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In this lecture, we're going to flip our character.

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So running right makes our character point right and running left makes our character point left.

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Just very quickly, I'm going to give myself a little bit more platform here so I can make my character

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run around without having him fall.

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And yet, there we go.

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Okay.

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Just a little bit more space to run, run, run to do what we're doing in this lecture.

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Now, I'm going to take you through a little bit of the logic, our flip and logic for this lecture

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haha that joke and we have our character facing right and we're flipping our character and our character

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is facing left.

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So if the player is pushing right the velocity will be positive.

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Yeah, because we know from our control input it's going from minus one to plus one and then we're applying

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our run speed multiply to that.

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So if it's left it's negative, if it's right, it's positive.

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If we're moving right, we want to face right.

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If we're moving left, we want to face to the left so we can change the facing direction to the right

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of the left by changing the local scale using positive or negative values.

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So let me just show you that bit of our logic very quickly in here.

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Click on the player.

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We've done this before into the transform.

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If we look at the scale on the x axis plus one and minus one, it will change our character.

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I was zooming a little bit here so you can see him doing a little pirouette.

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We have minus one, minus ZP minus one and plus one.

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So that's basically what we're going to be doing in code depending upon whether you're running to the

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right or running to the left.

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And then the last bit of our logic is to only change the facing direction if you're actually moving

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so that the weird things don't happen when our velocity is zero, I might leave them in for our first

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point and then we'll see what weird things happened.

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And then we'll put in a little bit of an if statement to say only flip if you are actually moving at

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the time.

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And the other bit of set up, I'm going to take you through here.

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We're going to be using some different math F methods.

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We're going to be using math for abs, which is absolute.

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It's not like rock hard abs of Steel six pack, it's a abs in absolute.

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And that is going to allow us to say, what's the absolute value of our number?

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If you're not familiar with absolute value, it means no matter what sign is on there, so positive

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or negative, we make it the positive value.

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So if -10.5, you can see in the example here becomes 10.5.

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So it's a way of us just cleaning away the sign.

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So we just get the absolute value irrespective of the science.

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That's math for abs.

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And then we also have math sign.

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What does that do?

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Well, that allows us to return a value of one when F is positive or zero and minus one when F is negative.

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So no matter what our value is, if we're pushing to the right or we've got a thumbstick on a gamepad

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and we're pushing halfway to the right, and it's plus 0.5 or plus 0.7 or it's -0.3 or -0.8.

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Whether it's positive or negative, we're going to return a value of one or minus one just so we can

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get the sign.

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And what do you think we're going to do with that one and minus one?

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We're going to apply it to our player on the local scale.

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And the last math F type thing we're going to use is epsilon, which is the smallest, a tiny floating

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point value, the smallest, most, most value.

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We try to use math for epsilon instead of saying zero.

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Sometimes we get some weird results if we say equal to zero because technically it's 0.000001.

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So then we get some confusion around that.

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So it's good practice to say greater or greater or equal to math after epsilon rather than to zero.

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So they're the three things we're going to be using.

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Now, let's get into our code and use some of these things.

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First of all, we need to create ourselves a new method.

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And I'm going to start by calling the method and I'll name this flip sprite.

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We don't have that yet.

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Parentheses, semicolon.

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So we're going to go and create that.

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I'll create that underneath.

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Run void flip sprite parentheses.

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Curly braces.

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What are we going to do in here?

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The first part of this is we're going to access the transform local scale.

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Local scale of our object equals vector two.

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And we need to put the new key word in front of that.

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Now in here I will start off with math f dot sign because I want to get the sign of a particular thing.

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I want to know, are you a positive or are you a negative?

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What do you think is a little micro challenge for you?

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What do we need to get the sign of?

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Just take a moment to think about that and add that in if you think you've got the answer.

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We've got a little bit of a hint up here.

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We've got my rigid body velocity y that's on the up and down.

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So let's use my rigid body dot velocity X.

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So here's the velocity on the x axis.

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Is it positive or negative?

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Because we need that sign and then we don't want to change anything on the Y axis.

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Leave it as it is.

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So we're just going to put one in there for our vector two that we're returning and that we're putting

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into our in here, into our scale.

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Just leave that as one.

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We don't need to go and change that.

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One is fine.

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Let's save and see if it's working.

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At this stage.

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There's more code for us to do, but it might maybe be working thus far.

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Like on play.

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Right?

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Right.

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Running left.

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I'll do that.

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He flips.

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Running right, running left.

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Now, as I indicated, when he turns left and then I let go, he flips back to the right again.

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That's because zero when you've got no velocity, all at all is being treated as a positive.

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So that's the next bit of our logic.

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We're going to jump back into Flip Sprite and create ourselves a ball that says you're either moving

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or you are not.

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So ball player what should we call this?

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Player has horizontal speed.

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I know it's a bit of a mouthful, but when we look back at this in six months time, we'd be like,

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Oh, I know what that means.

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Makes sense.

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Now, how do we find this?

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Well, we need to say, is your movement greater than nothing?

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But if we say movement greater than zero, that kind of thing, if we're currently moving to the left,

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our movement is going to be negative.

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And that's going to give us a bit of a mistake, because a negative movement is still movement.

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So we want to use our absolute value in here.

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So we want to use our math f dot absolute, our rock hard abs salute in there and we are going to pass

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into this my rigid body dot.

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What, what are we passing here.

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Well the same thing is just below velocity dot x.

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We need to know what's the absolute value of your movement.

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And then we're going to say is greater than.

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And I gave you a hint.

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It's greater than what?

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Greater than math F dot epsilon, which is another way of saying pretty much zero, but a little bit

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technically cleaner.

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So we'll save that.

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And we now know that.

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And within our actual flippy flippy in here, we're going to say if a player has horizontal speed.

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So in other words, if that is true, then we want to flip.

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Okay, we'll save all that up.

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Hopefully this explanation is clicked for you.

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It's a little bit tricky using math, words and concepts in there.

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Any time we play around with math, I know a lot of people kind of glaze over and say, Oh, what are

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we doing?

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But I think we've got it right, left, any staying facing left because when we're stopped, we don't

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need to go and flip it again.

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Excellent.

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So there we go.

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We've now flipped our character Sprite using a little bit of mathematics and a couple of extra methods

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in unity.

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So great work.

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I'll see you in the next lecture.