Game Development

Pikalek

02:06

@GabrieleVierti when I looked at your web page source, every time you used [link_name](link URL) you put a space in between the [link name] and the (link URL)

@GabrieleVierti I'm pretty sure that add the space breaks the markdown - try removing the space & that should fix it

PearsonArtPhoto

03:07

Better?

The Mattbat999

I'm bored.

PearsonArtPhoto

Is that a reference to the images?

DMGregory

03:27

Looking sharp! :)

The Mattbat999

@PearsonArtPhoto nah. Just reorganized my town in my game, but I am too lazy and tired to actually work on the inventory sytem and merchant script D:

Eh I am going to sleep. See y'all later

PearsonArtPhoto

03:52

@TheMattbat999 No worries!

Gabriele Vierti

05:45

@Pikalek yep, it did

aman awasthi

10:39

How do i setup OpenGL in codeblocks in ubuntu?

OMGtechy

What have you tried ?

aman awasthi

tried installing glew ?

but the glew site is showing me some eror

Project web is currently offline pending the final migration of its data to our new datacenter.

OMGtechy

I feel this is rather self explanatory , although you don't need their website for this

So tell me more about what you've tried

What makes you think it's not working?

aman awasthi

okay then how do i install glew?

OMGtechy

install the ubuntu package

I think it's called libglew-dev

aman awasthi

10:43

Project->Build options->Linker settings and then added glew32

opengl32

glu32

OMGtechy

glu != glew

aman awasthi

but none of them were recognized

OMGtechy

Have you tried following a tutorial ?

aman awasthi

yes

user92578

"I typed your symptoms into WebMD and it says you might have networking connectivity issues."

aman awasthi

10:44

quora.com/…

OMGtechy

@amanawasthi ... and at what point did that stop working ?

that is windows

not ubuntu

With any program that uses libraries, you need to do something like the following:
- Get the libraries
- Link the libraries
- Use the libraries

Installing the package is getting the libraries

Going to your linker flags is linking the libraries

aman awasthi

okay then how to get them?

OMGtechy

Writing code that uses them is the last bit

user92578

maybe sudo apt-get libglew-dev?

OMGtechy

3 mins ago, by OMGtechy

install the ubuntu package

user92578

10:46

^

aman awasthi

shows this eror Invalid operation libglew-dev

OMGtechy

if you don't know what a package is then you need to find a tutorial for Ubuntu (not Windows 10) and follow that

you need to write install before the package name

user92578

oh right yeah

aman awasthi

isn't it sudo apt-get libglew-dev?

OMGtechy

this is beside the point at this stage

@amanawasthi you need to google "OpenGL Hello World Ubuntu" and follow a tutorial you find there

aman awasthi

10:48

ok

OMGtechy

Good luck :)

The first link for me is an immediate mode one but whatever, it'll get you started

aman awasthi

thanks

for setting up opengl in codeblocks i've first installed these libraries using : sudo apt-get install freeglut3

now do how do i link them?

to use them in codeblocks

OMGtechy

forget codeblocks for now and follow whatever the tutorial you're using says

aman awasthi

it is saying to write that code , include those header files , and compile it

but i want to use it in codeblocks

OMGtechy

Forget codeblocks for now

Once you have it working outside of codeblocks, you can try and get it working inside of codeblocks

aman awasthi

11:01

ok

Free Internet Points

11:26

1

Q: Unity: Create large Terrain with accurate raycast detection?

I'm not using the Unity Terrain because it lacks certain features. Amongst them, you cannot tile them: You cannot create concave walls or make holes in it: No custom textures, no detail textures, awful sculpting tools... the list goes on and on. So I imported my own Terrain as a Mesh. The co...

aman awasthi

i downloaded libraries, then i wrote the following program using vi and saved it by name p.cpp and when i compiled using g++ p.cpp it gave an eror like this

#include <GL/glut.h>

void displayMe(void)
{
glClear(GL_COLOR_BUFFER_BIT);
glBegin(GL_POLYGON);
glVertex3f(0.0, 0.0, 0.0);
glVertex3f(0.5, 0.0, 0.0);
glVertex3f(0.5, 0.5, 0.0);
glVertex3f(0.0, 0.5, 0.0);
glEnd();
glFlush();
}

int main(int argc, char** argv)
{
glutInit(&argc, argv);
glutInitDisplayMode(GLUT_SINGLE);
glutInitWindowSize(300, 300);
glutInitWindowPosition(100, 100);
glutCreateWindow("Hello world :D");
glutDisplayFunc(displayMe);
glutMainLoop();
return 0;
}

my p.cpp looks like this :

#include <GL/glut.h>

void displayMe(void)
{
glClear(GL_COLOR_BUFFER_BIT);
glBegin(GL_POLYGON);
glVertex3f(0.0, 0.0, 0.0);
glVertex3f(0.5, 0.0, 0.0);
glVertex3f(0.5, 0.5, 0.0);
glVertex3f(0.0, 0.5, 0.0);
glEnd();
glFlush();
}

int main(int argc, char** argv)
{
glutInit(&argc, argv);
glutInitDisplayMode(GLUT_SINGLE);
glutInitWindowSize(300, 300);
glutInitWindowPosition(100, 100);
glutCreateWindow("Hello world :D");
glutDisplayFunc(displayMe);
glutMainLoop();
return 0;
}

the eror on compilation of above p.cpp using g++ p.cpp was :

aman@aman-Lenovo-ideapad-320-15ISK:~$ g++ p.cpp
/tmp/cce8c0y1.o: In function `displayMe()':
p.cpp:(.text+0xa): undefined reference to `glClear'
p.cpp:(.text+0x14): undefined reference to `glBegin'
p.cpp:(.text+0x25): undefined reference to `glVertex3f'
p.cpp:(.text+0x3a): undefined reference to `glVertex3f'
p.cpp:(.text+0x53): undefined reference to `glVertex3f'
p.cpp:(.text+0x68): undefined reference to `glVertex3f'
p.cpp:(.text+0x6d): undefined reference to `glEnd'
p.cpp:(.text+0x72): undefined reference to `glFlush'

aman awasthi

11:46

following OpenGL program not compiling, kindly guide me

#include <GL/glut.h>

void displayMe(void)
{
glClear(GL_COLOR_BUFFER_BIT);
glBegin(GL_POLYGON);
glVertex3f(0.0, 0.0, 0.0);
glVertex3f(0.5, 0.0, 0.0);
glVertex3f(0.5, 0.5, 0.0);
glVertex3f(0.0, 0.5, 0.0);
glEnd();
glFlush();
}

int main(int argc, char** argv)
{
glutInit(&argc, argv);
glutInitDisplayMode(GLUT_SINGLE);
glutInitWindowSize(300, 300);
glutInitWindowPosition(100, 100);
glutCreateWindow("Hello world :D");
glutDisplayFunc(displayMe);
glutMainLoop();
return 0;
}

aman awasthi

12:04

I've downloaded freeglut3 and freeglut3-dev GL

now how do i link these with codeblocks IDE?

user92578

Google should know that

The Mattbat999

@PearsonArtPhoto eh I will get to it sometime today.

aman awasthi

@Tyyppi_77 please tell me if you know this i am having trouble doing this

nwp

12:22

Type "codeblocks add library" into the address bar of your browser.

You probably did that already, but now you can ask a better question. Something like "This tutorial (link) told me that in order to add a library to codeblocks I need to do X, Y and Z. I did and get the following linker error" or "but I couldn't do step Z because there is no such option".

The Mattbat999

@amanawasthi (if you haven't already, I recommend Googling this)

aman awasthi

i downloaded freeglut3 and freeglut3-dev GL but only the .h extension files get downloaded not the .lib files why?

nwp

Are you sure there need to be .lib files and it's not a header-only library?

aman awasthi

I am not sure about that.

i am following this tutorial : learncpp.com/cpp-tutorial/a3-using-libraries-with-codeblocks

it says to Press the “Add” button, and add the path to the .h files for the library. If you are running Linux and installed the library via a package manager, make sure /usr/include is listed here.

i installed the GL using : sudo apt-get install freeglut3

and sudo apt-get install freeglut3-dev

not using any package manager

Kevin van der Velden

But you just said you used apt-get?

user92578

12:37

apt-get is a package manager

Kevin van der Velden

Also o/ chat

aman awasthi

ok i thought it is not sorry for that

so do i simply write /usr/include

nwp

You can apt-file list freeglut3-dev and see what it installed.

aman awasthi

to add the path to the .h files for the library

nwp

Also linux doesn't use .lib files, they have .a and .so instead.

aman awasthi

12:40

@nwp okay

here it is :aman@aman-Lenovo-ideapad-320-15ISK:~$ apt-file freeglut3-dev
The program 'apt-file' is currently not installed. You can install it by typing:
sudo apt install apt-file

nwp

@amanawasthi That tutorial was written with windows in mind and you don't need most of that on linux.

aman awasthi

@nwp ok ,then what should i do next?

user92578

lazyfoo.net/tutorials/OpenGL/01_hello_opengl/linux/index.php

nwp

@amanawasthi You realize that this is not a file list right? And that they told you what you need to do in order to get it?

@amanawasthi You probably want to start with #include <freeglutheader.h>. A freeglut tutorial or the listed files should tell you what the freeglutheader is actually called.

aman awasthi

@nwp ok i am trying,thanks!

nwp

12:50

Just so you know: If you say it doesn't compile because of fatal error: freeglutheader.h: No such file or directory I will not talk to you anymore.

The Mattbat999

@amanawasthi Where did you download them from? If it was an official site, simply try downloading it again or contact ling it's writer.

aman awasthi

everything worked fine ,thannk you all!

@Tyyppi_77 followed the tutorial and it worked! thanks

wish if someone explains to me that under Linker Settings what actually happened when i paste -lGL -lGLU -lglut
into the other linker options field?

nwp

13:27

@amanawasthi Here you go.

genaray

14:20

Hey there ! Does anyone has experience with servers for games ?

Anyone here ?

user92578

no and yes

nwp

not necessarily in that order

Kevin van der Velden

14:36

Also there's a maybe in there somewhere

Just for fun

genaray

Dammit... maybe just a logical question... My game is ... based on touch input. When the player double taps somewhere on the screen, he starts moving towards there. I send the tapped position to the server and push the new position in the database.

At the same time i send the new tapped position to the other players, where i simulate the players movement ( i just let the avatar move towards the received position ) As next i want to implement monsters or other types of enemys. When the player enters their area of interest, the enemys should follow them.

The enemys will be calculated and processed on the server due to security purposes. The problem is that the player actually needs to tap in the area of interest to trigger the enemy. So it could happen that the player moves through the aoi without triggering the enemy... What could be a possible solution for this ? Or should i just send the player position every few mili seconds to the server ?

user92578

Interpolate on the server?

Kevin van der Velden

Get a (mostly) synchronised clock between server and clients and send "At point T in time I start moving to point XY", then interpolate as Tyyppi said

genaray

Well... i didnt even thought about that... Thanks a lot :D And heres a security question... When i call somewhere in my code : "database.setPlayerInformation(name, id, gold, items)" is this a security lack ?

Kevin van der Velden

Where are you running that?

genaray

14:55

On my client. Not on the server itself

Kevin van der Velden

Why does the client have direct access to the database?

genaray

15:22

I thought that wouldnt be such a problem... I hoped it would make the dev process much faster :D

user92578

never ever trust the client

doppelgreener

15:56

right, because you can't ever (ever) be sure it's the actual proper client you're listening to. it may instead be a script i've crafted to tell you to give me all the items and gold and to wipe everyone else's inventories.

anything my game sends to the server, i can intercept on my computer to ensure a modified version reaches the server instead. or i can modify the game itself to ensure it sends what i want to begin with.

cheat apps will do that when the server makes it that easy for them.

user4704

16:52

@Bálint gamedev.stackexchange.com/posts/154388/revisions >_<

Gabriele Vierti

How do i get started with 3D?

user4704

Oh I did it too fast.

user4704

Nevermind.

user4704

(I refreshed the question and hit the edit button on what I thought was my post, but was instead yours because the page resorted the answers.)

user4704

@GabrieleVierti Draw stuff in 3D instead of 2D.

Gabriele Vierti

16:54

@JoshPetrie yeah, okay :D

user92578

use the Z coordinate

user4704

I mean you are already using OpenGL, so that part is taken care of.

user4704

It's just a matter of putting Z values in your geometry that aren't all 1 or 0 or whatever you use now.

user4704

(And probably using a perspective projection transform)

Gabriele Vierti

I've already done most of that

user4704

16:55

Then there you go.

user4704

3D.

Gabriele Vierti

I could load 3D models with an obj loader, but how do i render them ?

@JoshPetrie lol ahahahahaha

user4704

If you can load them, you already know how to render them.

user4704

You loaded them into vertex buffers, no? Render those like any other vertex buffer.

user4704

(If you didn't load them into vertex buffers you probably did it wrong.)

Gabriele Vierti

16:56

should i take in consideration materials, and stuff like that?

I didn't do anything yet, because I'd like to use this lib: github.com/syoyo/tinyobjloader

user4704

Don't worry about "materials."

Gabriele Vierti

It seems to work well

Bálint

@JoshPetrie Ah, thank you

user4704

Materials are a super broad topic and generally mean different things to different frameworks, so you have to decide how you want them to work.

Gabriele Vierti

but that library doesn't give me "vertex buffers" or anything that i can directly render..

user4704

16:58

@Bálint Since I made the edits too fast, the whole process looks like I"m even weirder.

Bálint

I didn't know why you edited my question with no actual changrs and the "I am dumb" message in the why section

But that makes sense

user4704

hehe

Bálint

In other news, I have no idea how ethereum is actually mined and the 90 thousand explanations of the ethereum VM don't really hel0

user4704

@GabrieleVierti Look at the examples.

user4704

If you're going to use a library to load a file format, they're likely not going to be making buffers directly for you.

user4704

17:01

Since they can't assume you're using OpenGL, or how.

user4704

They'll likely just give you their own representation of the data.

Gabriele Vierti

okay

user4704

@Bálint Google "how 2 mine eth," follow 5-step instructions that tell you to run "notakeylogger.exe -mine ETH -giveMe ALL_MONIES" and then log into your bank account to set up your periodic transfers of the... oops.

user4704

(I'd really like to see the results of a social experiment that record how many people happily give away access to their bank accounts in such a fashion.)

user92578

I mean surely the money has to go to a bank account, makes sense to me!

Gabriele Vierti

17:11

@JoshPetrie how should i write the shader, to render the 3D models? they have vertices, texture coordinates, normals and colors

user92578

google this stuff

user4704

Start by writing one that only handles the positions, and maybe the colors.

user4704

Then add handling of the texture coordinates.

user4704

Et cetera.

Gabriele Vierti

okay

thank you Josh for everything :D

user4704

17:13

A general solution to "how can I do X Y and Z?" is to start by just doing X. Then Y. Then Z.

user4704

We call this "problem solving."

Gabriele Vierti

@Tyyppi_77 yeah I know, I think I'm abusing this chat a little to much :P sorry everyone

Jimmy

A also-general tip is sometimes you have to alternate working on the specific thing and learning about the general thing.

In this case, if you're having trouble understanding what you're Googling for, you may want to work linearly through learnopengl.com examples until you do, then find the next thing you want to google for, etc.

Gabriele Vierti

17:38

Assimp's website changed..

Jimmy

woah, I haven't seen Joomla site in a while

Bálint

@JoshPetrie The problem isn't that I don't know how to mine it if I want to, but how exactly the miner executes ot

For instance, bitcoin miners get the transactions, create the block, start checking for values until they get that 30 zeroes and broadcast the result

user4704

Yeah I figured I was just being snarky.

Bálint

17:56

Right

Dom

18:13

Hi guys, I wonder if I can run a question past you in chat to do with calculating and rendering a bounce or should I take it to main?

user4704

You can ask it here, it's fine.

Dom

Thanks, bear with me :) I'll try to make it as clear as possible

Gabriele Vierti

@Jimmy it changed quite recently, it wasn't like this a month ago..

Dom

18:30

I'm working on a very simple app that spawns a ball moving in a random direction which then falls and bounces and few times. To calculate it's position at a point in time I use constant acceleration of gravity, -9.8, multiplied by the time to give the next vertical offset, however the problem arises when it encounters a boundary. Using the remainder of the vertical displacement that's below the boundary to displace it in the opposite direction is often going to result in a big unnatural jump.

How can I determine the remaining vertical velocity after the bounce (part way through a frame) in a natural or pseudo-natural way? I've looked for information about the physics of a bounce but I couldn't find anything particularly helpful.

Jimmy

why is it a big unnatural jump?

Dom

@Jimmy The best assumption I can make at the moment is that I'm not reducing it's velocity at all based on the bounce when I should be

Jimmy

I think the "reflect the position" method is a good first-order approximation. To get a more accurate simulation, you can split the simulation into two timesteps

assuming you have a good idea at what time the actual collision happens

Dom

@Jimmy It's a browser canvas based animation and my rendering engine is extremely basic. Just a function that calls x times per second using setTimeout. Does that affect the possibility of using 2 timesteps?

@Jimmy yeah I have the exact time.

Jimmy

I don't think it's a problem from that description

Dom

18:40

@Jimmy So would this be one frame of the projectile at the boundary and another at the reflected position?

Jimmy

nah, don't change the position, just flip the velocity

    function step(deltatime, skipCollisions) {
	velocity += acceleration * deltatime;
	position += velocity * deltatime;
	if (!skipCollisions) {
	    if (collision = getCollision()) {
		// we need to bounce
		var t = collision.collisionTime;

		// skip collisions to avoid precision issues possibly infinitely recursing
		step(collision.collisionTime - now, true);

		velocity = /* flip velocity around the collision plane */;

		step(deltatime - (collision.collisionTime - now), true);
	    }
	}
    }

uh, that logic isn't entirely correct, you'd probably want to set the position to slightly above the wall, and allow for collisions on the outbound side of the bounce

but this demonstrates the idea -- at the point where you [flip the velocity around], the position should be effectively against the wall, since that's what your collisionTime tells you

Dom

ahaaa! I think I see my problem. The exit velocity should be equal to the entry velocity, not the remainder of velocity left for the frame minus the entry velocity.

Does that sound right?

Jimmy

yes

flip it around the plane of the collision

Dom

Thanks a lot!

Jimmy

its magnitude shouldn't change, unless you want a slightly inelastic collision that absorbs some speed

Dom

18:47

@Jimmy I think that'll be something to implement at the next stage

essentially, I only need the horizontal velocity at the time of the collision multiplied by two

Jimmy

wait, what's being multiplied by 2?

I was thinking one component doesn't change, one component gets multiplied by -1

Dom

from what I understand, the projectile will be at the same vertical displacement after the bounce but a different horizontal displacement?

assuming it's travelling at an angle other than straight down or up

Is it normal for low-rep users to see comment flags? I got a bunch of chat notifications a minute ago about offensive comments elsewhere and they've disappeared as quickly as they appeared

Jimmy

chat uses your network reputation, which is 12.9k

Almo

from the LoL forum "That’s because in the Korean server, your League account is tied to your SSN making it so that once you get banned, your pretty much banned for life (unless ya know you use another number, which would fall under identity theft so...)"

Jimmy

Dom: if we're talking about a collision against the ground, the vertical displacement depends on when the collision happens

Almo as i understand it, all korean online games work like this

since they have some kind of stringent online gaming regulation

Almo

19:02

seems pretty smart to me

I'd love it if we could do that over here

Jimmy

I like it from the perspective of online community moderation

not sure if I like being required to hand my SSN out to random businesses. Especially since it's not easy to verify that I'm not just making up random SSN numbers

When I release my MMORPG, it's going to require a urine sample to log in

no smurfing unless you're willing to collect someone else's pee

Dom

Starts planning MLG gamer pee-trading platform

@Jimmy so if it happens 75% of the way through the frame, what percentage of the entry velocity would the exit velocity be?

what's the relationship please?

would it be a third?

Jimmy

19:18

there is no percentage. The magnitude is 100% of the entry velocity

the direction changes

Dom

sorry I'm muddling terms quite a bit, I meant what percentage of the pre-bounce vertical displacement should the post-bounce opposite vertical displacement be x% through a frame, but it appears that you're saying I should be doing the operation on the direction instead?

can you shed some light on the direction change?

I'll draw a diagram to try and make my misunderstanding clearer

Jimmy

there is no fixed displacement percentage

it depends on when the collision happens

for example, if you're simulation is at current time T = 0 and you have a collision at T=0.00001, then ending displacement is quite different from the collision at T=0.1

if your timespans are small enough, you can just fudge it with whatever value you want and most players probably won't notice

Dom

19:43

ms paints finest

user92578

Does it have to be accurate though?

Dom

only enough to not notice any problem

first off, does the diagram make sense?

I'd rather it have some base in true physics than just something I make up

user92578

At like 60fps I don't think anyone notices if you just resolve to the surface, flip velocity and continue from there the next frame

user92578

But anyways even doing it accurately shouldn't be too hard

Dom

I think I'll have to tweak the magnitudes of my calculations because it can fall as fast as half a screen in a frame

Bálint

20:09

I'll see if I can write a WebGL miner

What should I mine?

Almo

some obscure altcoin with low difficulty. hope you get lucky and it goes up in value

Jimmy

runs cmake on LLVM to generate Visual Studio 2017 solution -- 700 compile errors

why are we still doing this in 2018

user4704

As opposed to?

Jimmy

I dunno, I figure the toolchains for a 30-year-old language could have figured out how to build something without relying on brittle convolutions

lets use cmake to build a meta-makefile into a platform-specific makefile that builds a bunch of binaries that generate intermediate files because you can't shell-script cross-platform then cross your fingers and compile the whole thing

user4704

C++ is a brittle convolution.

user4704

20:21

And cmake seems to me like a pretty good stab at solving the problem, generally.

Jimmy

I admit seems better-thought out than autotools

user4704

I'd say what you're seeing as difficult is probably the result of the project (a) not using cmake correctly/the way it wants to be used and/or (b) the maintainers of the project not checking that specific cmake output target well

user4704

It's also more widely available. Autotools on your Windows machine is a terrible experience.

Jimmy

also it turns out if I build cmake from trunk I don't have this problem

user4704

Oh yeah.

user4704

20:23

(c) cmake not being updated to handle the bleeding-est edge of some output target :D

user4704

(c) happens a lot with Xcode; for a few days after an Xcode release, cmake will generate projects that Xcode warns should be updated to include new recommended settings that cmake didn't know about before they existed.

PearsonArtPhoto

22:33

Okay, I think I can finally start working on it!

nwp

Done shaving all the yaks? Are you sure you didn't forget any?

PearsonArtPhoto

I might have missed one or two, but they don't have that long of hair.

Jimmy

but yak shaving is where all the fun is

PearsonArtPhoto

Just feel better now that I have SOMETHING!

Jimmy

what is that

nwp

22:47

Is that your first approximation of the tesla approaching mars?

2

Jimmy

I also can't find the antecedent for "working on it"

PearsonArtPhoto

Yeah, that's my very early approximation, except it is leaving Earth.

Next step is to try and figure out how to get the real geometry plugged in.

Jimmy

ooh, a virtual spaceman

is this a webgl thingie going on your website?

PearsonArtPhoto

That is the goal.

Jimmy

after you're done with that make a webVR one so everyone can be first-person starman

PearsonArtPhoto

22:51

Never done anything VR before...

Not surprisingly, I'm not going to have nearly as many views today as I did yesterday.

It is hard to beat being on the front page of Reddit.

Using CSS, HTML, Javascript, Python, and C# all in the same product can make the mind a bit wobbly.

PearsonArtPhoto

23:25

I just realized, I did do the code in Javascript, and Unity supports Javascript...

But nah, I'll just re-program it. It isn't really that complex of code.

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