Gosu Forums

Blocks 2D (in development)

jlnr — Tue, 21 May 2013 06:22:56 GMT

...and you need Ruby 1.9 & the xml-simple gem :)

Looking for a Gosu tutorial(Video or Text)

RunnerPack — Tue, 21 May 2013 04:27:56 GMT

That's one way to do it, but that can get quite complicated/slow when you start using more than a few objects. Have a gander at: Gosu::Window#translate.

Use it like:

translate(world_x, world_y) {
  thing.draw(local_x, local_y, ...)
}

Keeping in mind, of course, that when the camera moves, e.g. right, the world "moves" left, and so on.

Can I use Gosu to make an Isometric 2D game?

RunnerPack — Tue, 21 May 2013 04:15:34 GMT

You can achieve * A N Y T H I N G * using Gosu! ;)

But seriously, yes you can. It's basically just a "top-down" perspective combined with the right graphical style (in fact, remember the dungeons in LoZ? The walls were top-down, but everything else was oblique!) The only semi-difficult thing is collision-detection, and then only if you want to be able to walk "behind" stuff (which LoZ games don't usually let you do).

If you want to do jumping or other "Z-axis" stuff, you just have to use the desired Z coordinate to modify the base Y coordinate. I've done this in Flash/AS3.

Error no such file to load - Gosu

SPK — Mon, 20 May 2013 13:57:30 GMT

Which OS? Under Linux you should be careful, when installing gems as root... they may be installed where your user's path doesn't look.

Error no such file to load - Gosu

SeamusFD — Mon, 20 May 2013 13:35:14 GMT

Need help with getting Gosu running. I am using a different computer that did not have gosu currently. However I think I have installed it...
But when I try to run anything I get the error:

LoadError: no such file to load — gosu

method gem_original_require in custom_require.rb at line 31
method require in custom_require.rb at line 31
at top level in main.rb at line 2

Could someone please help...

Bug in Gosu 0.7.47 Mac .app wrapper

carno — Mon, 20 May 2013 03:17:48 GMT

Thanks you.

The only problem with lipo solution is that it seems to break compatibility with the opengl gem. Can't wait for the next version.

Blink effect

jlnr — Sun, 19 May 2013 02:58:19 GMT

There are always many fun ways to implement visual effects... :) You can also create the white image once using TexPlay or even pure Gosu:

http://www.libgosu.org/cgi-bin/mwf/topic_show.pl?pid=6425

And then overlay the white image over the original with a changing alpha value (or the other way around). However the Ashton solution should handle semi-transparent pixels a lot more nicely.

Blink effect

SPK — Sat, 18 May 2013 19:41:22 GMT

Awesome. Ashton::Shader(fragment: :fade) provides everything I need. Though, the syntax is a bit special and the Ashton source files doesn't really help.

However, I got what I asked for. Thousand thanks. :-)

Blink effect

SPK — Sat, 18 May 2013 18:23:46 GMT

Thanks for the fast answer.

Pitty it's the first time I hear about it. I'll report back, once I tried it out.

Blink effect

lol_o2 — Sat, 18 May 2013 18:14:57 GMT

Try Ashton: http://www.libgosu.org/cgi-bin/mwf/topic_show.pl?tid=784
You just need a proper shader. And it's better to give up on TexPlay, because it's very slow.

Blink effect

SPK — Sat, 18 May 2013 17:59:49 GMT

Hello,

I need a blink effect (or called flash?) like the one used here: http://www.youtube.com/watch?v=go7rlvyI7Ys
I tried it using Texplay, but it's kinda limited. I coulnd't find a way to turn my image all white and slowly change it back.
My approach then was to copy my image, draw it over my original image and make it from white to 100% opacity. But
I noticed that's not the best performant way and I wasn't even able to turn my image white or change it's opacity... instead I drew a reddish rectangle on top
of my CLONED image. Then I switch between those two images every x frames to simulate a blink effect. Well, ...

can anyone suggest a better way to implement a blink using Texplay?

Can I use Gosu to make an Isometric 2D game?

Eamonn — Fri, 17 May 2013 14:46:43 GMT

Hey that IS what I'm looking for. I was told somewhere it was called isometric. Is this achievable using Gosu?

Looking for a Gosu tutorial(Video or Text)

Eamonn — Fri, 17 May 2013 14:39:27 GMT

Thank you all for your help! So really I should just read the main parts of the documentation and then when I understand the main concepts get some example games and mod them a little bit? The only thing that puzzles me is camera movement. What I think you would do would make the X/Y position of the object(s) that you want to move adjust depending on the way you move like up, down, left and right. I'll look into it though. Thanks you all for giving me some help on this!!! :D

Blocks 2D (in development)

lol_o2 — Fri, 17 May 2013 12:37:36 GMT

I'd note that you can even omit braces
@gracz.x, @gracz.y = 3, 5

Using Gosu without starting X server

jlnr — Fri, 17 May 2013 09:32:58 GMT

There was an attempt at porting Gosu in the very, very early days of the Pi:

http://www.libgosu.org/cgi-bin/mwf/topic_show.pl?pid=5638

From what I remember this continued on IRC and the biggest obstacle was in fact Gosu's dependency on X11 (or alternatively Win32/Apple APIs).

There was a snippet of code on github that demonstrated how to open an OpenGL ES context using a proprietary, binary driver, but the snippet itself had no license attached so I kept my hands off it.

Do you know how other libraries handle it? If there is a way to open an OpenGL ES context, then most of Gosu should immediately work. Font rendering, audio, input are the next step then.

I am also not sure if I can help much without owning one myself :) I only have a little zoo of mobile devices for general OpenGL ES development.

Blocks 2D (in development)

Spooner — Fri, 17 May 2013 09:27:28 GMT

Yes, I always just use x/y to avoid that problem. I was just showing how it should be done compared to how it was done. You can still do @gracz.x, @gracz.y = [3, 5] if you want to set the value with an Array.

Blocks 2D (in development)

jlnr — Fri, 17 May 2013 09:25:15 GMT

I would not offer the method pos, as it is tempting to write @gracz.pos.x = 5 which will not work (it only replaces the first element in a temporary array).

Not that my Ruby style is anywhere close to what's hip now - I still love then :)

Blocks 2D (in development)

Spooner — Fri, 17 May 2013 09:18:41 GMT

Oh, I'd also highly recommend using the bundler gem to manage the gems you need for your project.

#set & #show are a bit convoluted. Try:

attr_accessor :speed, :gravity, :x, :y

def pos; [@x, @y]; end
def pos=(value); @x, @y = value; end

Then you can do @gracz.pos = [5, 100] or @gracz.x = 5 or puts @gracz.gravity to manipulate the instance variables in a more friendly manner.

Although I said to use spaces instead of tabs, please don't mix them, because that is the worst of both worlds ;) Your editor should be able to automatically replace tabs with 2 spaces.

You might also consider putting your code up on somewhere like github.com, which makes it easier for people to get hold of (no real need to release Windows version on a site like this, since everyone here is a Gosu developer and they don't really need an executable).

Good luck with the project and I am looking forward to being able to interact with the terrain in the game!

Can I use Gosu to make an Isometric 2D game?

Spooner — Fri, 17 May 2013 08:59:22 GMT

I made an isometric game which worked quite well in Gosu: http://spooner.github.io/games/smash_and_grab/

Blocks 2D (in development)

Spooner — Fri, 17 May 2013 08:54:12 GMT

src/tiled.rb

Using Gosu without starting X server

misbehavens — Fri, 17 May 2013 05:28:06 GMT

I am planning on building a Gosu application which launches on startup of my Raspberry Pi. I installed Ruby 1.9.3 and the Gosu gem. When I ran a simple Gosu example game, I got the error "Cannot find display (RuntimeError)". That's when I realized that I could not run Gosu without starting the X window server.

I'm not that familiar with the lower level internals of Linux and Gosu, so I'm wondering, is there any way that I can run a Gosu application without starting X server? I would rather not waste the time and resources to start up all the GUI stuff just to ignore it by running a full screen Gosu application.

Thoughts?

--Andrew

Looking for a Gosu tutorial(Video or Text)

jlnr — Fri, 17 May 2013 04:58:15 GMT

There is no definitive list of concepts :) If you want to write a jigsaw puzzle game, the code will look completely different from a Super Mario clone. Gosu makes almost no assumptions about what you want to do.

I would suggest that you download a few smaller games from the Showcase and mod them a little, and get a feeling for which code style you prefer.

Can I use Gosu to make an Isometric 2D game?

RunnerPack — Thu, 16 May 2013 23:15:32 GMT

I think what you're referring to is called an "oblique projection". See: http://en.wikipedia.org/wiki/File:Graphical_projection_comparison.png

Looking for a Gosu tutorial(Video or Text)

RunnerPack — Thu, 16 May 2013 23:11:12 GMT

You don't have to read the documentation "cover-to-cover" to learn from it. Just skim over the main classes (Window, Image, etc.) and look at the included examples. When you have a general idea of how things are done, start making something. If there's something you want to do, but you don't know how, take a look in the docs. There's really not that much to Gosu (on the surface) and it's really well organized and logical. You should be able to pick up the basics very quickly with just a bit of practice.

Also, don't forget to use the search engine here on the forum. Most likely, your question has already been asked and answered at least once.

Screen goes black.

onnoowl — Thu, 16 May 2013 21:18:32 GMT

The draw function does not seem to be throwing any sort of exception. When the screen goes black, the rescue function does not trigger.
However, I can prove that the rescue function is in fact doing it's job, because if I try to interrupt the program (ctrl C) it prints the interruption error message and then just keeps on going.
The draw function is not throwing any sort of error. What else could be causing the blackness?

Looking for a Gosu tutorial(Video or Text)

Eamonn — Thu, 16 May 2013 20:09:46 GMT

Hello. I have recently finished learning the Ruby Programming Language and I would like to jump right into learning Gosu. I was looking at the ruby4kids tutorial series but it didn't really teach that much and wasn't very useful. I could not find any other tutorials. Does anyone know where I can find a simple easy(ish)-to-follow Gosu tutorial? I'd like it to teach enough concepts to program a full game. If a tutorial is not a good idea, how do other people learn Gosu? Can you tell me the best way to learn Gosu? I don't like reading though documentation so don't say to read the documentation(even if it's the best thing :P).

Thanks! Any help is welcome/appreciated! :D

Blocks 2D (in development)

SeamusFD — Thu, 16 May 2013 19:56:49 GMT

Hey guys... I really like the idea of this game, I really do. However I, (like ExplodingCookie) have the problem of only having access to mac's. However I think I figured out what to do and I attempted to install xml-simple and gosu (this is my first time running gosu on a particular computer,) however when I try to run the program through my code editor I come up with this error...

warning: already initialized constant VERSION
LoadError: no such file to load — gosu

method gem_original_require in custom_require.rb at line 31
method require in custom_require.rb at line 31
at top level in tiled.rb at line 10
Program exited with code #1 after 0.21 seconds.

I am so confused :(
Could someone please help me...

Screen goes black.

lol_o2 — Thu, 16 May 2013 18:14:15 GMT

Check this subject: http://www.libgosu.org/cgi-bin/mwf/topic_show.pl?tid=388

Solution looks like this:

some bad drawing code...

rescue Exception => e
puts e, e.backtrace

I think 'Exception' after rescue is what you need.

Blocks 2D (in development)

ExplodingCookie — Thu, 16 May 2013 16:51:16 GMT

Oh, I could not find which file to execute in the source.

Can I use Gosu to make an Isometric 2D game?

ExplodingCookie — Thu, 16 May 2013 15:05:36 GMT

Yes, Pokémon, Earthbound/Mother and early Legend of Zelda games used this viewpoint.

Multiframe animations

ExplodingCookie — Thu, 16 May 2013 15:02:31 GMT

Thanks for the quick responses everyone.
@oli.obk: I use "@cur_image = (milliseconds / 175 % 2 == 0) ? @walk1 : @walk2" as in the Cptn. Ruby Tutorial.
@jlnr: Thanks, I'll have a look at that
@lol_02: Thanks to you to!

Screen goes black.

onnoowl — Thu, 16 May 2013 14:16:53 GMT

I tried that, but it made no difference.
The rescue block is never running.
Here's the new draw block I tried:

  def draw
    begin
      coord = vec2(0, 0) - @drawOffset
      coord = vec2(coord.x % $size.x, coord.y % $size.y)
      @img.draw(coord.x, coord.y, 0, @imgScale.x, @imgScale.y)
      coord2 = coord - vec2($size.x, 0)
      @img.draw(coord2.x, coord2.y, 0, @imgScale.x, @imgScale.y)
      # c = 0xff333333
      # draw_quad(0, 0, c, $size.x, 0, c, $size.x, $size.y, c, 0, $size.y, c, 0)
      @creature.draw(self, @drawOffset)
    rescue
      puts "Error"
      puts $!.backtrace
    end
  end

Blocks 2D (in development)

jahmaican — Thu, 16 May 2013 14:12:59 GMT

You're right, I used other languages before and I'm not quite familiar with Ruby syntax yet. Thanks for the helpful post!

Multiframe animations

lol_o2 — Thu, 16 May 2013 13:15:41 GMT

Also check this for better timing method: http://www.libgosu.org/cgi-bin/mwf/topic_show.pl?tid=823

Can I use Gosu to make an Isometric 2D game?

jlnr — Thu, 16 May 2013 12:41:31 GMT

This game should be pretty good to learn from: http://www.libgosu.org/cgi-bin/mwf/topic_show.pl?pid=5117

Edit: Oh, Pokemon was not rendered at a 45° angle? Then it should be even easier :) I think these two games should be exactly right:

http://www.libgosu.org/cgi-bin/mwf/topic_show.pl?pid=6396
http://www.libgosu.org/cgi-bin/mwf/topic_show.pl?pid=4486

Multiframe animations

jlnr — Thu, 16 May 2013 12:39:18 GMT

The tutorial uses a complete animation for the rotating stars: https://github.com/jlnr/gosu/wiki/Ruby-Tutorial

Screen goes black.

jlnr — Thu, 16 May 2013 12:38:22 GMT

There was (is?) a bug in Gosu where an exception thrown in draw or other callbacks would be silently swallowed. Please try adding a begin … rescue … end block around your method implementations, and let me know if this problem still exists.

Blocks 2D (in development)

Spooner — Thu, 16 May 2013 11:25:12 GMT

Looks interesting so far! Glad you got some use from Releasy's :windows_folder builder!

I'd recommend you look at a higher level Gosu framework, such as Gamebox or Chingu, to make things easier for you once you add more functionality.

A few comments on the code, to help you along with Ruby in general:

Rather than using if/then/end on one line, we generally use the single conditional postfix this way:
close if button_down? KbEscape

Use two spaces rather than hard tab. Makes your code look a lot nicer when viewed online too.

if @obrot == :prawo then
We don't usually use then; It just isn't necessary. Also, that bit is crying out to be a case statement.

Rather than use your own #debug method, use Logger (standard library) or Log4r (gem) for logging.

for i in 0..2 do => (0..2).each do |i| (Although for might feel better if you are coming from another language, it is extremely limiting once you try to do a bit more with Ruby)

def block?(x,y); @map_main[(y/32)][(x/32)] != 0; end

Use ?: over if/then/else/end on one line (or put it on multiple lines).

print(Time.now.strftime("%H:%M:%S.%L") + " - " + message.to_s + "\n") => puts "#{Time.now.strftime("%H:%M:%S.%L")} - #{message}" (although I suggested using a logger for this).

Multiframe animations

oli.obk — Thu, 16 May 2013 11:02:51 GMT

please submit more info. are you using gosu's animations classes? how do you currently create two-frame animations?

Blocks 2D (in development)

jahmaican — Thu, 16 May 2013 10:38:49 GMT

Source is included in the package so you can run it yourself :)

Can I use Gosu to make an Isometric 2D game?

ExplodingCookie — Wed, 15 May 2013 23:11:30 GMT

These are the movement method I use in Stageoids

To activate the move command, put this function into the update function in main.rb file.

if button_down? Gosu::Button::KbLeft
   @player.move_left
end

This calls the move_left function in the player.rb file. This is...

def move_left
   //Move left at the speed the move_speed value
   @x = @x - @move_speed
   //Make it so we can't leave the screen
   if @x < 0
   @x = 0
   end
end

For this to work, you need to define these variables in the player.rb file's initialize function.
@x = 0
@y = 0
@move_speed = 10

This will start you in the bottom left corner.

For the other directions duplicate the functions and replace the values as follows...
::Right::
KbLeft -> KbRight
move_left -> move_right
@x - @move_speed -> @x + @move_speed
@x < 0 -> @x > 0

::Up::
KbLeft -> KbUp
move_left -> move_up
@x - @move_speed -> @y + @move_speed
@x < 0 -> @y > 0

::Down::
KbLeft -> KbDown
move_left -> move_down
@x - @move_speed -> @y - @move_speed
@x < 0 -> @y < 0

To create the player to move around in your game, use @player = Player.new(self) in the initialize function in main.rb

For collisions with walls, I suggest you have a look the Cptn. Ruby tutorial.

As for the scrolling, unfortunately, I have no idea.

When you have a working prototype, create a post in the showcase forum with the file attached so people can download it and help you work errors and bugs out.

Multiframe animations

ExplodingCookie — Wed, 15 May 2013 22:53:45 GMT

How do I do this, I can do two frame animations, however I don't know how to have three or more frames in an animation.

Blocks 2D (in development)

ExplodingCookie — Wed, 15 May 2013 22:52:17 GMT

Image looks good. Unfortunately, I use only Macs. Therefore I cannot try it out due to this apparently being windows only. Nice work for your first time with Gosu and Ruby, welcome aboard!

Blocks 2D (in development)

jahmaican — Wed, 15 May 2013 20:18:27 GMT

[http://i.imgur.com/EAyQ0SUs.png] [http://i.imgur.com/Ck6QI2ts.png] [http://i.imgur.com/3dITIeKs.png]
Hi! I'm relatively new to Gosu and Ruby in general, but still wanted to show my first creation.

What's new?
Did some building tests, pretty lame but works. Starting to feel kinda comfortable with ruby.
I'll probably rewrite the whole thing for Chingu some time soon.

What is it?
Intended to be a 2D Minecraft clone. Still needs a lot of effort.

What's done?
Drawing a 3-layer map, basic movement (no jumping yet), very simple physics, basic building.

What has to be done?
Improving movement.
Introducing bigger maps with scrolling; storing them in more friendly format maybe.
Creative mode just like in real Minecraft + flat map generation.
GUIs, menus etc.
Actually learning how to Ruby.
Then maybe some proper mining and crafting.

How do I play?
Left/A, right/D - move left/right.
Left click, right click - destroy/place blocks.
1, 2, 3 - choose material.
Middle click - teleport.

What was used?
Tiled editor - the map you see can be easily edited.
Coterie Craft Minecraft texture pack.
My Minecraft skin.

DOWNLOAD?
0.13 Right here!

Go on, share your thoughts and opinions.

Can I use Gosu to make an Isometric 2D game?

Eamonn — Wed, 15 May 2013 19:44:48 GMT

Hello. I am planning to make a game with Ruby and Gosu. I was gonna use RubyGame but found no good tutorials on it. So I found this nifty little library with a good few tutorials. Bear in mind I'm still learning Ruby.

So I am planning on making my game with the Isometric camera view. For those that don't know it's like the camera view from the old pokemon DS games(Pokemon Perl + Diamond). Can Gosu create that camera angle? If so could you maybe link me to a video/tutorial on how to do it? This may be a little stupid, so if it is would it become clearer when I finish learning Gosu and Ruby? Thank you for any feedback and please don't hate on this if it is stupid :D

Screen goes black.

lol_o2 — Wed, 15 May 2013 18:56:04 GMT

The possibility would be that @creature has wrong class object assigned, but it seems fine.
Try to move the draw code into Window's update to check if it still turns black with no exception. Such issue was in older versions of Gosu.

Screen goes black.

onnoowl — Wed, 15 May 2013 14:39:09 GMT

The update function and the draw functions are still called. I did notice that if I comment out @creature.draw(self) it does not turn black anymore. The weird thing is even if I comment out anything in the draw function for Creature, so the function does nothing, I still get the bug.

Screen goes black.

oli.obk — Wed, 15 May 2013 14:35:15 GMT

does the program keep running?
add some console-output each frame and check whether that also stops :)

Screen goes black.

onnoowl — Wed, 15 May 2013 13:04:02 GMT

Hi,
I've worked with Gosu for a while without this happening, and I don't know what's causing it. I'm trying to simulate evolution. This program creates lots of little creatures and breeds them together, kills off the slow ones, keeps the fast moving ones, and eventually they should evolve into well designed fast travelling creatures.
As the program evaluates the speed of each creature, it opens up a gosu window, and runs it for about 3 seconds to see how far the creature goes. The problem I'm having is that occasionally/randomly, the entire window goes black and shows nothing.
If you guys could figure out what's causing this, that would be great.
(Note: My window class is called Simulation and is towards the bottom of the evolvingCreatures.rb file)

Antialiasing in Gosu

carno — Fri, 10 May 2013 17:58:26 GMT

You are probably right. I just think it would look more consistent, it's not that it looks bad it's that it looks so different when they align perfectly.