater gesture. 77 00:05:38,380 --> 00:05:45,020 Recognize in fact I should record my whole video in the voice gesture recognizer that location. 78 00:05:45,330 --> 00:05:46,750 No not feeling it. 79 00:05:47,150 --> 00:05:47,540 All right. 80 00:05:47,700 --> 00:05:51,650 Well when you're talking to yourself for hours on end at a screen pretending that people are there he 81 00:05:51,670 --> 00:05:58,930 will talk in a Batman voice to let people gesture recognize their location in eye view. 82 00:05:59,190 --> 00:06:01,090 And so which view do you want the scene view. 83 00:06:01,260 --> 00:06:05,210 So we want to detect the location of the tap in the scene view. 84 00:06:05,220 --> 00:06:06,770 So it's going to find the location. 85 00:06:07,020 --> 00:06:12,240 And it's going to store it here so we can use it and get results we're going to see if it actually hit 86 00:06:12,240 --> 00:06:12,890 something. 87 00:06:13,020 --> 00:06:21,780 OK that's a scene view dot hit test and be very lucky that all of this code is written for us by Apple 88 00:06:21,780 --> 00:06:25,350 so we don't actually have to write great cast coding detection stuff. 89 00:06:25,350 --> 00:06:26,580 This makes it really easy. 90 00:06:26,670 --> 00:06:31,020 So we're going to pass and the point to see if something was hit and for the options we're going to 91 00:06:31,020 --> 00:06:38,490 go ahead and just put an empty dictionary here like so. 92 00:06:39,250 --> 00:06:39,900 OK. 93 00:06:39,910 --> 00:06:42,270 We don't need any options hit results. 94 00:06:42,310 --> 00:06:48,540 So we're going to see if anything was hit and if hit results count is greater than zero. 95 00:06:48,550 --> 00:06:50,160 So if we hit an object. 96 00:06:50,310 --> 00:06:53,520 OK this would have a result greater than zero. 97 00:06:53,530 --> 00:06:58,330 We'd have one or one or more object in our case we're looking for one. 98 00:06:58,390 --> 00:07:02,270 But what I'm saying is let's say we had five objects in the scene and we missed it. 99 00:07:02,290 --> 00:07:04,330 We're even seeing if the three we missed it. 100 00:07:04,360 --> 00:07:06,580 This is going to be zero and we hit nothing. 101 00:07:06,640 --> 00:07:09,630 So we're going to see if anything was hit. 102 00:07:09,880 --> 00:07:10,480 OK. 103 00:07:10,570 --> 00:07:14,860 And if something was hit we're just going to grab the node that was hit we can grab it right here and 104 00:07:14,860 --> 00:07:18,220 this is how you would do it with a game or Air care or anything when you're tapping the screen this 105 00:07:18,220 --> 00:07:19,670 is how you get a 3D object. 106 00:07:19,690 --> 00:07:21,230 And so you can reference it. 107 00:07:21,580 --> 00:07:26,870 And what we're going to do is we're going to say let no equals hit results. 108 00:07:27,180 --> 00:07:29,470 Zero note. 109 00:07:29,820 --> 00:07:30,680 OK. 110 00:07:30,780 --> 00:07:32,390 Where it is going to grab that node. 111 00:07:32,910 --> 00:07:34,200 No big deal. 112 00:07:34,830 --> 00:07:36,900 And then we're going to say switch. 113 00:07:37,350 --> 00:07:40,050 We're going to check now the name of the node. 114 00:07:40,290 --> 00:07:42,290 So switch no name. 115 00:07:42,570 --> 00:07:45,000 And we're going to forcefully unwrap this. 116 00:07:45,000 --> 00:07:49,620 And the reason why we're going to forcefully unwrap it is because we're developing we're still at compile 117 00:07:49,620 --> 00:07:52,390 time and the name of the node. 118 00:07:52,560 --> 00:07:53,380 OK. 119 00:07:53,640 --> 00:07:55,540 In our case will always be there. 120 00:07:55,770 --> 00:07:56,410 OK. 121 00:07:56,700 --> 00:08:01,340 And so at compile time we have to we have to force unwrap this here. 122 00:08:01,370 --> 00:08:05,630 We have to unwrap it here so we can know that it's there if it's not there or app won't even work. 123 00:08:05,730 --> 00:08:08,450 Now when would you not want to force and wrap this. 124 00:08:08,500 --> 00:08:08,950 OK. 125 00:08:09,090 --> 00:08:14,880 Well if you were let's say had a game and let's say the game had objects that were being deleted left 126 00:08:14,880 --> 00:08:17,960 and right like the lasers shooting aliens or something. 127 00:08:18,300 --> 00:08:21,540 And then you went to go check the no doubt name with a note that might not even be there could have 128 00:08:21,540 --> 00:08:22,230 been destroyed. 129 00:08:22,260 --> 00:08:24,910 Who knows that might not had a name at that point in time. 130 00:08:25,290 --> 00:08:30,480 And you could have a crash in that case you want to gracefully handle it with some some if let's regard 131 00:08:30,480 --> 00:08:31,180 statements. 132 00:08:31,260 --> 00:08:35,400 But in our case our app cannot function without this feature being there. 133 00:08:35,460 --> 00:08:39,810 So at compile time it will crash which is what we want we want it to crash. 134 00:08:39,810 --> 00:08:41,550 If it's if it's not there. 135 00:08:41,670 --> 00:08:43,420 So that's why I'm Force unwrapping it. 136 00:08:43,490 --> 00:08:48,270 So you'll hear me say don't ever force unwrap you know optionals or Apple crash. 137 00:08:48,270 --> 00:08:49,300 Well there are cases. 138 00:08:49,290 --> 00:08:53,010 Now you're becoming an advanced developer there are cases when it does not make sense to write a bunch 139 00:08:53,010 --> 00:08:59,960 of code for something that has to work no matter what and you understand more as time goes by as you 140 00:08:59,960 --> 00:09:05,100 program and swift So we're just checking the name of the notes so what we've done is we've tap the screen. 141 00:09:05,290 --> 00:09:08,180 OK we've gotten the location story here in P. 142 00:09:08,210 --> 00:09:12,590 This is the point or the location that was tapped in the screen and then what we do is we do a hit test 143 00:09:12,950 --> 00:09:17,060 when you pass a point into a hit test the sync it does all the math under the hood to see if you hit 144 00:09:17,060 --> 00:09:20,670 something and if it does OK the count will be greater than zero. 145 00:09:20,720 --> 00:09:21,870 The results that count. 146 00:09:22,130 --> 00:09:26,130 And then we grab the first element in there and we grab the note attached to it. 147 00:09:26,140 --> 00:09:30,830 There's other information attached with a hit but we're grabbing the node which so if we tapped the 148 00:09:30,830 --> 00:09:34,620 pyramid it would actually be grabbing the pyramid at this point in this node would be the pyramid. 149 00:09:34,970 --> 00:09:36,200 And then we're just checking the name. 150 00:09:36,200 --> 00:09:40,220 This is the identity that we set in the scene view when we're looking at her objects. 151 00:09:40,220 --> 00:09:41,880 The node name. 152 00:09:42,000 --> 00:09:43,830 And so I'm just doing a switch statement. 153 00:09:43,940 --> 00:09:49,720 We're going to say case if the case is a pipe What do we want to do. 154 00:09:49,950 --> 00:09:55,970 Well we want to basically tell the other view controller that we selected the pipe. 155 00:09:56,000 --> 00:09:58,440 We don't have code for that yet so we're just going to break. 156 00:09:58,820 --> 00:10:06,910 And if the case is quarter let's say pyramid pyramid we're going to break. 157 00:10:07,360 --> 00:10:17,330 And if the case is quarter we're going to break and then the default will just we'll just leave that 158 00:10:17,330 --> 00:10:18,550 empty for now. 159 00:10:23,920 --> 00:10:25,520 So this is looking good. 160 00:10:25,730 --> 00:10:28,740 It's yelling at us because we aren't doing anything here which is fine. 161 00:10:28,930 --> 00:10:39,730 But I want to we need to do now is have some way to let the other view controller know that we we selected 162 00:10:39,730 --> 00:10:46,870 something OK and that we we tap on something and then we want the other view controller to know that 163 00:10:47,440 --> 00:10:48,580 that's what we're going to do. 164 00:10:48,640 --> 00:10:51,290 We're going to grab that and place it on the screen. 165 00:10:51,340 --> 00:10:53,360 So there's two ways of doing this. 166 00:10:53,650 --> 00:10:58,320 We could do it with a protocol and become Adelia of the protocol. 167 00:10:58,330 --> 00:11:02,860 We could also hold a reference to the previous view controller as well. 168 00:11:02,980 --> 00:11:05,900 Either one would work just fine. 169 00:11:05,950 --> 00:11:08,460 And so let's just let's just keep it simple. 170 00:11:08,470 --> 00:11:09,600 First we can move to a protocol. 171 00:11:09,610 --> 00:11:14,720 We need to but let's just keep it simple and hold and hold a reference to the to the controller. 172 00:11:14,830 --> 00:11:17,910 So what I'm gonna do is appear at the top OK. 173 00:11:18,090 --> 00:11:21,840 We go back and fix this if we want a protocol's probably the best way going forward. 174 00:11:21,850 --> 00:11:25,910 But I think our app is simple enough where it doesn't need a protocol just yet. 175 00:11:26,180 --> 00:11:36,040 And I'm going to keep a weak bar ramp place or VC ramp place for ABC and the reason I'm going to make 176 00:11:36,040 --> 00:11:42,160 it week is because we we don't want to retain cycle is probably not going to happen but we don't want 177 00:11:42,160 --> 00:11:47,900 one we don't want ramp placer VC or excuse your rent picker received a reference from place to place 178 00:11:47,990 --> 00:11:53,040 reference this one with strong references because they will have a return cycle and have a memory leak. 179 00:11:53,170 --> 00:11:54,650 So we're making this week here. 180 00:11:54,730 --> 00:12:00,100 So rule of thumb if you don't understand this is if there are too few controllers referencing each other 181 00:12:00,160 --> 00:12:05,910 or to anything too if there are two objects ever referencing each other one of them needs to be weak 182 00:12:06,370 --> 00:12:11,740 or you will have a retain cycle possibly a memory leak which is which is no bueno. 183 00:12:11,740 --> 00:12:17,140 And if you need more information on it just do a research do some research on iOS retain cycles and 184 00:12:17,140 --> 00:12:19,010 you can learn more about it. 185 00:12:19,030 --> 00:12:20,380 So ramp service. 186 00:12:20,720 --> 00:12:28,730 OK what we want to do is when we're loading when we're loading the this view controller here we'll go 187 00:12:28,730 --> 00:12:29,610 ahead and set it. 188 00:12:29,630 --> 00:12:41,540 So what we'll do is here in our ramp place or see we will go find our pop over which is right here and 189 00:12:41,540 --> 00:12:49,450 then here's our ramp picker right and so what we can do is we can say ramp picker Visi ramp placer Visi 190 00:12:49,490 --> 00:12:50,520 equals self. 191 00:12:50,660 --> 00:13:00,050 OK we're just sending in this view controller over here to the ramp ramp placer Durham picker and we're 192 00:13:00,380 --> 00:13:01,860 setting the ramp place or other ramp picker. 193 00:13:01,880 --> 00:13:07,970 If you're not confuse yet and so then what we do need to do is we need to have a function here that 194 00:13:07,970 --> 00:13:10,400 we call from the ramp picker. 195 00:13:10,400 --> 00:13:21,360 When an item is actually selected and I'm just going to call this function on ramp selected and let's 196 00:13:21,360 --> 00:13:27,240 go ahead and just give it a rap name of type string. 197 00:13:27,720 --> 00:13:30,370 So on ramp selected. 198 00:13:30,510 --> 00:13:31,250 OK. 199 00:13:31,500 --> 00:13:33,180 So that's good. 200 00:13:33,190 --> 00:13:37,750 Let's just give it a let's give it an empty name there onramp selected. 201 00:13:37,770 --> 00:13:38,650 What do you want to do. 202 00:13:38,700 --> 00:13:40,390 Well that doesn't matter just yet. 203 00:13:40,410 --> 00:13:46,740 We just want to implement the function here so cool again if you're going to be doing a lot of back 204 00:13:46,740 --> 00:13:50,280 and forth between if you control you're going one has a protocol we're just doing one function here 205 00:13:50,280 --> 00:13:52,510 so I'm not overly concerned about it. 206 00:13:52,740 --> 00:13:54,450 And you can always refactor. 207 00:13:54,450 --> 00:13:56,360 So wrap picker visi. 208 00:13:56,370 --> 00:14:02,550 So what we're doing is in every single one of these here we're just going to pass in the name of the 209 00:14:02,550 --> 00:14:05,830 item that was selected so we can work with it. 210 00:14:05,850 --> 00:14:15,400 So it should be as simple as doing something like this ramp placer Visi dot on ramp selected in order 211 00:14:15,440 --> 00:14:20,910 to pass in the pipe and just literally do the same thing for each one just with a different object in 212 00:14:20,910 --> 00:14:25,680 there so cramped place or VCDs up on ramp selected. 213 00:14:26,370 --> 00:14:33,840 And we're going to pass and the name we're going to pass in. 214 00:14:33,840 --> 00:14:34,830 Pipe pyramid 215 00:14:37,590 --> 00:14:39,430 and then the quarter pipe. 216 00:14:39,870 --> 00:14:45,990 You know I'm wondering if we even need to do this at all on ramps like that we just pass and if we just 217 00:14:45,990 --> 00:14:51,540 pass in name without even doing a switch statement that would be weightless code so we could technically 218 00:14:51,540 --> 00:15:00,480 just say ramp place or AVC on ramp selected and let's just passing the node name and get rid of all 219 00:15:00,480 --> 00:15:04,680 this code that we just wrote make it more better. 220 00:15:05,910 --> 00:15:06,740 Yeah that'll work. 221 00:15:06,750 --> 00:15:10,440 And since we don't have anything else in the scene we only have three objects. 222 00:15:10,440 --> 00:15:12,290 We know it's only going be one of three names. 223 00:15:12,300 --> 00:15:15,440 And so I feel good I feel okay doing this putting this in here. 224 00:15:15,570 --> 00:15:19,590 And so yeah if there's is yeah we got a note here. 225 00:15:19,590 --> 00:15:20,540 This is great. 226 00:15:20,580 --> 00:15:21,940 I think this will work just fine. 227 00:15:21,960 --> 00:15:25,740 So we'll see if something's been tapped and if it's been tapped we just pass in the name of the object 228 00:15:26,460 --> 00:15:30,330 which will go over here to our ramp placer and then we can do what we want with it which is technically 229 00:15:30,330 --> 00:15:35,460 grabbing building that object again and then putting on the scene and maybe you're thinking it Mark 230 00:15:35,460 --> 00:15:43,180 why don't we just pass the whole note over to the ramp placer and use the same used the same object. 231 00:15:43,180 --> 00:15:49,090 Well we could but you know we've got an action running on a rotate action and we also the scale and 232 00:15:49,090 --> 00:15:53,140 the position are going to be off because it's different on the screen we need it full size now and I 233 00:15:53,140 --> 00:15:56,930 think it's cleaner to just recreate a new one. 234 00:15:56,950 --> 00:15:58,790 So I think this is great. 235 00:15:58,810 --> 00:16:05,710 We've got here is we've got a function that when we tap it it works well when it works actually let's 236 00:16:05,710 --> 00:16:06,720 test it here. 237 00:16:06,730 --> 00:16:16,320 Let's let's go ahead and just print and we're going to say no name and see if it actually works. 238 00:16:16,330 --> 00:16:17,050 How about that. 239 00:16:17,110 --> 00:16:20,160 Then we'll know if it's actually working OK. 240 00:16:20,460 --> 00:16:22,510 The secret button. 241 00:16:22,580 --> 00:16:23,690 So they're definitely spinning. 242 00:16:23,690 --> 00:16:33,410 So when I click these we should see names print out OK there does pipe pyramid quarter quarter quarter 243 00:16:33,950 --> 00:16:35,530 pyramid pipe. 244 00:16:35,570 --> 00:16:36,500 So it's definitely working. 245 00:16:36,500 --> 00:16:37,570 Our code is working. 246 00:16:37,640 --> 00:16:41,380 Look how easy it is to do hit detection with the scene. 247 00:16:41,480 --> 00:16:44,300 Did all the hard work for us under the hood and we just had to implement the code here. 248 00:16:44,300 --> 00:16:47,490 So really good stuff let's call this video done. 249 00:16:47,510 --> 00:16:52,490 And in the next exciting video what we'll do is we'll make it so when you select this it dismisses the 250 00:16:52,490 --> 00:16:58,250 view controller goes back to the other scene and then lets us place an object on the other scene. 251 00:16:58,280 --> 00:16:59,930 So that's it for now. 252 00:16:59,930 --> 00:17:02,470 Mark Price at death slopes Delcam moving on forward.