hello,
in order to move my rectangle toward the mouse X & Y coordinate i created this method
and it kinda work but sometimes it gives a strange behavior
so instead of moving like this (O=object, T=target) :
it does something similar to this
i hope you understand what i meant
and here is my methode code
// tx and ty are the target coordinates
public void move(int tx, int ty) {
// calculate distance to cross
int xdistance;
xdistance = tx - x;
// check if the target point is on the right or on the left
// go to it
// decrements/increments the distance so it will reach zero
// and break the condition
if (xdistance > 0) {
x += s;
xdistance -= s;
} else if (xdistance < 0) {
x -= s;
xdistance += s;
}
// same thing
int ydistance;
ydistance = ty - y;
if (ydistance > 0) {
y += s;
ydistance -= s;
} else if (ydistance < 0) {
y -= s;
ydistance += s;
}
}
Here is some code for that using LWJGLās Vector2f class:
//mouse is point B
Vector2f mouse = new Vector2f(Mouse.getX(), Mouse.getY());
//get direction
Vector2f dir = new Vector2f(mouse.x - x, mouse.y - y);
//normalize it
dir.normalise();
//scale the vector based on our movement speed
float speed = 2f;
dir.scale(speed);
//move the entity with our new direction vector
x += dir.x;
y += dir.y;
If youāre a crazy fool and youāre using Java2D, it might look like thisā¦
//mouse is point B
float mx = Mouse.getX();
float my = Mouse.getY();
//get direction
float dx = mx - x;
float dy = my - y;
//normalize it
float len = (float)Math.sqrt(dx * dx + dy * dy);
if (len!=0) {
dx /= len;
dy /= len;
}
//scale the vector based on our movement speed
float speed = 2f;
dx *= speed;
dy *= speed;
//move the entity with our new direction vector
x += dx;
y += dy;
You might also need a condition to avoid āflickeringā when the entity lies under point B (the mouse).
:o
seriously,
is it that bad :-\ ??
i thought itās better to start learning without any external library
well i need to finish this very tiny small game and then maybe i start to learn LWJGL
ps :
can you post a link for a nice explained tutorial for LWJGL please ?
A better option would be to use a framework like LibGDX. Not only does LibGDX handle all that low-level stuff for you, it also includes utilities like themable GUI, bitmap font generation, integration with Box2D physics, tiled map loading, particle editor tool, texture atlas management, efficient sprite rendering, and much more.
Then you can try making a game with that.
Then forget the rendering methods because immediate mode is useless for performance.
Then this for VBOs (donāt worry about 3D. Just stick to 2D):
Then you can try these:
Be aware that this will be a long process. It will probably take many months to learn all that.
I recommend to mix up 2D and 3D games while youāre at it.
But at least youāll understand OpenGL properly.
If you want to be lazy and donāt care about understanding, use LibGDX.
You donāt need to write the verbose OpenGL boilerplate in oder to understand how shaders and textures work.
Same goes for other areas like ShaderProgram, Mesh, etc. Ultimately LibGDX is just another OpenGL wrapper, and you can use it however you choose.
As I explain in my tutorial series, it may be easier to learn shaders and the programmable pipeline by using a high-level API (LibGDX, lwjgl-basics, etc) rather than getting bogged down on OpenGL boilerplate.
/**
* Moves this object to a specified point with a specific speed. Note that
* the velocity used is independent of vertical or horizontal velocities of
* this object.
*
* @param nx The new x-position
* @param ny The new y-position
* @param speed The speed with which to move
* @return True if the new point has been reached
*/
public boolean moveTo(float nx, float ny, float speed){
boolean _x = false;
boolean _y = false;
int distance = (int) Math.sqrt((double) ((x - nx) * (x - nx) + (y - ny) * (y - ny)));
float vel = Math.min(distance, speed);
float newx = x;
float newy = y;
if (x > nx) {
// We should move left
newx -= vel;
} else if (x < nx) {
// We should move right
newx += vel;
} else {
_x = true;
}
if (y > ny) {
// We should move up
newy -= vel;
} else if (y < ny) {
// We should move down
newy += vel;
} else {
_y = true;
}
x = newx;
y = newy;
return (_x && _y);
}
[analogy]
Because if I know how a wheel works, I can fix the car quicker if something goes wrong. I can also make the wheel better for me. And because I know how it works too, I can make a wheel out of different materials, some which may be better than the current. In the end, itās much better than relying on a one-size-fits-all wheel that goes slow, because despite being on a F1 car, it was also designed with trucks in mind too.
[/analogy]
Also, I want to be one of those āpeople way more talentedā. And Iām sure there are lots of others out there too. I know this for certain, because if there werenāt, LibGDX or any other library wouldnāt exist today. These people should not be told to just go and download loads of libraries to do things for them. Lazy people will always pick the lazy solution, no matter what you tell them. But talented people need some one to say āit will be good for youā before they go into the relatively unknown.
The only problem is, that you wouldnāt know how to produce a competing high-tech wheel without looking back on the experience of generations of engineers, using it, learning from it, and then, eventually, if it makes sense, creating your own improved thing.
Using a matured library is not the lazy but the professional way.
So uhmā¦ If you arenāt able to create a high tech thing, without looking back at other high tech things, then how did the first high tech things appear? Magic? And yes, using a full fledged library, before learning any basics is surely laziness. And very few on this forum can be called professional game developers.
And I really donāt get the whole argument that you should just use a library to do everything for you. Do you use a library to wipe your own ass too(Mmm, paper jokes)? I completely agree that a library can be helpful. But there never should be a point where someone say āOh, instead of learning how to actually do what you want to do, just use X library, itāll do everything for you, even make your coffee.ā
For simple 2d, for beginners, thereās nothing wrong with learning the robes, before taking on a full fledged library. At least encourage people to THINK before telling them that they can achieve world peace, if they use library X.
And whereās the need to use LWJGL for any of this?
Hereās the same code, using javax.vecmath.Vector2d:
//mouse is point B
Vector2d mouse = new Vector2d(Mouse.getX(), Mouse.getY());
//get direction
Vector2d dir = new Vector2d(mouse.x - x, mouse.y - y);
//normalize it
dir.normalize(); // This time, spelled with a z, instead of an s.
//scale the vector based on our movement speed
float speed = 2f;
dir.scale(speed);
//move the entity with our new direction vector
x += dir.x;
y += dir.y;
And Mouse.getX() / Mouse.getY() could be taken from my own MouseController class.
Teach people to learn some basic stuff, before teaching them to use a library, and please for the love of <whatever you think is epic/awesome/holy/etc>, do NOT involve new people in your wars of what library is the most epic. Itās just a waste of time.
@alaslipknot
Do a few basic Java2d games, before moving to a big fat library(The joke here is, that most of whatās shipped with Java is already libraries, which is why thereās the whole throwing around of āwhy not write machine code then, if you donāt want to use a library, blablablaā).
Just get a feel for how things work and how to structure your stuff. Onceās youāve gotten down sprites, etc. etc., then you can start learning OpenGL and one of the many libraries out there(Of which most use LWJGL internally, as far as Iāve seenā¦).
Seriously though, OpenGL is not like learning to fingerpaint. Itās vector math, and C, and NDC/camera Space/Clip Space/world spaceā¦
Methinks that Java2D sounds fun and informative.
yes i agree with that, but, wouldnāt be a wrong i started since the 1st game with LWJGL ??
i mean Java2D is the basics no ?
[quote]If you decide to use LWJGL, you need to build everything from the ground up. This can be complicated and daunting for a newbie,
[/quote]
Exactly, thatās why i think that the good way to start is Java2D, then start to learn LWJGL step by step, it would be easier no ?
[quote]A better option would be to use a framework like LibGDX. Not only does LibGDX handle all that low-level stuff for you, it also includes utilities like themable GUI, bitmap font generation, integration with Box2D physics, tiled map loading, particle editor tool, texture atlas management, efficient sprite rendering, and much more.
[/quote]
I donāt like that, specially if i donāt have the minimum knowledge of basics stuffs, i donāt know why i feel like this about using FrameWork or Engines but using them make me feel like am not intelligent enough (or lazy) to start with basics and reach that level one day, itās like using a GameMaker but with more advanced script features
donāt worry, i will handle that 8)
and nope, LibGDX is my last option for now
@SHC
thank you
then i will be a newbie forever
do you want me to be a newbie forever : ??
OKAY ;D !!
@BrassApparatus
xD
and yeees !! i tried to take a look at few openGl examples, and i was " :o !! "
weāll understand it one day
thank you guys very much for your help, i really appreciate that
I guess it depends what your end goals areā¦ if itās making games for a livingā¦ then itās smart to use libraries. If you are doing it for the learning experience or because you want to make your own libraryā¦ then go the LWJGL way!
