Baruco 2014: How I Built My Own Twitch-Plays-Pokémon

As the slides don't really say much, the content of the talk is going to be published as a series of blogposts.
http://ajipirijou.com/talks/how-i-built-my-own-tpp-part-1

This talk was given at Baruco 2014.
It explains the story of How I built my own TPP.

Transcript

1. When was the last time you worked on a non productive project, just for the fun of it?
2. February 14th 2014
3. Twitch Plays Pokémon
7. OMG
8. OMG I need to make my own
9. by @eljojo How I built my own Twitch Plays Pokémon
10. by @eljojo How I built my own Twitch Plays Pokémon
11. Saturday Morning
15. Ingredients List • 1 GameBoy Emulator • 1 screen-streaming app • 1 internet control for emulator
16. Ingredients List • 1 GameBoy Emulator • 1 screen-streaming app • 1 internet control for emulator
17. Ingredients List • 1 GameBoy Emulator • 1 screen-streaming app • 1 internet control for emulator
18. Ingredients List • 1 GameBoy Emulator • 1 screen-streaming app • 1 internet control for emulator
19. How do I control an emulator with Ruby?
20. “How do I send keystrokes from a ruby app?”
25. Problems with the Windows solution • WINDOWS!!!!!111! • I have no Windows machine • I want to run this on a server with no desktop environment
28. require 'sinatra' mappings = { "a" => java.awt.event::KeyEvent::VK_Z, "b" => java.awt.event::KeyEvent::VK_X, "up" => java.awt.event::KeyEvent::VK_UP, "down" => java.awt.event::KeyEvent::VK_DOWN, } robot = java.awt.Robot.new get '/:key' do |key| if key_code = mappings[key.downcase] robot.keyPress(key_code) robot.delay(100) robot.keyRelease(key_code) end end
31. Problems
32. Problems • Simulating Keystrokes • Requires desktop environment • Latency!
33. The perfect emulator • requires no desktop environment • streams the video online • has an API that allows to send button presses
37. What’s an emulator?
41. $ ./emulator pokemon_red.gb
44. $ ls lib cpu.rb gpu.rb ram.rb
47. @ram = [] rom = File.binread('pokemon.gb') @ram += rom.unpack('C*')
50. address operation 0x00 nop 0x04 inc_b 0x80 add_a_b 0xA0 and_b 0xC0 jp_nn CPU Instruction Table
51. address operation 0x00 nop 0x04 inc_b 0x80 add_a_b 0xA0 and_b 0xC0 jp_nn CPU Instruction Table class CPU OPS = [ :nop, … … :inc_b, … :add_a_b, … :and_b, … :jp_nn, ]
52. “the” loop class Emulator def step next_byte = @ram[@program_counter] next_instruction = OPS[next_byte] @cpu.send(next_instruction) @program_counter += 1 end end
53. “the” loop class Emulator def step next_byte = @ram[@program_counter] # => 0xC0 next_instruction = OPS[next_byte] @cpu.send(next_instruction) @program_counter += 1 end end
54. “the” loop class Emulator def step next_byte = @ram[@program_counter] # => 0xC0 next_instruction = OPS[next_byte] # => :jp_nn @cpu.send(next_instruction) @program_counter += 1 end end
55. “the” loop class Emulator def step next_byte = @ram[@program_counter] # => 0xC0 next_instruction = OPS[next_byte] # => :jp_nn @cpu.send(next_instruction) @program_counter += 1 end end
56. “the” loop class Emulator def step next_byte = @ram[@program_counter] # => 0xC0 next_instruction = OPS[next_byte] # => :jp_nn @cpu.send(next_instruction) @program_counter += 1 end end
57. “the” loop class Emulator def step next_byte = @ram[@program_counter] # => 0xC0 next_instruction = OPS[next_byte] # => :jp_nn @cpu.send(next_instruction) @program_counter += 1 end end
58. Why do we care?
59. we’ll write our own!
60. Advantages • No need for keypresses
61. Advantages • No need for keypresses • We can run on a headless server
62. Advantages • No need for keypresses • We can run on a headless server • We can stream closer to real-time
63. Advantages • No need for keypresses • We can run on a headless server • We can stream closer to real-time • We control the memory!
64. Advantages • version controlling of gameplays • rewind game sessions
65. Advantages • version controlling of gameplays • rewind game sessions • forking and branching
66. Advantages • version controlling of gameplays • rewind game sessions • forking and branching • machine learning
67. tom7.org/mario
68. Advantages • No need for keypresses • We can run on a headless server • We can stream closer to real-time • We control the memory!
73. if you want to succeed at conferences you should totally promise stuff you have no idea about that’s p good
74. Taking over Mimey
75. Jano González… … loves GameBoy … loves Pokémon … loves Ruby
76. Mimey • GameBoy emulator • written in Ruby
77. Mimey • GameBoy emulator • written in Ruby • only 10% done
79. How to draw an owl
80. How to draw an owl draw some circles
81. How to draw an owl draw some circles add the rest of the owl
82. bits and bytes
86. I had no real reason to know what that means
87. I was forced to learn
88. Sven Fuchs • he knows about computers
89. Sven Fuchs • he knows a lot about computers
90. “ugh, I learned that 20 years ago”
91. I never learned it because I didn’t have to.
92. Irresponsible Ruby
93. Steve Klabnik • also knows a lot about computers • gave talk in EuRuKo last year
94. “Ruby code that you wouldn't deploy at your day job because it's just too interesting or creative” - Steve Klabnik
95. Irresponsible Ruby • Neat Hacks • Weird metaprogramming • Unusual techniques • No Unit-Tests
96. “If you worry too much about being clean and tidy, you can’t push the boundaries” - _why
97. testing irresponsibly
98. CPU Steps Step Operation A B C D E F 1 nop 0 15 232 22 19 10 2 dec_d 0 15 232 21 19 10 3 inc_b 0 16 232 21 19 10
99. The specification of how the original GameBoy works was feature-frozen before I was born.
102. Rendering the first image
103. Patience
104. Patience
105. Patience
110. The memory was the same!
119. “It uses ruby everywhere!” - DHH
121. gameboy emulator
132. The Realization
133. I learned tons of things that I would have never learned by my own
134. I got out of my comfort zone
135. It was fun!
136. I can apply some of this to my work
137. Conference Driven Development
138. sometimes you need the right push
140. wear the hacker hat
141. write irresponsible ruby
142. get back the passion that got you into programming
143. thanks! @eljojo
144. github.com/eljojo/mimey