Give at ruby conf china 2021

1. 过纯中 Eric-Guo 2021-08-15
How to
becoming a
Dragon Rider
使⽤ Dragon Ruby 教孩⼦们开
始 Ruby 游戏编程

3. Dragon Ruby History
https://dragonrubydispatch.com/2019/04/24/Issue-21.html
https://rubykaigi.org/2019/presentations/amirrajan.html#apr19
http://slides.com/amirrajan/game-dev-ruby-happiness-part-2#/5/0/4

4. Dragon Ruby quick overview
It’s closed source, but depend on all open source and will open source if bankrupt.
• https://trello.com/b/lx2oPd6h/public-board (Road map)
• Components
• SDL 2
• mRuby 3
• C-ext
• Author
• Amir Rajan (acquire RubyMotion from Laurent)
• Ryan Gordon

5. Other game engine
From https://news.ycombinator.com/item?id=26719105
• Unreal
• Powerful, but not your
fi
rst game engine
• Unity
• It’s a C# vs Ruby choose.
• Console support only on Unity Pro
• Pico-8
• A bit of too low res, not console supports
• Godot
• Free, but not good console supports
• Cocos Creator (国内)

6. Compare with Processing
The relationship of Processing, P5.js or Scratch
• Processing is an environment/programming language that is meant to make
visual, interactive applications extremely easy to write. It can be used for
everything from teaching children how to code to visualizing scienti
fi
c data.
• Scratch is a high-level block-based visual programming language and
website targeted primarily at children 8–16 as an educational tool for
programming.
• We can learning from those book, further more ruby allow extend C and web
server, which provide more feature set and the same time give same easy
usage feature.

7. Compare with Scratch
Blockly for DragonRuby: https://github.com/Rabios/dragonblocks

8. Why become a Dragon Rider?
Or why Dragon Ruby as child’s
fi
rst programming language?
• Writing literary instead of graphic (compare with Scratch)
• Scratch is still preliminary step.
• No type notation every where
• Consistent syntax (compare with python)
• Hot-reload
• I ❤ Ruby (personal reason)

9. Quick overview
Rule #1, 1280x720 60Hz ticks
def tick args
ticks = args.state.tick_count
text_w, text_h = args.gtk.calcstringbox(ticks.to_s, 5)
board_w = text_w
board_h = text_h
board_x = (1280 - board_w) / 2
board_y = (720 - board_h) / 2
args.outputs.labels << [board_x + board_w / 2, board_y + board_h, ticks, 5, 1, 0, 255, 0, 255]
args.outputs.lines << [board_x, board_y, board_x + board_w, board_y + board_h, 100, 100, 100, 255]
args.outputs.lines << [board_x, board_y + board_h, board_x + board_w, board_y, 50, 50, 50, 255]
args.outputs.borders << [board_x, board_y, board_w, board_h, 0, 0, 200, 255]
args.outputs.solids << [board_x+1, board_y+1, board_w-2, board_h-2, 35, 0, 50, 100]
end

10. Now let’s learning DragonRuby # 1
Ticks with resize text box
def tick args
ticks = args.state.tick_count
text_w, text_h = args.gtk.calcstringbox(ticks.to_s, 5)
board_w = text_w
board_h = text_h
board_x = (1280 - board_w) / 2
board_y = (720 - board_h) / 2
args.outputs.labels << [board_x + board_w / 2, board_y + board_h, ticks, 5, 1, 0, 255, 0, 255]
args.outputs.lines << [board_x, board_y, board_x + board_w, board_y + board_h, 100, 100, 100, 255]
args.outputs.lines << [board_x, board_y + board_h, board_x + board_w, board_y, 50, 50, 50, 255]
args.outputs.borders << [board_x, board_y, board_w, board_h, 0, 0, 200, 255]
args.outputs.solids << [board_x+1, board_y+1, board_w-2, board_h-2, 35, 0, 50, 100]
end

11. Tank Vs Zombie the Game Ruby
A game jam piece https://github.com/shanshaji/Tank-Vs-Zombie-Game-Ruby

12. Cake stack
17 year old high school boy written https://github.com/Rabios/cakestack

13. Learning DragonRuby # 2
Processing ManyLines with mouse and accumulation render
$gtk.reset
def tick(args)
clear_target = args.state.tick_count.zero? || args.inputs.keyboard.key_down.space
args.render_target(:accumulation).clear_before_render = clear_target
args.render_target(:accumulation).lines << {
x: 640,
y: 360,
x2: args.inputs.mouse.x,
y2: args.inputs.mouse.y,
r: 0,
g: 0,
b: 0,
a: 255
}
args.outputs.sprites << [ 0, 0, 1280, 720, :accumulation]
end

14. Learning DragonRuby # 3
static_solids and static_borders also works
# frozen_string_literal: true
def tick(args)
args.outputs.background_color = [63, 63, 63]
args.outputs.debug << [10, 720, "FPS #{args.gtk.current_framerate.round}"].label
if args.inputs.keyboard.key_down.space || args.inputs.mouse.click
args.outputs.static_solids.clear
args.outputs.static_borders.clear
end
return if args.state.tick_count.zero?
args.outputs.static_solids << [args.inputs.mouse.x, args.inputs.mouse.y, 100, 100, rand(255),
rand(255), rand(255)]
args.outputs.static_borders << [args.inputs.mouse.x, args.inputs.mouse.y, 100, 100, rand(255),
rand(255), rand(255)]
end

15. We need git and smaug to Dragon Rider
Create games and share packages with the DragonRuby community
• Installation step see https://smaug.dev
┌─[ 1:53PM][git]
└─▪ smaug dragonruby list
* DragonRuby Pro 2.26
* DragonRuby 2.26
* DragonRuby 3.0
* DragonRuby Pro 3.0
Thanks for using Smaug!
📦 Explore the package registry at https://smaug.dev/
🦗 Find a bug? File an issue: https://github.com/ereborstudios/smaug/issues
🙋 Have a question? Start a discussion: https://github.com/ereborstudios/smaug/discussions
💬 Want to chat? Join us on Discord: https://discord.gg/rwT64EtDee

16. Now we write a Calculator
It’s not a game still…

17. Snake game with DragonRuby GTK
https://gist.github.com/marcheiligers/173634708371635e257dfba84c39f774

18. Now we need read the 1.6M HTML manual
Good news is it’s all o
ffi
cial documents, no more.
• Visit http://docs.dragonruby.org
• Mirror in China: https://dragonruby.redwoodjs.cn

19. What’s DragonRuby essentially.
Or we still be able to think like children when programming?
• An SDL2 ruby runtime which running in 60 Hz.
• Turn key builds for Windows, MacOS, and Linux with seamless publishing to
Itch.io.
• Targets every platform: PC, Mac, Linux, Web Assembly, iOS, Android,
Nintendo Switch, XBOX One, and PS4 (console compilation requires a
business entity, NDA veri
fi
cation, contact Amir at amir.rajan@dragonruby.org
for more info).

20. Dragon Ruby input and output support
It’s limit but cross platform
• Input support: keyboard, mouse, controller (2 pair)
• Output support:
• Primitives (:solid, :sprite, :label, :line, :border.)
• Sounds
• Debug
• Triangle Primitives (Pro)

21. What’s new in DragonRuby 3.0
Performance from 30% to 200% faster.
• Rendering 5,000 sprites up to 80,0000, higher than Unity
• Arithmetic and comparison operations no longer attempt to coerce/infer types.
• DragonRuby’s “Level 1” Runtime has been updated to mRuby 3.0.
• DragonRuby Replay (Pro Feature) but mp4 generate in standard.
• VR support (Oculus Quest 2)
• All Screen Mode, HD Mode and Portrait Mode.
• M1 supported

22. More time and FAQ
Flappy dragon, Gorillas Basic and dynamic chart demo