Game Programming - Episode 12 - Negative Bounds

Key Takeaways

yo what's going on guys my name is the welcome to episode 12 of game programming one more thing before I begin yesterday's video episode 11 didn't really publish correctly like at all I don't know what happened to YouTube I wasn't the only problem I mean obviously I was not the problem let me just try that again I wasn't the only um I guess content creator who actually experienced issues it was like sitewide um people's videos um didn't actually publish to the homepage they did publish so in other words they were live on the channel page and they were live in the actual um let me just show you guys actually just open YouTube real quick I go over here if you go to like I don't know like let's just say Hut right um they they wouldn't be on the front page but they would be on the actual like over here so if you did click on my name here and you uh you checked it out you know you'd see um you'd see my video but you wouldn't see it on your actual subscriptions page so you might have missed it if you did it it did actually come out yesterday last night as usual um and just go to my channel check it out it'll be like right there on my channel so just keep that in mind okay um and in the future if you see like a video that doesn't come out that that's actually why I ask you guys to follow me on Twitter and Facebook in case something something like like this happens I always link it so in other words um a lot of people actually see it before it even publishes to any anything on YouTube so a lot of people actually catch the video while it's still processing and sort of catch it before YouTube fully publishes it so if you do follow me on Twitter and Facebook you will never miss a video that I put out so that's just a Pro tip for you okay anyway back to this so yesterday we took a look at actually um managing you know getting off the screen now there is a problem I'm going to quickly reset this back and we're going to deal with with another part of Ray index out of bounds and that is the opposite of this so if I just put it like this so you guys can see it properly we'll make it like 50/50 oh even like 150 or something okay so we're tring slowly now there time to there time for me to talk we manag this problem when it gets off the screen now the problem is if we actually r vers this so I'm just going to come in here and change this to minus minus um one more thing actually a lot of people ask if they should take this code down including y time you don't have to okay I'm literally showing this to demonstrate to you how it works I will I will be getting rid of this code I will be getting rid of these two variables um and I will be replacing these back with X and Y in the for Loop okay I'm just literally just taking the time to actually explain to you guys how this works because that is the point of the series to take it nice and slow and to teach you guys how and why everything works so if I reverse it like I did here right so what's going to happen is this variable starts at50 respectively but it's going to get smaller so we're going to go the opposite way now what's going to happen is oh we've hit it there we go crash now why is there a crash because again it's still out of bounds remember we range uh if I go to variables we range from 0 to 9 uh to 0 to 503995 tried to access a negative um index that does not exist that is still out of bounds okay if it's over if it's too much or if it's too little so in other words negative then that causes an array index out of bounds exception how do we deal with that pretty simple okay what we've got here is if y time is greater than or equal to height we break it's pretty simple to fix this all we need to do is say that if y time is actually less than zero or if it's greater than height let's break okay okay simple as that we've done greater than height so in other words that's when it gets out of the screen going down when it gets out of the screen going up it's going to be less than zero and we can say that if it is less than zero let's break and we we need to do the exact same thing for X I assume you guys know how um how this uh Works in terms of um the actual if statement obviously we've got if x time is less than zero and then this this little double pipe thing um means or so in other words if the statement is true all this statement is true do this so break okay and um I think I explained break last time but now we can uh we can run this and you'll see that um we're fine we don't crash so that's the basis that that's the basics of um or the basis of of how this is going to work and if we just get rid of why you can see that the X works as well so here we are traveling nicely and then we're gone so um that is how that works um all we got now is uh probably next time so tomorrow we'll take a look at what are we going to do next no clue um H probably next time H what's next I have no idea what's next uh we'll probably move on to beginning um ooh I know um before we begin building tiles um we'll actually um probably add like a um like a an FPS counter as well as a timer to actually control um this and make sure that update only happens 60 times a second okay so we'll add of time tomorrow um but until then guys make sure to like the video if you did like the video and I will see you guys uh see you guys tomorrow bye [Music]