vec<x/y>, sin, cos

[Switch]

What does vecx/vecy, sin, and cos do/mean??

[Kyranki]

Vectors.

Level of Math Education Suggested: 10 - 11th Grade Calculus

[Switch]

darn im only at an 8th grader's math edu

so how about cos and sin?

[Knightmare1]

im 11 xD i only know algebra and can swear in 3 differant languages.....

[DustyPorViva]

vecx/y and sin cos are simple to learn with Graal. I learned that stuff way back in 7th grade on my own(I honestly don't know the true mathmatics behind it... though we did start getting into sine/cosine in Geometry).
vec stands for vector, in which you're getting the vectorx/y of a direction.
Basically, vecx and vecy are like the following arrays:
vecx={0,-1,0,1};
vecy={-1,0,1,0};
It's generally used to get the movement of a direction.
x=vecx(player.dir)
y=vecy(player.dir)
if your direction was 3, would return (1,0).
You can also multiply it like so:
player.x+=vecx(player.dir)*.5
player.y+=vecy(player.dir)*.5
Which would move the player .5 tiles in their direction. Sin/cos are kind of the same(in principle in Graal, I'm sure I will have the math guru's all over me for this post), in which it gets the 'movement' of an angle.

[Kyranki]

My suggestion applied to both subjects.

[DustyPorViva]

I honestly wouldn't dwell on the whole "I'm not in a high enough grade," thing. Best thing to do is find scripts that use the functions and pick them apart(this was a lot easier to do way back than it is now, as offline levels had a lot of scripts, and they weren't as overwhelming as they are now adays). You'll soon learn how they work by trial and error and be impressed with yourself. I learned a lot of stuff in Graal before I was ever taught it in a class, such as coordinates(a Graal level is just like a huge graph paper), arrays, problem solving and algorithms'
I mean, it might not apply the same in class, but you'll learn how to use them in Graal, and you won't feel completely out of the loop when you start learning them in school, unlike just about everyone else in your class.

[Crow]

We didnt learn cos/sin in school yet, though I already know how it works. You can really learn alot through Graal, but I guess I cannot help you understand it, because my english is not enough for such things ;P

[Chompy]

Ok, some basic things I learned from playing with sin and cos in graal:
They are from the math term 'trigonometry' where radians is used instead of degrees.
Radians goes from 0 to PI*2.

For example, if you want your player to move in the direction that the player is facing, do this:

PHP Code:

temp.angle = (pi/2 * (player.dir + 1));
temp.speed = 1.5;

player.x += cos(temp.angle)*temp.speed;
player.y -= sin(temp.angle)*temp.speed; 


However that will only move the player once, so it should probably be in a loop or when it is provoked by a key for example.
Cos belongs to the x-axis
Sin belongs to the y-axis

This is some simple basic stuff I first learned about cos and sin when I played around with it..
so I don't know if all above is fully correct, so if I'm not, someone else can correct me ;o

[coreys]

Originally Posted by Chompy

Ok, some basic things I learned from playing with sin and cos in graal:
They are from the math term 'trigonometry' where radians is used instead of degrees.
Radians goes from 0 to PI*2.

Actually, trig uses degrees. I guess it varies from place to place, but at least in America it uses degrees.

But really, I forgot all the trig I learned in Geometry and Algebra 2. >.<

[Chompy]

Originally Posted by coreys

Actually, trig uses degrees. I guess it varies from place to place, but at least in America it uses degrees.

But really, I forgot all the trig I learned in Geometry and Algebra 2. >.<

xD

[Switch]

Originally Posted by Kyranki

My suggestion applied to both subjects.

I didn't know because you only said "Vectors" then said you should be in 10th grade.

Originally Posted by Chompy

Ok, some basic things I learned from playing with sin and cos in graal:
They are from the math term 'trigonometry' where radians is used instead of degrees.
Radians goes from 0 to PI*2.

For example, if you want your player to move in the direction that the player is facing, do this:

PHP Code:

temp.angle = (pi/2 * (player.dir + 1));
temp.speed = 1.5;

player.x += cos(temp.angle)*temp.speed;
player.y -= sin(temp.angle)*temp.speed; 


so what does cos and sin really do, or should I not eally be worrying about them?

[Tolnaftate2004]

sin and cos are properties of angles. If you have a right triangle such that angle a is opposite of side A, b opposite of B, and c, the right angle, opposite of the hypotenuse, C, sin(a) = A/C, cos(a) = B/C, sin(b)=B/C, cos(b)=A/C, sin(c)=1, and cos(c)=0.

Though I'm sure you haven't learned it, trigonometry is essential to spherical, polar, and cylindrical coordinate systems. Vector calculations rely heavily on trigonometry, as well as 3D graphics.

They're basically only ever used in graal for pretty light effects and movement systems.

[coreys]

Originally Posted by Tolnaftate2004

They're basically only ever used in graal for pretty light effects and movement systems.

Yeah pretty much. Like that one stupid light in the graal.net snippet library that just goes around in a (sorta) circle.

[Codein]

Originally Posted by Tolnaftate2004

sin and cos are properties of angles. If you have a right triangle such that angle a is opposite of side A, b opposite of B, and c, the right angle, opposite of the hypotenuse, C, sin(a) = A/C, cos(a) = B/C, sin(b)=B/C, cos(b)=A/C, sin(c)=1, and cos(c)=0.

Though I'm sure you haven't learned it, trigonometry is essential to spherical, polar, and cylindrical coordinate systems. Vector calculations rely heavily on trigonometry, as well as 3D graphics.

They're basically only ever used in graal for pretty light effects and movement systems.

I was thinking I'd need to use cos and sin for the melee system I need to make. Rather than hit right in front of the player, damage is done to everything that's in the sector in which the sword moves.

[DustyPorViva]

Ya, you can do that. Or you can also specify a few check points (I did this once withe sword.gani, I opened the gani up in Graalshop and translated the pixel position of the tip of the sword into tiles for each frame, and did checks there.

[Codein]

That seems like a good alternative. However, I plan to use weapons which vary in length. It'd look silly if I had a large bamboo pole (there's a japanese word I'm trying to think of) that only did damage at the end of the pole. Obviously, I'm looking more towards doing damage if you're in the area of the sector rather than on the circumference.

[DustyPorViva]

You can define the area of a circle you're willing to check by specifying a point A with an angle and radius, then check all along a circle until getting to point B, which would also be an angle with a radius. Something like:

PHP Code:

this.width=pi/2;
this.checkcount=10;
this.checkwidth=this.width/this.checkcount;
this.radius=5;
this.angle=((player.dir-1)%4)*(pi/2);
for (i=0;i<this.checkcount;i++) {
  triggeraction(player.x+cos(this.angle+(this.checkwidth*i))*this.radius,player.y-sin(this.angle+(this.checkwidth*i))*this.radius,"attack");
} 


Or something like that.

[zokemon]

Grades of Math are different in every school so you can't really say "10th grade math".

[Codein]

I got taught about basic trig, including cos/sin/tan functions, at around 13 years old and was a recurring subject until I'd finished school, which was about 3 months ago or so.

As soon as it comes up once in your syllabus, it's more than likely to reoccur in the future. For example, I'm taking Maths at Sixth-Form (which is like Year 12 and 13 of school) and trigonometry makes up a good part of it.

[Switch]

Originally Posted by Codein

I got taught about basic trig, including cos/sin/tan functions, at around 13 years old and was a recurring subject until I'd finished school, which was about 3 months ago or so.

As soon as it comes up once in your syllabus, it's more than likely to reoccur in the future. For example, I'm taking Maths at Sixth-Form (which is like Year 12 and 13 of school) and trigonometry makes up a good part of it.

I'm learning 9th grade general stuff at age 12 so I guess I'll be learning next year.

[Codein]

Originally Posted by Switch

I'm learning 9th grade general stuff at age 12 so I guess I'll be learning next year.

I think Grade 8 is like Year 9 in England.

[Switch]

Originally Posted by Codein

I think Grade 8 is like Year 9 in England.

I'm in 7th grade o_O

[Codein]

Originally Posted by Switch

I'm in 7th grade o_O

Yeah, but you'll move on to 8th Grade sooner or later :P

Nothing is stopping you from learning though :P

[Switch]

Originally Posted by Codein

Yeah, but you'll move on to 8th Grade sooner or later :P

Nothing is stopping you from learning though :P

Next year = 8th grade = I learn sin/cos in school

[Codein]

Originally Posted by Switch

Next year = 8th grade = I learn sin/cos in school

Why wait if you have a desire to learn?

[Switch]

Originally Posted by Codein

Why wait if you have a desire to learn?

Cuz I don't understand what the hell they're talkin about xD

[Codein]

Originally Posted by Switch

Cuz I don't understand what the hell they're talkin about xD

Ever thought about googling it? If this yields no results, PM me :P